摘要
淮安换流站示范工程中,500 kV/10 kV站用变压器直挂500 kV母线,特殊的站用电系统接线及两级降压方式给站用变压器保护的配置及电流互感器选型带来一些问题。通过研究淮安换流站站用变压器保护定值整定应用算例,对短路电流计算、定值整定方法、各级时限配合关系进行探讨,针对500 kV/10 kV站用变压器低压侧电缆段出现短路故障且短路电流较小时提高灵敏度的问题,提出高压侧断路器配置失灵和小失灵保护的双套保护技术方案。该方案在分析高低压侧短路故障电流差异较大基础上,接入小变比电流互感器次级绕组,当低压侧故障电流较小时,小变比的失灵保护装置灵敏度较高,可实现故障的最小化隔离。
In the demonstration project of Huai’an converter station,500 kV/10 kV substation transformer is directly connected with 500 kV bus,and wiring of the special substation power system and the two-stage step down mode bring some problems to the configuration of substation transformer protection and CT selection.Aiming at the above problems,this paper discusses the calculation of short-circuit current,the method of setting value and the coordination of time limits at all levels by studying the setting value of substation transformer protection in Huai’an converter station.It puts forward two sets of protection technology schemes for configuration failure and small failure protection of high voltage side circuit breaker in view of the problem of improving the sensitivity as the short circuit fault is smaller in the cable section at the low voltage side of 500 kV/10 kV substation transformer.Based on the analysis of the large difference of short-circuit fault current between the high and the low voltage side,a small transformation ratio CT secondary winding is connected.When the fault current at the low voltage side is small,the failure protection device with small transformation ratio has high sensitivity and can realize the minimum isolation of the fault.
作者
孙楠
严佳梅
赵俊
冯兴荣
方力
SUN Nan;YAN Jiamei;ZHAO Jun;FENG Xingrong;FANG Li(State Grid Jiangsu Electric Power Company Maintenance Branch,Nanjing,Jiangsu 211102,China;Southern Branch of State Grid Customer Service Center,Nanjing,Jiangsu 211161,China)
出处
《广东电力》
2021年第8期86-93,共8页
Guangdong Electric Power
关键词
特高压
站用电
保护配置
定值整定
时限
ultra high voltage(UHV)
station power
protection configuration
value setting
time limit
作者简介
孙楠(1989),男,山东聊城人,工程师,硕士,主要研究方向为电力系统继电保护,E-mail:18795895087@163.com;严佳梅(1990),女,浙江金华人,工程师,硕士,主要研究方向为数据运营分析;赵俊(1989),男,江苏南京人,工程师,硕士,主要研究方向为电力系统继电保护;冯兴荣(1992),男,江苏泰州人,工程师,硕士,主要研究方向为电力系统继电保护;方力(1994),男,江苏盐城人,助理工程师,硕士,主要研究方向为电力系统继电保护。
