220kV变压器中性点绝缘保护方式的研究

Consideration of Protection Mode of the Neutral Insulation of 220 kV Transformers

对广西电力系统220kV变压器中性点绝缘采用阀式避雷器保护方式所存在的绝缘不配合问题进行了研究。通过对电力系统过电压计算分析、间隙保护的放电特性试验以及有关参数的对比分析,提出了变压器中性点绝缘的保护,应采用水平间隙(距离为330mm)与 FCZ_3—110J 型避雷器并联及附加中性点电流时间继电器组成的配合保护方式,能可靠地保护其中性点绝缘,解决了变压器中性点绝缘与阀式避雷器保护不配合的问题。

The problem of uncoordination which exists in neutral insulation of 220 kV transformers of Guangxi Electric Power System in protection mode of valve-type lightning arresters is considered.It is suggested that the coordination protection mode composed of level gap(distance of 330mm)in parallel with Model FCZ-110J arresters and the additional neutral point current time relay for the protection of neutral insula- tion of transformers should be adopted by means of the calculation anti analysis of over- voltage of the electric power system,the tests of discharge characteristics of gap protec- tion and the comparative analysis of related parameters.The reliable protection of its neutral insulation obtains and the problem of uncoordination of neutral insulation of transformers with valve-type lightning arresters is solved thereby.