变压器抗短路能力核算与治理

为有效评估和治理华北电网内大型电力变压器的抗短路能力,提高电网安全稳定运行水平,提出了一整套变压器抗短路能力核算与治理的方法。提出由系统侧出发的短路电流计算方法,阐述了其原理及计算过程,通过网内实际发生的故障录波数据对方法进行了验证,并对母线短路电流与变压器短路电流的关系进行了分析。根据电网的实际短路容量对网内变压器分类进行了最大短路电流水平计算,统计出存在抗短路能力不足风险的变压器。总结并比较了国内外主要的变压器抗短路能力治理方法,根据各电压等级变压器的情况提出了不同类型变压器抗短路能力治理的总体原则及实施方案,对电网的安全生产及稳定运行具有重要意义。

Transformer anti-short circuit capability calculation and reinforcement

In order to evaluate and reinforce transformer anti-short circuit capability in North China Grid Company Limited(NCGC),a complete set of transformer anti-short circuit capability calculation and reinforcement method is proposed.Based on the system equivalent impedance,the principle and process of a short circuit current calculation method is discussed and verified with recorded field fault data.The mutual influence of short circuit current in buses and transformer windings is analyzed.The maximum transformer short circuit current level is calculated.The results reveal high risk transformers with low anti-short circuit capability.The main methods to improve transformer anti-short circuit capability are compared and summarized.The principles and implementations are proposed according to different transformer conditions with various operation voltage levels.