【作者】 王晓旭；

【导师】 杨振强；

【作者基本信息】 大连理工大学 ， 电机与电器， 2011， 硕士

【摘要】 近年来,随着电力电子技术、运动控制技术、材料科学技术以及计算机技术的不断发展,作为机电能量转换装置的无刷直流电机,得到了快速的发展,其应用范围也从军事领域逐步扩展到交通运输、仪表、化工、医疗等各个领域。无刷直流电机结构简单、运行可靠且具有优越的调速性能。相对于有刷直流电机而言,无刷直流电机用电子换相取代了传统的机械电刷换相,避免了换相过程中产生的火花以及电磁干扰,极大的提高了电机的运行寿命及可靠性。但是电子式转子位置传感器的安装,加重了无刷直流电机的负担,也在一定程度上限制了电机的应用场合,因此无位置传感器无刷直流电机控制系统的提出具有及其深远的意义,已成为当前研究的热点。本文在详细分析无刷直流电机结构特点及运行原理的基础上,实现了无刷直流电机无位置传感器闭环控制系统。在控制算法方面,采用“反电势法”(Back Electromotive Force,简称BEMF)检测三相反电势过零点来确定电机转子位置,完成换相过程。同时,针对反电势法所存在的起动困难的缺点,本文提出了一种“高频脉冲注入法”的实现方法来检测永磁无刷直流电机转子在静止状态下的位置,配合“三段式起动法”,实现电机平滑无反转起动。本文以TI公司生产的高性能数字信号处理器TMS320F2407A型DSP作为主控芯片,ATmega168作为键盘数码管手持单元控制芯片,设计了无刷直流电机的核心硬件控制系统,及其外围电路,并搭建了简单可靠的反电势过零检测电路。结合DSP的特性,充分利用片内资源,运用C语言编辑了模块化的控制程序。实验运行结果表明,本无刷直流电机无位置传感器控制系统能够准确检测到电机初始位置,平稳起动,在实现电机正确的换相以及闭环运行的基础上,具有键盘和端子双重控制,报警显示等功能,证明了系统设计的可行性。更多还原

【Abstract】 Recent years, with the development of power electronic technology, motion control technolegy, material science technology and computer technology, brushless DC motor, which works as a kind of electromechanical switching equipment has been developed rapidly. Its application has extended from military to transportation, gauges, chemical engineering, medical science and many other areas. Brushless DC motor has the capability of simple structure, operational reliability and excellent speed regulation performance. Compared to a brush DC motor, brushless DC motor uses electronic commutator to take the place of traditional mechanical commutator. This method could avoid the spark coming from the process of commutation and the electromagnetic interference, and the service life and reliability of the motor has been improved a lot. However, the installment for electronic rotor posture sensor would increase the burden of brushless DC motor, which becomes a certain limiting factor to its application. As a result, the propound of sensorless brushless DC control system with profound significance has became a hot research point recently.In this paper, on the basis of detailed analysis for the structure characteristic and operation principle of brushless DC motor, sensorless brushless DC motor closed loop control system is realized. In the aspect of control algorithm, Back Electromotive Force (BEMF) is adopted to detect the triphase back electromotive force zero-crossing and then determine the position of the motor rotor, achieve the commutation process. At the same time, because of the starting problem brought about by back electromotive force, this paper puts forward a kind of "high-frequency pulse injection method" to detect the brushless DC motor rotor in the static position, along with "three-step startup method" and realize the motor starts smooth without reverse.In this paper, high-powered digital signal processor TMS320F2407 type DSP produced by TI is as the master chip, and ATmegal68 is designed as keyboard digital tube handheld unit control chip. In addition, the control system core hardware of the brushless DC motor, its peripheral circuit and a simple reliable back electromotive force zero crossing detection circuit are also presented. Modular control procedures using C language are edited combining with the characteristics of DSP and making full use of the resources.The experimental results show that the sensorless brushless DC motor control system could accurately detect the initial position of the motor and smooth start. On the basis of realizing the correct reversing and closed loop operation, the system has the functions of alarm display and double controlled both by keyboard and terminal. All of those proved the feasibility of this system.更多还原