交变磁场对直流电阻测量影响的分析

Effect of Alternating Magnetic Field on DC Resistance Measurement

介绍了新丰江发电有限责任公司在1号水轮发电机转子磁极检修过程中,用双臂电桥法测量转子磁极线圈直流电阻的试验过程及数据,并对所发生的测量误差进行了分析,发现误差是由邻近隐蔽的发电机中性点母线电流形成的交变磁场在被测磁极线圈中产生感应电势引起的,提出在今后的试验工作中进行直流电阻测量时要注意测试环境磁场的影响,特别是隐蔽的大电流磁场的影响。

In the course of overhauling the rotor magnetic pole of unit No. 1 in the Xinfengjiang Hydropower Plant, the double bridge method is applied to the measurement of the DC resistance of the rotor magnetic pole winding. Error analysis indicates that the measurement error is caused by pole inductive EMF induced by the alternating magnetic field formed by adjacent covert generator neutral point bus current. It is proposed that the effect of environmental magnetic field should be considered in DC resistance measurement, especially the effect of covert high current magnetic field.