A matrix converter is capable of suppressing a harmonic current and effectively using regenerative power and hence, the matrix converter has received attention as a new power converter. The matrix converter includes, in some cases, a plurality of bidirectional switches for connecting each phase line of an alternating current source and each phase line of a dynamo-electric machine to perform power conversion by controlling the bidirectional switches.
Furthermore, the matrix converter includes, in some cases, a snubber circuit for ensuring the commutation passage (conduction passage bypassing the bidirectional switch) of a current having flowed immediately before the bidirectional switch is switched over from the ON-state to the OFF-state.
For example, Japanese Patent Application Laid-open No. H11-262264 discloses a matrix converter in which a snubber circuit is provided to each of a plurality of bidirectional switches. However, the conventional matrix converter has room for improvement with respect to the optimization of the snubber circuit.