Patent ID: 10516332

Abstract:
In a case where a switching element of an inverter does not operate properly due to failure or the like, a three-phase short circuit cannot be made, and an induced voltage cannot be suppressed. An induced voltage suppression device is electrically connected to the three-phase wiring between the power converter and the motor, in parallel to the power converter. A rectification circuit including a three-phase diode bridge circuit. A DC voltage source including a capacitor. A voltage detection circuit detects a voltage of both ends of the DC voltage source. In a short circuit, when a transistor of the voltage detection circuit is turned on, transistors are turned on to perform three-phase short-circuit operation to suppress an induced voltage of the motor. Since the induced voltage suppression device secures a DC voltage by the induced voltage of the motor as a drive source in a self-excited manner, it is possible to suppress the induced voltage even when an abnormality occurs in the power converter.