HIGH-EFFICIENCY DRIVE DUE TO POWER-FACTOR CONTROL OF A PERMANENT-MAGNET SYNCHRONOUS MOTOR

A drive system of a permanent magnet motor without magnetic position d etector is described, Generally, the position data of a magnet is obta ined from terminal voltage of the motor, In the newly developed method , the inverter dc-link current waveform provides the control signal fo r driving a permanent magnet motor without a detector, Since the power factor of the motor is controlled around 1.0, the motor runs at a hig her efficiency than one controlled by the conventional method, Therefo re, this control method saves energy, Current pulsation induced by sud den load fluctuations has been studied and its stabilization has been achieved, This paper provides the principle and operation of the new c ontrol method, simulated characteristics, and experimental results.