Patent ID: 8508957

Claim:
A power conversion device comprising: a converter including a multi-level circuit configured to be capable of conversion between a DC voltage and an AC voltage varying between at least three voltage values, and converting DC power to AC power to supply the AC power to a load; a filter including a reactor and a capacitor and removing harmonics generated by said converter; a DC power supply generating DC power; a DC positive bus and a DC negative bus for transmitting said DC power to said converter; and first and second capacitors connected in series between said DC positive bus and said DC negative bus, said multi-level circuit including: first and second semiconductor switching elements connected in series between said DC positive bus and said DC negative bus; first and second free-wheeling diodes connected in anti-parallel to said first and second semiconductor switching elements, respectively; and an AC switch connected between a neutral point of said first and second capacitors and a connection point of said first and second semiconductor switching elements.