Four-quadrant sensorless SRM drive with high accuracy at all speeds

This paper describes a sensorless, four-quadrant switched reluctance motor (SRM) drive with high position resolution and accuracy at all operating speeds. In order to achieve sensorless control, a modified amplitude modulation scheme is used. Using this method, very high position resolution and accuracy comparable to that of a 14-bit resolver has been achieved. Detailed simulation of the drive system has been carried out using Matlab-Simulink in order to understand the dynamics of the system. For validation purposes, comprehensive set of experiments were performed on a 500 W, 100 V, 3000 RPM, 6/4, three-phase drive system and results are presented. The desired operations of a typical 4-quadrant drive, viz., motoring and generating in the forward and reverse directions have been achieved experimentally and the results are included. A brief analysis on the resolution, accuracy, speed range and transient stability of the sensorless method, which are very essential for practical design of any drive system is also presented. Some of the practical constraints in implementing the modulation scheme like the effect of high frequency signal injection on the sensitivity, effect of mutual coupling on the performance of the sensorless scheme are also discussed.

[1]  Mehrdad Ehsani,et al.  Commutation of SR motors , 1993 .

[2]  Mehrdad Ehsani,et al.  Improvement of the accuracy and speed range in sensorless control of switched reluctance motors , 1998, APEC '98 Thirteenth Annual Applied Power Electronics Conference and Exposition.

[3]  Jeffrey H. Lang,et al.  State observers for variable-reluctance motors , 1990 .

[4]  Sanjib Kumar Panda,et al.  Comparison of two techniques for closed-loop drive of VR step motors without direct rotor position sensing , 1991 .

[5]  S.R. MacMinn,et al.  Application of sensor integration techniques to switched reluctance motor drives , 1988, Conference Record of the 1988 IEEE Industry Applications Society Annual Meeting.

[6]  G. Gallegos-Lopez,et al.  A new sensorless method for switched reluctance motor drives , 1997 .

[7]  Mehrdad Ehsani,et al.  Analysis of amplitude modulation methods for sensorless SRM drives , 1998, IECON '98. Proceedings of the 24th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.98CH36200).

[8]  M. Ehsani,et al.  New modulation encoding techniques for indirect rotor position sensing in switched reluctance motors , 1992, Conference Record of the 1992 IEEE Industry Applications Society Annual Meeting.

[9]  Erkan Mese,et al.  Sensorless position estimation for variable-reluctance machines using artificial neural networks , 1997, IAS '97. Conference Record of the 1997 IEEE Industry Applications Conference Thirty-Second IAS Annual Meeting.

[10]  Iqbal Husain,et al.  Error analysis in indirect rotor position sensing of switched reluctance motors , 1994, IEEE Trans. Ind. Electron..

[11]  J.H. Lang,et al.  A simple motion estimator for variable-reluctance motors , 1988, Conference Record of the 1988 IEEE Industry Applications Society Annual Meeting.

[12]  Bernard Multon,et al.  Sensorless rotor position analysis using resonant method for switched reluctance motor , 1993, Conference Record of the 1993 IEEE Industry Applications Conference Twenty-Eighth IAS Annual Meeting.