Application Of DSP In The BLDC Motor Control System

This document presents the theory and process of the design for a sensor BLDC motor using DSP. Regard how to structure the control system with DSP chip as the center in this paper. The basic component parts, the basic running principle, the mathematical model of the BLDC motor are detailed analyzed. Followed, the course of changing phase is also researched and the control structure, technology, strategy and chip are confirmed. In order to improve the speeding performance, we adopt the two closed-loop control strategy of speed and current. The MCU of system is the TMS320F2812 DSP chip. In virtue of powerful processing capacity and plenty peripherals of DSP, the system adopt more reasonable software structure instead of the former complicated hardware circuit, and get better dependability. To overcome the problems in the classical PID algorithm, the nonlinear changing integral rate PID algorithm is presented and applied in the design system. Pulse Width Modulation (PWM) technology is used in the system.Based on TI's DSP TMS320F2812 and IR's driving chip IR2130 and MOSFET IRF540 the hardware circuit is designed. And the protection circuit is offered in the design. The C program is offered here .The structures of the software of the whole design is made of the main program and interrupt program. Main program finished the initiation of the chip and variable of the program. The interrupt program finished the tasks of A/D transform, digital PlD control, the converting of the phase and PWM generating etc.Experimental results show that the motor start fast and stable with wider area of speeding. This BLCDM control system has the characteristic of simple structure, high dependability, and can be used in many fields.