MOTOR CONTROLLING DEVICE AND METHOD OF DETECTING INSULATION DEGRADATION IN A MOTOR

摘要

The present invention easily detects insulation resistance at a motor control device having a high internal pressure IC and individually grasps the insulation aging state of multiple motors. When a detecting indication of insulation resistance of a motor (M1) is received, a detecting action control unit opens a circuit breaker (130) and closes a detecting switch (155) and forms a current path for insulation resistance detection. The detecting action control unit opens a direct power connection switch (149-2) of all inverter circuits (140-2) which is formed using a high internal pressure IC excluding an inverter circuit which is connected to the motor (M1) to be detected. The detecting action control unit prevents a current from being inserted into the current path for insulation resistance detection. The detecting action control unit closes a direct current power connection switch (149-1) of an inverter circuit (140-1) which is connected to the motor (M1) to be detected. The detecting action control unit outputs a PWM signal to a first driving circuit (145) which is connected to the motor (M1) to be detected. An insulation resistance detection unit detects insulation resistance (R1i) of the motor (M1) to be tested using voltage between terminals of a resistor (160). [Reference numerals] (120) Alternating current power source; (170) Detection operation commander; (175) PW control circuit; (AA) Detection instruction