Pulse vector control of induction and synchronous

978-1-5090-1081-3/17/$31.00 ©2017 IEEE

2017 International Siberian Conference on Control and Communications (SIBCON)

Pulse-vector control of induction and synchronous

motors

A.A. Imanova

ANO CPE MOMENTUM

Chelyabinsk, Russian Federation

[email protected]

S.P Gladyshev IEEE

Detroit

[email protected]

A.N. Gorozhankin

Automated Electric Drive

South Ural State University (National Research University),

SUSU (NRU)

Chelyabinsk, Russian Federation

[email protected]

Abstract—The combustion engine is yielded the position to the

tractional aggregate gradually. Electric drive is come on its

replaced including traction drive, electric generator, diesel plant.

The pulse vector control system of the wound rotor asynchronous

motor is one of the most promising options such electric drives.

South Ural State University is grateful for financial support of

the Ministry of Education and Science of the Russian Federation

(grant No 13.9662.2017/BP).

Keywords— control circuit for elcric drive, pulse vector

control

I. INTRODUCTION

Simplified scheme is observed, which expound the functioning principle of the pulse-vector control. The rate control is performed using in the electric drive based on the wound rotor induction motor a thyristor converter, collected on a three-phase bridge schema (Fig. 1) [1]. The input circuits of the converter are united to the supply via the stator coils of the motor. The armature winding of motor is connected up on the output rectified voltage of converter.

Fig.1. Functional circuit of electric drive

Thyristor Bridge is controlled so that the magneto-motive force (MMF) produced by the current in the stator coils, the rotating torque of the engine is created always. The MMF of stator is created that discrete rotating with a step a 60 (Fig. 2) degrees due currents in the stator coil under thyristor bridges are commutated. [2]. The thyristors are commutated when the orientation vector of MMF stator and rotor coils conforms to the motor torque [3].

A pulse-type regulator current in pulse-vector control of synchronous motor with thyristor switch shows in Fig. 3. The feedback coupling of pulse-type regulator has a key that shorts

the regulator capacitor Cfc and sets the initial values of zero for

the signal ban regulator operation Uban [4].

Fig.2. Vector diagrams for different rotor position a) α=240°;

b) α=300°; c) α=240°; d) α=60°; e) α=120°; f) α=180°

Time diagrams of continuous and pulsed current regulator circuit in the pulse-vector control of synchronous motor shown in Fig. 4 a,b.

Suppose that the required current value stator is set by

applying a gate pulse Ucont, moved in time relative to supply voltage U on the value of t1-t0. When using a continuous proportional-integral (PI) current regulator, assignment UZT to the current regulator is fed discontinuously at time t1, and the

A B C

Y

Z

Ra

x by

z

c

VD

VD

VD

VD

VD

VD

1 2

45

63

X

F

F

FF F

F

F

F

FF

F

F

FF

F F

F F

F

F

FF

FF

а) b) c)

f)e)d)


capacitor Cfc of PI current regulator is charging [5]. When the voltage URC on the regulator output is equal to the voltage opening of the thyristors, couple of thyristors opening, belong to different groups of the switch, and current begins to flow through the corresponding circuit [6].

Fig. 3. The pulse-type regulator current pulse-vector control of synchronous

motor with thyristor switch

In the time period from t2 to t3 (Fig. 4a) the voltage is negative, vectors MMF armature and inductor create a braking torque. Thyristors are closed, and the current sensor signal is zero UDT = 0. However, the current regulator reference is still positive and proportional UZT, so the capacitor continues to be charged to the power supply voltage of operating amplifier. As a result, the output of the current regulator is formed URT maximum value that is greater than the opening voltage of thyristors.

Therefore, when the power supply voltage becomes positive again (time t3, Fig.4, a.), the gating impulse becomes to the positive half-wave voltage (t3 t4), thyristors opened with a zero angle [7].

As a result, the thyristor switch is losing control, and the current in the main circuit is maintained maximum. This situation is easy to change, if you reset capacitor voltage in the negative half-wave of the power supply voltage [8]. This requires the capacitor short-circuit at those times when it should not be charged.

Fig. 4. Waveforms operation PI current regulation:

a) continuous; b) pulse

Time diagrams pulse-vector control of synchronous motor and pulse current regulation shown in Fig. 4b. From the previous case, they are distinguished by the delay time Δt feed gate pulse [9]. This delay occurs due to the fact that the voltage current regulation is zero in the negative half-wave t2-t3.

So, operation of the pulse current regulation can be divided into two sections (Fig. 3): the first section when IE1 key in the current feedback regulation is open; second, when the key is closed. In the first section, the regulator behaves as a normal continuous PI regulator, the second - is short-circuited, and gives zero into output [10].

II. CALCULATION AND EXPERIMENT

The computation was executed for the motor MTF111-6 (P = 3.5 kW; U = 380 V; I1 = 10.4 A; T = 40 N/m; n = 895 rev/min; I2 = 15 А; η = 70 %; J = 0.05 kg•m

2) that

have the next electrical circuit specification: LAA = LBB = LCC = 0.116 H, Lр = 0,027 H, LM = 0.098 H, f = 50 Hz – supply frequency, LAB = LAC = LCB = -0,045 H , J = 1 kg•m

2, r1 = 2.1 Ω, r2 = 0.6 Ω. Also the experiment was

realized for this electric drive, which confirms these computations [11].

The natural mechanical and electromechanical characteristics are go for archetype of electric drive, which achieved by united this electric drive to a supply 380 V [12].

The limit mechanical and electromechanical characteristics of electric drive are confirmed by the greatest possible of voltage impulses are supplied on the stator at the pulse control. It’s like as characteristics of the direct current series motor. Limit values of the current and torque are diminished while velocity increases under the influence of electro-motive force of the motor [13]. The value of torque produced by the motor is decreased significantly if engine operates on the speed higher than synchronous speed.

Noteworthy the small quantity relation stator current to the torque (at the rated torque is the ratio is I1 / T ≈ 1.1) [14]. That should be expounded by close to orthogonal relative to space orientation vectors MMF stator and armature coils in the

a)

It0 t1 t2 t3 t4 t

US

U ,US CONT

Pulsecurrent

regulation

t

It0 t1 t2 t3 t4 t5 t

t

Dt

b)Pulsecurrent

regulationUS

U ,US CONT

UЗАПР .

Сеть 50 Гц

RrcCFC

UCONTR1

UDTR2

CRUURT .

.

UZAPR

supply voltage 50 Hz


impulse control schema. This ratio remains close to unity, when rate control with constant torque static load close to the rated torque. The relative value of the current is increased at low loads because a large proportion of it is necessary to the magnetizing component. For example, when torque is equal 0.1, the rated value of the stator current is enlarged to 0.6 ... 0.7 times the rated value. On the other hand electric drive is capable develop torque more breakdown torque in the low-velocity zone.

The Increment of torque outstripped the increment of the stator current: for example, at the torque are equal 2.5 the current is equal 1.5 [15]. The electric drive characteristics are located lower than natural characteristics of engine in the average speed. It should be expected: by the electric grid 380 V unit two series coils (stator and rotor) instead of one as in a natural schema. The electric drive characteristics are rise up if the electric drive stator circuit is connected by the electric grid 660 V instead 380 V [16, 17].

To investigate the properties of the regulator in the "big", over several periods of the regulator in the pulse-vector control system, it is advisable to apply the device pseudofrequency characteristics [18, 19]. The essence of this method lies in the fact that the cyclic frequency signal w, used for the construction of frequency characteristics, is replaced by pseudofrequency:

λ = 2 / T,

where T = 2π / ω - the sample period of pulse system.

Fig. 5. Block scheme of the current loop with pulse current regulator

Block scheme of the current loop with pulse current regulator shown in Fig. 5. Here the AC - the equivalent electrical circuit of the synchronous motor armature, which can be expressed in an aperiodic link; TS- thyristor switch, which is replaced by a simple proportional link for simplicity; CS - current sensor, which is proportional to the coefficient taken equal to unity; CR - continuous current PI regulator. Elements of IE1 and IE2 are shown in the form of contacts reflect intermittent flow of current in the armature circuit: IE1 characterizes pulse current operation mode of the regulator; IE2 allows for half-wave mode of rectification power supply voltage by thyristor switch [20].

In the pulse-vector scheme a frequency quantization of pulse elements is variable and depends on the engine speed, so the calculation has been made for three constant speeds (10, 40, 100 rad/s), for each of which the period quantization of

pulse element IE1 can be assumed to be constant. So we have the pulse system, then two additional conditions imposed (according to [21, 22]):

1) A "tail" of the frequency characteristic should always be below the straight line lg(M /(M + 1)), where M - index of oscillation uncorrected pulse system;

2) The cutoff frequency of the closed system should be less than 2/T. Pseudofrequency characteristics of the current control loop system of pulse-vector control of synchronous motor shown in Fig. 6 [23].

III. TOTAL RESULTS

On the Figure 6 are represented depending to the total power consumption from electric grid and total power of the electric drive stator terminal from speed at a two static load torque [24]. The voltage on the stator terminal is reduced due small speed also, hence, power is consumption from electric drive very small (about 0,3 from electric drive rated power). The power is determined the loss in the electric drive.

The motor stator voltage is increased by the increases the speed of the motor and the total power consumed by the motor is committed to the total power consumed by the electric grid [25].

The diagrams (see. Fig. 7) showed the pseudofrequency characteristics of an open uncorrected system (curves 1) and the desired pseudofrequency characteristics of open corrected system (curves 2) [26].

Fig.6. Relationship between total power and motor speed:

1 – total power calculated on stator terminals when Ts/Tn= 0,16; 2 – when Ts/Tn=0,25; 3 – total power delivered from electric grid

UCONT

IE1

CR

IE2

TS EMI

CS

Pule Current regulator n/n0

S/P0

1

0,5

1 2

3

2

11

1 10 100

10

100

l, rad/s

lСР

l=2/Т

L, A/B

M/(M+1)


Fig.7. Pseudofrequency characteristics of current control loop with engine

speeds: a) ω = 10 rad/s; b) ω = 40 rad/s; a) ω = 100 rad/s

IV. CONCLUSION

Pulse control has low cost and a small power loss in a comparison with other variants of the rate control. Therefore, it can be recommended for transport applications where are extreme launch conditions, especially in winter season [10, 15].

REFERENCES

[1] Antonov,B.M., Baranov, N.N., Kryukov, K.V., A direct current converter for power supply systems with alternative energy sources, Russ. Electr. Eng., 2015, vol. 86, no.7, pp. 385-390.

[2] Grigoryev, M.A., Kinas, S.I., A mathematical model of the synchronous reluctance machine with independent control along the excitation line, Russ. Electr. Eng., 2014, vol. 85, no.10, pp. 645-648.

[3] Bestem’yanov, P.F., A method of statistical modeling of electromagnetic interference in automatics and telemechanics channels in railway transport, Russ. Electr. Eng., 2015, vol. 86, no.9, pp. 503-508.

[4] Ismagilov, F.R., Khairullin, I.K., Polikhach, E.A., Vavilov, V.E., A study of magnetic rotor systems of high-speed electromechanical energy converters, Russ. Electr. Eng., 2016, vol. 87, no.4, pp. 194-198.

[5] Korshunov, A.I., A study of the conditions of induction generator self-excitation, Russ. Electr. Eng., 2015, vol. 86, no.4, pp. 187-193.

[6] Nos, O.V., Kharitonov, S.A., A system to control power currents of ineffective instantaneous power compensation, Russ. Electr. Eng., 2015, vol. 86, no.2, pp. 72-78.

[7] Grigor’ev, M.A., Naumovich, N.I., Belousov, E.V., A traction electric drive for electric cars, Russ. Electr. Eng., 2015, vol. 86, no.12, pp. 731-734.

[8] Afenchenko, R.V., Barskii, V.A., Kurdyumov, D.S., Malyar, A.V., Automated electrical machine test facilities, Russ. Electr. Eng., 2015, vol. 86, no.10, pp. 567-570.

[9] Filyushov, Yu.P., Filyushov, V.Yu., Control of an asynchronous machine under conditions of minimum reactive power, Russ. Electr. Eng., 2014, vol. 85, no.2, pp. 77-82.

[10] Pavlenko, A.V., Vasyukov, I.V.,Puzin, V.S., Grinchenkov, V.P., Bol’shenko, A.V., Designing of the output stage of the impulse power source, Russ. Electr. Eng., 2015, vol. 86, no.8, pp. 453-458.

[11] Kosmodamianskii, A.S., Vorob’ev, V.I., Pugachev, A.A., Direct torque control of induction motors fed by a single frequency converter, Russ. Electr. Eng., 2015, vol. 86, no.9, pp. 527-533.

[12] Grigoryev, M.A., Gorozhankin, A.N., Kinas, S.I., Belousov, E.V., Dynamic parameters of active rectifiers, Russ. Electr. Eng., 2014, vol. 85, no.10, pp. 638-640.

[13] Feoktistov, V.P., In’kov, Y.M., Tretinnikov,O.V., Electric brakes for fast electric passenger trains, Russ. Electr. Eng., 2015, vol. 86, no.9, pp. 514-518.

[14] Ryabtsev, G.G., Zheltov, K.S., Functional inspection of subway car electric equipment, Russ. Electr. Eng., 2015, vol. 86, no.9, pp. 524-526.

[15] Masandilov, L.B., Kuraev, N.M., Kuzikov, S.V., Fumm, G.Y., Gearless electric drives with low-frequency asynchronous motors, Russ. Electr. Eng., 2015, vol. 86, no.1, pp. 29-32.

[16] Nikitin, V.V., Marikin, A.N., Tret’yakov, A.V., Generator cars with hybrid power plants, Russ. Electr. Eng., 2016, vol. 87, no.5, pp. 260-265.

[17] Grigor’ev, M.A., Sychev, D.A., Zhuravlev, A.M., Khayatov, E.S., Savosteenko, N.V., Improving the reliability of electric drives of exhausters of the oxygen-converter process, Russ. Electr. Eng., 2015, vol. 86, no.12, pp. 728-730.

[18] Kruglikov, O.V., Low-speed induction motors for directly driven elevator machines, Russ. Electr. Eng., 2015, vol. 86, no.3, pp. 118-124.

[19] Dmitrievskii, V.A., Prakht, V.A., Mathematical simulation of a high-speed single-phase machine with alternating current direction, Russ. Electr. Eng., 2016, vol. 87, no.6, pp. 327-332.

[20] Stashinov, Y.P., On the issue of control system adjustment of a direct current drive on the modular optimum. Part 1, Russ. Electr. Eng., 2016, vol. 87, no.1.

[21] Gorozhankin, A.N., Grigor’ev, M.A., Zhuravlev, A.M., Sychev, D.A., Parametric optimization ofa synchronous electric drive with improved mass and size parameters, Russ. Electr. Eng., 2015, vol. 86, no.12, pp. 697-699.

[22] Kazantsev, V.P., Dadenkov, D.A., Position-servo drives with finite control, Russ. Electr. Eng., 2015, vol. 86, no.6, pp. 344-349.

[23] Gulyaev, A.V., Fokin, D.S., Ten, E.E., Skorik, V.G., Shukharev, S.A., Research and development of conversion of direct current voltage to the quasi-sinusoidal voltage with pulse-width modulation, Russ. Electr. Eng., 2016, vol. 87, no.2, pp. 90-92.

[24] Grigoryev, M.A., Specifics of power circuit arrangements of semiconductor converters for power supply to synchronous reluctance machines, Russ. Electr. Eng., 2014, vol. 85, no.10, pp. 601-603.

[25] Grigor’ev, M.A., Synthesis of electric drives realizing limit operating regimes in terms of operation speed and overload capacity, Russ. Electr. Eng., 2015, vol. 86, no.12, pp. 694 - 696.

[26] Rusakov, A.M., Sugrobov, A.M., Okuneeva, N.A., Solomin, A.N., The effect of electromagnetic load on the basic dimensions of induction salient pole generators, Russ. Electr. Eng., 2016, vol. 87, no.3, pp. 130-133.

100

L, A/B

10

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1 10 100

l=2/Т

M/(M+1)lСР

L, A/B

100

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1

2 l=2/Т

M/(M+1)lСР

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Pulse vector control of induction and synchronous