| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem with a multilevel conversion circuit for producing an AC high voltage in which a significant voltage change at switching applies a surge voltage to a load circuit to cause a dielectric breakdown.SOLUTION: The multilevel power conversion circuit includes: a DC power supply series circuit of two power supplies; a first semiconductor switch series circuit of a combination of a series circuit of 2n IGBTs connected between PN potentials, and a capacitor; a second semiconductor switch series circuit of a combination of a series circuit of 2n-2 IGBTs connected between an emitter of the first IGBT and a collector of the 2n-th IGBT of the former semiconductor switch circuit, and a capacitor; and a bidirectional switch connected between a midpoint of the second semiconductor switch series circuit and a midpoint of the DC power supply. An AC output has a smaller voltage change at semiconductor switching than before. |
