关键词: 无刷直流电动机, 无传感器, 贝塞尔滤波器, 非理想反电动势, 零序电压, 换相

Abstract:

Aiming at the problem of commutation of brushless direct current motor (BLDCM), an adaptive position sensorless BLDCM commutation control scheme based on improved zero-sequence voltage signal processing technology was presented. The new scheme will extract the relevant information from the zero sequence voltage signal to determine the commutation time. The original zero-sequence voltage signal can be calculated by the terminal voltage acquisition and can be suppressed by the low-pass Bessel filter, and the fixed-time displacement independent of the rotational speed can be obtained. The zero-sequence voltage fundamental frequency is determined by the median filter algorithm. This algorithm, combined with an adaptive speed limiter, eliminates false zero-crossings. The new sensorless commutation technology can be implemented in a wide range of rotational speeds of BLDCM driving system. The test results verify that the new sensorless commutation technology has a good effect under various operating conditions of the motor.

Key words: brushless direct current motor (BLDCM), sensorless, Bessel filter, nonideal back electromagnetic force, zero sequence voltage, commutation