Development Status of Brushless DC Motor-1
The development status of brushless DC motors: the birth of brushless motors was marked by the United States in 1955. D. Harrison et al. first applied for a patent for replacing mechanical brushes with transistor commutation circuits. The electronically commutated brushless DC motor really entered the practical stage with the introduction of the MAC classic brushless DC motor and its driver in 1978. After that, in-depth research was carried out on the brushless DC motor in the world, and the square wave brushless motor and the sine wave DC brushless motor were developed successively. Over the past 20 years, with the development of new permanent magnet materials, microelectronics technology, automatic control technology and power electronics technology, especially high-power switching devices, brushless motors have made great progress. The brushless DC motor no longer specifically refers to a DC motor with electronic commutation, but generally refers to an electronically commutated motor with the external characteristics of a brushed DC motor.