Variable-structure torque control of induction motors using space vector modulation

Compared with field orient control (FOC), direct torque control (DTC) is known to provide fast and robust response for induction motors. However, while offering high dynamic performance, classical DTC produces notable torque, flux, and current ripples, and operates with a variable inverter switching frequency. In this paper, a novel torque control scheme for induction motors is proposed. The stator flux and the electrical torque are directly controlled by variable-structure controllers, and stator voltage vectors calculated by the variable-structure controllers are applied to the motor by means of space vector modulation. The proposed scheme therefore provides smooth, fast and robust regulations of the electrical torque and the stator flux. Moreover, the implementation of the scheme is simple. Theoretical analysis shows the asymptotical convergence of electrical torque and stator flux tracking. Simulation and experimental results are provided to evaluate the performance of the proposed scheme.

[1]  M. I. Valla,et al.  Direct torque and flux control of an induction motor with sliding mode control approach , 2000, ISIE'2000. Proceedings of the 2000 IEEE International Symposium on Industrial Electronics (Cat. No.00TH8543).

[2]  Nik Rumzi Nik Idris,et al.  An improved stator flux estimation in steady state operation for direct torque control of induction machines , 2000 .

[3]  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.

[4]  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).

[5]  Yen-Shin Lai,et al.  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 , 2001 .

[6]  Vadim I. Utkin,et al.  Sliding mode control design principles and applications to electric drives , 1993, IEEE Trans. Ind. Electron..

[7]  L. Tang,et al.  An investigation of a modified direct torque control strategy for flux and torque ripple reduction for induction machine drive system with fixed switching frequency , 2002, Conference Record of the 2002 IEEE Industry Applications Conference. 37th IAS Annual Meeting (Cat. No.02CH37344).

[8]  Toshihiko Noguchi,et al.  A New Quick-Response and High-Efficiency Control Strategy of an Induction Motor , 1986, IEEE Transactions on Industry Applications.

[9]  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.

[10]  Thomas G. Habetler,et al.  Zero-speed tacholess IM torque control: simply a matter of stator voltage integration , 1998 .

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

[12]  Kyo-Beum Lee,et al.  Torque ripple reduction in DTC of induction motor driven by three-level inverter with low switching frequency , 2002 .

[13]  Julio H. Braslavsky,et al.  A RIPPLE MINIMIZATION STRATEGY FOR DIRECT TORQUE AND FLUX CONTROL OF INDUCTION MOTORS USING SLIDING MODES , 2002 .

[14]  F. Blaabjerg,et al.  A modified direct torque control (DTC) for induction motor sensorless drive , 1998, Conference Record of 1998 IEEE Industry Applications Conference. Thirty-Third IAS Annual Meeting (Cat. No.98CH36242).

[15]  Thierry Meynard,et al.  Switching frequency imposition and ripple reduction in DTC drives by using a multilevel converter , 2002 .

[16]  Chi Kwan Lee,et al.  A randomized voltage vector switching scheme for three-level power inverters , 2002 .