220kV变电所所用电系统改进方案

Improved Schema of the Home-load Supply System of 220 kV Substation

所用变高压侧设熔断器的方式不能有效保护其低压侧经小阻抗短路故障,低压侧主回路电缆一旦发生弧光短路故障而不能及时切除会造成事故扩大,为防止此类事故发生,有必要对此类所用电系统进行改进。通过对我省某220 kV变电所由于35 kV所用变低压侧电缆故障导致变电所停电事故的计算方法,提出适用于新建和已建变电所所用电系统改进方案。

Fuse at high voltage side of the home-load supply transformer of a substation could not act correctly when a short circuit bake place at its low voltage side after a small resistance. When an arc short circuit take place at the main cables of the home-load supply transformer low voltage side the short circuit could not be excised timely and the accident could be enlarged .To avoid the accident some improvements are necessary. Some improved schemata are presented in this chapter based on the calculation and analysis to the accident occured at a 220 kV substation in Zhejiang province.