Analysis of switching loss of an AC fed direct converter for a switched reluctance machine

Abstract

This paper evaluates switching and conduction losses of a direct AC fed converter for switched reluctance machine drives. The commutation process of the converter employing space vector modulation is analyzed, and the switching losses associated with "hard" turn-on and "hard" turn-off events are quantified based on experimentally validated device characteristics. It is shown that for a given dc load current, the switching loss varies with the voltage stress across a device, whilst the conduction loss is independent of the input voltage and modulation index. The total converter loss over a fundamental electrical period is obtained by taking the average value of the switching and conduction losses over 60 0 electrical period.

Space Vector Modulation for DC-Link Current Ripple Reduction in Back-to-Back Current-Source Converters for Microgrid Applications

“…On the other hand, the current source converters have the inherent current limiting capability and thus enhance the reliability [8][9][10][11]. Furthermore, they allow forbidden states in the case of voltage source converters that may cause short-circuit, being in case of current source a desirable possibility to achieve soft-switching operation [12].…”