Design And Research Of Brushless DC Motor Controller For Electric Vehicle Based On Direct Torque Control

Because electric vehicles have the characteristics of cleanness,efficient and convenient in electric drive,all kinds of electric vehicles(including electric motorcycles,bicycles,automobiles)have been widely used and popularized.The exhaust emission of new energy vehicles is close to ‘0',which is one of the options to solve the shortage of resources and air pollution.Brushless DC motor(BLDCM)is one of the types of motor and a special form of DC motor.It emerges with the rise of motor technology and permanent magnet materials.It has many advantages,such as small size,high efficiency,good speed regulation performance,simple control and easy to realize digital control.It is widely used in many fields.Therefore,it has of far-reaching significance to study the control of BLDCM.In this paper,firstly,the working principle of brushless DC motor is analyzed.According to the requirement of smooth operation of electric vehicle,the research work of brushless DC motor controller is carried out.Finally,the brushless DC motor for electric vehicle can be accurately controlled.The main work of this paper is as follows:In this paper,the structure,operation principle and control mode of BLDCM are analyzed,and the overall design scheme of the controller for driving BLDCM is determined.The Brushless DC motor is controlled by direct torque.The controller of the Brushless DC motor consists of two parts: control part and power drive part.In the hardware design of the controller,STM32F103VET6 chip with ARM Cortec-M3 core produced by ST Company is used as the central control chip.This paper designs the power supply part,power drive part,voltage and current detection part,control signal detection part,over-current and over-voltage protection part of the brushless DC motor controller.In the software design,the control program is precisely divided into several control subroutines according to the driving requirements of electric vehicles and the characteristics of BLDCM.These subroutines mainly include: system initialization program,PWM signal output program,voltage and current protection program,operation parameters detection program and anti-interference program.In the experimental stage,we debugged the software and hardware of each module of the BLDCM controller to modify the existing problems in the controller design.Finally,we test the controller and get the experimental waveform.The experimental results are consistent with the design objectives.