Design And Study Of BLDC Control System Based On32-bit Microcontroller

Brushless DC (BLDC) motor has found more and more widely applications in the fieldsof electrical vehicle, household appliance, servo systems and robotics etc, due to its lightelectromanetic pollution, extensive speeding range, greater overload Performance, high powerdensity, and high reliability. To Research brushless DC motor control system has a certaintheoretical and practical values.This paper use SH7125chip as the control core,BLDC as thecontrol object,to research the BLDC control system base on32-bit microcontroller,to achievecontinuously viable.Firstly, this paper conduct a study of the basic working principle,speed controlmethod and mathematical model of BLDC.Then building the BLDC mathematicalmodel.Simulation shows the feasibility of simulation models and controlalgorithms, provides a theoretical basis for the control system hardware and software design.According to the characteristics of BLDC, mathematical model and simulation, putforward closed-loop control system design scheme. Including the powersupply module, current detection circuit, position detection circuit, drive circuit,communication module and the protection circuit system’s requirement. The system useSH7125chip as the control core,IPM FSB50325as the drive unit. The position of rotor isdetected by the Hall-effect position sensor.Then according to the relationship between rotorposition and commutation, the control system implements the commutation and obtains themotor speed information.Finally the closed-loop control of motor speed is fulfilled by usingthe algorithm of PID control.The required software include main program, initial program, interrupt service,monitoring and commutation program is developed.Thereafter the start of the motor, detectionof current, calculation of PID parameters and the speed of the motor,commutation, PWM dutycycle update and remote monitoring tasks are achieved.Ultimately the stepless speed controlof the motor is accomplished.The hardware and software have been tested on an experimental platform.Parametersinclude current and the speed of the motor indicates that the speed of the motor is adjusted quickly and accurately.And also the effectiveness of the control algorithm is proved.