DC brushless motor PWM speed regulation principle

The principle of PWM speed regulation of DC motor is different from that of AC motor. It does not adjust the speed of the motor by frequency modulation, but by adjusting the pulse width of the driving voltage and matching with some corresponding energy storage components in the circuit. The amplitude of the armature voltage is delivered to achieve the purpose of changing the speed of the DC motor. Its modulation method is amplitude modulation.

Pulse width modulation is an analog control method, which modulates the bias of the transistor base or the gate of the MOS transistor according to the change of the corresponding load to realize the change of the on-time of the transistor or the MOS transistor, thereby realizing the output of the switching regulator power supply. change. This way, the output voltage of the power supply can be kept constant when the operating conditions change, which is a very effective technique for controlling the analog circuit by using the digital signal of the microprocessor.

PWM control technology has become the most widely used control method of power electronics technology because of its simple control, flexibility and good dynamic response. It is also a research hotspot. Since the development of science and technology today has no boundaries between disciplines, combining modern control theory or implementing resonant-free switching technology will become one of the main directions for the development of PWM control technology.