DRIVING CONTROLLER OF AC MOTOR

摘要

A driving controller of an AC motor, which is provided with a structure for preventing occurrence of excessive voltage between lines of the motor and between contact points of a motor open contactor irrespective of a form of a caused fault even if a phase in which a current zero point does not occur and a phase in which the current zero point occurs coexist in a fault current flowing between an inverter and the motor and preventing an arc from continuing between the contact points of the motor open contactor. A control part (17A) performs control for opening a motor-side contactor (16) in response to not time when a detected state of current is judged to be abnormal but to time when it is judged to be normal after that even if a basic contact supply command (MKC0) becomes OFF (L level).