交流发电机定子换位股线电流测量方法研究

Study on measuring method of stator transposed strand current in AC generator

针对交流发电机定子绕组多根并联换位股线编织胶化的特殊结构,提出了一种测量换位股线电流的方法,该方法以测量定子绕组不同位置的漏磁场为基础,根据电磁感应定律与麦克斯韦方程反演定子绕组换位股线电流。首先根据定子绕组股线结构,推导了换位股线电流与测量位置漏磁场的关联方程,采用仿真验证了关联方程的正确性以及测量方法的可行性,然后对传感器结构进行了讨论,采用PCB板设计了一种线阵式霍尔传感器,并用螺线管校准了霍尔灵敏系数,最后以测量定子0°/不足360°/0°换位绕组股线电流为例,搭建了定子绕组换位股线电流测试平台,结果表明实测换位股线电流值与理论分析值相比,最大绝对误差为0.52 A,平均绝对误差为0.18 A,验证了测量方法的有效性。

Aiming at the special structure of many parallel transposed strands treated by weaving and gelling in AC generator,a measuring method of the transposed strand current is proposed. The method is based on the leakage magnetic field measured at different positions of the stator winding,and the transposed strand current of the stator winding is inversed by the law of electromagnetic induction and the Maxwell equation. Firstly,according to the structure of the stator winding,the correlation equation between the transposed strand current and the leakage magnetic field of the measurement position is formulated. Meanwhile,the correctness of the correlation equation and the feasibility of the measurement method are verified by simulation. Secondly,the structure of sensor is discussed,and one kind of Hall sensor with linear array structure is designed by utilizing PCB plate. The sensitivity coefficient of the Hall sensor is calibrated by using solenoid. Finally,measuring strand current of the stator winding with different situations are studied,including 0° stator,less than360°,and 0° transposition. The evaluation platform of current measurement for transposition strand is built. The current value of the measured transposed strand is compared with the theoretical analysis. Experimental results show the maximum absolute error is 0. 52 A and the mean absolute error is 0. 18 A. The validity of measurement method is verified.