500kV主变压器低压侧总断路器对继电保护的影响

Influence of Low-Voltage Side Circuit Breaker of 500 kV Main Transformer on Relay Protection

500 kV主变压器的低压侧一般有两种接线方式,分别是装设总断路器方式与不装设总断路器方式.早期投运的500 kV变电站,为节约建设成本、节省场地资源,往往采用主变压器低压侧不装设总断路器的接线方式.近年来,新建500 kV变电站中往往采用低压侧装设总断路器方式,一些已投运变电站也开始进行主变压器低压侧加装总断路器改造.500 kV主变压器低压侧加装总断路器后,改变变电站一次结构的同时对继电保护产生影响,基于江苏地区500 kV变电站加装总断路器的实践,对相关影响进行了分析.

The low-voltage side of the 500 kV main transformer generally has two wiring methods,which are the installed main circuit breaker mode and the non-installed main circuit breaker mode.In order to save construction costs and site resources,500 kV substations put into operation in the early stage often adopt the wiring mode of not installing the main circuit breaker on the low-voltage side of the main transformer.In recent years,the new 500 kV substation often adopts the low-voltage side installation of the main circuit breaker,and some substations already put into operation have also begun to install the main circuit breaker on the low-voltage side of the main transformer in the retrofitting.After the main circuit breaker is installed on the low-voltage side of the 500 kV main transformer,the primary structure of the substation is changed and the relay protection is affected.This paper is based on the practice of installing the main circuit breaker in 500 kV substation in Jiangsu area to make analysis on the relevant influence.