Modification of a switching strategy for asymmetric half-bridge converters for switched reluctance motor drives

This paper presents an improved switching scheme for asymmetric half-bridge converters, the standard inverters for switched reluctance machine drives. The modified switching strategy bases on the idea that every electrical cycle the two switches in each leg of the converter alternate their commutating and chopping functions. Consequently, the upper and lower transistors of the converter can balance their switching losses. Such method has been implemented in DS1102 digital signal processor (DSP) control environment driving a 1-hp 4-phase 8/6 switched reluctance motor (SRM) with a 4-phase IGBT asymmetric half-bridge converter. Measured switching losses of the proposed method are compared with those of a basic switching scheme. The experimental results have confirmed an acceptable performance of this proposed technique.