影响变压器和应涌流的各种因素

空投一台变压器时会导致相邻变压器出现和应涌流,和应涌流的存在往往导致继电保护误动作以及出现谐波过电压现象.针对简化等效电路,从两台并联变压器的磁链解析表达式和偏磁衰减规律出发,阐述了和应涌流的产生机理.然后深入分析了初始合闸角、系统阻抗、运行变压器带负载、并联电容、空投变压器的剩磁、串联连接、接地方式对和应涌流的影响,利用计算机仿真和动态模拟试验验证了分析的结论,为正确认识和应涌流和解决其带来的影响提供了有益的结论与参考.

The Influencing Factors on Sympathetic Inrush Phenomena in Transformers

There would be sympathetic inrush current appearing in a transformer when its adjacent transformer is switched without load. This would generally leads to mal-tripping of the protective relay equipment in addition to harmonic over-voltage problem. Based on simplified equivalent circuit of two shunt-wound transformers, this paper analyzes the transformer magnetic analytical expression and rule of bias magnetic attenuation. Then summarizes the reasons of sympathetic inrush current generation. The influence of initial close angle, system impedance, load of transformer, shunt-wound capacitors, residual flux, connection in series and grounding mode on sympathetic inrush current are illustrated deeply. The analytical results are tested and verified by computer simulation as well as dynamic simulation test. It provides useful conclusion and reference for estimating sympathetic inrush current.