A new switching technique for DC-link capacitor minimisation in switched reluctance machine drives

In this paper, a new switching technique to minimise the dc-link capacitor size of a switched reluctance (SR) machine drive is described. In conventional SR drives, the commutation induced energy exchange between the DC supply and the SR machine is the main cause of the DC-link voltage and current ripples and hence the need for a large capacitor. The commutation induced DC-link current fluctuation is significantly reduced by controlling the switching time and switching logic of the SR converter according to a specified average DC-link current over a defined switching period. The performance of the proposed new switching technique is investigated by comprehensive simulation studies on a 3-phase SR drive.