Method for controlling freewheeling paths in a matrix converter

摘要

A method for controlling positive or negative freewheeling paths of the phases of a matrix converter with nine bidirectional power switches arranged in a 3x3 switch matrix is described. Each power switch has two back-to-back series-connected semiconductor switches. Those semiconductor switches are actuated that have the most positive/negative line voltage to provide a negative/positive freewheeling path capable of carrying a negative/positive load current. The matrix converter can be immediately disconnected if an error is detected or if the matrix converter is inadvertently switched off, without damaging the matrix converter.