中文摘要：

无刷直流电机是一种在日常生活比较常用的电机。主要针对无刷电机的无传感器控制系统部分展开研究。首先讲述了无刷电机的结构、原理和数学模型,并简要介绍了无传感器的控制方式。其次,讲述基于反电势法的无传感器控制技术,主要是其原理和反电势过零点的提取。然后设计无刷电机无传感器控制系统。最后,结合硬件电路对系统进行调试,将数据发送到上位机,对结果进行分析,验证其控制策略的合理性。

英文摘要：

Brushless DC motor （BLDCM） is a kind of motor which is commonly used in daily life. In this paper, sensorless control system of brushless DC motor is mainly research. Firstly, the structure, working principle and mathematical model of brushless DC motor are described, and the sensorless control mode of brushless DC motor is briefly introduced. Secondly, the sensorlcss control technology based on back EMF is presented, which mainly includes the principle of back EMF method and the extraction of BEMF-zero-crossing-point. Thirdly, the design of sensorless control system for brushless DC motor is completed. Finally, combined with the hardware circuit to debug the system, the data is sent to the host computer, and the result is output. The results are analyzed to verify the rationality of the control strategy.