Sliding mode observer for sensorless control of switched reluctance motor drives

The research is primarily devoted to the development of a reliable and accurate indirect source of position information and to the use of the information for high-performance controllers for switched reluctance motor (SRM) drives. The sliding mode concept has been used in this research to develop a sliding mode observer (SMO) for robust state reconstruction. The states estimated by the SMO are the indirect source of position and speed information. The continuous position information from the SMO makes it possible to implement sophisticated controllers. The theoretical development of the SMO in the context of SRM drives has been presented. The design guidelines provided have been justified through simulation and experiments. A Luenberger state observer (LSO) has also been implemented for comparison. Unlike previous research, nonlinear models were used for state estimations in the LSO, which improved its performance. Relevant quality factors have been defined to judge the performance of the indirect estimators. The error analysis and robustness tests performed in this research showed excellent performance of both the observer-based methods.; The requirement of a good model by the observers has been eliminated in this research by self-tuning or adaptation techniques. The online identification provides an efficient way of calibrating machine characteristics. The online identification helps to improve the estimation by reducing the model discrepancies, which was also verified in both simulation and experiments.; In this research, a high-performance controller using the developed sensorless method has been realized. The controller works over wide-speed-range and minimizes torque ripple. The realization of high-performance controller proves the validity and applicability of SMO based position and speed estimation for SRM drives.; In this research, the pulse injection method using the same power converter has been used to develop a novel hybrid mechanism for sensorless operation. The developed starting algorithm is capable of starting and running the motor from zero speed. The SMO based sensorless algorithm takes over the role of position sensing after the motor reaches a certain minimum speed.; The applicability of SMO based sensorless operation for high-performance SRM drive was verified in simulation using Matlab/Simulink and in experiments using a TMS320C30 digital signal processor.