| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor drive device which drives a motor by an inverter circuit and can check whether an overcurrent protection function operates normally or not by itself before a motor is driven to rotate to avoid the short circuit failure and abnormal overheat of the motor. SOLUTION: A DC power of a rectifier circuit 3 connected to an AC power supply 1 is converted into an AC power by an inverter circuit 4 to drive a motor 5, and the inverter circuit 4 is controlled by a control means 11. The control means 11 has an inverter drive circuit 11b which drives the inverter circuit 4, an overcurrent decision circuit 11d which decides an overcurrent in accordance with an output signal of a current detection means 6 which detects the current of the inverter circuit 4, and an inverter output control circuit 11a which controls the output of the inverter drive circuit 11b in accordance with the output signal of the overcurrent decision circuit 11d. Before the motor 5 is driven to rotate, a current is applied forcibly to at least one phase of motor coils for a predetermined time and the existence of an abnormality is decided by the output signal of the overcurrent decision circuit 11d. |
