高速永磁无刷直流电机无位置全转速控制策略

Sensorless full speed range control strategy of high-speed maglev brushless DC motor

针对高速磁悬浮大功率永磁无刷直流电机无位置传感器起动问题,分析了高速磁悬浮无刷直流电机运行时导通相磁链函数与相电压的精确表达式,给出了转子位置和电机磁链的函数方程,分析了高速磁悬浮无刷直流电机低速时转子位置难以检测的原因。据此分析提出了一种基于高速电机绕组磁链函数的新型无位置控制G函数方法,以换相前后非换相相电流幅值等值为控制目标,以G函数换相阈值为控制量,通过PI调节来保证相位可靠校正,实验验证了该闭环校正方法应用于磁悬浮鼓风机无刷直流电机时,在20 000 r/min范围内能够对换相信号误差进行了实时补偿,实现全转速运行。

This paper focuses on start-up strategy of high-speed maglev brushless DC Motor, and the accu- rate expressions of voltage and flux linkage have been obtained, and the functional equation of rotor posi-tion and motor flux linkage have been pointed out. The reason of the rotor position being difficult to be tested in the low speed of the high speed maglev brushless DC motor has been analyzed. A G function method of high speed maglev brushless DC motor has been proposed. This method took the equivalent phase current of non-commutation phase amplitude as the target and takes the phase current difference of non-commutation phase before and after the commutation as feedback amount, and corrected the commutation signals automatically through G function threshold by PI regulator. Experimental results show that the proposed sensorless full speed range control strategy can ensure the full speed range of 20 000 r/min.