Direct Torque Control with Space Vector Modulation (DTC-SVM) of ...

More documents

Recommendations

Info

Control methods of PM Synchronous motor For many years the CTA control ( I _ = 0 ) method has been a popular technique for a sd ref long time because of simple control. This method was dedicated for surface permanent magnet synchronous motor (SPMSM), where the magnetic saliency does not exist [126]. So the maximum torque per ampere is obtained, when stator current vector is shifted in respect to rotor flux vector 90 degree. However, in IPMSM, maximum torque per ampere is obtained with torque angle more than 90 degree. This is because of existence of reluctance torque component due to magnetic saliency (see subchapter 2.2.2). Therefore, the I sd_ ref should be negative value [44]. The main question is how or in which manner produce the reference currents in d-q frame. Its leads to many realization of current control structure. Among them generally we can distinguish two structures of current control loop. One of them is hysteresis based control (Fig.4.7a) [3,52] and the second one is PI based current controllers (Fig.4.7b). Hysteresis based current control has following disadvantage such as [3]: • measurement of three phase currents are required, • three independent hysteresis current controllers are required, • variable switching frequency is achieved, • fast sampling time is required. All this listed above disadvantage can be eliminate, when the PI current control are used. This structure are mostly used in industrial application (Fig. 4.7b). a) U DC M e _ ref Fig. 4.5 I d _ ref I q _ ref d,q/ABC I A _ ref I B _ ref I C _ ref − − S A S B S C Inverter current feedback − I A current I sensors B I C rotor position sensor PMSM 56
Control methods of PM Synchronous motor b) U DC M e _ ref Fig. 4.5 I sd _ ref I sq _ ref - e Isd - e Isq PI PI U sd U sq Reference VoltageVector Calculation U s _ ref ϕ Us _ ref Space Vector Modulator S A S B S C Inverter γ s I sd I sq dq/ABC current sensors I s γ m rotor position sensor PMSM Figure 4.7 Vector control structure for PM synchronous motor with: a) hysteresis current control, b) synchronous PI current control 4.3 Direct torque control (DTC) The name direct torque control is deliver by the fact that, on the basis of the errors between the reference and the estimated values of torque and flux, it is possible to directly control the inverter states without inner current control loop as for FOC [32,34,35,50] and [57-66]. The basic idea of this control rely on stator voltage vector equation of AC motor. U dΨ s s = RsIs + (4.1) dt Making the assumption that ohmic voltage drop on the stator resistor can be neglected the equation for stator flux vector takes the form: Ψ =∫ ( U ) dt (4.2) s s It can be said that the stator voltage vector has directly influence on control stator flux vector. Using a three phase voltage source inverter to supply the AC motor, there are six non-zero vectors and two zero voltage vectors. The active vectors change the amplitude and position of stator flux vector, while the zero vectors stop the stator flux vector as shown in Fig. 4.8. 57
Page 1 and 2:
POLITECHNIKA WARSZAWSKA WARSAW UNIV
Page 3 and 4:
Contents Table of Contents Chapter
Page 5 and 6:
Introduction Chapter 1 INTRODUCTION
Page 7 and 8:
Introduction to surface-mounted mac
Page 9 and 10: Introduction vector control, which
Page 11 and 12: Introduction presented and studied.
Page 13 and 14: Modeling and control modes of PM sy
Page 39 and 40: Voltage source PWM inverter for PMS
Page 57 and 58: Control methods of PM Synchronous m
Page 59: Control methods of PM Synchronous m
Page 69 and 70: Direct Torque Control with Space Ve
Page 111 and 112:
Direct Torque Control with Space Ve
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
Sensorless Speed Direct Torque Cont
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
DSP implementation of DTC-SVM contr
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Summary and closing conclusion Chap
Page 167 and 168:
Appendices APPENDICES A1 Rotor and
Page 169 and 170:
Appendices ⎡ ⎤ ⎢ 1 0 ⎥ ⎡K
Page 171 and 172:
Appendices i(t1->t0)+=it1 it1: it1=
Page 173 and 174:
Appendices A7 PWM technique - six s
Page 175 and 176:
List of symbol List of symbols Symb
Page 177 and 178:
References Books and PhD-Thesis 1.
Page 179 and 180:
References 39. J.-I. Itoh, N. Nomur
Page 181 and 182:
References 74. N. Ertugrul, P. Acar
Page 183 and 184:
References 108. D. Świerczyński,
show all

Direct Torque Control with Space Vector Modulation (DTC-SVM) of ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?