Minimising torque ripple of SRM by applying DB-DTFC

Since the traditional direct torque control (DTC) of switched reluctance motors (SRMs) has the shortcomings of large torque ripple and non-constant switching frequency, this study proposes the deadbeat-direct torque and flux-linkage control (DB-DTFC) method for SRM. By analysing the basic principles of SRM, a discrete-time model is established to predict the future states of the SRM drive system. With DB-DTFC, the stator flux and torque can be manipulated during each pulse-width modulation cycle to minimise torque ripple during operation. As a result, the proposed DB-DTFC can minimise the torque ripple as well as apply space-vector modulation with a constant switching frequency. Finally, to verify its effectiveness, DB-DTFC was applied to the 15 kW three-phase 12/8-pole SRM test bench in real time and the results are compared with conventional DTC.