Method and device for controlling a brushless alternating current motor

摘要

A method and a device for controlling a brushless alternating current motor (23) driven by an inverter (31-36) connected to a direct current supply (24,25). The direct current supplied to the inverter is sensed. The signal is passed through a peak detector (41) to a regulator (45), which decreases its frequency controlling output signal if the peak value input signal exceeds a predetermined value. A control signal corresponding to the torque demand of the motor is also produced. This signal controls the voltage supplied to the motor. Negative pulses at the turning off of the inverter switches are also sensed and used for controlling the degree of magnetization of the motor.