Research On PID Control Method For Brushless DC Motor Based On BP Neural Network

With the development of the power electronics, motor control technology and microprocessor, brushless DC motor is a new type motor which is developed on base of DC Motor. The Brushless DC motor has the advantages of AC motor in its simple structure, reliable operation and convenient maintenance, as well as those of DC motor in its high efficiency, no excitation loss and easy control, so it has wonderful foreground in many fields. The research of brushless DC motor has draw lots of attention of the researchers at home and abroad. The traditional analysis and designing method of the brushless DC motor have been developed maturely, therefore it is important to find out a good control method for brushless DC motor evidently.PID control is widely adopted in many fields because of its simple structure, high reliability and easily implementation. PID controller has good control effect if the parameters of system model have not big variation, but there are a lot of complex, non-linear control systems and many objects that can not be established with accurate mathematics model on industry, if these systems are controlled with the traditional PID controller, it is impossible to get ideal control effect.For brushless DC motor, it has high non-linear trait, PID controller with fixed parameter can not achieve good performance index. So a kind of PID controller based on neural network is proposed. This design regards brushless DC Motor as a control object. By analyzing mathematics model of brushless DC motor, the design of related neural network PID control system based on BP neural network is provided.By using MATLAB, the simulation on the performance of a typical time-varying non-linear system was carried out by using the PID controller based on the neural network, and the algorithm was presented. The results show that the controller based on the neural networks can improve the robustness of the system and has better adaptabilities to the model and environments, compared with the classical PID control. The simulation model of a brushless DC motor control system was established based on the analysis of its mathematic model. A simulation on the different circumstances by the conventional PID controller and the neural network PID controller was carried out. The results show the validity of the model and the advantages of the neural network PID controller.