Experimental validation of a new switching technique for DC-link capacitor minimization in switched reluctance machine drives

A switched reluctance (SR) motor has many advantages in terms of reliability and fault tolerance, which makes it particularly suitable for safety critical applications. However, an SR motor drive requires a large DC-link capacitor to buffer the de-fluxing magnetic energy during a phase commutation period and to filter the ac harmonic current from contaminating the DC supply. This paper describes a switching technique for minimisation of the DC-link capacitance in SR motor drives and presents the experimental results from a laboratory demonstrator. The proposed switching method aims to maintain a constant power transfer between the DC supply and the SR converter over a switching cycle, thus minimising the DC-link current ripple. The implementation of the proposed switching technique is described in details and its effectiveness is demonstrated by experiments on a dSPACE control platform.