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Research ArticleResearch on Dual-Carrier Pulse-Train-ControlledBuck Converter
Ming Qin and Shiwei Li
School of Electrical Engineering Zhengzhou University Zhengzhou 450001 China
Correspondence should be addressed to Ming Qin qinmingzzueducn
Received 18 June 2019 Accepted 24 August 2019 Published 10 September 2019
Academic Editor Daniel Morinigo-Sotelo
Copyright copy 2019 Ming Qin and Shiwei Li -is is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited
In order to solve the low-frequency oscillation of pulse-train- (PT-) controlled switching converter operating in a continuousconduction mode (CCM) a dual-carrier pulse-train (DCPT) control technique is proposed in this paper With the CCM buckconverter as an example the operational principle pulse control law and output voltage ripple of the DCPT-controlled converterare studied-e experimental results are provided to verify the theoretical analysis and simulation results Compared with the PT-controlled converter the DCPT-controlled CCM buck converter enjoys much better operating characteristics and smaller outputvoltage ripple
1 Introduction
With the development of electronic technology the steady-state performance and transient response of power suppliesare very important in many electronic devices However forpulse-width modulation (PWM) switching DC-DC con-verters with the disadvantages of slow transient responseand complicated compensational network it is hard to meetthe requirements of modern electronic equipments [1ndash4]
In order to get a great transient response a pulse-train(PT) control technique for DC-DC converter was proposed[5] When the PT-controlled switching converter operates indiscontinuous conduction mode (DCM) the output voltagewill increase during each high-energy pulse PH and decreaseduring each low-energy pulse PL which improves thetransient characteristic of the converter Qin and Xu [6]proposed a multiple pulse-train (MPT) control technique bysetting several duty cycle pulses to get better output char-acteristics Qin and Xu [7] introduced a current-referencedpulse-train (CRPT) control technique to enlarge the loadrange and improve the voltage accuracy of the converterConsidering the spectrum of the switching converter the bi-frequency pulse-train (BFPT) control technique was pro-posed [8] However all the control techniques mentioned
above were used in DCM converters which limited theapplications
Wang et al [9] applied the PT control technique to abuck converter operating in the continuous conductionmode (CCM) and indicated that the low-frequency oscil-lation existed at this time which confused the pulse controllaw and enlarged the output voltage ripple In order to solvethis problem several control techniques have been pro-posed By limiting the valley value of the inductor currentthe valley current mode PT (VCM-PT) controlled buckconverter eliminated the low-frequency oscillation but itlimited the output power range at the same time [10] Bydetecting the load current the sliding current valley PT(SCV-PT) controlled buck converter changed the valleyvalue of the inductor current adaptively and improved theoutput power range of the converter [11] However loadcurrent inductor current and output voltage were detectedat the same time for SCV-PT control which is quite com-plicated Sha et al [12] indicated that by limiting the peakvalue of the capacitor current within one switching cycle thelow-frequency oscillation could be eliminated although thecontrol parameters were complicated to design By con-trolling the leading edge of the pulse the pulse phase shift-based PT (PPS-PT) control was proposed [13] Although the
HindawiJournal of Control Science and EngineeringVolume 2019 Article ID 7514621 9 pageshttpsdoiorg10115520197514621
PPS-PT-controlled buck converter could eliminate the low-frequency oscillation it weakened the transient character-istic In [14] the PT control technique was applied to boostconverter operated in the pseudo continuous conductionmode (PCCM) -is converter enjoyed wide power rangewithout low-frequency oscillation but the efficiency of theconverter was poor due to the freewheeling phase In ad-dition by improving the topology of the converter the low-frequency oscillation could be suppressed but it wascomplicated to the integration of the switching converter[15ndash20]
In this paper a dual-carrier pulse-train (DCPT) controltechnique is proposed and studied in detail In the DCPT-controlled CCM buck converter the capacitor current islimited to the preset valley current by a carrier signal at thebeginning of each switching cycle -e output voltage willincrease during one PH switching cycle and decrease duringeach PL switching cycle which indicates that the low-fre-quency oscillation did not exist in the DCPT-controlledconverter -e theoretical analysis simulation and experi-mental results verify that the DCPT-controlled CCM buckconverter enjoys small output ripple and fast transientresponse
2 Operational Principle
For a buck converter when the switch S is on the inductorcurrent will increase with a slope of (Vin minus Vo)L when S isoff the inductor current will decrease with a slope of VoLSince the capacitor current reflects the ripple of the inductorcurrent completely the slope of the capacitor current is also(Vin minus Vo)L or VoL when the switch is on or off re-spectively If a control signal vsaw with a slope of VoL isapplied to the capacitor current the capacitor current willmove along with the trajectory of vsaw after the switch turnsoff
Figure 1(a) shows the schematic diagram of the DCPT-controlled buck converter In the controller a comparator isused to compare the output voltage of the switching converterwith a reference value a sense resistor connected to the outputcapacitor and its auxiliary circuit are employed to obtain thecapacitor current and two DA converters are acquired togenerate the carrier signals Besides that there is no extracompensational network in the controller which indicates theDCPT-controlled converter enjoys convenient design processand fast response -e main working waveforms includingcapacitor current ic control pulse control signal vp andoutput voltage vo are shown in Figure 1(b)-e carrier signalsvsawH and vsawL generated by the controller have the samevalley current Iv and slope VrefL However the frequency ofvsawH or vsawL is different which is fH or fL respectivelyBecause the control pulse is generated by comparing thecapacitor current with the carrier signal in the DCPT con-troller the switching frequency of the converter is also fH or fLcorrespondingly
-e working principle of the DCPT-controlled buckconverter is as follows -e carrier signal vsaw is chosenbetween vsawH and vsawL When vsaw decreases to the valleycurrent Iv the switch S turns on immediately and the output
voltage is compared with the reference voltage Vref Ifvo ltVref the carrier signal vsawH is selected as vsaw When thecapacitor current icgt vsawH the switch S turns off which isrecorded as a high-energy pulse PH Similarly if vo geVref atthe time when vsaw decreases to Iv the carrier signal vsawLwill be selected When icgt vsawL S turns off which isrecorded as the low-energy pulse PL When the converteroperates in a steady state the DCPTcontroller will generate apulse train which consists of PH and PL to stabilize theoutput voltage
3 Steady-State Analysis
31 Design of Control Parameters In order to avoid low-frequency oscillation the output voltage should be increasedduring PH and decreased during PL Based on this principlethe control parameters the frequencies of the carrier signalsand the valley current can be designed properly
Figure 2 shows the capacitor current waveform of theDCPT-controlled buck converter within one switching cy-cle For the switching converter with a low output voltagethe on-state voltage of the diode has a significant influenceon the process of control law analysis When the on-statevoltage VD of the diode is considered the rising or fallingslope of the capacitor current is (Vin minus Vo)L or (Vo +VD)Lrespectively
During t1 or t2 the peak value of the capacitor current Ipcan be expressed as
Ip Vin minus Vo
Lt1 (1)
Ip Vo + VD
Lt2 (2)
By combining equations (1) and (2) we have
t1 + t2 LIp Vin + VD( 1113857
Vin minus Vo( 1113857 Vo + VD( 1113857 (3)
Based on Figure 2 and equation (3) the area of thetriangle ABC can be written as
SΔABC 12
t1 + t2( 1113857Ip Vin + VD( 1113857LI2p
2 Vin minus Vo( 1113857 Vo + VD( 1113857 (4)
-e area of the quadrangle BCED within one switchingperiod T is
SBCED minus12
t1 + t2 + T( 1113857Iv minusVin + VD( 1113857LIvIp
2 Vin minus Vo( 1113857 Vo + VD( 1113857minus12
IvT
(5)
Similarly the areas of the triangle BOD and the triangleCFE can be expressed as
SΔBOD + SΔCFE SOFED minus SBCED minus12
IvT
+Vin + VD( 1113857LIvIp
2 Vin minus Vo( 1113857 Vo + VD( 1113857
(6)
2 Journal of Control Science and Engineering
According to equation (6) the charge variation of theoutput capacitor during one switching cycle T can be cal-culated asΔq SΔABC minus SΔBOD + SΔCFE( )
Vin + VD( )LI2p
2 Vin minus Vo( ) Vo + VD( )+12IvT minus
Vin + VD( )LIvIp2 Vin minus Vo( ) Vo + VD( )
(7)
During the conduction time of the switch Ip can bewritten as
Ip Iv +Vin minus Vo
LDT Iv +
Vin minus Vo( ) Vo + VD( )L Vin + VD( )
T
(8)
By combining equations (7) and (8) it is available that
Δq IvT +Vin minus Vo( ) Vo + VD( )
2L Vin + VD( )T2 (9)
erefore the variation of the output voltage within oneswitching cycle can be calculated as
Δvo ΔqCIvCT +
Vin minus Vo( ) Vo + VD( )2LC Vin + VD( )
T2 (10)
By choosing dierent TH or TL the variation of theoutput voltage within PH or PL can be obtained as
ΔvHo IvCTH +
Vin minus Vo( ) Vo + VD( )2LC Vin + VD( )
T2H
ΔvLo IvCTL +
Vin minus Vo( ) Vo + VD( )2LC Vin + VD( )
T2L
(11)
Based on equation (11) the output voltage iterativeequation of the DCPT-controlled buck converter can beexpressed as
von+1
von +IvCTH +
Vin minus Vo( ) Vo + VD( )2LC Vin + VD( )
T2H von ltVref
von +IvCTL +
Vin minus Vo( ) Vo + VD( )2LC Vin + VD( )
T2L von geVref
(12)
According to the principle of the DCPT control tech-nique ΔvHo gt 0 and ΔvLo lt 0 should be guaranteed ereforeit is available that
minusVin minus Vo( ) Vo + VD( )2LC Vin + VD( )
TH lt Iv lt minusVin minus Vo( ) Vo + VD( )
2L Vin + VD( )TL
(13)
e control parameter Iv can be determined by the presetinput voltage range of the converter Since the falling slope ofthe carrier signals vsawH and vsawL isVref L the peak value ofthe carrier signals can be calculated when the frequencies ofthe carrier signals fH and fL and the valley current Iv are
Vin
S L
D
iL ic
RE
VoDriverC
Rvp
Vref
vsawH
vsawL
FPGA
DAconverter
DAconverter
vsaw
R2 R1
R3R4
ic
(a)
tIv
0
t0
vsawH
vsawL
ic
vp
Vref
vo
PH PHPL PL PL
(b)
Figure 1 Working principle diagram of the DCPT-controlled buck converter (a) Schematic diagram (b) Working waveforms
IvD
t1 t2
Ip
OB
A
C
E
Ft
ic
Figure 2 Capacitor current of the DCPT-controlled buckconverter
Journal of Control Science and Engineering 3
determined Based on the analysis above the parameters ofthe researched the DCPT-controlled buck converter arelisted in Table 1
From equation (12) it can be known that the outputvoltage variations ΔvHo and ΔvLo vary with the input voltageVin In order to achieve ΔvHo gt 0 and ΔvLo lt 0 Vin would belimited within a valid range
Assuming the output voltage variation is zero in one PHswitching cycle (ΔvHo 0) the lower boundary of the inputvoltage for the DCPT-controlled buck converter will becalculated as
Vinmin Vo + VD( )2TH
Vo + VD( )T minus 2LIvminus VD (14)
Similarly assuming the output voltage variation is zeroin one PL switching cycle (ΔvLo 0) the upper boundary ofthe input voltage will be
Vinmax Vo + VD( )2TL
Vo + VD( )T minus 2LIvminus VD (15)
Substituting the parameters of Table 1 into equation (14)the operating range of the input voltage can be calculatedwhich is [811V 19V] When the input voltage varies in thisrange the output voltage will increase during each PH anddecrease during each PL thus the low-frequency oscillationcan be avoided
By using equation (12) the relationship between theoutput voltage variation ΔvHo gt 0 and minus ΔvLo lt 0 and the inputvoltage Vin can be obtained as shown in Figure 3 It can beseen that with the increasing input voltage the variation ofthe output voltage ΔvHo gt 0 increases and minus ΔvLo lt 0 decreases
32AnalysisofPulseControlLaw According to the principleof charge balance the variation of the output voltage is zeroin a whole pulse train that is
μHΔvHo + μLΔv
Lo 0 (16)
By combining equations (12) and (16) it can be obtainedthat
μHμL minus
Vin minus Vo( ) Vo + VD( )T2L minus 2LIvTL Vin + VD( )
Vin minus Vo( ) Vo + VD( )T2H minus 2LIvTH Vin + VD( )
(17)
Substituting the parameters shown in Table 1 intoequation (17) the relationship between the pulse ratio μHμLand the input voltage Vin can be obtained as shown inFigure 4 It can be known that the pulse ratio μHμL de-creases gradually with the increase of Vin which is caused bythe increase of ΔvHo gt 0 and the decrease of minus ΔvLo lt 0erefore the proportion of the high-energy pulse PH in thepulse train gradually decreases with the increase in the inputvoltage
According to equation (17) the typical pulse train of theDCPT-controlled buck converter in the condition of dif-ferent input voltages can be obtained as listed in Table 2
33 Analysis of the Output Voltage Ripple To analyse theoutput voltage variation the capacitor current ic and outputvoltage vo of the DCPT-controlled buck converter withinone switching cycle are shown in Figure 5
During [0 ton] the capacitor current ic (t) and the outputvoltage of the converter can be written as
Table 1 Parameters of the DCPT-controlled buck converter
Parameters ValueRated input voltage Vin 12 VReference voltage Vref 5 VInductor L 100 μHCapacitor C 560 μFEquivalent series resistance RE 30mΩFrequency fL of carrier vsawL 40 kHzFrequency fH of carrier vsawH 20 kHzValley current Iv minus 05 A
∆νoH
ndash∆νoL
109 11 12 13 14 15Vin (V)
0
5
10
15
20
Δνo (
mV
) 25
30
35
40
Figure 3 Output voltage variation versus input voltage of theDCPT-controlled buck converter
109 11 12 13 14 15Vin (V)
0
05
1
15
2
μ H (μ
L)
25
3
35
Figure 4 Pulse ratio versus input voltage of the DCPT-controlledbuck converter
4 Journal of Control Science and Engineering
ic(t) Iv +Vin minus Vo
Lt (18)
vo(t) 1Cintt
0ic(t)dt + ic(t)RE
IvCt
+Vin minus Vo
2LCt2 +
Vin minus Vo
LREt
(19)
By taking the derivation of equation (19) one obtains
dvo(t)dt
IvC+Vin minus Vo
2LCt +
Vin minus Vo
LCRE (20)
Substituting the parameters listed in Table 1 intoequation (20) it can be known that the output voltage risesto the maximum at the time tonerefore it is available that
ΔvHpp IvCton +
Vin minus Vo
2LCt2on +
Vin minus Vo
LREton (21)
For the DCPT-controlled buck converter the outputvoltage ripple is closely related to the pulse train Taking thepulse train 2PH-1PL as an example the capacitor current icand the output voltage vo are shown in Figure 6(a) Obvi-ously the output voltage ripple of the converter is Δvo ΔvHpp + ΔvHo at this time
In general when the pulse train is nPH-1PL the outputvoltage ripple of the converter is
Δvo (n minus 1)ΔvHpp + ΔvHo (22)
When the pulse train is 1PH-nPL the capacitor current icand the output voltage vo are shown in Figure 6(b) Ap-parently the output voltage ripple on this condition is
Δvo ΔvHpp (23)
By using equations (21)ndash(23) the output voltage rippleΔvo of the DCPT-controlled buck converter can be calcu-lated as listed in Table 3 For the DCPT-controlled buckconverter the output voltage ripple increases gradually withthe increase of the input voltage
4 Simulation and Experimental Results
41 SimulationResults To verify the theoretical analysis thesimulation results are provided in Figure 7 which includecarrier signal vsaw control pulse vp capacitor current ic andoutput voltage vo
As shown in Figure 7(a) when the input voltage equals to868V the pulse train is 2PH-1PL the pulse ratio is μHμL 2and the output voltage ripple is 40mV which are consistentwith the theoretical analysis Similarly as shown inFigures 7(b)ndash7(d) when the input voltage equals to 92V1083V or 12V the pulse train is 1PH-1PL 1PH-3PL or 1PH-5PL the pulse ratio is 1 13 or 15 and the output voltageripple is 40mV 55mV or 60mV respectively
According to Figure 7 the following conclusion of theDCPT-controlled buck converter can be obtained as theinput voltage Vin increases μHμL decreases gradually iethe proportion of PH in the pulse train decreases which isconsistent with the theoretical analysis in Section 32
In addition the value of the capacitor current at thebeginning of each switching cycle is equal to the preset valleycurrent Iv due to the traction of the carrier signals Since thecapacitor current reects the ripple of the inductor currentthe value of the inductor current is constant at the beginningof each switching cycle erefore the variation of theoutput voltage is only inuenced by the control pulse PH orPL which indicates that the low-frequency oscillation doesnot exist in the DCPT-controlled buck converter
42 Experimental Results In order to verify and test theproposed technique a prototype of the DCPT-controlledbuck converter is designed with the parameters in Table 1 Inthe prototype the control scheme is achieved by an FPGAdevice with a type of EP4CE15F17C8 An operationalamplicenter OPA228 and a 10mΩ sense resistor connectedwith the output capacitor are employed to obtain the ca-pacitor current Two DA DAC0808 converters are appliedto generate the carrier signals and an analogue multiplexerCD4051 is used to select the carrier signal between vsawH andvsawL Besides the type of the comparators in this prototypeis LM393
When the input voltage equals to 868V the experi-mental waveforms are shown in Figure 8(a) e pulse trainis 2PH-1PL and the output voltage ripple is 40mV ap-proximately Similarly when the input voltage equals to92V 1083V or 12V the pulse train is 1PH-1PL 1PH-3PL
Iv
ton
O t
ic
t
vo
O
ΔνHpp
T
Figure 5 Capacitor current and output voltage of the DCPT-controlled buck converter
Table 2 Pulse train of the DCPT-controlled buck converter atdierent voltages
Vin (V) μHμL Pulse train849 3 3PH-1PL868 2 2PH-1PL92 1 1PH-1PL1083 13 1PH-3PL12 15 1PH-5PL
Journal of Control Science and Engineering 5
or 1PH-5PL and the output voltage ripple is 40mV 50mV or60mV respectively
According to the principle of DCPT control the controlpulse is generated by comparing the capacitor current with thecarrier signals It can be seen from Figure 8 that the combi-nation of the carrier signals changes with the variation of the
input voltage which causes the variation of the pulse trainBased on the experimental results it can be known that theDCPT-controlled buck converter can operate in a steady stateby adjusting the pulse train when the input voltage changes
In order to study the transient response of the DCPTcontrol method the experimental transient waveforms are
2PH-1PL
40mV5045
10
1
2
85 86 87t (ms)
88 89 9
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
(a)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-1PL
40mV
(b)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-3PL
55mV
(c)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-5PL
60mV
(d)
Figure 7 Simulation waveforms of the DCPT-controlled buck converter (a) Vin 868V (b) Vin 92 V (c) Vin 1083V (d) Vin 12V
ic
vo
Vref
Iv
2PH-1PL
ΔvHPP
ΔvHo
Δvo
(a)
1PH-3PL
ΔvHPP
ic
vo
Vref
Iv
(b)
Figure 6 Output voltage ripple of the DCPT-controlled buck converter (a) -e case of 2PH-1PL (b) -e case of 1PH-3PL
Table 3 -e output voltage ripple of the DCPT-controlled buck converter
Vin (V) ΔvHo (mV) ΔvHpp (mV) Δvo (mV)
849 33 343 409868 49 363 41292 89 415 4151083 191 522 52212 248 577 577
6 Journal of Control Science and Engineering
provided in Figure 9 When the load current increases from2A to 3A two high-energy pulses are generated successivelyby the controller to stabilize the output voltage and thisconverter enjoys excellent transient response Consideringthe parasitic parameters such as the on-state resistor of theMOSFET when the load current increases the input voltageof the inductor will decrease slightly which causes theproportion of PH in the pulse train to increase
In order to verify the suppression effect on the low-frequency oscillation the comparative experimental resultsare provided in Figure 10 -e control parameters of
traditional PT-controlled buck converter are as followsDH 06 DL 03 and T 25 μs
As shown in Figure 10(a) the pulse train is 1PH-5PL forthe DCPT-controlled CCM converter and the output voltageripple is 60mV In contrast the pulse train of the PT-controlled buck converter is 4PH-4PL and the output voltageripple is 120mV as shown in Figure 10(b) -is phenom-enon of successive several high-energy pulses followed bysuccessive several low-energy pulses indicates that the low-frequency oscillation exists in the PT-controlled CCMconverter -e low-frequency oscillation has not occurred in
2PH-1PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]
4
3
2
1
lt2HzF
(a)
1PH-1PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]
4
3
2
1
lt2HzF
(b)
1PH-3PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]273306kHz
4
3
2
1
F
(c)
1PH-5PL vsaw [2Vdiv]
Time [50 μsdiv] 331936kHzF
4
3
2
1
vp [2Vdiv]ic [1Adiv]
vo [50 mVdiv]
(d)
Figure 8 Experimental waveforms of the DCPT-controlled buck converter (a)Vin 868V (b)Vin 92V (c)Vin 1083V (d)Vin 12V
2PH
lt2HzFTime [100μsdiv]
vp [2Vdiv]
ic [1Adiv]
vo [50mVdiv]
Io [1Adiv]
2
3
14
Figure 9 Experimental transient waveforms of the DCPT-controlled buck converter while load changes
Journal of Control Science and Engineering 7
the DCPT-controlled CCM buck converter e proposedDCPT control technique enjoys much better output char-acteristics compared with the traditional PT controltechnique
5 Conclusions
In this paper a dual-carrier pulse-train control technique isproposed With the CCM buck converter as an example theoperational principle is analysed in detail Based on theoutput voltage variation of the DCPT-controlled buckconverter within one switching cycle the pulse control lawand the output voltage ripple are analysed e simulationand experimental results verify the theoretical analysis andindicate that there is no low-frequency oscillation in theDCPT-controlled CCM buck converter Compared with thetraditional PTcontrol technique the DCPT-controlled buckconverter enjoys better control characteristics and muchsmaller output voltage ripple
Data Availability
e data used to support the centndings of this study are in-cluded within the article
Conflicts of Interest
e authors declare that there are no conicts of interestregarding the publication of this paper
Acknowledgments
is work was supported by the National Natural ScienceFoundation of China (51507155) and the Key ResearchProgram of Hersquonan Higher Education (16A470014)
References
[1] C Y-F Ho B W-K Ling Y Yan-Qun Liu P K-S Tam andK Kok-Lay Teo ldquoOptimal PWM control of switched-ca-pacitor DC-DC power converters via model transformationand enhancing control techniquesrdquo IEEE Transactions on
Circuits and Systems I Regular Papers vol 55 no 5pp 1382ndash1391 2008
[2] C Duan and D Wu ldquoNonlinear voltage regulation algorithmfor DC-DC boost converter with centnite-time convergencerdquoJournal of Control Science and Engineering vol 2019 ArticleID 6761784 5 pages 2019
[3] X Zhang Q-C Zhong and W-L Ming ldquoStabilization ofcascaded DCDC converters via adaptive series-virtual-im-pedance control of the load converterrdquo IEEE Transactions onPower Electronics vol 31 no 9 pp 6057ndash6063 2016
[4] S Kennedy M R Yuce and J-M Redoute ldquoFully integratedswitched-capacitor DCDC converters with clock slope EMIcontrolrdquo IEEE Transactions on Electromagnetic Compatibilityvol 60 no 6 pp 2073ndash2075 2018
[5] M Telefus A Shteynberg M Ferdowsi and A Emadi ldquoPulsetrain control technique for yback converterrdquo IEEE Trans-actions on Power Electronics vol 19 no 3 pp 757ndash764 2004
[6] M Qin and J Xu ldquoMultiduty ratio modulation technique forswitching DC-DC converters operating in discontinuousconduction moderdquo IEEE Transactions on Industrial Elec-tronics vol 57 no 10 pp 3497ndash3507 2010
[7] M Qin and J Xu ldquoImproved pulse regulation controltechnique for switching DC-DC converters operating inDCMrdquo IEEE Transactions on Industrial Electronics vol 60no 5 pp 1819ndash1830 2013
[8] J Xu and J Wang ldquoBifrequency pulse-train control techniquefor switching DC-DC converters operating in DCMrdquo IEEETransactions on Industrial Electronics vol 58 no 8pp 3658ndash3667 2011
[9] J Wang J Xu G Zhou and B Bao ldquoPulse-train-controlledCCM buck converter with small ESR output-capacitorrdquo IEEETransactions on Industrial Electronics vol 60 no 12pp 5875ndash5881 2013
[10] J Sha S Liu S Zhong and J Xu ldquoValley current mode pulsetrain control technique for switching DC-DC convertersrdquoElectronics Letters vol 50 no 4 pp 311ndash313 2014
[11] L Wang D Yu R Xu Z Ye and P Wang ldquoSliding current-valley based pulse train control for buck converterrdquo in IECON2017mdash43rd Annual Conference of the IEEE Industrial Elec-tronics Society pp 4978ndash4981 Beijing China October-No-vember 2017
[12] J Sha D Xu Y Chen J Xu and B W Williams ldquoA peak-capacitor-current pulse-train-controlled buck converter withfast transient response and a wide load rangerdquo IEEE
Time [100μsdiv]lt2HzF
vp [2Vdiv]
ic [1Adiv]
vo [100mVdiv]
Io [1Adiv]2
1
3
4
1PH-5PL
(a)
2
Time [100μsdiv]
vp [2Vdiv]
ic [1Adiv]
vo [100mVdiv]
Io [1Adiv]
4PH-4PL
13
4
F 398217kHz
(b)
Figure 10 Experimental waveforms(a) DCPT-controlled buck converter (b) PT-controlled buck converter
8 Journal of Control Science and Engineering
Transactions on Industrial Electronics vol 63 no 3pp 1528ndash1538 2016
[13] D Yu Y Geng H H C Iu T Fernando and R Xu ldquoPulsephase shift based low-frequency oscillation suppression forPT controlled CCM buck converterrdquo IEEE Transactions onCircuits and Systems II Express Briefs vol 65 no 10pp 1465ndash1469 2018
[14] G Zhou W Tan S Zhou Y Wang and X Ye ldquoAnalysis ofpulse train controlled PCCM boost converter with low fre-quency oscillation suppressionrdquo IEEE Access vol 6pp 68795ndash68803 2018
[15] D Yu LWang Y Geng CMa Z Ye and Y Liu ldquoPulse traincontrolled buck converter with coupled inductorsrdquo IET PowerElectronics vol 10 no 10 pp 1231ndash1239 2017
[16] R Xu Y Zhang S Lu G Chen D Yu and L Wang ldquoPulsetrain-controlled CCM boost converter with suppression oflow-frequency oscillationrdquo IET Power Electronics vol 10no 8 pp 957ndash967 2017
[17] X Jin L Wang D Yu Y Geng and R Xu ldquoPulse traincontrolled single-input dual-output buck converter withcoupled inductorsrdquo IEEE Access vol 6 pp 41504ndash415172018
[18] J Sha J Xu S Zhong S Liu and L Xu ldquoControl pulsecombination-based analysis of pulse train controlled DCMswitching DC-DC convertersrdquo IEEE Transactions on In-dustrial Electronics vol 62 no 1 pp 246ndash255 2015
[19] S Kapat ldquoConfigurable multimode digital control for lightload DC-DC converters with improved spectrum and smoothtransitionrdquo IEEE Transactions on Power Electronics vol 31no 3 pp 2680ndash2688 2016
[20] K Muppala Kumar and K Anbukumar ldquoPulse train con-trolled quadratic buck converter operating in discontinuousconduction moderdquo IET Circuits Devices amp Systems vol 12no 4 pp 486ndash496 2018
Journal of Control Science and Engineering 9
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Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
PPS-PT-controlled buck converter could eliminate the low-frequency oscillation it weakened the transient character-istic In [14] the PT control technique was applied to boostconverter operated in the pseudo continuous conductionmode (PCCM) -is converter enjoyed wide power rangewithout low-frequency oscillation but the efficiency of theconverter was poor due to the freewheeling phase In ad-dition by improving the topology of the converter the low-frequency oscillation could be suppressed but it wascomplicated to the integration of the switching converter[15ndash20]
In this paper a dual-carrier pulse-train (DCPT) controltechnique is proposed and studied in detail In the DCPT-controlled CCM buck converter the capacitor current islimited to the preset valley current by a carrier signal at thebeginning of each switching cycle -e output voltage willincrease during one PH switching cycle and decrease duringeach PL switching cycle which indicates that the low-fre-quency oscillation did not exist in the DCPT-controlledconverter -e theoretical analysis simulation and experi-mental results verify that the DCPT-controlled CCM buckconverter enjoys small output ripple and fast transientresponse
2 Operational Principle
For a buck converter when the switch S is on the inductorcurrent will increase with a slope of (Vin minus Vo)L when S isoff the inductor current will decrease with a slope of VoLSince the capacitor current reflects the ripple of the inductorcurrent completely the slope of the capacitor current is also(Vin minus Vo)L or VoL when the switch is on or off re-spectively If a control signal vsaw with a slope of VoL isapplied to the capacitor current the capacitor current willmove along with the trajectory of vsaw after the switch turnsoff
Figure 1(a) shows the schematic diagram of the DCPT-controlled buck converter In the controller a comparator isused to compare the output voltage of the switching converterwith a reference value a sense resistor connected to the outputcapacitor and its auxiliary circuit are employed to obtain thecapacitor current and two DA converters are acquired togenerate the carrier signals Besides that there is no extracompensational network in the controller which indicates theDCPT-controlled converter enjoys convenient design processand fast response -e main working waveforms includingcapacitor current ic control pulse control signal vp andoutput voltage vo are shown in Figure 1(b)-e carrier signalsvsawH and vsawL generated by the controller have the samevalley current Iv and slope VrefL However the frequency ofvsawH or vsawL is different which is fH or fL respectivelyBecause the control pulse is generated by comparing thecapacitor current with the carrier signal in the DCPT con-troller the switching frequency of the converter is also fH or fLcorrespondingly
-e working principle of the DCPT-controlled buckconverter is as follows -e carrier signal vsaw is chosenbetween vsawH and vsawL When vsaw decreases to the valleycurrent Iv the switch S turns on immediately and the output
voltage is compared with the reference voltage Vref Ifvo ltVref the carrier signal vsawH is selected as vsaw When thecapacitor current icgt vsawH the switch S turns off which isrecorded as a high-energy pulse PH Similarly if vo geVref atthe time when vsaw decreases to Iv the carrier signal vsawLwill be selected When icgt vsawL S turns off which isrecorded as the low-energy pulse PL When the converteroperates in a steady state the DCPTcontroller will generate apulse train which consists of PH and PL to stabilize theoutput voltage
3 Steady-State Analysis
31 Design of Control Parameters In order to avoid low-frequency oscillation the output voltage should be increasedduring PH and decreased during PL Based on this principlethe control parameters the frequencies of the carrier signalsand the valley current can be designed properly
Figure 2 shows the capacitor current waveform of theDCPT-controlled buck converter within one switching cy-cle For the switching converter with a low output voltagethe on-state voltage of the diode has a significant influenceon the process of control law analysis When the on-statevoltage VD of the diode is considered the rising or fallingslope of the capacitor current is (Vin minus Vo)L or (Vo +VD)Lrespectively
During t1 or t2 the peak value of the capacitor current Ipcan be expressed as
Ip Vin minus Vo
Lt1 (1)
Ip Vo + VD
Lt2 (2)
By combining equations (1) and (2) we have
t1 + t2 LIp Vin + VD( 1113857
Vin minus Vo( 1113857 Vo + VD( 1113857 (3)
Based on Figure 2 and equation (3) the area of thetriangle ABC can be written as
SΔABC 12
t1 + t2( 1113857Ip Vin + VD( 1113857LI2p
2 Vin minus Vo( 1113857 Vo + VD( 1113857 (4)
-e area of the quadrangle BCED within one switchingperiod T is
SBCED minus12
t1 + t2 + T( 1113857Iv minusVin + VD( 1113857LIvIp
2 Vin minus Vo( 1113857 Vo + VD( 1113857minus12
IvT
(5)
Similarly the areas of the triangle BOD and the triangleCFE can be expressed as
SΔBOD + SΔCFE SOFED minus SBCED minus12
IvT
+Vin + VD( 1113857LIvIp
2 Vin minus Vo( 1113857 Vo + VD( 1113857
(6)
2 Journal of Control Science and Engineering
According to equation (6) the charge variation of theoutput capacitor during one switching cycle T can be cal-culated asΔq SΔABC minus SΔBOD + SΔCFE( )
Vin + VD( )LI2p
2 Vin minus Vo( ) Vo + VD( )+12IvT minus
Vin + VD( )LIvIp2 Vin minus Vo( ) Vo + VD( )
(7)
During the conduction time of the switch Ip can bewritten as
Ip Iv +Vin minus Vo
LDT Iv +
Vin minus Vo( ) Vo + VD( )L Vin + VD( )
T
(8)
By combining equations (7) and (8) it is available that
Δq IvT +Vin minus Vo( ) Vo + VD( )
2L Vin + VD( )T2 (9)
erefore the variation of the output voltage within oneswitching cycle can be calculated as
Δvo ΔqCIvCT +
Vin minus Vo( ) Vo + VD( )2LC Vin + VD( )
T2 (10)
By choosing dierent TH or TL the variation of theoutput voltage within PH or PL can be obtained as
ΔvHo IvCTH +
Vin minus Vo( ) Vo + VD( )2LC Vin + VD( )
T2H
ΔvLo IvCTL +
Vin minus Vo( ) Vo + VD( )2LC Vin + VD( )
T2L
(11)
Based on equation (11) the output voltage iterativeequation of the DCPT-controlled buck converter can beexpressed as
von+1
von +IvCTH +
Vin minus Vo( ) Vo + VD( )2LC Vin + VD( )
T2H von ltVref
von +IvCTL +
Vin minus Vo( ) Vo + VD( )2LC Vin + VD( )
T2L von geVref
(12)
According to the principle of the DCPT control tech-nique ΔvHo gt 0 and ΔvLo lt 0 should be guaranteed ereforeit is available that
minusVin minus Vo( ) Vo + VD( )2LC Vin + VD( )
TH lt Iv lt minusVin minus Vo( ) Vo + VD( )
2L Vin + VD( )TL
(13)
e control parameter Iv can be determined by the presetinput voltage range of the converter Since the falling slope ofthe carrier signals vsawH and vsawL isVref L the peak value ofthe carrier signals can be calculated when the frequencies ofthe carrier signals fH and fL and the valley current Iv are
Vin
S L
D
iL ic
RE
VoDriverC
Rvp
Vref
vsawH
vsawL
FPGA
DAconverter
DAconverter
vsaw
R2 R1
R3R4
ic
(a)
tIv
0
t0
vsawH
vsawL
ic
vp
Vref
vo
PH PHPL PL PL
(b)
Figure 1 Working principle diagram of the DCPT-controlled buck converter (a) Schematic diagram (b) Working waveforms
IvD
t1 t2
Ip
OB
A
C
E
Ft
ic
Figure 2 Capacitor current of the DCPT-controlled buckconverter
Journal of Control Science and Engineering 3
determined Based on the analysis above the parameters ofthe researched the DCPT-controlled buck converter arelisted in Table 1
From equation (12) it can be known that the outputvoltage variations ΔvHo and ΔvLo vary with the input voltageVin In order to achieve ΔvHo gt 0 and ΔvLo lt 0 Vin would belimited within a valid range
Assuming the output voltage variation is zero in one PHswitching cycle (ΔvHo 0) the lower boundary of the inputvoltage for the DCPT-controlled buck converter will becalculated as
Vinmin Vo + VD( )2TH
Vo + VD( )T minus 2LIvminus VD (14)
Similarly assuming the output voltage variation is zeroin one PL switching cycle (ΔvLo 0) the upper boundary ofthe input voltage will be
Vinmax Vo + VD( )2TL
Vo + VD( )T minus 2LIvminus VD (15)
Substituting the parameters of Table 1 into equation (14)the operating range of the input voltage can be calculatedwhich is [811V 19V] When the input voltage varies in thisrange the output voltage will increase during each PH anddecrease during each PL thus the low-frequency oscillationcan be avoided
By using equation (12) the relationship between theoutput voltage variation ΔvHo gt 0 and minus ΔvLo lt 0 and the inputvoltage Vin can be obtained as shown in Figure 3 It can beseen that with the increasing input voltage the variation ofthe output voltage ΔvHo gt 0 increases and minus ΔvLo lt 0 decreases
32AnalysisofPulseControlLaw According to the principleof charge balance the variation of the output voltage is zeroin a whole pulse train that is
μHΔvHo + μLΔv
Lo 0 (16)
By combining equations (12) and (16) it can be obtainedthat
μHμL minus
Vin minus Vo( ) Vo + VD( )T2L minus 2LIvTL Vin + VD( )
Vin minus Vo( ) Vo + VD( )T2H minus 2LIvTH Vin + VD( )
(17)
Substituting the parameters shown in Table 1 intoequation (17) the relationship between the pulse ratio μHμLand the input voltage Vin can be obtained as shown inFigure 4 It can be known that the pulse ratio μHμL de-creases gradually with the increase of Vin which is caused bythe increase of ΔvHo gt 0 and the decrease of minus ΔvLo lt 0erefore the proportion of the high-energy pulse PH in thepulse train gradually decreases with the increase in the inputvoltage
According to equation (17) the typical pulse train of theDCPT-controlled buck converter in the condition of dif-ferent input voltages can be obtained as listed in Table 2
33 Analysis of the Output Voltage Ripple To analyse theoutput voltage variation the capacitor current ic and outputvoltage vo of the DCPT-controlled buck converter withinone switching cycle are shown in Figure 5
During [0 ton] the capacitor current ic (t) and the outputvoltage of the converter can be written as
Table 1 Parameters of the DCPT-controlled buck converter
Parameters ValueRated input voltage Vin 12 VReference voltage Vref 5 VInductor L 100 μHCapacitor C 560 μFEquivalent series resistance RE 30mΩFrequency fL of carrier vsawL 40 kHzFrequency fH of carrier vsawH 20 kHzValley current Iv minus 05 A
∆νoH
ndash∆νoL
109 11 12 13 14 15Vin (V)
0
5
10
15
20
Δνo (
mV
) 25
30
35
40
Figure 3 Output voltage variation versus input voltage of theDCPT-controlled buck converter
109 11 12 13 14 15Vin (V)
0
05
1
15
2
μ H (μ
L)
25
3
35
Figure 4 Pulse ratio versus input voltage of the DCPT-controlledbuck converter
4 Journal of Control Science and Engineering
ic(t) Iv +Vin minus Vo
Lt (18)
vo(t) 1Cintt
0ic(t)dt + ic(t)RE
IvCt
+Vin minus Vo
2LCt2 +
Vin minus Vo
LREt
(19)
By taking the derivation of equation (19) one obtains
dvo(t)dt
IvC+Vin minus Vo
2LCt +
Vin minus Vo
LCRE (20)
Substituting the parameters listed in Table 1 intoequation (20) it can be known that the output voltage risesto the maximum at the time tonerefore it is available that
ΔvHpp IvCton +
Vin minus Vo
2LCt2on +
Vin minus Vo
LREton (21)
For the DCPT-controlled buck converter the outputvoltage ripple is closely related to the pulse train Taking thepulse train 2PH-1PL as an example the capacitor current icand the output voltage vo are shown in Figure 6(a) Obvi-ously the output voltage ripple of the converter is Δvo ΔvHpp + ΔvHo at this time
In general when the pulse train is nPH-1PL the outputvoltage ripple of the converter is
Δvo (n minus 1)ΔvHpp + ΔvHo (22)
When the pulse train is 1PH-nPL the capacitor current icand the output voltage vo are shown in Figure 6(b) Ap-parently the output voltage ripple on this condition is
Δvo ΔvHpp (23)
By using equations (21)ndash(23) the output voltage rippleΔvo of the DCPT-controlled buck converter can be calcu-lated as listed in Table 3 For the DCPT-controlled buckconverter the output voltage ripple increases gradually withthe increase of the input voltage
4 Simulation and Experimental Results
41 SimulationResults To verify the theoretical analysis thesimulation results are provided in Figure 7 which includecarrier signal vsaw control pulse vp capacitor current ic andoutput voltage vo
As shown in Figure 7(a) when the input voltage equals to868V the pulse train is 2PH-1PL the pulse ratio is μHμL 2and the output voltage ripple is 40mV which are consistentwith the theoretical analysis Similarly as shown inFigures 7(b)ndash7(d) when the input voltage equals to 92V1083V or 12V the pulse train is 1PH-1PL 1PH-3PL or 1PH-5PL the pulse ratio is 1 13 or 15 and the output voltageripple is 40mV 55mV or 60mV respectively
According to Figure 7 the following conclusion of theDCPT-controlled buck converter can be obtained as theinput voltage Vin increases μHμL decreases gradually iethe proportion of PH in the pulse train decreases which isconsistent with the theoretical analysis in Section 32
In addition the value of the capacitor current at thebeginning of each switching cycle is equal to the preset valleycurrent Iv due to the traction of the carrier signals Since thecapacitor current reects the ripple of the inductor currentthe value of the inductor current is constant at the beginningof each switching cycle erefore the variation of theoutput voltage is only inuenced by the control pulse PH orPL which indicates that the low-frequency oscillation doesnot exist in the DCPT-controlled buck converter
42 Experimental Results In order to verify and test theproposed technique a prototype of the DCPT-controlledbuck converter is designed with the parameters in Table 1 Inthe prototype the control scheme is achieved by an FPGAdevice with a type of EP4CE15F17C8 An operationalamplicenter OPA228 and a 10mΩ sense resistor connectedwith the output capacitor are employed to obtain the ca-pacitor current Two DA DAC0808 converters are appliedto generate the carrier signals and an analogue multiplexerCD4051 is used to select the carrier signal between vsawH andvsawL Besides the type of the comparators in this prototypeis LM393
When the input voltage equals to 868V the experi-mental waveforms are shown in Figure 8(a) e pulse trainis 2PH-1PL and the output voltage ripple is 40mV ap-proximately Similarly when the input voltage equals to92V 1083V or 12V the pulse train is 1PH-1PL 1PH-3PL
Iv
ton
O t
ic
t
vo
O
ΔνHpp
T
Figure 5 Capacitor current and output voltage of the DCPT-controlled buck converter
Table 2 Pulse train of the DCPT-controlled buck converter atdierent voltages
Vin (V) μHμL Pulse train849 3 3PH-1PL868 2 2PH-1PL92 1 1PH-1PL1083 13 1PH-3PL12 15 1PH-5PL
Journal of Control Science and Engineering 5
or 1PH-5PL and the output voltage ripple is 40mV 50mV or60mV respectively
According to the principle of DCPT control the controlpulse is generated by comparing the capacitor current with thecarrier signals It can be seen from Figure 8 that the combi-nation of the carrier signals changes with the variation of the
input voltage which causes the variation of the pulse trainBased on the experimental results it can be known that theDCPT-controlled buck converter can operate in a steady stateby adjusting the pulse train when the input voltage changes
In order to study the transient response of the DCPTcontrol method the experimental transient waveforms are
2PH-1PL
40mV5045
10
1
2
85 86 87t (ms)
88 89 9
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
(a)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-1PL
40mV
(b)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-3PL
55mV
(c)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-5PL
60mV
(d)
Figure 7 Simulation waveforms of the DCPT-controlled buck converter (a) Vin 868V (b) Vin 92 V (c) Vin 1083V (d) Vin 12V
ic
vo
Vref
Iv
2PH-1PL
ΔvHPP
ΔvHo
Δvo
(a)
1PH-3PL
ΔvHPP
ic
vo
Vref
Iv
(b)
Figure 6 Output voltage ripple of the DCPT-controlled buck converter (a) -e case of 2PH-1PL (b) -e case of 1PH-3PL
Table 3 -e output voltage ripple of the DCPT-controlled buck converter
Vin (V) ΔvHo (mV) ΔvHpp (mV) Δvo (mV)
849 33 343 409868 49 363 41292 89 415 4151083 191 522 52212 248 577 577
6 Journal of Control Science and Engineering
provided in Figure 9 When the load current increases from2A to 3A two high-energy pulses are generated successivelyby the controller to stabilize the output voltage and thisconverter enjoys excellent transient response Consideringthe parasitic parameters such as the on-state resistor of theMOSFET when the load current increases the input voltageof the inductor will decrease slightly which causes theproportion of PH in the pulse train to increase
In order to verify the suppression effect on the low-frequency oscillation the comparative experimental resultsare provided in Figure 10 -e control parameters of
traditional PT-controlled buck converter are as followsDH 06 DL 03 and T 25 μs
As shown in Figure 10(a) the pulse train is 1PH-5PL forthe DCPT-controlled CCM converter and the output voltageripple is 60mV In contrast the pulse train of the PT-controlled buck converter is 4PH-4PL and the output voltageripple is 120mV as shown in Figure 10(b) -is phenom-enon of successive several high-energy pulses followed bysuccessive several low-energy pulses indicates that the low-frequency oscillation exists in the PT-controlled CCMconverter -e low-frequency oscillation has not occurred in
2PH-1PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]
4
3
2
1
lt2HzF
(a)
1PH-1PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]
4
3
2
1
lt2HzF
(b)
1PH-3PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]273306kHz
4
3
2
1
F
(c)
1PH-5PL vsaw [2Vdiv]
Time [50 μsdiv] 331936kHzF
4
3
2
1
vp [2Vdiv]ic [1Adiv]
vo [50 mVdiv]
(d)
Figure 8 Experimental waveforms of the DCPT-controlled buck converter (a)Vin 868V (b)Vin 92V (c)Vin 1083V (d)Vin 12V
2PH
lt2HzFTime [100μsdiv]
vp [2Vdiv]
ic [1Adiv]
vo [50mVdiv]
Io [1Adiv]
2
3
14
Figure 9 Experimental transient waveforms of the DCPT-controlled buck converter while load changes
Journal of Control Science and Engineering 7
the DCPT-controlled CCM buck converter e proposedDCPT control technique enjoys much better output char-acteristics compared with the traditional PT controltechnique
5 Conclusions
In this paper a dual-carrier pulse-train control technique isproposed With the CCM buck converter as an example theoperational principle is analysed in detail Based on theoutput voltage variation of the DCPT-controlled buckconverter within one switching cycle the pulse control lawand the output voltage ripple are analysed e simulationand experimental results verify the theoretical analysis andindicate that there is no low-frequency oscillation in theDCPT-controlled CCM buck converter Compared with thetraditional PTcontrol technique the DCPT-controlled buckconverter enjoys better control characteristics and muchsmaller output voltage ripple
Data Availability
e data used to support the centndings of this study are in-cluded within the article
Conflicts of Interest
e authors declare that there are no conicts of interestregarding the publication of this paper
Acknowledgments
is work was supported by the National Natural ScienceFoundation of China (51507155) and the Key ResearchProgram of Hersquonan Higher Education (16A470014)
References
[1] C Y-F Ho B W-K Ling Y Yan-Qun Liu P K-S Tam andK Kok-Lay Teo ldquoOptimal PWM control of switched-ca-pacitor DC-DC power converters via model transformationand enhancing control techniquesrdquo IEEE Transactions on
Circuits and Systems I Regular Papers vol 55 no 5pp 1382ndash1391 2008
[2] C Duan and D Wu ldquoNonlinear voltage regulation algorithmfor DC-DC boost converter with centnite-time convergencerdquoJournal of Control Science and Engineering vol 2019 ArticleID 6761784 5 pages 2019
[3] X Zhang Q-C Zhong and W-L Ming ldquoStabilization ofcascaded DCDC converters via adaptive series-virtual-im-pedance control of the load converterrdquo IEEE Transactions onPower Electronics vol 31 no 9 pp 6057ndash6063 2016
[4] S Kennedy M R Yuce and J-M Redoute ldquoFully integratedswitched-capacitor DCDC converters with clock slope EMIcontrolrdquo IEEE Transactions on Electromagnetic Compatibilityvol 60 no 6 pp 2073ndash2075 2018
[5] M Telefus A Shteynberg M Ferdowsi and A Emadi ldquoPulsetrain control technique for yback converterrdquo IEEE Trans-actions on Power Electronics vol 19 no 3 pp 757ndash764 2004
[6] M Qin and J Xu ldquoMultiduty ratio modulation technique forswitching DC-DC converters operating in discontinuousconduction moderdquo IEEE Transactions on Industrial Elec-tronics vol 57 no 10 pp 3497ndash3507 2010
[7] M Qin and J Xu ldquoImproved pulse regulation controltechnique for switching DC-DC converters operating inDCMrdquo IEEE Transactions on Industrial Electronics vol 60no 5 pp 1819ndash1830 2013
[8] J Xu and J Wang ldquoBifrequency pulse-train control techniquefor switching DC-DC converters operating in DCMrdquo IEEETransactions on Industrial Electronics vol 58 no 8pp 3658ndash3667 2011
[9] J Wang J Xu G Zhou and B Bao ldquoPulse-train-controlledCCM buck converter with small ESR output-capacitorrdquo IEEETransactions on Industrial Electronics vol 60 no 12pp 5875ndash5881 2013
[10] J Sha S Liu S Zhong and J Xu ldquoValley current mode pulsetrain control technique for switching DC-DC convertersrdquoElectronics Letters vol 50 no 4 pp 311ndash313 2014
[11] L Wang D Yu R Xu Z Ye and P Wang ldquoSliding current-valley based pulse train control for buck converterrdquo in IECON2017mdash43rd Annual Conference of the IEEE Industrial Elec-tronics Society pp 4978ndash4981 Beijing China October-No-vember 2017
[12] J Sha D Xu Y Chen J Xu and B W Williams ldquoA peak-capacitor-current pulse-train-controlled buck converter withfast transient response and a wide load rangerdquo IEEE
Time [100μsdiv]lt2HzF
vp [2Vdiv]
ic [1Adiv]
vo [100mVdiv]
Io [1Adiv]2
1
3
4
1PH-5PL
(a)
2
Time [100μsdiv]
vp [2Vdiv]
ic [1Adiv]
vo [100mVdiv]
Io [1Adiv]
4PH-4PL
13
4
F 398217kHz
(b)
Figure 10 Experimental waveforms(a) DCPT-controlled buck converter (b) PT-controlled buck converter
8 Journal of Control Science and Engineering
Transactions on Industrial Electronics vol 63 no 3pp 1528ndash1538 2016
[13] D Yu Y Geng H H C Iu T Fernando and R Xu ldquoPulsephase shift based low-frequency oscillation suppression forPT controlled CCM buck converterrdquo IEEE Transactions onCircuits and Systems II Express Briefs vol 65 no 10pp 1465ndash1469 2018
[14] G Zhou W Tan S Zhou Y Wang and X Ye ldquoAnalysis ofpulse train controlled PCCM boost converter with low fre-quency oscillation suppressionrdquo IEEE Access vol 6pp 68795ndash68803 2018
[15] D Yu LWang Y Geng CMa Z Ye and Y Liu ldquoPulse traincontrolled buck converter with coupled inductorsrdquo IET PowerElectronics vol 10 no 10 pp 1231ndash1239 2017
[16] R Xu Y Zhang S Lu G Chen D Yu and L Wang ldquoPulsetrain-controlled CCM boost converter with suppression oflow-frequency oscillationrdquo IET Power Electronics vol 10no 8 pp 957ndash967 2017
[17] X Jin L Wang D Yu Y Geng and R Xu ldquoPulse traincontrolled single-input dual-output buck converter withcoupled inductorsrdquo IEEE Access vol 6 pp 41504ndash415172018
[18] J Sha J Xu S Zhong S Liu and L Xu ldquoControl pulsecombination-based analysis of pulse train controlled DCMswitching DC-DC convertersrdquo IEEE Transactions on In-dustrial Electronics vol 62 no 1 pp 246ndash255 2015
[19] S Kapat ldquoConfigurable multimode digital control for lightload DC-DC converters with improved spectrum and smoothtransitionrdquo IEEE Transactions on Power Electronics vol 31no 3 pp 2680ndash2688 2016
[20] K Muppala Kumar and K Anbukumar ldquoPulse train con-trolled quadratic buck converter operating in discontinuousconduction moderdquo IET Circuits Devices amp Systems vol 12no 4 pp 486ndash496 2018
Journal of Control Science and Engineering 9
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Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
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Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
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Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
According to equation (6) the charge variation of theoutput capacitor during one switching cycle T can be cal-culated asΔq SΔABC minus SΔBOD + SΔCFE( )
Vin + VD( )LI2p
2 Vin minus Vo( ) Vo + VD( )+12IvT minus
Vin + VD( )LIvIp2 Vin minus Vo( ) Vo + VD( )
(7)
During the conduction time of the switch Ip can bewritten as
Ip Iv +Vin minus Vo
LDT Iv +
Vin minus Vo( ) Vo + VD( )L Vin + VD( )
T
(8)
By combining equations (7) and (8) it is available that
Δq IvT +Vin minus Vo( ) Vo + VD( )
2L Vin + VD( )T2 (9)
erefore the variation of the output voltage within oneswitching cycle can be calculated as
Δvo ΔqCIvCT +
Vin minus Vo( ) Vo + VD( )2LC Vin + VD( )
T2 (10)
By choosing dierent TH or TL the variation of theoutput voltage within PH or PL can be obtained as
ΔvHo IvCTH +
Vin minus Vo( ) Vo + VD( )2LC Vin + VD( )
T2H
ΔvLo IvCTL +
Vin minus Vo( ) Vo + VD( )2LC Vin + VD( )
T2L
(11)
Based on equation (11) the output voltage iterativeequation of the DCPT-controlled buck converter can beexpressed as
von+1
von +IvCTH +
Vin minus Vo( ) Vo + VD( )2LC Vin + VD( )
T2H von ltVref
von +IvCTL +
Vin minus Vo( ) Vo + VD( )2LC Vin + VD( )
T2L von geVref
(12)
According to the principle of the DCPT control tech-nique ΔvHo gt 0 and ΔvLo lt 0 should be guaranteed ereforeit is available that
minusVin minus Vo( ) Vo + VD( )2LC Vin + VD( )
TH lt Iv lt minusVin minus Vo( ) Vo + VD( )
2L Vin + VD( )TL
(13)
e control parameter Iv can be determined by the presetinput voltage range of the converter Since the falling slope ofthe carrier signals vsawH and vsawL isVref L the peak value ofthe carrier signals can be calculated when the frequencies ofthe carrier signals fH and fL and the valley current Iv are
Vin
S L
D
iL ic
RE
VoDriverC
Rvp
Vref
vsawH
vsawL
FPGA
DAconverter
DAconverter
vsaw
R2 R1
R3R4
ic
(a)
tIv
0
t0
vsawH
vsawL
ic
vp
Vref
vo
PH PHPL PL PL
(b)
Figure 1 Working principle diagram of the DCPT-controlled buck converter (a) Schematic diagram (b) Working waveforms
IvD
t1 t2
Ip
OB
A
C
E
Ft
ic
Figure 2 Capacitor current of the DCPT-controlled buckconverter
Journal of Control Science and Engineering 3
determined Based on the analysis above the parameters ofthe researched the DCPT-controlled buck converter arelisted in Table 1
From equation (12) it can be known that the outputvoltage variations ΔvHo and ΔvLo vary with the input voltageVin In order to achieve ΔvHo gt 0 and ΔvLo lt 0 Vin would belimited within a valid range
Assuming the output voltage variation is zero in one PHswitching cycle (ΔvHo 0) the lower boundary of the inputvoltage for the DCPT-controlled buck converter will becalculated as
Vinmin Vo + VD( )2TH
Vo + VD( )T minus 2LIvminus VD (14)
Similarly assuming the output voltage variation is zeroin one PL switching cycle (ΔvLo 0) the upper boundary ofthe input voltage will be
Vinmax Vo + VD( )2TL
Vo + VD( )T minus 2LIvminus VD (15)
Substituting the parameters of Table 1 into equation (14)the operating range of the input voltage can be calculatedwhich is [811V 19V] When the input voltage varies in thisrange the output voltage will increase during each PH anddecrease during each PL thus the low-frequency oscillationcan be avoided
By using equation (12) the relationship between theoutput voltage variation ΔvHo gt 0 and minus ΔvLo lt 0 and the inputvoltage Vin can be obtained as shown in Figure 3 It can beseen that with the increasing input voltage the variation ofthe output voltage ΔvHo gt 0 increases and minus ΔvLo lt 0 decreases
32AnalysisofPulseControlLaw According to the principleof charge balance the variation of the output voltage is zeroin a whole pulse train that is
μHΔvHo + μLΔv
Lo 0 (16)
By combining equations (12) and (16) it can be obtainedthat
μHμL minus
Vin minus Vo( ) Vo + VD( )T2L minus 2LIvTL Vin + VD( )
Vin minus Vo( ) Vo + VD( )T2H minus 2LIvTH Vin + VD( )
(17)
Substituting the parameters shown in Table 1 intoequation (17) the relationship between the pulse ratio μHμLand the input voltage Vin can be obtained as shown inFigure 4 It can be known that the pulse ratio μHμL de-creases gradually with the increase of Vin which is caused bythe increase of ΔvHo gt 0 and the decrease of minus ΔvLo lt 0erefore the proportion of the high-energy pulse PH in thepulse train gradually decreases with the increase in the inputvoltage
According to equation (17) the typical pulse train of theDCPT-controlled buck converter in the condition of dif-ferent input voltages can be obtained as listed in Table 2
33 Analysis of the Output Voltage Ripple To analyse theoutput voltage variation the capacitor current ic and outputvoltage vo of the DCPT-controlled buck converter withinone switching cycle are shown in Figure 5
During [0 ton] the capacitor current ic (t) and the outputvoltage of the converter can be written as
Table 1 Parameters of the DCPT-controlled buck converter
Parameters ValueRated input voltage Vin 12 VReference voltage Vref 5 VInductor L 100 μHCapacitor C 560 μFEquivalent series resistance RE 30mΩFrequency fL of carrier vsawL 40 kHzFrequency fH of carrier vsawH 20 kHzValley current Iv minus 05 A
∆νoH
ndash∆νoL
109 11 12 13 14 15Vin (V)
0
5
10
15
20
Δνo (
mV
) 25
30
35
40
Figure 3 Output voltage variation versus input voltage of theDCPT-controlled buck converter
109 11 12 13 14 15Vin (V)
0
05
1
15
2
μ H (μ
L)
25
3
35
Figure 4 Pulse ratio versus input voltage of the DCPT-controlledbuck converter
4 Journal of Control Science and Engineering
ic(t) Iv +Vin minus Vo
Lt (18)
vo(t) 1Cintt
0ic(t)dt + ic(t)RE
IvCt
+Vin minus Vo
2LCt2 +
Vin minus Vo
LREt
(19)
By taking the derivation of equation (19) one obtains
dvo(t)dt
IvC+Vin minus Vo
2LCt +
Vin minus Vo
LCRE (20)
Substituting the parameters listed in Table 1 intoequation (20) it can be known that the output voltage risesto the maximum at the time tonerefore it is available that
ΔvHpp IvCton +
Vin minus Vo
2LCt2on +
Vin minus Vo
LREton (21)
For the DCPT-controlled buck converter the outputvoltage ripple is closely related to the pulse train Taking thepulse train 2PH-1PL as an example the capacitor current icand the output voltage vo are shown in Figure 6(a) Obvi-ously the output voltage ripple of the converter is Δvo ΔvHpp + ΔvHo at this time
In general when the pulse train is nPH-1PL the outputvoltage ripple of the converter is
Δvo (n minus 1)ΔvHpp + ΔvHo (22)
When the pulse train is 1PH-nPL the capacitor current icand the output voltage vo are shown in Figure 6(b) Ap-parently the output voltage ripple on this condition is
Δvo ΔvHpp (23)
By using equations (21)ndash(23) the output voltage rippleΔvo of the DCPT-controlled buck converter can be calcu-lated as listed in Table 3 For the DCPT-controlled buckconverter the output voltage ripple increases gradually withthe increase of the input voltage
4 Simulation and Experimental Results
41 SimulationResults To verify the theoretical analysis thesimulation results are provided in Figure 7 which includecarrier signal vsaw control pulse vp capacitor current ic andoutput voltage vo
As shown in Figure 7(a) when the input voltage equals to868V the pulse train is 2PH-1PL the pulse ratio is μHμL 2and the output voltage ripple is 40mV which are consistentwith the theoretical analysis Similarly as shown inFigures 7(b)ndash7(d) when the input voltage equals to 92V1083V or 12V the pulse train is 1PH-1PL 1PH-3PL or 1PH-5PL the pulse ratio is 1 13 or 15 and the output voltageripple is 40mV 55mV or 60mV respectively
According to Figure 7 the following conclusion of theDCPT-controlled buck converter can be obtained as theinput voltage Vin increases μHμL decreases gradually iethe proportion of PH in the pulse train decreases which isconsistent with the theoretical analysis in Section 32
In addition the value of the capacitor current at thebeginning of each switching cycle is equal to the preset valleycurrent Iv due to the traction of the carrier signals Since thecapacitor current reects the ripple of the inductor currentthe value of the inductor current is constant at the beginningof each switching cycle erefore the variation of theoutput voltage is only inuenced by the control pulse PH orPL which indicates that the low-frequency oscillation doesnot exist in the DCPT-controlled buck converter
42 Experimental Results In order to verify and test theproposed technique a prototype of the DCPT-controlledbuck converter is designed with the parameters in Table 1 Inthe prototype the control scheme is achieved by an FPGAdevice with a type of EP4CE15F17C8 An operationalamplicenter OPA228 and a 10mΩ sense resistor connectedwith the output capacitor are employed to obtain the ca-pacitor current Two DA DAC0808 converters are appliedto generate the carrier signals and an analogue multiplexerCD4051 is used to select the carrier signal between vsawH andvsawL Besides the type of the comparators in this prototypeis LM393
When the input voltage equals to 868V the experi-mental waveforms are shown in Figure 8(a) e pulse trainis 2PH-1PL and the output voltage ripple is 40mV ap-proximately Similarly when the input voltage equals to92V 1083V or 12V the pulse train is 1PH-1PL 1PH-3PL
Iv
ton
O t
ic
t
vo
O
ΔνHpp
T
Figure 5 Capacitor current and output voltage of the DCPT-controlled buck converter
Table 2 Pulse train of the DCPT-controlled buck converter atdierent voltages
Vin (V) μHμL Pulse train849 3 3PH-1PL868 2 2PH-1PL92 1 1PH-1PL1083 13 1PH-3PL12 15 1PH-5PL
Journal of Control Science and Engineering 5
or 1PH-5PL and the output voltage ripple is 40mV 50mV or60mV respectively
According to the principle of DCPT control the controlpulse is generated by comparing the capacitor current with thecarrier signals It can be seen from Figure 8 that the combi-nation of the carrier signals changes with the variation of the
input voltage which causes the variation of the pulse trainBased on the experimental results it can be known that theDCPT-controlled buck converter can operate in a steady stateby adjusting the pulse train when the input voltage changes
In order to study the transient response of the DCPTcontrol method the experimental transient waveforms are
2PH-1PL
40mV5045
10
1
2
85 86 87t (ms)
88 89 9
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
(a)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-1PL
40mV
(b)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-3PL
55mV
(c)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-5PL
60mV
(d)
Figure 7 Simulation waveforms of the DCPT-controlled buck converter (a) Vin 868V (b) Vin 92 V (c) Vin 1083V (d) Vin 12V
ic
vo
Vref
Iv
2PH-1PL
ΔvHPP
ΔvHo
Δvo
(a)
1PH-3PL
ΔvHPP
ic
vo
Vref
Iv
(b)
Figure 6 Output voltage ripple of the DCPT-controlled buck converter (a) -e case of 2PH-1PL (b) -e case of 1PH-3PL
Table 3 -e output voltage ripple of the DCPT-controlled buck converter
Vin (V) ΔvHo (mV) ΔvHpp (mV) Δvo (mV)
849 33 343 409868 49 363 41292 89 415 4151083 191 522 52212 248 577 577
6 Journal of Control Science and Engineering
provided in Figure 9 When the load current increases from2A to 3A two high-energy pulses are generated successivelyby the controller to stabilize the output voltage and thisconverter enjoys excellent transient response Consideringthe parasitic parameters such as the on-state resistor of theMOSFET when the load current increases the input voltageof the inductor will decrease slightly which causes theproportion of PH in the pulse train to increase
In order to verify the suppression effect on the low-frequency oscillation the comparative experimental resultsare provided in Figure 10 -e control parameters of
traditional PT-controlled buck converter are as followsDH 06 DL 03 and T 25 μs
As shown in Figure 10(a) the pulse train is 1PH-5PL forthe DCPT-controlled CCM converter and the output voltageripple is 60mV In contrast the pulse train of the PT-controlled buck converter is 4PH-4PL and the output voltageripple is 120mV as shown in Figure 10(b) -is phenom-enon of successive several high-energy pulses followed bysuccessive several low-energy pulses indicates that the low-frequency oscillation exists in the PT-controlled CCMconverter -e low-frequency oscillation has not occurred in
2PH-1PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]
4
3
2
1
lt2HzF
(a)
1PH-1PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]
4
3
2
1
lt2HzF
(b)
1PH-3PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]273306kHz
4
3
2
1
F
(c)
1PH-5PL vsaw [2Vdiv]
Time [50 μsdiv] 331936kHzF
4
3
2
1
vp [2Vdiv]ic [1Adiv]
vo [50 mVdiv]
(d)
Figure 8 Experimental waveforms of the DCPT-controlled buck converter (a)Vin 868V (b)Vin 92V (c)Vin 1083V (d)Vin 12V
2PH
lt2HzFTime [100μsdiv]
vp [2Vdiv]
ic [1Adiv]
vo [50mVdiv]
Io [1Adiv]
2
3
14
Figure 9 Experimental transient waveforms of the DCPT-controlled buck converter while load changes
Journal of Control Science and Engineering 7
the DCPT-controlled CCM buck converter e proposedDCPT control technique enjoys much better output char-acteristics compared with the traditional PT controltechnique
5 Conclusions
In this paper a dual-carrier pulse-train control technique isproposed With the CCM buck converter as an example theoperational principle is analysed in detail Based on theoutput voltage variation of the DCPT-controlled buckconverter within one switching cycle the pulse control lawand the output voltage ripple are analysed e simulationand experimental results verify the theoretical analysis andindicate that there is no low-frequency oscillation in theDCPT-controlled CCM buck converter Compared with thetraditional PTcontrol technique the DCPT-controlled buckconverter enjoys better control characteristics and muchsmaller output voltage ripple
Data Availability
e data used to support the centndings of this study are in-cluded within the article
Conflicts of Interest
e authors declare that there are no conicts of interestregarding the publication of this paper
Acknowledgments
is work was supported by the National Natural ScienceFoundation of China (51507155) and the Key ResearchProgram of Hersquonan Higher Education (16A470014)
References
[1] C Y-F Ho B W-K Ling Y Yan-Qun Liu P K-S Tam andK Kok-Lay Teo ldquoOptimal PWM control of switched-ca-pacitor DC-DC power converters via model transformationand enhancing control techniquesrdquo IEEE Transactions on
Circuits and Systems I Regular Papers vol 55 no 5pp 1382ndash1391 2008
[2] C Duan and D Wu ldquoNonlinear voltage regulation algorithmfor DC-DC boost converter with centnite-time convergencerdquoJournal of Control Science and Engineering vol 2019 ArticleID 6761784 5 pages 2019
[3] X Zhang Q-C Zhong and W-L Ming ldquoStabilization ofcascaded DCDC converters via adaptive series-virtual-im-pedance control of the load converterrdquo IEEE Transactions onPower Electronics vol 31 no 9 pp 6057ndash6063 2016
[4] S Kennedy M R Yuce and J-M Redoute ldquoFully integratedswitched-capacitor DCDC converters with clock slope EMIcontrolrdquo IEEE Transactions on Electromagnetic Compatibilityvol 60 no 6 pp 2073ndash2075 2018
[5] M Telefus A Shteynberg M Ferdowsi and A Emadi ldquoPulsetrain control technique for yback converterrdquo IEEE Trans-actions on Power Electronics vol 19 no 3 pp 757ndash764 2004
[6] M Qin and J Xu ldquoMultiduty ratio modulation technique forswitching DC-DC converters operating in discontinuousconduction moderdquo IEEE Transactions on Industrial Elec-tronics vol 57 no 10 pp 3497ndash3507 2010
[7] M Qin and J Xu ldquoImproved pulse regulation controltechnique for switching DC-DC converters operating inDCMrdquo IEEE Transactions on Industrial Electronics vol 60no 5 pp 1819ndash1830 2013
[8] J Xu and J Wang ldquoBifrequency pulse-train control techniquefor switching DC-DC converters operating in DCMrdquo IEEETransactions on Industrial Electronics vol 58 no 8pp 3658ndash3667 2011
[9] J Wang J Xu G Zhou and B Bao ldquoPulse-train-controlledCCM buck converter with small ESR output-capacitorrdquo IEEETransactions on Industrial Electronics vol 60 no 12pp 5875ndash5881 2013
[10] J Sha S Liu S Zhong and J Xu ldquoValley current mode pulsetrain control technique for switching DC-DC convertersrdquoElectronics Letters vol 50 no 4 pp 311ndash313 2014
[11] L Wang D Yu R Xu Z Ye and P Wang ldquoSliding current-valley based pulse train control for buck converterrdquo in IECON2017mdash43rd Annual Conference of the IEEE Industrial Elec-tronics Society pp 4978ndash4981 Beijing China October-No-vember 2017
[12] J Sha D Xu Y Chen J Xu and B W Williams ldquoA peak-capacitor-current pulse-train-controlled buck converter withfast transient response and a wide load rangerdquo IEEE
Time [100μsdiv]lt2HzF
vp [2Vdiv]
ic [1Adiv]
vo [100mVdiv]
Io [1Adiv]2
1
3
4
1PH-5PL
(a)
2
Time [100μsdiv]
vp [2Vdiv]
ic [1Adiv]
vo [100mVdiv]
Io [1Adiv]
4PH-4PL
13
4
F 398217kHz
(b)
Figure 10 Experimental waveforms(a) DCPT-controlled buck converter (b) PT-controlled buck converter
8 Journal of Control Science and Engineering
Transactions on Industrial Electronics vol 63 no 3pp 1528ndash1538 2016
[13] D Yu Y Geng H H C Iu T Fernando and R Xu ldquoPulsephase shift based low-frequency oscillation suppression forPT controlled CCM buck converterrdquo IEEE Transactions onCircuits and Systems II Express Briefs vol 65 no 10pp 1465ndash1469 2018
[14] G Zhou W Tan S Zhou Y Wang and X Ye ldquoAnalysis ofpulse train controlled PCCM boost converter with low fre-quency oscillation suppressionrdquo IEEE Access vol 6pp 68795ndash68803 2018
[15] D Yu LWang Y Geng CMa Z Ye and Y Liu ldquoPulse traincontrolled buck converter with coupled inductorsrdquo IET PowerElectronics vol 10 no 10 pp 1231ndash1239 2017
[16] R Xu Y Zhang S Lu G Chen D Yu and L Wang ldquoPulsetrain-controlled CCM boost converter with suppression oflow-frequency oscillationrdquo IET Power Electronics vol 10no 8 pp 957ndash967 2017
[17] X Jin L Wang D Yu Y Geng and R Xu ldquoPulse traincontrolled single-input dual-output buck converter withcoupled inductorsrdquo IEEE Access vol 6 pp 41504ndash415172018
[18] J Sha J Xu S Zhong S Liu and L Xu ldquoControl pulsecombination-based analysis of pulse train controlled DCMswitching DC-DC convertersrdquo IEEE Transactions on In-dustrial Electronics vol 62 no 1 pp 246ndash255 2015
[19] S Kapat ldquoConfigurable multimode digital control for lightload DC-DC converters with improved spectrum and smoothtransitionrdquo IEEE Transactions on Power Electronics vol 31no 3 pp 2680ndash2688 2016
[20] K Muppala Kumar and K Anbukumar ldquoPulse train con-trolled quadratic buck converter operating in discontinuousconduction moderdquo IET Circuits Devices amp Systems vol 12no 4 pp 486ndash496 2018
Journal of Control Science and Engineering 9
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determined Based on the analysis above the parameters ofthe researched the DCPT-controlled buck converter arelisted in Table 1
From equation (12) it can be known that the outputvoltage variations ΔvHo and ΔvLo vary with the input voltageVin In order to achieve ΔvHo gt 0 and ΔvLo lt 0 Vin would belimited within a valid range
Assuming the output voltage variation is zero in one PHswitching cycle (ΔvHo 0) the lower boundary of the inputvoltage for the DCPT-controlled buck converter will becalculated as
Vinmin Vo + VD( )2TH
Vo + VD( )T minus 2LIvminus VD (14)
Similarly assuming the output voltage variation is zeroin one PL switching cycle (ΔvLo 0) the upper boundary ofthe input voltage will be
Vinmax Vo + VD( )2TL
Vo + VD( )T minus 2LIvminus VD (15)
Substituting the parameters of Table 1 into equation (14)the operating range of the input voltage can be calculatedwhich is [811V 19V] When the input voltage varies in thisrange the output voltage will increase during each PH anddecrease during each PL thus the low-frequency oscillationcan be avoided
By using equation (12) the relationship between theoutput voltage variation ΔvHo gt 0 and minus ΔvLo lt 0 and the inputvoltage Vin can be obtained as shown in Figure 3 It can beseen that with the increasing input voltage the variation ofthe output voltage ΔvHo gt 0 increases and minus ΔvLo lt 0 decreases
32AnalysisofPulseControlLaw According to the principleof charge balance the variation of the output voltage is zeroin a whole pulse train that is
μHΔvHo + μLΔv
Lo 0 (16)
By combining equations (12) and (16) it can be obtainedthat
μHμL minus
Vin minus Vo( ) Vo + VD( )T2L minus 2LIvTL Vin + VD( )
Vin minus Vo( ) Vo + VD( )T2H minus 2LIvTH Vin + VD( )
(17)
Substituting the parameters shown in Table 1 intoequation (17) the relationship between the pulse ratio μHμLand the input voltage Vin can be obtained as shown inFigure 4 It can be known that the pulse ratio μHμL de-creases gradually with the increase of Vin which is caused bythe increase of ΔvHo gt 0 and the decrease of minus ΔvLo lt 0erefore the proportion of the high-energy pulse PH in thepulse train gradually decreases with the increase in the inputvoltage
According to equation (17) the typical pulse train of theDCPT-controlled buck converter in the condition of dif-ferent input voltages can be obtained as listed in Table 2
33 Analysis of the Output Voltage Ripple To analyse theoutput voltage variation the capacitor current ic and outputvoltage vo of the DCPT-controlled buck converter withinone switching cycle are shown in Figure 5
During [0 ton] the capacitor current ic (t) and the outputvoltage of the converter can be written as
Table 1 Parameters of the DCPT-controlled buck converter
Parameters ValueRated input voltage Vin 12 VReference voltage Vref 5 VInductor L 100 μHCapacitor C 560 μFEquivalent series resistance RE 30mΩFrequency fL of carrier vsawL 40 kHzFrequency fH of carrier vsawH 20 kHzValley current Iv minus 05 A
∆νoH
ndash∆νoL
109 11 12 13 14 15Vin (V)
0
5
10
15
20
Δνo (
mV
) 25
30
35
40
Figure 3 Output voltage variation versus input voltage of theDCPT-controlled buck converter
109 11 12 13 14 15Vin (V)
0
05
1
15
2
μ H (μ
L)
25
3
35
Figure 4 Pulse ratio versus input voltage of the DCPT-controlledbuck converter
4 Journal of Control Science and Engineering
ic(t) Iv +Vin minus Vo
Lt (18)
vo(t) 1Cintt
0ic(t)dt + ic(t)RE
IvCt
+Vin minus Vo
2LCt2 +
Vin minus Vo
LREt
(19)
By taking the derivation of equation (19) one obtains
dvo(t)dt
IvC+Vin minus Vo
2LCt +
Vin minus Vo
LCRE (20)
Substituting the parameters listed in Table 1 intoequation (20) it can be known that the output voltage risesto the maximum at the time tonerefore it is available that
ΔvHpp IvCton +
Vin minus Vo
2LCt2on +
Vin minus Vo
LREton (21)
For the DCPT-controlled buck converter the outputvoltage ripple is closely related to the pulse train Taking thepulse train 2PH-1PL as an example the capacitor current icand the output voltage vo are shown in Figure 6(a) Obvi-ously the output voltage ripple of the converter is Δvo ΔvHpp + ΔvHo at this time
In general when the pulse train is nPH-1PL the outputvoltage ripple of the converter is
Δvo (n minus 1)ΔvHpp + ΔvHo (22)
When the pulse train is 1PH-nPL the capacitor current icand the output voltage vo are shown in Figure 6(b) Ap-parently the output voltage ripple on this condition is
Δvo ΔvHpp (23)
By using equations (21)ndash(23) the output voltage rippleΔvo of the DCPT-controlled buck converter can be calcu-lated as listed in Table 3 For the DCPT-controlled buckconverter the output voltage ripple increases gradually withthe increase of the input voltage
4 Simulation and Experimental Results
41 SimulationResults To verify the theoretical analysis thesimulation results are provided in Figure 7 which includecarrier signal vsaw control pulse vp capacitor current ic andoutput voltage vo
As shown in Figure 7(a) when the input voltage equals to868V the pulse train is 2PH-1PL the pulse ratio is μHμL 2and the output voltage ripple is 40mV which are consistentwith the theoretical analysis Similarly as shown inFigures 7(b)ndash7(d) when the input voltage equals to 92V1083V or 12V the pulse train is 1PH-1PL 1PH-3PL or 1PH-5PL the pulse ratio is 1 13 or 15 and the output voltageripple is 40mV 55mV or 60mV respectively
According to Figure 7 the following conclusion of theDCPT-controlled buck converter can be obtained as theinput voltage Vin increases μHμL decreases gradually iethe proportion of PH in the pulse train decreases which isconsistent with the theoretical analysis in Section 32
In addition the value of the capacitor current at thebeginning of each switching cycle is equal to the preset valleycurrent Iv due to the traction of the carrier signals Since thecapacitor current reects the ripple of the inductor currentthe value of the inductor current is constant at the beginningof each switching cycle erefore the variation of theoutput voltage is only inuenced by the control pulse PH orPL which indicates that the low-frequency oscillation doesnot exist in the DCPT-controlled buck converter
42 Experimental Results In order to verify and test theproposed technique a prototype of the DCPT-controlledbuck converter is designed with the parameters in Table 1 Inthe prototype the control scheme is achieved by an FPGAdevice with a type of EP4CE15F17C8 An operationalamplicenter OPA228 and a 10mΩ sense resistor connectedwith the output capacitor are employed to obtain the ca-pacitor current Two DA DAC0808 converters are appliedto generate the carrier signals and an analogue multiplexerCD4051 is used to select the carrier signal between vsawH andvsawL Besides the type of the comparators in this prototypeis LM393
When the input voltage equals to 868V the experi-mental waveforms are shown in Figure 8(a) e pulse trainis 2PH-1PL and the output voltage ripple is 40mV ap-proximately Similarly when the input voltage equals to92V 1083V or 12V the pulse train is 1PH-1PL 1PH-3PL
Iv
ton
O t
ic
t
vo
O
ΔνHpp
T
Figure 5 Capacitor current and output voltage of the DCPT-controlled buck converter
Table 2 Pulse train of the DCPT-controlled buck converter atdierent voltages
Vin (V) μHμL Pulse train849 3 3PH-1PL868 2 2PH-1PL92 1 1PH-1PL1083 13 1PH-3PL12 15 1PH-5PL
Journal of Control Science and Engineering 5
or 1PH-5PL and the output voltage ripple is 40mV 50mV or60mV respectively
According to the principle of DCPT control the controlpulse is generated by comparing the capacitor current with thecarrier signals It can be seen from Figure 8 that the combi-nation of the carrier signals changes with the variation of the
input voltage which causes the variation of the pulse trainBased on the experimental results it can be known that theDCPT-controlled buck converter can operate in a steady stateby adjusting the pulse train when the input voltage changes
In order to study the transient response of the DCPTcontrol method the experimental transient waveforms are
2PH-1PL
40mV5045
10
1
2
85 86 87t (ms)
88 89 9
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
(a)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-1PL
40mV
(b)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-3PL
55mV
(c)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-5PL
60mV
(d)
Figure 7 Simulation waveforms of the DCPT-controlled buck converter (a) Vin 868V (b) Vin 92 V (c) Vin 1083V (d) Vin 12V
ic
vo
Vref
Iv
2PH-1PL
ΔvHPP
ΔvHo
Δvo
(a)
1PH-3PL
ΔvHPP
ic
vo
Vref
Iv
(b)
Figure 6 Output voltage ripple of the DCPT-controlled buck converter (a) -e case of 2PH-1PL (b) -e case of 1PH-3PL
Table 3 -e output voltage ripple of the DCPT-controlled buck converter
Vin (V) ΔvHo (mV) ΔvHpp (mV) Δvo (mV)
849 33 343 409868 49 363 41292 89 415 4151083 191 522 52212 248 577 577
6 Journal of Control Science and Engineering
provided in Figure 9 When the load current increases from2A to 3A two high-energy pulses are generated successivelyby the controller to stabilize the output voltage and thisconverter enjoys excellent transient response Consideringthe parasitic parameters such as the on-state resistor of theMOSFET when the load current increases the input voltageof the inductor will decrease slightly which causes theproportion of PH in the pulse train to increase
In order to verify the suppression effect on the low-frequency oscillation the comparative experimental resultsare provided in Figure 10 -e control parameters of
traditional PT-controlled buck converter are as followsDH 06 DL 03 and T 25 μs
As shown in Figure 10(a) the pulse train is 1PH-5PL forthe DCPT-controlled CCM converter and the output voltageripple is 60mV In contrast the pulse train of the PT-controlled buck converter is 4PH-4PL and the output voltageripple is 120mV as shown in Figure 10(b) -is phenom-enon of successive several high-energy pulses followed bysuccessive several low-energy pulses indicates that the low-frequency oscillation exists in the PT-controlled CCMconverter -e low-frequency oscillation has not occurred in
2PH-1PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]
4
3
2
1
lt2HzF
(a)
1PH-1PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]
4
3
2
1
lt2HzF
(b)
1PH-3PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]273306kHz
4
3
2
1
F
(c)
1PH-5PL vsaw [2Vdiv]
Time [50 μsdiv] 331936kHzF
4
3
2
1
vp [2Vdiv]ic [1Adiv]
vo [50 mVdiv]
(d)
Figure 8 Experimental waveforms of the DCPT-controlled buck converter (a)Vin 868V (b)Vin 92V (c)Vin 1083V (d)Vin 12V
2PH
lt2HzFTime [100μsdiv]
vp [2Vdiv]
ic [1Adiv]
vo [50mVdiv]
Io [1Adiv]
2
3
14
Figure 9 Experimental transient waveforms of the DCPT-controlled buck converter while load changes
Journal of Control Science and Engineering 7
the DCPT-controlled CCM buck converter e proposedDCPT control technique enjoys much better output char-acteristics compared with the traditional PT controltechnique
5 Conclusions
In this paper a dual-carrier pulse-train control technique isproposed With the CCM buck converter as an example theoperational principle is analysed in detail Based on theoutput voltage variation of the DCPT-controlled buckconverter within one switching cycle the pulse control lawand the output voltage ripple are analysed e simulationand experimental results verify the theoretical analysis andindicate that there is no low-frequency oscillation in theDCPT-controlled CCM buck converter Compared with thetraditional PTcontrol technique the DCPT-controlled buckconverter enjoys better control characteristics and muchsmaller output voltage ripple
Data Availability
e data used to support the centndings of this study are in-cluded within the article
Conflicts of Interest
e authors declare that there are no conicts of interestregarding the publication of this paper
Acknowledgments
is work was supported by the National Natural ScienceFoundation of China (51507155) and the Key ResearchProgram of Hersquonan Higher Education (16A470014)
References
[1] C Y-F Ho B W-K Ling Y Yan-Qun Liu P K-S Tam andK Kok-Lay Teo ldquoOptimal PWM control of switched-ca-pacitor DC-DC power converters via model transformationand enhancing control techniquesrdquo IEEE Transactions on
Circuits and Systems I Regular Papers vol 55 no 5pp 1382ndash1391 2008
[2] C Duan and D Wu ldquoNonlinear voltage regulation algorithmfor DC-DC boost converter with centnite-time convergencerdquoJournal of Control Science and Engineering vol 2019 ArticleID 6761784 5 pages 2019
[3] X Zhang Q-C Zhong and W-L Ming ldquoStabilization ofcascaded DCDC converters via adaptive series-virtual-im-pedance control of the load converterrdquo IEEE Transactions onPower Electronics vol 31 no 9 pp 6057ndash6063 2016
[4] S Kennedy M R Yuce and J-M Redoute ldquoFully integratedswitched-capacitor DCDC converters with clock slope EMIcontrolrdquo IEEE Transactions on Electromagnetic Compatibilityvol 60 no 6 pp 2073ndash2075 2018
[5] M Telefus A Shteynberg M Ferdowsi and A Emadi ldquoPulsetrain control technique for yback converterrdquo IEEE Trans-actions on Power Electronics vol 19 no 3 pp 757ndash764 2004
[6] M Qin and J Xu ldquoMultiduty ratio modulation technique forswitching DC-DC converters operating in discontinuousconduction moderdquo IEEE Transactions on Industrial Elec-tronics vol 57 no 10 pp 3497ndash3507 2010
[7] M Qin and J Xu ldquoImproved pulse regulation controltechnique for switching DC-DC converters operating inDCMrdquo IEEE Transactions on Industrial Electronics vol 60no 5 pp 1819ndash1830 2013
[8] J Xu and J Wang ldquoBifrequency pulse-train control techniquefor switching DC-DC converters operating in DCMrdquo IEEETransactions on Industrial Electronics vol 58 no 8pp 3658ndash3667 2011
[9] J Wang J Xu G Zhou and B Bao ldquoPulse-train-controlledCCM buck converter with small ESR output-capacitorrdquo IEEETransactions on Industrial Electronics vol 60 no 12pp 5875ndash5881 2013
[10] J Sha S Liu S Zhong and J Xu ldquoValley current mode pulsetrain control technique for switching DC-DC convertersrdquoElectronics Letters vol 50 no 4 pp 311ndash313 2014
[11] L Wang D Yu R Xu Z Ye and P Wang ldquoSliding current-valley based pulse train control for buck converterrdquo in IECON2017mdash43rd Annual Conference of the IEEE Industrial Elec-tronics Society pp 4978ndash4981 Beijing China October-No-vember 2017
[12] J Sha D Xu Y Chen J Xu and B W Williams ldquoA peak-capacitor-current pulse-train-controlled buck converter withfast transient response and a wide load rangerdquo IEEE
Time [100μsdiv]lt2HzF
vp [2Vdiv]
ic [1Adiv]
vo [100mVdiv]
Io [1Adiv]2
1
3
4
1PH-5PL
(a)
2
Time [100μsdiv]
vp [2Vdiv]
ic [1Adiv]
vo [100mVdiv]
Io [1Adiv]
4PH-4PL
13
4
F 398217kHz
(b)
Figure 10 Experimental waveforms(a) DCPT-controlled buck converter (b) PT-controlled buck converter
8 Journal of Control Science and Engineering
Transactions on Industrial Electronics vol 63 no 3pp 1528ndash1538 2016
[13] D Yu Y Geng H H C Iu T Fernando and R Xu ldquoPulsephase shift based low-frequency oscillation suppression forPT controlled CCM buck converterrdquo IEEE Transactions onCircuits and Systems II Express Briefs vol 65 no 10pp 1465ndash1469 2018
[14] G Zhou W Tan S Zhou Y Wang and X Ye ldquoAnalysis ofpulse train controlled PCCM boost converter with low fre-quency oscillation suppressionrdquo IEEE Access vol 6pp 68795ndash68803 2018
[15] D Yu LWang Y Geng CMa Z Ye and Y Liu ldquoPulse traincontrolled buck converter with coupled inductorsrdquo IET PowerElectronics vol 10 no 10 pp 1231ndash1239 2017
[16] R Xu Y Zhang S Lu G Chen D Yu and L Wang ldquoPulsetrain-controlled CCM boost converter with suppression oflow-frequency oscillationrdquo IET Power Electronics vol 10no 8 pp 957ndash967 2017
[17] X Jin L Wang D Yu Y Geng and R Xu ldquoPulse traincontrolled single-input dual-output buck converter withcoupled inductorsrdquo IEEE Access vol 6 pp 41504ndash415172018
[18] J Sha J Xu S Zhong S Liu and L Xu ldquoControl pulsecombination-based analysis of pulse train controlled DCMswitching DC-DC convertersrdquo IEEE Transactions on In-dustrial Electronics vol 62 no 1 pp 246ndash255 2015
[19] S Kapat ldquoConfigurable multimode digital control for lightload DC-DC converters with improved spectrum and smoothtransitionrdquo IEEE Transactions on Power Electronics vol 31no 3 pp 2680ndash2688 2016
[20] K Muppala Kumar and K Anbukumar ldquoPulse train con-trolled quadratic buck converter operating in discontinuousconduction moderdquo IET Circuits Devices amp Systems vol 12no 4 pp 486ndash496 2018
Journal of Control Science and Engineering 9
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
ic(t) Iv +Vin minus Vo
Lt (18)
vo(t) 1Cintt
0ic(t)dt + ic(t)RE
IvCt
+Vin minus Vo
2LCt2 +
Vin minus Vo
LREt
(19)
By taking the derivation of equation (19) one obtains
dvo(t)dt
IvC+Vin minus Vo
2LCt +
Vin minus Vo
LCRE (20)
Substituting the parameters listed in Table 1 intoequation (20) it can be known that the output voltage risesto the maximum at the time tonerefore it is available that
ΔvHpp IvCton +
Vin minus Vo
2LCt2on +
Vin minus Vo
LREton (21)
For the DCPT-controlled buck converter the outputvoltage ripple is closely related to the pulse train Taking thepulse train 2PH-1PL as an example the capacitor current icand the output voltage vo are shown in Figure 6(a) Obvi-ously the output voltage ripple of the converter is Δvo ΔvHpp + ΔvHo at this time
In general when the pulse train is nPH-1PL the outputvoltage ripple of the converter is
Δvo (n minus 1)ΔvHpp + ΔvHo (22)
When the pulse train is 1PH-nPL the capacitor current icand the output voltage vo are shown in Figure 6(b) Ap-parently the output voltage ripple on this condition is
Δvo ΔvHpp (23)
By using equations (21)ndash(23) the output voltage rippleΔvo of the DCPT-controlled buck converter can be calcu-lated as listed in Table 3 For the DCPT-controlled buckconverter the output voltage ripple increases gradually withthe increase of the input voltage
4 Simulation and Experimental Results
41 SimulationResults To verify the theoretical analysis thesimulation results are provided in Figure 7 which includecarrier signal vsaw control pulse vp capacitor current ic andoutput voltage vo
As shown in Figure 7(a) when the input voltage equals to868V the pulse train is 2PH-1PL the pulse ratio is μHμL 2and the output voltage ripple is 40mV which are consistentwith the theoretical analysis Similarly as shown inFigures 7(b)ndash7(d) when the input voltage equals to 92V1083V or 12V the pulse train is 1PH-1PL 1PH-3PL or 1PH-5PL the pulse ratio is 1 13 or 15 and the output voltageripple is 40mV 55mV or 60mV respectively
According to Figure 7 the following conclusion of theDCPT-controlled buck converter can be obtained as theinput voltage Vin increases μHμL decreases gradually iethe proportion of PH in the pulse train decreases which isconsistent with the theoretical analysis in Section 32
In addition the value of the capacitor current at thebeginning of each switching cycle is equal to the preset valleycurrent Iv due to the traction of the carrier signals Since thecapacitor current reects the ripple of the inductor currentthe value of the inductor current is constant at the beginningof each switching cycle erefore the variation of theoutput voltage is only inuenced by the control pulse PH orPL which indicates that the low-frequency oscillation doesnot exist in the DCPT-controlled buck converter
42 Experimental Results In order to verify and test theproposed technique a prototype of the DCPT-controlledbuck converter is designed with the parameters in Table 1 Inthe prototype the control scheme is achieved by an FPGAdevice with a type of EP4CE15F17C8 An operationalamplicenter OPA228 and a 10mΩ sense resistor connectedwith the output capacitor are employed to obtain the ca-pacitor current Two DA DAC0808 converters are appliedto generate the carrier signals and an analogue multiplexerCD4051 is used to select the carrier signal between vsawH andvsawL Besides the type of the comparators in this prototypeis LM393
When the input voltage equals to 868V the experi-mental waveforms are shown in Figure 8(a) e pulse trainis 2PH-1PL and the output voltage ripple is 40mV ap-proximately Similarly when the input voltage equals to92V 1083V or 12V the pulse train is 1PH-1PL 1PH-3PL
Iv
ton
O t
ic
t
vo
O
ΔνHpp
T
Figure 5 Capacitor current and output voltage of the DCPT-controlled buck converter
Table 2 Pulse train of the DCPT-controlled buck converter atdierent voltages
Vin (V) μHμL Pulse train849 3 3PH-1PL868 2 2PH-1PL92 1 1PH-1PL1083 13 1PH-3PL12 15 1PH-5PL
Journal of Control Science and Engineering 5
or 1PH-5PL and the output voltage ripple is 40mV 50mV or60mV respectively
According to the principle of DCPT control the controlpulse is generated by comparing the capacitor current with thecarrier signals It can be seen from Figure 8 that the combi-nation of the carrier signals changes with the variation of the
input voltage which causes the variation of the pulse trainBased on the experimental results it can be known that theDCPT-controlled buck converter can operate in a steady stateby adjusting the pulse train when the input voltage changes
In order to study the transient response of the DCPTcontrol method the experimental transient waveforms are
2PH-1PL
40mV5045
10
1
2
85 86 87t (ms)
88 89 9
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
(a)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-1PL
40mV
(b)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-3PL
55mV
(c)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-5PL
60mV
(d)
Figure 7 Simulation waveforms of the DCPT-controlled buck converter (a) Vin 868V (b) Vin 92 V (c) Vin 1083V (d) Vin 12V
ic
vo
Vref
Iv
2PH-1PL
ΔvHPP
ΔvHo
Δvo
(a)
1PH-3PL
ΔvHPP
ic
vo
Vref
Iv
(b)
Figure 6 Output voltage ripple of the DCPT-controlled buck converter (a) -e case of 2PH-1PL (b) -e case of 1PH-3PL
Table 3 -e output voltage ripple of the DCPT-controlled buck converter
Vin (V) ΔvHo (mV) ΔvHpp (mV) Δvo (mV)
849 33 343 409868 49 363 41292 89 415 4151083 191 522 52212 248 577 577
6 Journal of Control Science and Engineering
provided in Figure 9 When the load current increases from2A to 3A two high-energy pulses are generated successivelyby the controller to stabilize the output voltage and thisconverter enjoys excellent transient response Consideringthe parasitic parameters such as the on-state resistor of theMOSFET when the load current increases the input voltageof the inductor will decrease slightly which causes theproportion of PH in the pulse train to increase
In order to verify the suppression effect on the low-frequency oscillation the comparative experimental resultsare provided in Figure 10 -e control parameters of
traditional PT-controlled buck converter are as followsDH 06 DL 03 and T 25 μs
As shown in Figure 10(a) the pulse train is 1PH-5PL forthe DCPT-controlled CCM converter and the output voltageripple is 60mV In contrast the pulse train of the PT-controlled buck converter is 4PH-4PL and the output voltageripple is 120mV as shown in Figure 10(b) -is phenom-enon of successive several high-energy pulses followed bysuccessive several low-energy pulses indicates that the low-frequency oscillation exists in the PT-controlled CCMconverter -e low-frequency oscillation has not occurred in
2PH-1PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]
4
3
2
1
lt2HzF
(a)
1PH-1PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]
4
3
2
1
lt2HzF
(b)
1PH-3PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]273306kHz
4
3
2
1
F
(c)
1PH-5PL vsaw [2Vdiv]
Time [50 μsdiv] 331936kHzF
4
3
2
1
vp [2Vdiv]ic [1Adiv]
vo [50 mVdiv]
(d)
Figure 8 Experimental waveforms of the DCPT-controlled buck converter (a)Vin 868V (b)Vin 92V (c)Vin 1083V (d)Vin 12V
2PH
lt2HzFTime [100μsdiv]
vp [2Vdiv]
ic [1Adiv]
vo [50mVdiv]
Io [1Adiv]
2
3
14
Figure 9 Experimental transient waveforms of the DCPT-controlled buck converter while load changes
Journal of Control Science and Engineering 7
the DCPT-controlled CCM buck converter e proposedDCPT control technique enjoys much better output char-acteristics compared with the traditional PT controltechnique
5 Conclusions
In this paper a dual-carrier pulse-train control technique isproposed With the CCM buck converter as an example theoperational principle is analysed in detail Based on theoutput voltage variation of the DCPT-controlled buckconverter within one switching cycle the pulse control lawand the output voltage ripple are analysed e simulationand experimental results verify the theoretical analysis andindicate that there is no low-frequency oscillation in theDCPT-controlled CCM buck converter Compared with thetraditional PTcontrol technique the DCPT-controlled buckconverter enjoys better control characteristics and muchsmaller output voltage ripple
Data Availability
e data used to support the centndings of this study are in-cluded within the article
Conflicts of Interest
e authors declare that there are no conicts of interestregarding the publication of this paper
Acknowledgments
is work was supported by the National Natural ScienceFoundation of China (51507155) and the Key ResearchProgram of Hersquonan Higher Education (16A470014)
References
[1] C Y-F Ho B W-K Ling Y Yan-Qun Liu P K-S Tam andK Kok-Lay Teo ldquoOptimal PWM control of switched-ca-pacitor DC-DC power converters via model transformationand enhancing control techniquesrdquo IEEE Transactions on
Circuits and Systems I Regular Papers vol 55 no 5pp 1382ndash1391 2008
[2] C Duan and D Wu ldquoNonlinear voltage regulation algorithmfor DC-DC boost converter with centnite-time convergencerdquoJournal of Control Science and Engineering vol 2019 ArticleID 6761784 5 pages 2019
[3] X Zhang Q-C Zhong and W-L Ming ldquoStabilization ofcascaded DCDC converters via adaptive series-virtual-im-pedance control of the load converterrdquo IEEE Transactions onPower Electronics vol 31 no 9 pp 6057ndash6063 2016
[4] S Kennedy M R Yuce and J-M Redoute ldquoFully integratedswitched-capacitor DCDC converters with clock slope EMIcontrolrdquo IEEE Transactions on Electromagnetic Compatibilityvol 60 no 6 pp 2073ndash2075 2018
[5] M Telefus A Shteynberg M Ferdowsi and A Emadi ldquoPulsetrain control technique for yback converterrdquo IEEE Trans-actions on Power Electronics vol 19 no 3 pp 757ndash764 2004
[6] M Qin and J Xu ldquoMultiduty ratio modulation technique forswitching DC-DC converters operating in discontinuousconduction moderdquo IEEE Transactions on Industrial Elec-tronics vol 57 no 10 pp 3497ndash3507 2010
[7] M Qin and J Xu ldquoImproved pulse regulation controltechnique for switching DC-DC converters operating inDCMrdquo IEEE Transactions on Industrial Electronics vol 60no 5 pp 1819ndash1830 2013
[8] J Xu and J Wang ldquoBifrequency pulse-train control techniquefor switching DC-DC converters operating in DCMrdquo IEEETransactions on Industrial Electronics vol 58 no 8pp 3658ndash3667 2011
[9] J Wang J Xu G Zhou and B Bao ldquoPulse-train-controlledCCM buck converter with small ESR output-capacitorrdquo IEEETransactions on Industrial Electronics vol 60 no 12pp 5875ndash5881 2013
[10] J Sha S Liu S Zhong and J Xu ldquoValley current mode pulsetrain control technique for switching DC-DC convertersrdquoElectronics Letters vol 50 no 4 pp 311ndash313 2014
[11] L Wang D Yu R Xu Z Ye and P Wang ldquoSliding current-valley based pulse train control for buck converterrdquo in IECON2017mdash43rd Annual Conference of the IEEE Industrial Elec-tronics Society pp 4978ndash4981 Beijing China October-No-vember 2017
[12] J Sha D Xu Y Chen J Xu and B W Williams ldquoA peak-capacitor-current pulse-train-controlled buck converter withfast transient response and a wide load rangerdquo IEEE
Time [100μsdiv]lt2HzF
vp [2Vdiv]
ic [1Adiv]
vo [100mVdiv]
Io [1Adiv]2
1
3
4
1PH-5PL
(a)
2
Time [100μsdiv]
vp [2Vdiv]
ic [1Adiv]
vo [100mVdiv]
Io [1Adiv]
4PH-4PL
13
4
F 398217kHz
(b)
Figure 10 Experimental waveforms(a) DCPT-controlled buck converter (b) PT-controlled buck converter
8 Journal of Control Science and Engineering
Transactions on Industrial Electronics vol 63 no 3pp 1528ndash1538 2016
[13] D Yu Y Geng H H C Iu T Fernando and R Xu ldquoPulsephase shift based low-frequency oscillation suppression forPT controlled CCM buck converterrdquo IEEE Transactions onCircuits and Systems II Express Briefs vol 65 no 10pp 1465ndash1469 2018
[14] G Zhou W Tan S Zhou Y Wang and X Ye ldquoAnalysis ofpulse train controlled PCCM boost converter with low fre-quency oscillation suppressionrdquo IEEE Access vol 6pp 68795ndash68803 2018
[15] D Yu LWang Y Geng CMa Z Ye and Y Liu ldquoPulse traincontrolled buck converter with coupled inductorsrdquo IET PowerElectronics vol 10 no 10 pp 1231ndash1239 2017
[16] R Xu Y Zhang S Lu G Chen D Yu and L Wang ldquoPulsetrain-controlled CCM boost converter with suppression oflow-frequency oscillationrdquo IET Power Electronics vol 10no 8 pp 957ndash967 2017
[17] X Jin L Wang D Yu Y Geng and R Xu ldquoPulse traincontrolled single-input dual-output buck converter withcoupled inductorsrdquo IEEE Access vol 6 pp 41504ndash415172018
[18] J Sha J Xu S Zhong S Liu and L Xu ldquoControl pulsecombination-based analysis of pulse train controlled DCMswitching DC-DC convertersrdquo IEEE Transactions on In-dustrial Electronics vol 62 no 1 pp 246ndash255 2015
[19] S Kapat ldquoConfigurable multimode digital control for lightload DC-DC converters with improved spectrum and smoothtransitionrdquo IEEE Transactions on Power Electronics vol 31no 3 pp 2680ndash2688 2016
[20] K Muppala Kumar and K Anbukumar ldquoPulse train con-trolled quadratic buck converter operating in discontinuousconduction moderdquo IET Circuits Devices amp Systems vol 12no 4 pp 486ndash496 2018
Journal of Control Science and Engineering 9
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
or 1PH-5PL and the output voltage ripple is 40mV 50mV or60mV respectively
According to the principle of DCPT control the controlpulse is generated by comparing the capacitor current with thecarrier signals It can be seen from Figure 8 that the combi-nation of the carrier signals changes with the variation of the
input voltage which causes the variation of the pulse trainBased on the experimental results it can be known that theDCPT-controlled buck converter can operate in a steady stateby adjusting the pulse train when the input voltage changes
In order to study the transient response of the DCPTcontrol method the experimental transient waveforms are
2PH-1PL
40mV5045
10
1
2
85 86 87t (ms)
88 89 9
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
(a)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-1PL
40mV
(b)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-3PL
55mV
(c)
85 86 87t (ms)
88 89 9
5045
10
1
2
v o (V
)i c
(A)
v p (V
)v s
aw (V
)
Iv
Iv
1PH-5PL
60mV
(d)
Figure 7 Simulation waveforms of the DCPT-controlled buck converter (a) Vin 868V (b) Vin 92 V (c) Vin 1083V (d) Vin 12V
ic
vo
Vref
Iv
2PH-1PL
ΔvHPP
ΔvHo
Δvo
(a)
1PH-3PL
ΔvHPP
ic
vo
Vref
Iv
(b)
Figure 6 Output voltage ripple of the DCPT-controlled buck converter (a) -e case of 2PH-1PL (b) -e case of 1PH-3PL
Table 3 -e output voltage ripple of the DCPT-controlled buck converter
Vin (V) ΔvHo (mV) ΔvHpp (mV) Δvo (mV)
849 33 343 409868 49 363 41292 89 415 4151083 191 522 52212 248 577 577
6 Journal of Control Science and Engineering
provided in Figure 9 When the load current increases from2A to 3A two high-energy pulses are generated successivelyby the controller to stabilize the output voltage and thisconverter enjoys excellent transient response Consideringthe parasitic parameters such as the on-state resistor of theMOSFET when the load current increases the input voltageof the inductor will decrease slightly which causes theproportion of PH in the pulse train to increase
In order to verify the suppression effect on the low-frequency oscillation the comparative experimental resultsare provided in Figure 10 -e control parameters of
traditional PT-controlled buck converter are as followsDH 06 DL 03 and T 25 μs
As shown in Figure 10(a) the pulse train is 1PH-5PL forthe DCPT-controlled CCM converter and the output voltageripple is 60mV In contrast the pulse train of the PT-controlled buck converter is 4PH-4PL and the output voltageripple is 120mV as shown in Figure 10(b) -is phenom-enon of successive several high-energy pulses followed bysuccessive several low-energy pulses indicates that the low-frequency oscillation exists in the PT-controlled CCMconverter -e low-frequency oscillation has not occurred in
2PH-1PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]
4
3
2
1
lt2HzF
(a)
1PH-1PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]
4
3
2
1
lt2HzF
(b)
1PH-3PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]273306kHz
4
3
2
1
F
(c)
1PH-5PL vsaw [2Vdiv]
Time [50 μsdiv] 331936kHzF
4
3
2
1
vp [2Vdiv]ic [1Adiv]
vo [50 mVdiv]
(d)
Figure 8 Experimental waveforms of the DCPT-controlled buck converter (a)Vin 868V (b)Vin 92V (c)Vin 1083V (d)Vin 12V
2PH
lt2HzFTime [100μsdiv]
vp [2Vdiv]
ic [1Adiv]
vo [50mVdiv]
Io [1Adiv]
2
3
14
Figure 9 Experimental transient waveforms of the DCPT-controlled buck converter while load changes
Journal of Control Science and Engineering 7
the DCPT-controlled CCM buck converter e proposedDCPT control technique enjoys much better output char-acteristics compared with the traditional PT controltechnique
5 Conclusions
In this paper a dual-carrier pulse-train control technique isproposed With the CCM buck converter as an example theoperational principle is analysed in detail Based on theoutput voltage variation of the DCPT-controlled buckconverter within one switching cycle the pulse control lawand the output voltage ripple are analysed e simulationand experimental results verify the theoretical analysis andindicate that there is no low-frequency oscillation in theDCPT-controlled CCM buck converter Compared with thetraditional PTcontrol technique the DCPT-controlled buckconverter enjoys better control characteristics and muchsmaller output voltage ripple
Data Availability
e data used to support the centndings of this study are in-cluded within the article
Conflicts of Interest
e authors declare that there are no conicts of interestregarding the publication of this paper
Acknowledgments
is work was supported by the National Natural ScienceFoundation of China (51507155) and the Key ResearchProgram of Hersquonan Higher Education (16A470014)
References
[1] C Y-F Ho B W-K Ling Y Yan-Qun Liu P K-S Tam andK Kok-Lay Teo ldquoOptimal PWM control of switched-ca-pacitor DC-DC power converters via model transformationand enhancing control techniquesrdquo IEEE Transactions on
Circuits and Systems I Regular Papers vol 55 no 5pp 1382ndash1391 2008
[2] C Duan and D Wu ldquoNonlinear voltage regulation algorithmfor DC-DC boost converter with centnite-time convergencerdquoJournal of Control Science and Engineering vol 2019 ArticleID 6761784 5 pages 2019
[3] X Zhang Q-C Zhong and W-L Ming ldquoStabilization ofcascaded DCDC converters via adaptive series-virtual-im-pedance control of the load converterrdquo IEEE Transactions onPower Electronics vol 31 no 9 pp 6057ndash6063 2016
[4] S Kennedy M R Yuce and J-M Redoute ldquoFully integratedswitched-capacitor DCDC converters with clock slope EMIcontrolrdquo IEEE Transactions on Electromagnetic Compatibilityvol 60 no 6 pp 2073ndash2075 2018
[5] M Telefus A Shteynberg M Ferdowsi and A Emadi ldquoPulsetrain control technique for yback converterrdquo IEEE Trans-actions on Power Electronics vol 19 no 3 pp 757ndash764 2004
[6] M Qin and J Xu ldquoMultiduty ratio modulation technique forswitching DC-DC converters operating in discontinuousconduction moderdquo IEEE Transactions on Industrial Elec-tronics vol 57 no 10 pp 3497ndash3507 2010
[7] M Qin and J Xu ldquoImproved pulse regulation controltechnique for switching DC-DC converters operating inDCMrdquo IEEE Transactions on Industrial Electronics vol 60no 5 pp 1819ndash1830 2013
[8] J Xu and J Wang ldquoBifrequency pulse-train control techniquefor switching DC-DC converters operating in DCMrdquo IEEETransactions on Industrial Electronics vol 58 no 8pp 3658ndash3667 2011
[9] J Wang J Xu G Zhou and B Bao ldquoPulse-train-controlledCCM buck converter with small ESR output-capacitorrdquo IEEETransactions on Industrial Electronics vol 60 no 12pp 5875ndash5881 2013
[10] J Sha S Liu S Zhong and J Xu ldquoValley current mode pulsetrain control technique for switching DC-DC convertersrdquoElectronics Letters vol 50 no 4 pp 311ndash313 2014
[11] L Wang D Yu R Xu Z Ye and P Wang ldquoSliding current-valley based pulse train control for buck converterrdquo in IECON2017mdash43rd Annual Conference of the IEEE Industrial Elec-tronics Society pp 4978ndash4981 Beijing China October-No-vember 2017
[12] J Sha D Xu Y Chen J Xu and B W Williams ldquoA peak-capacitor-current pulse-train-controlled buck converter withfast transient response and a wide load rangerdquo IEEE
Time [100μsdiv]lt2HzF
vp [2Vdiv]
ic [1Adiv]
vo [100mVdiv]
Io [1Adiv]2
1
3
4
1PH-5PL
(a)
2
Time [100μsdiv]
vp [2Vdiv]
ic [1Adiv]
vo [100mVdiv]
Io [1Adiv]
4PH-4PL
13
4
F 398217kHz
(b)
Figure 10 Experimental waveforms(a) DCPT-controlled buck converter (b) PT-controlled buck converter
8 Journal of Control Science and Engineering
Transactions on Industrial Electronics vol 63 no 3pp 1528ndash1538 2016
[13] D Yu Y Geng H H C Iu T Fernando and R Xu ldquoPulsephase shift based low-frequency oscillation suppression forPT controlled CCM buck converterrdquo IEEE Transactions onCircuits and Systems II Express Briefs vol 65 no 10pp 1465ndash1469 2018
[14] G Zhou W Tan S Zhou Y Wang and X Ye ldquoAnalysis ofpulse train controlled PCCM boost converter with low fre-quency oscillation suppressionrdquo IEEE Access vol 6pp 68795ndash68803 2018
[15] D Yu LWang Y Geng CMa Z Ye and Y Liu ldquoPulse traincontrolled buck converter with coupled inductorsrdquo IET PowerElectronics vol 10 no 10 pp 1231ndash1239 2017
[16] R Xu Y Zhang S Lu G Chen D Yu and L Wang ldquoPulsetrain-controlled CCM boost converter with suppression oflow-frequency oscillationrdquo IET Power Electronics vol 10no 8 pp 957ndash967 2017
[17] X Jin L Wang D Yu Y Geng and R Xu ldquoPulse traincontrolled single-input dual-output buck converter withcoupled inductorsrdquo IEEE Access vol 6 pp 41504ndash415172018
[18] J Sha J Xu S Zhong S Liu and L Xu ldquoControl pulsecombination-based analysis of pulse train controlled DCMswitching DC-DC convertersrdquo IEEE Transactions on In-dustrial Electronics vol 62 no 1 pp 246ndash255 2015
[19] S Kapat ldquoConfigurable multimode digital control for lightload DC-DC converters with improved spectrum and smoothtransitionrdquo IEEE Transactions on Power Electronics vol 31no 3 pp 2680ndash2688 2016
[20] K Muppala Kumar and K Anbukumar ldquoPulse train con-trolled quadratic buck converter operating in discontinuousconduction moderdquo IET Circuits Devices amp Systems vol 12no 4 pp 486ndash496 2018
Journal of Control Science and Engineering 9
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
provided in Figure 9 When the load current increases from2A to 3A two high-energy pulses are generated successivelyby the controller to stabilize the output voltage and thisconverter enjoys excellent transient response Consideringthe parasitic parameters such as the on-state resistor of theMOSFET when the load current increases the input voltageof the inductor will decrease slightly which causes theproportion of PH in the pulse train to increase
In order to verify the suppression effect on the low-frequency oscillation the comparative experimental resultsare provided in Figure 10 -e control parameters of
traditional PT-controlled buck converter are as followsDH 06 DL 03 and T 25 μs
As shown in Figure 10(a) the pulse train is 1PH-5PL forthe DCPT-controlled CCM converter and the output voltageripple is 60mV In contrast the pulse train of the PT-controlled buck converter is 4PH-4PL and the output voltageripple is 120mV as shown in Figure 10(b) -is phenom-enon of successive several high-energy pulses followed bysuccessive several low-energy pulses indicates that the low-frequency oscillation exists in the PT-controlled CCMconverter -e low-frequency oscillation has not occurred in
2PH-1PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]
4
3
2
1
lt2HzF
(a)
1PH-1PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]
4
3
2
1
lt2HzF
(b)
1PH-3PL vsaw [2Vdiv]
Time [50μsdiv]
vp [2Vdiv]ic [1Adiv]
vo [50mVdiv]273306kHz
4
3
2
1
F
(c)
1PH-5PL vsaw [2Vdiv]
Time [50 μsdiv] 331936kHzF
4
3
2
1
vp [2Vdiv]ic [1Adiv]
vo [50 mVdiv]
(d)
Figure 8 Experimental waveforms of the DCPT-controlled buck converter (a)Vin 868V (b)Vin 92V (c)Vin 1083V (d)Vin 12V
2PH
lt2HzFTime [100μsdiv]
vp [2Vdiv]
ic [1Adiv]
vo [50mVdiv]
Io [1Adiv]
2
3
14
Figure 9 Experimental transient waveforms of the DCPT-controlled buck converter while load changes
Journal of Control Science and Engineering 7
the DCPT-controlled CCM buck converter e proposedDCPT control technique enjoys much better output char-acteristics compared with the traditional PT controltechnique
5 Conclusions
In this paper a dual-carrier pulse-train control technique isproposed With the CCM buck converter as an example theoperational principle is analysed in detail Based on theoutput voltage variation of the DCPT-controlled buckconverter within one switching cycle the pulse control lawand the output voltage ripple are analysed e simulationand experimental results verify the theoretical analysis andindicate that there is no low-frequency oscillation in theDCPT-controlled CCM buck converter Compared with thetraditional PTcontrol technique the DCPT-controlled buckconverter enjoys better control characteristics and muchsmaller output voltage ripple
Data Availability
e data used to support the centndings of this study are in-cluded within the article
Conflicts of Interest
e authors declare that there are no conicts of interestregarding the publication of this paper
Acknowledgments
is work was supported by the National Natural ScienceFoundation of China (51507155) and the Key ResearchProgram of Hersquonan Higher Education (16A470014)
References
[1] C Y-F Ho B W-K Ling Y Yan-Qun Liu P K-S Tam andK Kok-Lay Teo ldquoOptimal PWM control of switched-ca-pacitor DC-DC power converters via model transformationand enhancing control techniquesrdquo IEEE Transactions on
Circuits and Systems I Regular Papers vol 55 no 5pp 1382ndash1391 2008
[2] C Duan and D Wu ldquoNonlinear voltage regulation algorithmfor DC-DC boost converter with centnite-time convergencerdquoJournal of Control Science and Engineering vol 2019 ArticleID 6761784 5 pages 2019
[3] X Zhang Q-C Zhong and W-L Ming ldquoStabilization ofcascaded DCDC converters via adaptive series-virtual-im-pedance control of the load converterrdquo IEEE Transactions onPower Electronics vol 31 no 9 pp 6057ndash6063 2016
[4] S Kennedy M R Yuce and J-M Redoute ldquoFully integratedswitched-capacitor DCDC converters with clock slope EMIcontrolrdquo IEEE Transactions on Electromagnetic Compatibilityvol 60 no 6 pp 2073ndash2075 2018
[5] M Telefus A Shteynberg M Ferdowsi and A Emadi ldquoPulsetrain control technique for yback converterrdquo IEEE Trans-actions on Power Electronics vol 19 no 3 pp 757ndash764 2004
[6] M Qin and J Xu ldquoMultiduty ratio modulation technique forswitching DC-DC converters operating in discontinuousconduction moderdquo IEEE Transactions on Industrial Elec-tronics vol 57 no 10 pp 3497ndash3507 2010
[7] M Qin and J Xu ldquoImproved pulse regulation controltechnique for switching DC-DC converters operating inDCMrdquo IEEE Transactions on Industrial Electronics vol 60no 5 pp 1819ndash1830 2013
[8] J Xu and J Wang ldquoBifrequency pulse-train control techniquefor switching DC-DC converters operating in DCMrdquo IEEETransactions on Industrial Electronics vol 58 no 8pp 3658ndash3667 2011
[9] J Wang J Xu G Zhou and B Bao ldquoPulse-train-controlledCCM buck converter with small ESR output-capacitorrdquo IEEETransactions on Industrial Electronics vol 60 no 12pp 5875ndash5881 2013
[10] J Sha S Liu S Zhong and J Xu ldquoValley current mode pulsetrain control technique for switching DC-DC convertersrdquoElectronics Letters vol 50 no 4 pp 311ndash313 2014
[11] L Wang D Yu R Xu Z Ye and P Wang ldquoSliding current-valley based pulse train control for buck converterrdquo in IECON2017mdash43rd Annual Conference of the IEEE Industrial Elec-tronics Society pp 4978ndash4981 Beijing China October-No-vember 2017
[12] J Sha D Xu Y Chen J Xu and B W Williams ldquoA peak-capacitor-current pulse-train-controlled buck converter withfast transient response and a wide load rangerdquo IEEE
Time [100μsdiv]lt2HzF
vp [2Vdiv]
ic [1Adiv]
vo [100mVdiv]
Io [1Adiv]2
1
3
4
1PH-5PL
(a)
2
Time [100μsdiv]
vp [2Vdiv]
ic [1Adiv]
vo [100mVdiv]
Io [1Adiv]
4PH-4PL
13
4
F 398217kHz
(b)
Figure 10 Experimental waveforms(a) DCPT-controlled buck converter (b) PT-controlled buck converter
8 Journal of Control Science and Engineering
Transactions on Industrial Electronics vol 63 no 3pp 1528ndash1538 2016
[13] D Yu Y Geng H H C Iu T Fernando and R Xu ldquoPulsephase shift based low-frequency oscillation suppression forPT controlled CCM buck converterrdquo IEEE Transactions onCircuits and Systems II Express Briefs vol 65 no 10pp 1465ndash1469 2018
[14] G Zhou W Tan S Zhou Y Wang and X Ye ldquoAnalysis ofpulse train controlled PCCM boost converter with low fre-quency oscillation suppressionrdquo IEEE Access vol 6pp 68795ndash68803 2018
[15] D Yu LWang Y Geng CMa Z Ye and Y Liu ldquoPulse traincontrolled buck converter with coupled inductorsrdquo IET PowerElectronics vol 10 no 10 pp 1231ndash1239 2017
[16] R Xu Y Zhang S Lu G Chen D Yu and L Wang ldquoPulsetrain-controlled CCM boost converter with suppression oflow-frequency oscillationrdquo IET Power Electronics vol 10no 8 pp 957ndash967 2017
[17] X Jin L Wang D Yu Y Geng and R Xu ldquoPulse traincontrolled single-input dual-output buck converter withcoupled inductorsrdquo IEEE Access vol 6 pp 41504ndash415172018
[18] J Sha J Xu S Zhong S Liu and L Xu ldquoControl pulsecombination-based analysis of pulse train controlled DCMswitching DC-DC convertersrdquo IEEE Transactions on In-dustrial Electronics vol 62 no 1 pp 246ndash255 2015
[19] S Kapat ldquoConfigurable multimode digital control for lightload DC-DC converters with improved spectrum and smoothtransitionrdquo IEEE Transactions on Power Electronics vol 31no 3 pp 2680ndash2688 2016
[20] K Muppala Kumar and K Anbukumar ldquoPulse train con-trolled quadratic buck converter operating in discontinuousconduction moderdquo IET Circuits Devices amp Systems vol 12no 4 pp 486ndash496 2018
Journal of Control Science and Engineering 9
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
the DCPT-controlled CCM buck converter e proposedDCPT control technique enjoys much better output char-acteristics compared with the traditional PT controltechnique
5 Conclusions
In this paper a dual-carrier pulse-train control technique isproposed With the CCM buck converter as an example theoperational principle is analysed in detail Based on theoutput voltage variation of the DCPT-controlled buckconverter within one switching cycle the pulse control lawand the output voltage ripple are analysed e simulationand experimental results verify the theoretical analysis andindicate that there is no low-frequency oscillation in theDCPT-controlled CCM buck converter Compared with thetraditional PTcontrol technique the DCPT-controlled buckconverter enjoys better control characteristics and muchsmaller output voltage ripple
Data Availability
e data used to support the centndings of this study are in-cluded within the article
Conflicts of Interest
e authors declare that there are no conicts of interestregarding the publication of this paper
Acknowledgments
is work was supported by the National Natural ScienceFoundation of China (51507155) and the Key ResearchProgram of Hersquonan Higher Education (16A470014)
References
[1] C Y-F Ho B W-K Ling Y Yan-Qun Liu P K-S Tam andK Kok-Lay Teo ldquoOptimal PWM control of switched-ca-pacitor DC-DC power converters via model transformationand enhancing control techniquesrdquo IEEE Transactions on
Circuits and Systems I Regular Papers vol 55 no 5pp 1382ndash1391 2008
[2] C Duan and D Wu ldquoNonlinear voltage regulation algorithmfor DC-DC boost converter with centnite-time convergencerdquoJournal of Control Science and Engineering vol 2019 ArticleID 6761784 5 pages 2019
[3] X Zhang Q-C Zhong and W-L Ming ldquoStabilization ofcascaded DCDC converters via adaptive series-virtual-im-pedance control of the load converterrdquo IEEE Transactions onPower Electronics vol 31 no 9 pp 6057ndash6063 2016
[4] S Kennedy M R Yuce and J-M Redoute ldquoFully integratedswitched-capacitor DCDC converters with clock slope EMIcontrolrdquo IEEE Transactions on Electromagnetic Compatibilityvol 60 no 6 pp 2073ndash2075 2018
[5] M Telefus A Shteynberg M Ferdowsi and A Emadi ldquoPulsetrain control technique for yback converterrdquo IEEE Trans-actions on Power Electronics vol 19 no 3 pp 757ndash764 2004
[6] M Qin and J Xu ldquoMultiduty ratio modulation technique forswitching DC-DC converters operating in discontinuousconduction moderdquo IEEE Transactions on Industrial Elec-tronics vol 57 no 10 pp 3497ndash3507 2010
[7] M Qin and J Xu ldquoImproved pulse regulation controltechnique for switching DC-DC converters operating inDCMrdquo IEEE Transactions on Industrial Electronics vol 60no 5 pp 1819ndash1830 2013
[8] J Xu and J Wang ldquoBifrequency pulse-train control techniquefor switching DC-DC converters operating in DCMrdquo IEEETransactions on Industrial Electronics vol 58 no 8pp 3658ndash3667 2011
[9] J Wang J Xu G Zhou and B Bao ldquoPulse-train-controlledCCM buck converter with small ESR output-capacitorrdquo IEEETransactions on Industrial Electronics vol 60 no 12pp 5875ndash5881 2013
[10] J Sha S Liu S Zhong and J Xu ldquoValley current mode pulsetrain control technique for switching DC-DC convertersrdquoElectronics Letters vol 50 no 4 pp 311ndash313 2014
[11] L Wang D Yu R Xu Z Ye and P Wang ldquoSliding current-valley based pulse train control for buck converterrdquo in IECON2017mdash43rd Annual Conference of the IEEE Industrial Elec-tronics Society pp 4978ndash4981 Beijing China October-No-vember 2017
[12] J Sha D Xu Y Chen J Xu and B W Williams ldquoA peak-capacitor-current pulse-train-controlled buck converter withfast transient response and a wide load rangerdquo IEEE
Time [100μsdiv]lt2HzF
vp [2Vdiv]
ic [1Adiv]
vo [100mVdiv]
Io [1Adiv]2
1
3
4
1PH-5PL
(a)
2
Time [100μsdiv]
vp [2Vdiv]
ic [1Adiv]
vo [100mVdiv]
Io [1Adiv]
4PH-4PL
13
4
F 398217kHz
(b)
Figure 10 Experimental waveforms(a) DCPT-controlled buck converter (b) PT-controlled buck converter
8 Journal of Control Science and Engineering
Transactions on Industrial Electronics vol 63 no 3pp 1528ndash1538 2016
[13] D Yu Y Geng H H C Iu T Fernando and R Xu ldquoPulsephase shift based low-frequency oscillation suppression forPT controlled CCM buck converterrdquo IEEE Transactions onCircuits and Systems II Express Briefs vol 65 no 10pp 1465ndash1469 2018
[14] G Zhou W Tan S Zhou Y Wang and X Ye ldquoAnalysis ofpulse train controlled PCCM boost converter with low fre-quency oscillation suppressionrdquo IEEE Access vol 6pp 68795ndash68803 2018
[15] D Yu LWang Y Geng CMa Z Ye and Y Liu ldquoPulse traincontrolled buck converter with coupled inductorsrdquo IET PowerElectronics vol 10 no 10 pp 1231ndash1239 2017
[16] R Xu Y Zhang S Lu G Chen D Yu and L Wang ldquoPulsetrain-controlled CCM boost converter with suppression oflow-frequency oscillationrdquo IET Power Electronics vol 10no 8 pp 957ndash967 2017
[17] X Jin L Wang D Yu Y Geng and R Xu ldquoPulse traincontrolled single-input dual-output buck converter withcoupled inductorsrdquo IEEE Access vol 6 pp 41504ndash415172018
[18] J Sha J Xu S Zhong S Liu and L Xu ldquoControl pulsecombination-based analysis of pulse train controlled DCMswitching DC-DC convertersrdquo IEEE Transactions on In-dustrial Electronics vol 62 no 1 pp 246ndash255 2015
[19] S Kapat ldquoConfigurable multimode digital control for lightload DC-DC converters with improved spectrum and smoothtransitionrdquo IEEE Transactions on Power Electronics vol 31no 3 pp 2680ndash2688 2016
[20] K Muppala Kumar and K Anbukumar ldquoPulse train con-trolled quadratic buck converter operating in discontinuousconduction moderdquo IET Circuits Devices amp Systems vol 12no 4 pp 486ndash496 2018
Journal of Control Science and Engineering 9
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
Transactions on Industrial Electronics vol 63 no 3pp 1528ndash1538 2016
[13] D Yu Y Geng H H C Iu T Fernando and R Xu ldquoPulsephase shift based low-frequency oscillation suppression forPT controlled CCM buck converterrdquo IEEE Transactions onCircuits and Systems II Express Briefs vol 65 no 10pp 1465ndash1469 2018
[14] G Zhou W Tan S Zhou Y Wang and X Ye ldquoAnalysis ofpulse train controlled PCCM boost converter with low fre-quency oscillation suppressionrdquo IEEE Access vol 6pp 68795ndash68803 2018
[15] D Yu LWang Y Geng CMa Z Ye and Y Liu ldquoPulse traincontrolled buck converter with coupled inductorsrdquo IET PowerElectronics vol 10 no 10 pp 1231ndash1239 2017
[16] R Xu Y Zhang S Lu G Chen D Yu and L Wang ldquoPulsetrain-controlled CCM boost converter with suppression oflow-frequency oscillationrdquo IET Power Electronics vol 10no 8 pp 957ndash967 2017
[17] X Jin L Wang D Yu Y Geng and R Xu ldquoPulse traincontrolled single-input dual-output buck converter withcoupled inductorsrdquo IEEE Access vol 6 pp 41504ndash415172018
[18] J Sha J Xu S Zhong S Liu and L Xu ldquoControl pulsecombination-based analysis of pulse train controlled DCMswitching DC-DC convertersrdquo IEEE Transactions on In-dustrial Electronics vol 62 no 1 pp 246ndash255 2015
[19] S Kapat ldquoConfigurable multimode digital control for lightload DC-DC converters with improved spectrum and smoothtransitionrdquo IEEE Transactions on Power Electronics vol 31no 3 pp 2680ndash2688 2016
[20] K Muppala Kumar and K Anbukumar ldquoPulse train con-trolled quadratic buck converter operating in discontinuousconduction moderdquo IET Circuits Devices amp Systems vol 12no 4 pp 486ndash496 2018
Journal of Control Science and Engineering 9
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
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Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom