IMPROVING THE EFFICIENCY OF POWER ELECTRONIC CONVERTERS BY UTILIZING COMBINATIONS OF DIFFERENT TYPES OF SWITCHING DEVICES

Abstract

In this study, switching losses of different types of semiconductor switching devices in power electronic converters are compared. Even though each particular switching device has its advantages and disadvantages, the minimisation of switching and conduction losses of the converter is the point of interest. In high frequency applications switching losses are significant and in contrast, conduction losses are dominant in low frequency applications.

For this particular reason, it is sometimes essential to utilise different type of switching devices for specific purposes. For example, in commonly used 3+1 type three phase Switched Reluctance Motor (SRM) Drive only one type of semiconductor device is generally utilised both for high frequency PWM switch and low frequency commutating switches.

This paper presents an SRM converter in which two types of switching devices, MOSFET and MCTs (for PWM and commutation, respectively) are utilised. The paper also discusses the combination of these switching devices, the calculation of total losses and provides a comparison.