An Intersection-Method-Based Current Controller for Switched Reluctance Machines With Robust Tracking Performance

Abstract

Good current tracking is beneficial to the torque ripple suppression methods like current profiling techniques for the switched reluctance machines (SRMs). An intersection-method-based current controller for the SRM with robust tracking performance is proposed in this article. First, with the aid of the predicted current at the next sampling instant, the prestored reference current, and the flux-linkage information, the required duty cycle for the next control period under specific reference current is estimated through the intersection method. To compensate for the difference between the adopted flux-linkage model and the real ones inside the machine, a Lyapunov-based adaptive flux-linkage observer is presented. Hence, the heavy dependence issue on the accurate flux-linkage model for the current controller is resolved. With the above techniques, robust reference current tracking is achieved in a simple form and only one observer gain. Besides, a balanced switching scheme is presented to reduce the switching frequency requirement of the power transistors and evenly distribute the switching losses. Extensive experimental tests have been carried out on a four-phase 5.1-kW 8/6 SRM setup for the proposed method and conventional current control methods at different operation conditions. These testing results verified the effectiveness of the proposed method.