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

More documents

Recommendations

Info

Control methods of PM Synchronous motor 4.4 Summary ‣ In FOC drive flux linkage and electromagnetic torque are controlled indirectly and independently by PI controllers with space vector modulator (SVM). In this control concept current control loop is required, ‣ In DTC drive, flux linkage and electromagnetic torque are controlled directly and independently by hysteresis controllers and selection of optimum inverter switching modes. In this control concept flux and torque control loop is required, ‣ In DTC all switch changes of the inverter are based on the electromagnetic state of the motor. ‣ The DTC technique is different from the traditional methods of controlling torque, where the current controllers in the rotor reference frame are used. It is completely different control concept (approach) from FOC. The new control technology was characterized by simplicity, good performance and robustness, because of bang-bang hysteresis control. Using DTC it is possible to obtain a good dynamic control of the torque without current controllers and any mechanical transducers on the machine shaft. Moreover, in this control structure the PWM modulator is not required. Its is occupied by variable switching frequency. ‣ The flux weakening control becomes easier because stator flux linkage can be controlled directly in the DTC system of PMSM. 64
Direct Torque Control with Space Vector Modulation Chapter 5 DIRECT TORQUE CONTROL WITH SPACE VECTOR MODULATION (DTC-SVM) 5.1 Introduction The DTC-SVM greatly improves torque and flux performance by: • Achieved fixed switching frequency, • Reduced torque and flux ripples. The main idea of DTC-SVM is based on analyze of the torque equation M Assuming that the Ld = Lq = Ls e 3 Ψ sin 2 s ΨPM δΨ Ψs ( Lq −Ld)sin2δ Ψ = pb[ − ] (5.1) 2 L 2L L d d q M e 3 Ψs ΨPM sinδ = pb[ Ψ ] (5.2) 2 L From equation (5.2) we can see that for constant stator flux amplitude by permanent magnet Ψ PM s Ψ s and flux produced , the electromagnetic torque can be changed by control of the torque angle δ Ψ . This is the angle between the stator and rotor flux linkage, when the stator resistance is neglected. The torque angle, in turn, can be changed by changing position of the stator flux vector θ Ψ s in respect to PM vector using the actual voltage vector supplied by PWM inverter. In the steady state, δ Ψ is constant and corresponds to a load torque, whereas stator and rotor flux rotate at synchronous speed. In transient operation, δ Ψ varies and the stator and rotor flux rotate at different speeds (Fig. 5.1). 65
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 15 and 16:
Modeling and control modes of PM sy
Page 17 and 18: 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 67: Control methods of PM Synchronous m
Page 71 and 72: Direct Torque Control with Space Ve
Page 119 and 120:
Direct Torque Control with Space Ve
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?