CONTROLLING BRUSHLESS PERMANENT-MAGNET MOTOR

PROBLEM TO BE SOLVED: To provide a technology for controlling a brushless permanent-magnet motor.SOLUTION: The method for controlling the brushless permanent-magnet motor comprises a step of rectifying an alternating voltage to provide a rectified voltage having a ripple of at least 50%, and a step of exciting a winding of the motor with the rectified voltage. The winding is excited in advance of a zero-crossing of counter electromotive force only during an advance period and is excited during a conduction period over each electrical half-cycle of the motor. The advance period and/or the conduction period are adjusted in response to a change in either of a speed of the motor or RMS value of the alternating voltage so as to maintain constant average power. Additionally, a control system that implements the method, and a motor system that incorporates the control system are provided.