摘要：介绍了一种高速无刷直流电机无传感器控制策略的特点，解决高速控制的难点。基于无刷直流电机无位置传感器反电动势过零检测法原理，及低通滤波理论设计了反电动势检测电路，提出了一种反电动势过零检测算法。围绕高速下逆变电路的保护，分析了MOSFET电路等效模型，对振荡电路的机理进行了深入研究，设计了逆变电路保护电路。最后利用STM32微控制器实现了高速无刷电机控制系统，通过实验验证了其有效性。

关键词：高速；无刷直流；反电动势过零检测；MOSFET保护电路
Abstract: This paper introduced the characteristics of a proposed sensorless control scheme of hi-speed brushless DC (BLDC) motor, and solved the key difficulties of hi-speed control. It designed a practical back-electromotive-force (BEMF) detection circuits and presented the revelent algorithm in software, which was based on the theory of BEMF zero crossing detection for sensorless BLDC motor drive system and the principle of low pass filter. Take the protection of inverter circuits constituted by power MOSFET into consideration , this paper analysed the equal model for inverter circuits. Then researched the reason to the oscillating of voltage on grid electrode of MOSFET, and proposed a protection circuits to avoid short circuit. The control system of hi-speed BLDC motor was realized by STM32 microcontroller, and it was verified with experiments.

Key words: hi-speed; brushless DC; BEMF zero-crossing detection; MOSFET protection circuits