MOTOR CONTROLLER FOR COMPRESSOR

摘要

PURPOSE: To reduce the vibration of a compressor caused by the pulsating load torque of a motor by hourly calculating the load torque on the basis of the information on the rotational position of the motor and making the load torque nearly equal to the output torque of the motor by controlling at least the electric current or voltage supplied to the motor. CONSTITUTION: A temperature detector 17-l of a condenser 14 in a refrigerating cycle and a detector 17-2 which detects the temperature of an evaporator 16 detect the information on the load applied to a compressor 13 and a position detector 18 detects the rotational position of the compressor 13 while the rotor of a motor rotates one round. The signals from the detectors are outputted to a control section 20 through a signal converting section 19. The control section 20 calculates the load torque and the output torque of the motor and controls the output torque of the motor so that the output torque can become nearly equal to the pulsating load torque on the calculated values. Therefore, the vibration of the compressor 13 caused by the difference between the output torque of the motor and the load torque which pulsates during the one rotation of the rotor can be reduced.