The popularity of brushless motors, which are becoming more and more popular, is not just the actual use of the brushless motor body, but also the application of related technologies, such as sinusoidal drive technology. So, what is the sine drive technology? What is the role? Let's not guard against deepening the knowledge in this area.
The sinusoidal drive technology uses the voltage applied to the brushless motor windings to generate a sinusoidal current in the brushless motor windings, and achieves the purpose of controlling the motor torque by controlling the amplitude and phase of the sinusoidal current. Compared with the traditional square wave control, the phase current is sinusoidal and continuously changes without sudden change in the commutation current, so the motor has low operating noise.
According to the complexity of the control, the sine drive technology of the brushless motor can be divided into: simple sine wave control and complex sine wave control.
Simple sine wave control is to control the motor current by controlling the amplitude and phase of the motor's sinusoidal phase voltage. Normally, a sinusoidal phase voltage is generated at both ends of the winding by applying a form of voltage to the terminal line of the motor. The common generation methods are: sine PWM and space vector PWM. Since the principle of sine PWM is simple and easy to implement, it is usually used as a PWM generation method in simple sine wave control. Figure 1 is a BLDC control structure diagram, where Ux, Uy, Uz are the bridge arm voltages, and Ua, Ub, Uc are the phase voltages of the motor windings. The following descriptions of different types of PWM modulation methods will be based on this structure diagram.
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