Analysis on Short Circuit Current Limiting Effect of Installing Small Reactance in 500kV Autotransformer's Neutral-point

2019 4th Asia Conference on Power and Electrical Engineering

能源学;电工学

Fangfang, Shi^1 ; Zeqing, Zhao^2 ; Chao, Yang^1 ; Zehui, Zhang^3 ; Zhaohui, Zhang^4 ; Mengmeng, Sun^5 ; Meng, Liu^1

State Grid Shandong Electric Power Research Institute, Shandong Province, Jinan

250001, China^1

State Grid Shandong Electric Power Maintenance Company, Shandong Province, Jinan

250118, China^2

Qing Dao Power Supply Company, State Grid Shandong Electric Power Company, Shandong Province, Qingdao

266002, China^3

Wei Fang Power Supply Company, State Grid Shandong Electric Power Company, Shandong Province, Weifang

261000, China^4

Shandong Zhongshiyitong Group Co., Ltd., Shandong Province, Jinan

250003, China^5

关键词: Neutral grounding;    Neutral points;    Protection settings;    Shandong;    Short-circuit current limiting;    Single-phase short circuits;    Three-phase short-circuit current;    Zero sequences;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/486/1/012034/pdf
DOI  :  10.1088/1757-899X/486/1/012034

来源: IOP

【 摘 要 】

For the condition that single-phase short circuit current exceeds three-phase short circuit current occurs on some of Shandong 500kV substations' 220kV bus, this paper studies the principle of limiting 500kV autotransformer's short circuit current by installing small reactance. Considering that installing small reactance at 500kV autotransformer's neutral point influences the zero sequence circuit, this paper suggests to configure independent relay protection on small reactance which aims at supervision the short circuit current and improving reliability. Protection setting for neutral-grounding small reactance is proposed. Simulation results and protection setting software show the effect of limiting short circuit current by installing small neutral-point reactance.