【作者】 郑许峰；

【导师】 林明耀；

【作者基本信息】 东南大学 ， 电机与电器， 2006， 硕士

【摘要】 无刷直流电机是随着电力电子技术的发展和高性能永磁材料的出现而迅速发展起来的一种新型机电一体化电机。随着无刷直流电机在各个领域的广泛应用,无位置传感器控制方法的优势越来越明显,特别是“反电势法”无刷直流电机控制方法已经发展成为最实用的无位置传感器控制方法。论文在介绍常用的无位置传感器无刷直流电机控制方法的基础上,详细分析了“反电势法”无刷直流电机控制原理。深入研究了两种反电势过零检测方法,采用“直接反电势法”设计了反电势过零检测电路。该方法不需要引出电机中性点,通过选择PWM和导通控制策略,就能直接从电机端电压获得反电势过零点信号。它避免了开关高频调制产生的干扰,不需要对端电压进行滤波。建立了基于PSPICE软件的仿真模型并对其进行了仿真验证。以按摩椅用无刷直流电机为样机,设计了“直接反电势法”无刷直流电机控制系统的硬件电路,详细介绍了电路各个组成部分,同时给出了控制系统中所采用的软硬件抗干扰措施。论文介绍了“直接反电势法”无刷直流电机控制常用的起动方法,深入讨论了“三段式”起动技术,对“三段式”起动技术中转子预定位、外同步加速和外同步到自同步的切换进行了详细的分析,并围绕“三段式”起动技术详细介绍了“直接反电势法”控制软件设计流程。最后,通过实验验证了这种方法的可行性和正确性。更多还原

【Abstract】 The brushless DC motor(BLDCM) is a kind of electromechanical integration machinery, and it has been rapidly developing in recent years with the help of the development of power electronic technique and the appearance of new type of permanent magnet material. With it’s widely used in many fields, the sensorless control especially back-EMF method of the motors is more useful than sensor control in many applications.In this thesis, the common methods of sensorless control of BLDCM are presented, and the principle of back-EMF method is introduced in detail. Two kinds of methods of the zero-crossing of back-EMF sensing are analyzed,and the mothod of direct back-EMF is adopted to design the zero-crossing of back-EMF sensing circuit in which the motor neutral point voltage information isn’t needed. The zero crossing signal of the true phase back EMF can be directly obtained from the motor terminal voltage by properly choosing the PWM and switch control strategy. As the result, the method proposed is not sensitive to the switching noise, no filtering of the motor terminal voltage is required. The circuit model is established by PSPICE software and the simulation results verify the theoretical analysis. In this system, the BLDC motor applied in the massage chair is used as a sample and the hardware of the BLDCM control system on direct back-EMF method are designed , each part of this system is introduced in detail. In additional, the methods to reduce electromagnetic interference(EMI) are also analyzed.The common start methods of sensorless BLDCM control system are introduced, and the three-step start technique, including the rotor pre-setting, accelerating and state-changing step, is discussed carefully. The control software flow of direct back-EMF is introduced around three-step start technique in detail.Finally, The experimental results show the method useful and correct.更多还原