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Sine wave control of brushless DC motor
Apr 21, 2017

The sine wave control of brushless DC motor is by exerting a certain voltage on the winding of the motor, causing sinusoidal current in the winding of the motor, and controlling the amplitude and phase of the sinusoidal current to control the torque of the motor. Compared with the traditional square wave control, the motor phase current is sine, and the continuous change, no commutation current mutation, so the motor running noise is low. According to the complexity of control, DC brushless motor can be divided into: simple sine wave control and complex sine wave control. (1) Simple sine wave control: to the motor winding exert a certain voltage, so that the motor phase voltage is sine wave, because the motor winding is inductive load, so the motor phase current also for sine wave. By controlling the amplitude and phase of the motor phase voltage, the phase and amplitude of the current are controlled, and the realization is simpler for the voltage loop control. (2) Complex sine wave control: Unlike the simple sine wave control, the complex sine control target is the current of the motor phase, and the current loop is established, and the phase and amplitude of the phase current is controlled by direct control of the motor. Because the current of the motor phase is sine signal, the decoupling operation of the current is required, which is more complicated and common for magnetic field directional control (FOC) and direct torque Control (DTC).