网络接线简化存在的问题及其对主变中性点电抗器选择的影响分析  

Problems Existing in Simplification of Network Wiring and Analysis of Its Influence on Selection of Neutral Point Reactor of Main Transformer

作　　者：卫皇莅 曹炜 黄阮明 庞爱莉 郭明星 张梦瑶 赵鹏飞 WEI Huangli;CAO Wei;HUANG Ruanming;PANG Aili;GUO Mingxing;ZHANG Mengyao;ZHAO Pengfei(College of Electric Engineering,Shanghai University of Electric Power,Shanghai 200090,China;State Grid Shanghai Electric Power Economic&Technological Institute,Shanghai 200233,China)

机构地区：[1]上海电力大学电气工程学院,上海200090 [2]国网上海市电力公司经济技术研究院,上海200233

出　　处：《电力电容器与无功补偿》2021年第5期173-179,共7页Power Capacitor & Reactive Power Compensation

基　　金：国家自然科学基金青年自然基金项目(51807114);国网上海电力公司咨询项目(SGSHJY00GPJS1900054)。

摘　　要：目前,针对电力系统短路电流仿真计算中将负荷挂在某一较高的电压等级上,研究网络只保留2~3级电压的网络接线,网络接线的简化势必造成零序通路不完整的情况。本文首先分析了简化零序通路后存在的问题;其次分析了简化零序通路后对主变中性点电抗器选择的影响。算例分析表明,对于单相接地短路电流濒临超标且急需精确计算的节点,不完整的零序通路会给规划电网单相接地短路电流计算结果、500 kV主变中性点接地小电抗的选值等带来一些不确定性因素。因此,有必要对这些节点的下级网络完善1~2级电压的网络接线,使得母线单相接地短路电流计算结果更加精确。In view of such present situation that the load is put on a higher voltage level in the short-circuit current simulation calculation of the power system,the network wiring of 2~3 voltage level in the study network is only retained and simplification of the network will certainly cause incomplete zero sequence path.First,the problem after simplifying the zero-sequence path is analyzed.Then,the influence on selection of neutral point reactor of main transformer after simplifying the zero-sequence path is analyzed.The analysis of the calculation example shows that for the nodes where the single-phase grounding short-circuit current is on the verge of exceeding the standard and needs to be accurately calculated,the incomplete zero-sequence path will bring uncertainty factor to the calculation result of single phase grounded short circuit current of the planned network and the selection of grounded small reactance of the neutral point of 500 kV main transformer.Therefore,it is necessary to improve the network wiring of the 1 to 2 voltage levels for the lowerlevel networks of these nodes so to make the calculation results of the bus single-phase grounding short-circuit current more accurate.

关 键 词：零序通路 网络接线 简化等值 单相接地短路 

分 类 号：TM47[电气工程—电器] TM862