Development of torque and flux ripple minimization algorithm for direct torque control of induction motor drive

Direct torque control (DTC) is known to produce quick and robust response in AC drives. However, during steady state, notable torque and flux ripple occur. They are reflected in speed estimation, speed response and also in increased noise. This paper proposes a new control algorithm, which provides decoupled control of the torque, and flux with constant inverter switching frequency and a minimum torque and flux ripple. Compared to the other DTC methods, this algorithm is much simpler and has less mathematical operations, and can be implemented on most existing digital drive controllers. Algorithm is based on imposing the flux vector spatial orientation and rotation speed, which defines the unique solution for reference stator voltage. This paper contributes (a) Calculation of stator flux vector, torque and flux increments (b) The position of new stator flux vector determination (c) Calculation of the stator reference voltage (d) comparison of errors of different control strategies. In this paper, computer simulations and experimental results have been discussed for the proposed algorithm.

[1]  Seiji Kondo,et al.  Enlarging switching frequency in direct torque-controlled inverter by means of dithering , 1999 .

[2]  M. Vasudevan,et al.  Different viable torque control schemes of induction motor for electric propulsion systems , 2004, Conference Record of the 2004 IEEE Industry Applications Conference, 2004. 39th IAS Annual Meeting..

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

[4]  Giuseppe Buja,et al.  DTC-based strategies for induction motor drives , 1997, Proceedings of the IECON'97 23rd International Conference on Industrial Electronics, Control, and Instrumentation (Cat. No.97CH36066).

[5]  Marian P. Kazmierkowski,et al.  Direct torque control of PWM inverter-fed AC motors - a survey , 2004, IEEE Transactions on Industrial Electronics.

[6]  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.

[7]  A. Tenconi,et al.  The Universal Field Oriented(UFO) Controller in the Airgap Reference Frame. , 1993 .

[8]  T. G. Habetler,et al.  A simple, tacho-less, IM drive with direct torque control down to zero speed , 1997, Proceedings of the IECON'97 23rd International Conference on Industrial Electronics, Control, and Instrumentation (Cat. No.97CH36066).

[9]  Thomas G. Habetler,et al.  Performance evaluation of a direct torque controlled drive in the continuous PWM-square wave transition region , 1993 .

[10]  Peter Vas,et al.  Sensorless vector and direct torque control , 1998 .

[11]  C. Lascu,et al.  Combining the principles of sliding mode, direct torque control, and space-vector modulation in a high-performance sensorless AC drive , 2002, IEEE Transactions on Industry Applications.

[12]  P.N. Enjeti,et al.  Auto-connected electronic transformer (ACET) based multi-pulse rectifiers for utility interface of power electronic systems , 1998, Conference Record of 1998 IEEE Industry Applications Conference. Thirty-Third IAS Annual Meeting (Cat. No.98CH36242).

[13]  R.D. Lorenz,et al.  Stator and rotor flux based deadbeat direct torque control of induction machines , 2001, Conference Record of the 2001 IEEE Industry Applications Conference. 36th IAS Annual Meeting (Cat. No.01CH37248).

[14]  Thomas G. Habetler,et al.  Direct torque control of induction machines over a wide speed range , 1992, Conference Record of the 1992 IEEE Industry Applications Society Annual Meeting.

[15]  T.G. Habetler,et al.  Control strategies for direct torque control using discrete pulse modulation , 1989, Conference Record of the IEEE Industry Applications Society Annual Meeting,.

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

[17]  S. Sul,et al.  New direct torque control of induction motor for minimum torque ripple and constant switching frequency , 1999 .

[18]  D. Grieve,et al.  44 MW 4 pole motor selected for compressor drive , 1997, Record of Conference Papers. IEEE Industry Applications Society 44th Annual Petroleum and Chemical Industry Conference.

[19]  S. Noodleman,et al.  Duty Cycle Characteristics for DC Servo Motors , 1973 .

[20]  T. Ohtani,et al.  Vector control of induction motor without shaft encoder , 1989, Conference Record of the IEEE Industry Applications Society Annual Meeting,.

[21]  Thomas A. Lipo,et al.  Direct field orientation controller using the stator phase voltage third harmonic , 1992, Conference Record of the 1992 IEEE Industry Applications Society Annual Meeting.