Improved torque regulator to reduce steady-state error of torque response for direct torque control of permanent magnet synchronous machine drives

This study presents an improved switching-table-based direct torque control method for three-phase permanent magnet synchronous machine drives. The instantaneous variation rates of stator flux and torque of each converter output voltage vector are analysed. It is found that large steady-state error of torque response exists because of the difference in the decreasing and increasing variation rates. A novel and simple on-line band-shifted torque regulator is proposed to reduce this steady-state error of torque response. The experimental results verify that the proposed method can significantly reduce the steady-state error of torque response with the extra bonus of slight reduction of both the torque ripple and average commutation frequency, while preserve the merits of the conventional direct torque control, that is, simple structure, good robustness and excellent transient response.

[1]  O. A. Mahgoub,et al.  Implementation of a new fast direct torque control algorithm for induction motor drives , 2010 .

[2]  F. Blaabjerg,et al.  “Active Flux” DTFC-SVM Sensorless Control of IPMSM , 2009, IEEE Transactions on Energy Conversion.

[3]  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).

[4]  J. H. Leong,et al.  Analysis and Mitigation of Torsional Vibration of PM Brushless AC/DC Drives With Direct Torque Controller , 2012, IEEE Transactions on Industry Applications.

[5]  Robert D. Lorenz,et al.  Deadbeat-Direct Torque and Flux Control of Interior Permanent Magnet Synchronous Machines With Discrete Time Stator Current and Stator Flux Linkage Observer , 2011, IEEE Transactions on Industry Applications.

[6]  M.F. Rahman,et al.  Direct torque and flux control of an IPM synchronous motor drive using a backstepping approach , 2009, 2009 13th European Conference on Power Electronics and Applications.

[7]  K. W. Lim,et al.  Analysis of direct torque control in permanent magnet synchronous motor drives , 1997 .

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

[9]  Jie Wu,et al.  Integral Sliding-Mode Direct Torque Control of Doubly-Fed Induction Generators Under Unbalanced Grid Voltage , 2010, IEEE Transactions on Energy Conversion.

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

[11]  F. Blaabjerg,et al.  Direct torque control of sensorless induction motor drives: a sliding-mode approach , 2004, IEEE Transactions on Industry Applications.

[12]  Salih Baris Ozturk,et al.  Direct Torque and Indirect Flux Control of Brushless DC Motor , 2011, IEEE/ASME Transactions on Mechatronics.

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

[14]  Jiabing Hu,et al.  Investigation on Switching Patterns of Direct Power Control Strategies for Grid-Connected DC–AC Converters Based on Power Variation Rates , 2011, IEEE Transactions on Power Electronics.

[15]  Syed Nasar,et al.  Torque Vector Control (TVC)-A Class of Fast and Robust Torque-Speed and Position Digital Controllers for Electric Drives , 1988 .

[16]  G. Abad,et al.  Two-Level VSC Based Predictive Direct Torque Control of the Doubly Fed Induction Machine With Reduced Torque and Flux Ripples at Low Constant Switching Frequency , 2008, IEEE Transactions on Power Electronics.

[17]  Giuseppe Buja,et al.  Band-constrained technique for direct torque control of induction motor , 2004, IEEE Transactions on Industrial Electronics.

[18]  M. Pacas,et al.  Predictive direct torque control for the PM synchronous machine , 2005, IEEE Transactions on Industrial Electronics.

[19]  Ming-Ji Yang,et al.  Global Minimum Torque Ripple Design for Direct Torque Control of Induction Motor Drives , 2010, IEEE Transactions on Industrial Electronics.

[20]  Marko Hinkkanen,et al.  Modified integrator for voltage model flux estimation of induction motors , 2003, IEEE Trans. Ind. Electron..

[21]  T. Sutikno,et al.  An Optimized Switching Strategy for Quick Dynamic Torque Control in DTC-Hysteresis-Based Induction Machines , 2011, IEEE Transactions on Industrial Electronics.

[22]  Yongchang Zhang,et al.  Direct Torque Control of Permanent Magnet Synchronous Motor With Reduced Torque Ripple and Commutation Frequency , 2011, IEEE Transactions on Power Electronics.

[23]  S. Bacha,et al.  Low-Cost Direct Torque Control Algorithm for Induction Motor Without AC Phase Current Sensors , 2012, IEEE Transactions on Power Electronics.

[24]  Yongchang Zhang,et al.  A Novel Duty Cycle Control Strategy to Reduce Both Torque and Flux Ripples for DTC of Permanent Magnet Synchronous Motor Drives With Switching Frequency Reduction , 2011, IEEE Transactions on Power Electronics.

[25]  Yongchang Zhang,et al.  A Simple Method to Reduce Torque Ripple in Direct Torque-Controlled Permanent-Magnet Synchronous Motor by Using Vectors With Variable Amplitude and Angle , 2011, IEEE Transactions on Industrial Electronics.