STARTING CONTROL DEVICE FOR COMPRESSOR

摘要

PURPOSE:To suppress abrupt torque generation and reduce vibrations and noises by controlling extremely low velocity of commutation current when a motor is started in a step mode operation. CONSTITUTION:A compressor is operated for compressing a refrigerant. A motor 25 rotationally drives the compressor. A driving circuit 10 drives the motor 25. A rotation detection means 1 detects whether or not the motor 25 is in a normal rotational condition. A control means 8 is operated for executing step-mode operation of the motor 25 with an extremely low speed rotation through the driving circuit 10 when the motor 25 is started, and executing sensorless operation of the motor 25 when the motor 25 is in the normal rotation condition. When the motor 25 is started in the step-mode operation, especially, the control means 8 controls a commutation current of the extremely low velocity to gradually increase or decrease. The motor current thus shows pseudo- sinusoidal wave, so that the compressor hardly vibrates even under a backlash factor.