Research On Vector Control System Of Brushless DC Motor For Electric Vehicles

Environmental and energy issues have cost the international community wide concern,the electric car as an environmentally-friendly,resource-saving transportation to be accepted by people.China is the most populous country in the world,the production of electric vehicles also ranked first in the world,but China's electric vehicle research and development technology is still relatively backward,so to develop the superior performance of the electric vehicle has a very important practical value for the development of China's environment and energy.The electric car mostly adopts brushless DC motor as the hub motor,the research and design of controller of Brushless DC motor has become a priority among priorities of the development of electric vehicles.This article gives theoretical study on electric vehicle controller of Brushless DC motor,uses STM 32 series microcontroller as the main control chip of motor controller.In the basic theory research of the brushless DC motor,working principle and control strategy,software simulation and experiments are used to verify the proposed algorithms,which can realize the effective control of electric brushless DC motor.The main research work is as follows:(1)Study on the traditional brushless DC motor control method,using double closed loop control method to control the motor,and the speed and current loop are used in PI control algorithm;the control methods above in PSIM are simulated,and the simulation results are analyzed.(2)Research on brushless DC motor vector control system,then the mathematical model of the brushless DC motor and the three-phase inverter is established in different coordinate system;the principle of SVPWM algorithm is analyzed;the vector control of Brushless DC motor based on Lyapunov method is analyzed and designed,which can solve problems in reducing the torque pulsation.(3)Speed sensorless vector control system of brushless DC motor is studied;the principle of sliding mode variable structure control is analyzed,which is applied to the brushless DC motor speed sensorless control;A adaptive sliding mode observer is built in the two-phase stationary coordinate system model,and the observer can accurately observes EMF of brushless DC motor,then realize the target of sensorless control for brushless DC motor.(4)The experimental platform of Brushless DC motor control is designed,and the theory of this paper is proved by experiments.