A novel approach to control of switched reluctance motors considering mutual inductance

Torque control algorithms for switched reluctance motor (SRM) drives, hitherto have neglected mutual coupling between phases. Significant torque ripple in the magnitude of 6 to 10% is contributed by the mutual coupling effects of the phase windings. That is an unacceptable magnitude of torque ripple in high performance SRM drive systems. A novel torque control algorithm, which adopts simultaneous excitation of two phases, is proposed to improve the performance of the SRM drive. By exciting two adjacent phases Instead of a single phase, the rate of change of phase currents and their magnitudes are very much reduced. The electromagnetic torque that requires to be generated is efficiently apportioned to each phase by the proposed torque distribution function (TDF) algorithm. It also compensates the effects of mutual coupling. The key to the control of torque is the current control that is complicated in the SRM drive by the mutual inductance between two adjacent phases and time variations of the self and mutual inductances. To achieve a high performance current control, a feedback linearizing current controller is proposed to linearize and decouple the current control loop together with a gain scheduling scheme. The proposed controller has been modeled, simulated, analyzed and correlated with experimental results from a laboratory prototype