Upload
diego-holt
View
228
Download
6
Tags:
Embed Size (px)
Citation preview
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 11
Explanation of Electromagnetic Interference Explanation of Electromagnetic Interference (EMI) in Switching Power Supply(EMI) in Switching Power Supply
Speakers
Dr. Franki Poon, Dr. Joe Liu
Power eLabThe PowerELab Limited
© copyright 2006
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 22
EMI solutions: Passive filterEMI solutions: Passive filter
Conventional EMI solutions depend on passive filter using inductors and capacitors:
Inductors: CMC, DMC Capacitors: X-cap, Y-cap
There are limitations when using passive filters: Inductors: Large size and high conduction loss Capacitors: leakage current specifications
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 33
Active EMI cancellation IC WT6001:Active EMI cancellation IC WT6001:An effective EMI solution – Y-cap boosterAn effective EMI solution – Y-cap booster
A patented technology developed in PowerELab. An SO-8 IC WT6001 developed with W2.W2. Equivalent to a Y-cap with very large value within the EMI concerned
frequency range only. No boosting effect in the leakage current test concerned frequency
range (50 – 800Hz). Greatly reduce the common mode inductor size and requirements. Reduce converter size and improve conversion efficiency. Provide effective and efficient EMI solution. Built-in electrical surge protection which can easily pass the
EN61000-4-4 and EN61000-4-5 immunity standard.
WT6001
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 44
Applications: Replace passive Y-cap Applications: Replace passive Y-cap
LISN
Replaced by Y-cap booster
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 55
Effect measurable by oscilloscope Effect measurable by oscilloscope when using Y-cap boosterwhen using Y-cap booster
Noise voltage across Y-cap in switching converter
Noise voltage across Y-cap booster in switching converter
More application examples can be found in the datasheet of WT6001
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 66
Practical application examplesPractical application examples
The original EMI filter design cannot pass the EN55022 class B limit.
Filter component:
2 x 20mm high mu toroid for common mode filters 2 x 0.15uF X – cap 1 x 1n Y1-cap connected between primary and secondary
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 77
Practical application examples:Practical application examples: Original filter schematic Original filter schematic
C2
L2B
13
24
C1
L1B
13
24
P1
1
P2
1
TH1 F1
• It is a commonly used filter configuration
• L2B is wound with many turns which intends to suppress the low to mid-frequency common mode noise. Its leakage inductance together with C1 also provides differential mode noise filtering
• L1B is a single layer, bi-filer wound common mode choke for high frequency common mode noise filtering
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 88
Practical application examples: Practical application examples: EMI measurementEMI measurement
230V pri-sec Y1n U shielded original
EN 55022; Class B Conducted, Average
EN 55022; Class B Conducted, Quasi-Peak
0
10
20
30
40
50
60
70
80
1 10
dBuV
10/3/2005 10:55:40 (Start = 0.15, Stop = 30.00) MHz
DM noiseCM noise
230V pri-sec Y3n3 U shielded original
EN 55022; Class B Conducted, Average
EN 55022; Class B Conducted, Quasi-Peak
0
10
20
30
40
50
60
70
80
1 10
dBuV
10/3/2005 16:08:11 (Start = 0.15, Stop = 30.00) MHz
Y-cap: From 1n to 3n3Improved but not enough
Failure was identified to be caused by:• Insufficient leakage inductance of the common mode choke for DM noise
attenuation.• The two common mode choke cannot effectively block out the common mode
current.• Further increase of Y-cap can reduce CM noise but fail to meet leakage current
specifications.
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 99
Practical application examples:Practical application examples: Solution using Y-cap booster Solution using Y-cap booster
230V CB U shield SDMC SCMC .33uFEN 55022; Class B Conducted, Average
EN 55022; Class B Conducted, Quasi-Peak
0
10
20
30
40
50
60
70
80
1 10
dBuV
10/3/2005 16:39:55 (Start = 0.15, Stop = 30.00) MHz
Y-cap booster is used to replace the primary to secondary Y-cap
After using the Y-cap booster, L2B is replaced by a small differential mode filter and L1B is reduced to a 9mm toroid with only a few turns to tackle the high frequency common node noise. The test results pass the required limit lines
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 1010
Practical application examples:Practical application examples: Filter comparison: Before and After... Filter comparison: Before and After...
Failed design even with morecost, loss and bigger size for thefilter
Passed design using Y-cap booster with much smaller filter size that saves cost, power and space
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 1111
Another practical application examples:Another practical application examples: Filter comparison: Before and After... Filter comparison: Before and After...
Original EMI solution using passive filterin ATX converter
New EMI solution using Y-cap boosterin ATX converter
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 1212
ConclusionConclusion
Y-cap booster breaks the relationship between the Y-cap values and leakage current requirement.
Greatly reduce product design period and resources.
It can be applied to any position with conventional Y-cap.
Significantly reduce the size and loss of common mode choke implies higher power density and efficiency.
EMI less sensitive to transformer winding capacitance implies more rooms for improving transformer coupling.
Very suitable for equipment required low leakage current like medical equipment.
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 1313
Active Diode – An easy to use and high Active Diode – An easy to use and high efficiency rectifier suitable for all convertersefficiency rectifier suitable for all converters
Stringent requirements of nowadays converters:
Compact size Low heat generation and high conversion efficiency High output power and output current Low cost ………!!!
Conventional technologies cannot meet the requirements!!
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 1414
Synchronous rectifierSynchronous rectifier Use MOSFETs to replace diode rectifiers.
AK 7.8 m9 m0.24 V
AK
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 1515
Synchronous rectifierSynchronous rectifier
0 2 4 6 8 100
0.5
1
1.5
2
2.5
3
STPS30L30SO8 Active Diode
Losses comparison between SCK and AD
A
W
MOSFET 0.7W losses @ 10A
SCK 2.8W losses @ 10A
Provides low conduction loss.
Can operate at higher high current without heatsink.
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 1616
Synchronous rectifierSynchronous rectifier Usage not limited to converters with high profit margin.
Price of nowadays low RDSon MOSFETs comparable to schottky diodes using the state of the art technology.
Provide even lower converter cost because of reduced heatsink, more output power, higher conversion efficiency…..
Emerge in low cost converter like adaptors, standard open frame converters, ATX …… .
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 1717
Synchronous rectifierSynchronous rectifierA
D
AD
Problematic for some conventional topologies
Special and sometimes complicated driving circuits SR
are needed for different topologies
Performance sensitive to transformer leakage
inductance and operating conditions
Converter cannot be paralleled – Reverse current
Poor efficiency at low load
Limited input voltage range
Simple circuit
Discontinuous mode is allowed
Good low load efficiency
Converter can be paralleled
High conversion efficiency
Works just like a diode
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 1818
Active diode – Operating principleActive diode – Operating principle
N1 is the current sense winding N2 provides MOSFET driving signals A1 driver circuit (IC WT6002) N1 N3 & D1 form energy recovery
circuit N4 & D2 form reset circuit
AK
N1 N2
N3 N4
D1 D2
A1
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 1919
Active diode – Operating principleActive diode – Operating principle
Voltage across winding N2 or gate drive voltage Von of SR depends on ratio of N2 to N3
and voltage Vo
Voltage source Vo
can be any voltage source in a converter, e.g. output voltage
3
2N
NVV oon
AK
N1 N2
N3 N4
D1 D2
A1
Toff
Vo
Vo
VN2
VN3
VN4
Von
Ii
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 2020
Application of Active Diode in Application of Active Diode in different topologiesdifferent topologies
FlybackFlyback ForwardForward
S
Flyback SR
Co
+
Vin
-
+
Vo
-
S
MagneticReset
Forward SR
FreewheelSR
Lf
Co
+
Vo
-
+
Vin
-
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 2121
Application of Active Diode in Application of Active Diode in different topologiesdifferent topologies
Half Bridge centre tapHalf Bridge centre tap Current DoublerCurrent Doubler
S1
S2
C1
C2
SR1
SR2
Lf
Co
+
Vin
-
+Vo
-
+Vo
-
S1
S2
C1
C2
SR1
SR2
Lf1
Co
Lf2
+
Vin
-
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 2222
Application of Active Diode in Application of Active Diode in different topologiesdifferent topologies
Resonant converterResonant converter
and many others….and many others….
SR1
SR2
Co
+Vo
-ISIN
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 2323
Successful application of Active Diode Successful application of Active Diode in converter productsin converter products
AD on 150W ACDC AD on 120W ACDC
AD on 50W ACDC AD on 300W ACDC AD on 60W ACDC AD on 100W DCDC
AD on 1.5 V 200 A ACDC
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 2424
ConclusionConclusion A new “Active Diode” technology is presented.
A kind of current driven synchronous rectifier technology that provides high conversion efficiency and eliminates many conventional synchronous rectifier application problems.
Patented technologies.
An Active Diode driver IC WT6002 for easy implementation of the technology.
Well proven by many converter product design.
PowerPowereeLabLab
Designing a 90% efficiency 150W power supply with PFC in hoursPrepared by Dr. Franki PoonPrepared by Dr. Franki Poon & Dr. Joe Liu & Dr. Joe Liu PowerELab LimitedPowerELab Limited www.powerEsim.comwww.powerEsim.com 2525
ReferencesReferences• Liu, J.C.P.; Poon, F.N.K.; Xuefei Xie; Pong, M.H.; current driven synchronous rectifier with energy recovery sensor Power
Electronics and Motion Control Conference, 2000. Proceedings. PIEMC 2000. The Third International , Volume: 1 , 2000, page(s): 375 -380 vol.1
• Xuefei Xie; Liu, J.C.P.L.; Poon, F.N.K.; Man Hay Pong; Current-driven synchronous rectification technique for flyback topology, Power Electronics Specialists Conference, 2001. PESC. 2001 IEEE 32nd Annual , Volume: 1 , 2001, Page(s): 345 -350 vol. 1
• Xuefei Xie; Liu, J.C.P.; Poon, F.N.K.; Man Hay Pong; A novel high frequency current-driven synchronous rectifier for low voltage high current applications, Applied Power Electronics Conference and Exposition, 2001. APEC 2001. Sixteenth Annual IEEE , Volume: 1 , 2001, Page(s): 469 -475 vol.1
• Liu, J.C.P.; Xuefei Xie; Poon, F.N.K.; Pong, B.M.H.; Practical solutions to the design of current-driven synchronous rectifier with energy recovery from current sensing, Applied Power Electronics Conference and Exposition, 2002. APEC 2002. Seventeenth Annual IEEE , Volume: 2 , 2002, Page(s): 878 -884 vol.2
• Xuefei Xie; Joe Chui Pong Liu; Poon, F.N.K.; Man Hay Pong; A novel high frequency current-driven synchronous rectifier applicable to most switching topologies, Power Electronics, IEEE Transactions on , Volume: 16 Issue: 5 , Sep 2001, Page(s): 635 -648
• Xie Xuefei; Liu, J.C.P.; Poon, F.N.K.; Pong, B.M.H.; Two methods to drive synchronous rectifiers during dead time in forward topologies, Applied Power Electronics Conference and Exposition, 2000. APEC 2000. Fifteenth Annual IEEE , Volume: 2 , 2000, Page(s): 993 -999 vol.2
• US patent "Current driven synchronous rectifier with energy recovery" patent number 6,134,131
• US patent “Self-driven synchronous rectifier by retention of gate charge” patent number 6,377,477
• US patent “Current driven synchronous rectifier with energy recovery using hysterisis driver”, patent number 6,597,587