工频磁场对单相电能表的影响 .pdfVIP

学兔兔 第5l卷 第7期 电测与仪表 V01．51 NO．7 2014年 4月lO日 Electricai Measurement lnstrumentation Apr．10，2014 工频磁场对单相电能表的影响 谢永明，李英莲 (华立仪表集团股份有限公司，杭州310023) 摘要：针对单相电能表在0．5mT工频磁场干扰下存在误计量的问题，分析其主要原因在于工频磁场在电能表 电流采样回路上产生了大于电能表起动的感应电流。对此，通过定量分析0．5mT工频磁场的影响量，根据磁 通在交错的环中产生的感应电压是可抵消的，提出在不改变原有电路设计基础上，仅通过对分流器穿孔及改变 双绞线焊接方式，来减小电能表电流采样回路上的感应电流。经外部工频磁场影响试验测试证明了该方法的 可行性。 关键词：0．5mT工频磁场；电流采样回路；感应电流；分流器；双绞线 中图分类号：TM933 文献标识码：B 文章编号：1001—1390(2014)07—0014—04 Effects of Power Frequency Magnetic Field Oil Single Phase Electricity Meter XIE Yong—ruing，LI Ying—lian (Holley Metering LTD，Hangzhou 3 1 0023，China) Abstract：The main reason for the measurement error problem existing in the single phase electricity meter under the 0．5 mT power frequency magnetic field interference is that the current generated by the power frequency magnetic field is larger than the start current in the current sampling circuit of electricity meter．The value interfered by the 0．5mT power frequency magnetic field is analyzed quantitatively based on the theory of the induced voltage generated by mag— netic flux in the alternating loop offsets each other，and the method of only perforating the shunt and changing the welding position of twisted—pair cable is proposed to reduce the induced current in the current sampling circuit without changing the original circuit design．Actual experiments in the external power frequency magnetic field demonstration proves the feasibility of