摘要：无刷直流电机控制系统集电机、逆变电路、检测元件、控制软件和硬件于一体，具有高可靠、高效率、寿命长、调速方便等优点，在电动调速领域有着广泛的应用。电动自行车的发明和使用对解决燃油车造成的严重环境污染和缓解日益突出的能源危机问题有一定的现实意义。
根据项目参数要求，采用Mcrochip公司的PIC16F72单片机作为控制芯片，在硬件方面，进行了微控制单元电路设计、逻辑互锁电路设计、转子位置信号采集电路设计、电源电路设计、升压电路设计、系统硬件保护电路设计、三相全桥逆变电路设计、逆变器驱动电路设计和显示电路设计。采用开关型霍尔传感器作为电机转子位置传感器，微控制单元根据转子位置信号向驱动电路传递PWM (脉宽调制)信号、逆变器上下臂驱动信号控制电机。
在软件方面利用汇编语言，采用模块化编程和结构化编程。根据无刷直流电机的控制原理，对系统的控制部分进行了详细分析。设计了系统状态显示面板程序模块。利用数字PI控制理论实现电机速度的闭环调制，提出了一种电机控制系统的接线模式自识别功能设计方案，能够自动识别电机的换相角度、霍尔相位和电机输出相位。在系统可靠性方面:设计了系统的欠压、过流和堵转保护。本文还对影响控制器和单片机系统可靠性的因素进行了分析，并且给出了解决方案.
本文所设计的无刷电机控制器实现了电动、定速、助力三种工作模式并且在系统出错情况下具有自检功能。保护功能较完善、硬件结构简单、成本较低，具有升级空间，便于用户二次开发。
关键词:无刷直流电机； PIC单片机； 电动自行车； 控制系统
Abstract：The control system consists of Brushless DC Motor,controlling part,sensor part，hardware and software controlling part. With its unique advantages of high efficiency, high reliability, good controllability and maintenance-free,it is widely used in many fields.To d evelop the electric-bike will be helpful to solve the pollution problem caused by the waste gas from the gasoline-automobiles and energy sources problems.
The task is to design a Brushless DC Motor (BLDCM) controls ystem For electric-bike.According to the project,PIC16F72MCU produced by Microchip Company has been selected.T he design of hardware including MCU circuit,logic lock circuit,position of the rotor circuit, power circuit, voltage up circuit, hardware protection circuit, electronic commutatorci rcuitan dd isplayc ircuith aveb eenc arriedo ut.Th erea reth reeh allse nsorsfor he position of the rotor, according to the position of the rotor and pwm (pulsewidth modulation)controlsi gnals,the electronicc ommutator works.
The software was designed following the principle of modularization and structured programming and using assembly as the programme languages.The display module is designed.Ty pical PI control strategy is used to control the speed.Mode identified module can identify the angle of the BLDCM, the position of the rotor and the output of the system automatically. Less voltage protection, current excessive protection and wrong angle protection are designed to reinforce th e system. Also,factors that affect the reliability of the system are discussed in this paper,and some m ethods are introduced soon after.
This controller realizes three work modes-electromotion,stationary speed and assisting work mode.Another self-test mode,which work sunder error,is also designed.This kind of brushless DC motor control system is superior in many fields such as high reliability, simple hardware st ructure,lowcost,and convenient for the further development.
Key Words: Electric bike; Brushless DC Motor; PIC; Control System
目 录
1 第一章 绪论 5
1.1无刷直流电机的现状 5
1.2电动自行车介绍和发展状况 5
1.3 无刷直流电机控制器概述 8
1.4本设计的主要工作 9
2 第二章 无刷电机控制系统分析 10
2.1电机的基本原理 10
2.1.1稀土永磁无刷直流电机的基本结构 10
2.1.2电机的基本工作原理 11
2.1.3三相无刷直流电机星形连接全桥驱动原理 12
2.2 电机的特性分析 14
2.2.1电机的运行特性分析 14
2.2.2机械特性和调速特性分析 16
2.2.3其他特性分析 17
2.3直流电动机的PWM调速原理 18
2.4霍尔传感器 19
2.4.1开关型霍尔集成传感器 19
2.4.2霍尔器件在无刷直流电机中的应用 19
3 第三章 无刷直流电机控制器硬件设计