Comparison of instantaneous and average torque control for a switched reluctance motor

The purpose of this paper is to compare two different techniques to adjust the reference torque in a speed control loop for variable speed control of switched reluctance machine. The first technique is "instantaneous", i.e., the torque is instantaneously regulated to fit the reference by modulating the current profile with respect to rotor position using the electromagnetic torque characteristics. This data is obtained by finite element calculations. The second technique is "averaged" and has to maintain an accurate average shaft torque at a commanded torque level. This goal is achieved by adjusting switching angles and reference current level which is kept constant with respect to the position. Those parameters are tuned off line and tabulated in look-up tables for real time control. The principles of both methods are discussed in detailed. Simulation results are shown. Conclusions are dressed concerning the advantages and drawbacks of each method.