JPS5579686A - Power converter - Google Patents

Abstract

PURPOSE: To obtain a power converter which has a low dielectric strength in its main silicon controlled rectifiers and a high operation efficiency, by connecting some terminals of three-phase half-wave rectification circuits to the connection points of series circuits consisting of the main silicon controlled rectifiers and diodes and by coupling the first, second, third and fourth auxiliary silicon controlled rectifiers between the other terminals of the rectification circuits.

CONSTITUTION: The arms of an inverter circuit, which is connected to a DC power source 11 through a DC reactor 12, are made of series circuits consisting of main silicon controlled rectifiers U∼W, X∼Z and diodes DU∼DW, DX∼DZ. One-side terminals of three-phase half-wave rectification circuits 18, 19 are coupled to the connection points of the series circuits. Another series circuit comprising the first auxiliary silicon controlled rectifier 23, a capacitor 24 and the second auxiliary silicon controlled rectifier 21 is connected between the other terminals of the three-phase half- wave rectification circuits 18, 19. The third and fourth auxiliary silicon controlled rectifiers 20, 21 are coupled between the DC input terminals of the inverter and both the terminals of a capacitor. In the commutation of the main silicon controlled rectifiers U∼W, the auxiliary silicon controlled rectifiers 20, 21 are closed. In the commutation of the main silicon controlled rectifiers X∼Z, the auxiliary silicon controlled rectifiers 22, 23 are closed. As a result, energy released from a load motor 14 is stored in the capacitor 24.

COPYRIGHT: (C)1980,JPO&Japio