电子式电能表工频外磁场试验方法的探讨

分析了电子式电能表工频外磁场试验引入的附加误差与试验条件的关系,指明国标规定的电能表工频外磁场试验方法不能保证锰铜分流器变换式电能表在其全电流量程内的抗工频外磁场能力。提出在电能表电流测量范围的下限,即10%Ib(直接式)、5%In(互感式)进行该项试验的改进型试验方法。经仿真验证,电能表若满足文章建议的试验要求,其在该工频磁场下的感应电流必小于起动电流,不会出现空载走字。针对国网新增的工频磁场潜动性能试验,指明其在潜动时间设置上取20倍理论起动时间有失合理,应以不大于1/0.6倍理论起动时间为宜。测量统计了我国近5年内锰铜分流器变换式电能表的抗工频外磁场能力,总体看该性能逐年提升,在2014年有突破性提高(附加误差<0.2%)。

Discussing the test method of power frequency magnetic fields to static energy meter

The relationship between test conditions for power frequency magnetic fields of external origin and the measurement additional error of energy meter was introduced. PresentsSdoing power frequency magnetic fieldsStest at the lower bound of energy meter current range. Simulation indicates, if meter meet the test requirements of 0.5mT power frequency magnetic field at the load point suggested in article, it can ensure the induced current is less than the starting current. To the test method of no load testSin the power frequency magnetic field, proposed itsSdeficiency.SStatistical measuring additionalSerrors of different types of energy meter using copper-manganese shunt in the pastS5 years,Sfinding theSantiSpower frequencySmagnetic fieldScapacity of energy meter increased year by year, a breakthrough improvement (<0.2%) in 2014.