基于EMTP/ATP的220 kV变压器非全相运行故障分析

Open-phase Operation Fault Analysis of 220 kV Transformer Based on EMTP/ATP

以四川电网某220 k V变电站主变压器非全相运行故障为契机,基于变压器非全相运行时各侧电压相量的理论分析,利用电磁暂态软件EMTP/ATP进行仿真计算分析,合理推断了主变压器非全相运行故障的原因,对理清变压器非全相运行故障机理和防止该类故障具有重要意义。计算结果表明:主变压器低压侧避雷器烧坏是由高压侧中性点接地刀闸拉开时在低压侧产生的周期性励磁涌流过电压引起的,但该操作不会导致高压侧出现过电压,高压侧避雷器动作是由于充电试验中断路器非全相合闸造成的。

Taking the open - phase operation fault of main transformer in a 220 kV substation of Sichuan power grid as an op- portunity, based on the analysis of voltage vector in each side when the transformer is in open - phase operation, the simula- tion and calculation are carried out with EMTP/ATP, the reasons for open - phase operation fault of main transformer are de- duced, which is of great significance for clearing the mechanism of open - phase operation fault of transformer and avoiding from this kind of fault. The calculation results show that because of the periodic excitation inrush current overvoltage in low - voltage side which is generated by the opening of neutral point disconnector in high - voltage side, the arrester in low - voltage side of main transformer burns out, but this operation will not generate overvoltage in high - voltage side, the action of the ar- rester in high - voltage side are caused by the open - phase closing of circuit breaker in the charging tests.