NEUTRAL-POINT CLAMPING-TYPE POWER CONVERSION APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a neutral-point clamping-type power conversion apparatus which can suppress a surge voltage due to a snubber circuit and whose reliability is higher. ;SOLUTION: Surge suppression circuits HZD2, HZD3, HR2, HR3, HD2, HD3 are added to a first snubber circuit that comprises a series circuit by a capacitor SC1 and by a diode SD1 and of a resistor SR1 which is connected across the series connection point of the series circuit and a neutral-point output terminal O, to a second snubber circuit that comprises a capacitor SC2, of a diode SD2 and of a resistor SR2 which is connected across the series connection point by the diode SD2 and by the capacitor SC2 and a DC positive bus P, to a third snubber circuit that comprises a capacitor SC3, of a diode SD3 and of a resistor SR3 which is connected across a series connection point by the diode SD3 and by the capacitor SC3 and a DC negative bus N, to a fourth snubber circuit that comprises a series circuit by a capacitor SC4 and by a diode SD4 and of a resistor SR4 which is connected across the series connection point of the series circuit and the neutral-point output terminal O, to a second switching element S2 and to a third switching element S3.;COPYRIGHT: (C)1998,JPO