关键词: 永磁电机, 无位置传感器控制, 高频旋转注入, 极性判断

Abstract: High-frequency rotating signal injection scheme was widely used for startup and low-speed operation in sensorless vector control for interior permanent magnet synchronous motors. However, when the second harmonic current method was used to distinguish the polarity of the rotor’ s magnetic poles,the polar current at the polar edge position fails to distinguish the polarity. To solve this problem,an improved compensation algorithm was proposed by analyzing the influence of filter delay and digital control delay on the accuracy of the polarity judgement. The compensation method evenly adjusted the secondary positive sequence current, leveraging the phase deviation extracted from the secondary negative sequence current signal,so as to improve the accuracy of polarity judgment of the polar edge position. Employing this method, the
accuracy for estimating the initial position in the high-frequency rotating voltage injection process had been considerably elevated,thus eliminating the potential for startup issues. The effectiveness of this method has been validated through both simulation and experimental analysis.