35kV主变保护电压切换开关逻辑问题分析

Analysis of logical problems on voltage transfer switch of 35kV transformer protection

针对主变低电压闭锁过流保护中电压切换开关出现的切换逻辑问题,分析了一起某35k V变电站主变保护屏电压切换回路在母线电压选择上存在逻辑问题的原因,提出了两种改进的电压开关切换逻辑原理图,对比了两种原理图在不同工况下的适应性,并在施工管理、图纸审核、新投验收及备品备件等方面提出了预防此类事故的具体措施。分析结果表明,通过修改电压切换逻辑,实现了电压切换开关的正确动作,保障了35k V主变的顺利投运,提高了电网的安全稳定性。

Aiming at the switching logic problem of voltage transfer switch in low voltage lockout overcurrent protection of transformer,the reasons of voltage selection logic problem which has happened on the bus voltage selection of transformer protection device are analyzed in a35kV transformer substation.Two logic schematic diagrams about voltage transfer switch are proposed.And the adaptability of the two schematics in different conditions are compared.To prevent such accidents in construction management,the specific measures of drawing review,new investment acceptance and spare parts are put forward.The analysis results show that the correct actions of voltage transfer switch are achieved by amending the voltage switching logic.It ensures35kV transformer smooth operation,and the stability of power grid is improved.