Safe control of four-quadrant switches

Abstract

A radical solution for the commutation problem of four is proposed. The solution concerns four-quadrant switches where separated internal conduction paths exist in the two possible directions of the load current. It is shown that the switching of these conduction paths must not be simultaneous but has to take place in the well-defined four-stepped switching order. The actual switching policy depends on the direction of the commutated current. The description deals mainly with the switching policy for two four-quadrant switches. Some hints for the extension of the switching policy for general polyphase matrix converter schemes are also given.