Control method of brushless DC motor.

Control method of brushless DC motor.There are three types of control for brushless DC motors: those with position sensors, those without position sensors, and those with intelligent control.

1、 Equipped with position sensor control

Position sensor control is a method of installing position sensors on the stator of a brushless DC motor to detect the rotor position and control the stator winding commutation. The position sensors used include electromagnetic (such as magneto resistive rotary transformers), photoelectric (such as shading plates), and magnetic sensitive (such as Hall sensors), among which Hall sensors are the most widely used.

2、 No position sensor control

The control method of DC brushless motor without position sensor does not directly install position sensors on the stator of the DC brushless motor to detect the rotor position. It generally uses direct back electromotive force detection, back electromotive force third harmonic method, current path monitoring method, open circuit phase voltage detection method, phase inductance method, back electromotive force logic level integration comparison method and other methods to indirectly detect the position of the rotor.

3、 Intelligent control
Intelligent control is an advanced stage in the development of control theory, generally including fuzzy control, neural network control, expert systems, etc. Intelligent control systems have functions such as self-learning, adaptation, and self-organization, which can solve model uncertainty problems, nonlinear control problems, and other complex problems. Strictly speaking, BLDCM is a multivariable, nonlinear, and strongly coupled object, so using intelligent control can achieve satisfactory control results. At present, many mature intelligent control methods have been applied to the control of brushless DC motors, such as Fuzzy PID control combining fuzzy control and PID control, composite control combining fuzzy control and neural networks, fuzzy control optimized by genetic algorithm for membership parameters, and single neuron adaptive control.