五次谐波 meaning in English

quintuple harmonics

According to the present actual underground power system which neutral point is grounded through arc suppression coil in many supper big shaft , the development history and present situation of synthetic protection system used in hv flameproof switchgear are reviewed , and on the basis of analyzing the problems existed in high voltage flameproof switchgear , the selective leakage protective method based on the detecting harmonic direction of zero sequence current as well as the value of zero sequence voltage is proposed in this paper , and at the same time , harmonics extracting schematic and transforming circuit are also designed
本文深入系统地研究了基于intel80c196kb单片机控制的6kv防爆开关综合保护系统，主要内容如下：针对大型及特大型矿井供电系统中性点普遍采用消弧线圈接地方式的现状，回顾了国内外矿用高压防爆开关保护系统的发展历史，分析了目前国内高压馈电开关保护系统所存在的问题，提出了“基于零序电压基波启动，五次谐波功率方向比较”的选择性漏电保护原理，设计了相应的五次谐波提取电路和功率方向鉴别电路。