| 摘要 |
A multilevel conversion circuit for generating a high-voltage alternate current is problematic in that when voltage change is large during switching, a surge voltage is applied to a load circuit, leading to insulation breakdown. A multilevel power conversion circuit has a DC power supply formed by a series circuit consisting of two power supplies and comprises: a first semiconductor switch series circuit formed by combining a capacitor and a series circuit consisting of 2n IGBTs connected between P and N; a second semiconductor switch series circuit formed by combining a capacitor and a series circuit consisting of 2n-2 IGBTs connected between the emitter of the first IGBT of the first semiconductor switch circuit and the collector of the 2n-th IGBT of the first semiconductor switch circuit; and a bidirectional switch connected between an intermediate point of the second semiconductor switch series circuit and an intermediate point of the DC power supply. This provides a multilevel power conversion circuit having a small voltage change in the AC output during switching of semiconductor switches as compared with a conventional one. |
