A New Approach to Direct Torque Control of Induction Motor Drives for Constant Inverter Switching Frequency and Torque Ripple Reduction Yen-Shin Lai, Member, IEEEand Jian-Ho Chen

In this paper a new approach to direct torque control (DTC) of induction motor drive is presented. In comparison with the conventional DTC methods (1), (22) the inverter switching fre- quency is constant and is dramatically increased, requiring neither any increase of the sampling frequency, nor any high frequency dither signal. The well-developed space vector modulation tech- nique is applied to inverter control in the proposed DTC-based induction motor drive system, thereby dramatically reducing the torque ripple and speed ripple. As compared to the existing DTC approach (2), (23) with constant inverter switching frequency, the presented new approach does not invoke any concept of deadbeat control, thereby dramatically reducing the computations. Experi- mental results are illustrated in this paper confirming that the pro- posed DTC method has the above-mentioned features even at the low speed range down to 1 r/min.

[1]  P. Tiitinen,et al.  The next generation motor control method, DTC direct torque control , 1996, Proceedings of International Conference on Power Electronics, Drives and Energy Systems for Industrial Growth.

[2]  J.N. Nash.  Direct torque control, induction motor vector control without an encoder , 1996, Conference Record of 1996 Annual Pulp and Paper Industry Technical Conference.

[3]  Toshihiko Noguchi,et al.  High frequency switching operation of PWM inverter for direct torque control of induction motor , 1997, IAS '97. Conference Record of the 1997 IEEE Industry Applications Conference Thirty-Second IAS Annual Meeting.

[4]  Yen-Shin Lai,et al.  The relationship between space-vector modulation and regular-sampled PWM , 1997, IEEE Trans. Ind. Electron..

[5]  M. Depenbrock,et al.  Direct self-control (DSC) of inverter-fed induction machine , 1988 .

[6]  Yen-Shin Lai.  Modeling and vector control of induction machines-a new unified approach , 1999, IEEE Power Engineering Society. 1999 Winter Meeting (Cat. No.99CH36233).

[7]  T. G. Habetler,et al.  A stator flux-oriented voltage source variable-speed drive based on DC link measurement , 1991 .

[8]  L.M. Tolbert,et al.  Direct torque control of induction machines using space vector modulation , 1991, Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting.

[9]  Giuseppe Buja,et al.  Direct stator flux and torque control of an induction motor: theoretical analysis and experimental results , 1998, IECON '98. Proceedings of the 24th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.98CH36200).

[10]  S. Bowes.  New sinusoidal pulsewidth-modulated invertor , 1975 .

[11]  M. P. Kazmierkowski,et al.  Improved direct torque and flux vector control of PWM inverter-fed induction motor drives , 1995, IEEE Trans. Ind. Electron..

[12]  H. van der Broeck,et al.  Analysis and Realization of a Pulse Width Modulator Based on Voltage Space Vectors , 1986, 1986 Annual Meeting Industry Applications Society.

[13]  Yen-Shin Lai,et al.  A universal space vector modulation strategy based on regular-sampled pulse-width modulation [invertors] , 1996, Proceedings of the 1996 IEEE IECON. 22nd International Conference on Industrial Electronics, Control, and Instrumentation.

[14]  Barry W. Williams,et al.  Derivation of motor line-current waveforms from the DC-link current of an inverter , 1989 .