反电动势三次谐波高占比五相永磁同步电动机转子初始位置估计方法

Initial Rotor Position Estimation Method for Five Phase PMSM With High Proportion of Third Harmonic Back EMF

含有三次谐波反电动势的五相永磁同步电动机,注入三次谐波电流可进一步提高其负载能力,预先获得其精确的转子初始位置直接决定其启动性能。针对反电动势三次谐波高占比的五相永磁同步电动机,提出一种基于脉冲电压注入的转子初始位置估计方法。利用两相静止坐标系下基波平面数学模型,推导转子位置估计公式;分析转子处于不同位置时应注入的最优电压矢量,根据初步估计的转子位置角选择优化电压矢量,通过二次注入提高估计精度。基于绕组函数法,分析电枢磁动势与基波和三次谐波电流的关系,提出在三次谐波平面向电机施加方向相反的2个电压矢量,根据三次谐波平面电流幅值判断转子磁极极性的策略。实验结果验证了所提转子位置估计算法的有效性,最大估计误差为±5°。

The load capacity of five phase permanent magnet synchronous motor(PMSM)with third harmonic back electromotive force(EMF)can be further improved by injecting third harmonic current.The accurate initial position of the rotor directly determines the starting performance of the motor.An initial rotor position estimation method based on pulsed voltage injection was proposed for five-phase PMSMs with high proportion of third harmonic back EMF.Based on the fundamental wave plane mathematical model in the two-phase static coordinate system,the rotor position estimation formula was derived.The optimal voltage vector that should be injected when the rotor was in different position was analyzed.The voltage vector was selected according to the rotor position Angle estimated preliminarily in order to improve estimation accuracy.Based on winding function method,the relationship between armature magnetomotive force and fundamental and third harmonic currents were analyzed.In this paper,two voltage vectors in opposite directions were applied to the motor in the third harmonic plane,and the polarity of rotor was judged according to the amplitude of the third harmonic plane current.Experimental results verify the effectiveness of the proposed rotor position estimation algorithm,and the maximum estimation error is±5 degrees.