【作者】 张弛；

【导师】 张兴敢；

【作者基本信息】 南京大学 ， 信号与信息处理， 2015， 硕士

【摘要】 直流电动机将电能转化为机械能,具有体积小、运行可靠、控制简便等特点。直流无刷电动机是从有刷电动机演变而来的,其不仅继承了直流有刷电动机的优点,还克服了有刷电动机机械电刷换向带来的一系列问题,在现代社会生活和生产活动的各个方面得到广泛应用。如何就直流无刷电动机构建一个可靠实用的控制系统,达到反应快、精度高、定位准的目的,并能够应用到其他行业领域,是研究人员关注的一项重要内容,因此对直流无刷电动机控制系统的研究具有重要的应用价值。本文首先介绍了直流无刷电动机的组成部分、工作过程、驱动方式、换相过程和调速原理。采用单极性PWM(Pulse Width Modulation)调制方式对电动机进行调速控制时,可以较好地抑制转矩脉动。本文在建立数学模型的基础上,对无刷直流电机换相过程进行分析,计算得到相应的转矩脉动。最后,介绍了采用PI调速器的速度控制策略。本文设计了以STM32芯片为控制核心的电动户外广告控制系统。硬件电路主要由控制芯片电路、功率驱动电路、检测电路和电源电路组成。其中,功率驱动电路、控制芯片电路和位置信号检测电路实现了电动机的运转和控制；检测电路通过对系统电压电流的实时检测,控制电机过载,增加了电路的安全性。系统软件采用层次化的设计思想,分成主程序和子程序,依据功能划分各模块,用C语言开发。主程序主要进行系统内各端口、模块、中断、变量和外设的初始化,根据功能需要,实现子程序调用。子程序采用中断函数实现电动机工作时位置信号的捕获、PWM的产生、电子换相和AD转换等控制功能。通过激活STM32芯片的功能模块和调用相关函数,子程序还具有系统待机、定时开启／关闭、循环展示、画面定位、串口通信等应用功能。最后,在搭建的简易实验平台上对控制系统进行实验调试,系统运行稳定,达到预期的效果,为今后的进一步深入研究提供了平台。更多还原

【Abstract】 DC motors are devices which convert electrical energy into mechanical energy, and possess many characteristics, such as:reliable operation, high efficiency, good speed regulation performance and simple structure. But At the same time, there are some shortcomings existing in the brush DC motor. For example, the mechanical brush is easy to damage due to wear and tear, so it needs frequent maintenance. Brushless DC motor, which is emerged and developed on the basis of the DC motor, is a typical electromechanical integration product. Brushless DC motors not only reserve merits from DC motor, but also successfully deal with the problems caused by mechanical commutation, so brushless DC motors have been widely used in all aspects of the modern social life. How to build a reliable and practical control system of brushless DC motor, to achieve the purpose of quick response, high precision, accurate positioning, and to be applied to other industries, that has become an important issue in the Brushless DC Motor control field and plays an important role in industry application. So the research in the control system of brushless DC motor has great economic benefit.It is introduced that the basic component, driving circuit, working principle, Commutation process and modulation mode of brushless DC motor. On the basis of mathematical model established, torque ripple occurring in commutation process, which can be suppressed effectively by using H_PWM (Pulse Width Modulation)-L_ON Modulation mode in the procession of running motor, is analyzed and calculated. In the last part of this chapter, speed control strategy of PI speed regulator is raised.In this thesis, a STM32 chip is designed as the core of control system of brushless DC motor. Hardware platform is consisted of control chip circuit, power driver circuit, detecting circuit and power circuit. The normal operation of the motor and speed control is ensured by power drive circuit, control chip circuit and the position signal detection circuit. Security is kept by Detecting voltage and current of the circuits and overload is controlled.On the method of hierarchical and modular software program design, the software completed with C language, is composed of main program and subroutines. The internal ports, program modules, interrupts, peripherals and variables of software are initialized, and subroutines needed are invoked in main system. The functions, which are completed by interrupting service routines, including position signal capture, PWM generation, electronic commutation and AD testing, are used to make the motor running. By activating modules of the STM32 chip and invoking the correlation subroutines, the functions of system standby, running on time, cycling-display, picture-positioning and communication are called.Finally, the experiments results show that the control system of Brushless DC Motor researched in this thesis achieve the anticipated effects, which provide a platform for further research in the future.更多还原