SINGLE-PHASE THREE-LEVEL INVERTER

摘要

A single-phase three-level inverter includes an input capacitor (Cdc), six power switches (S1, S2, S3, S4, S5, S6), two free-wheeling diodes (D7, D8) and a single-phase output filter (F). The switching operation is performed by the cooperation of the six power switches and the free-wheeling diodes, so that when the output voltage from the inverter is zero level, the output AC side and the input DC side of the inverter are in a decoupled state, which insures that the common-mode voltage is maintained at a constant while the output voltage from the inverter is performed with three levels, so as to completely eliminate the common-mode current.