考虑磁滞回线的变压器仿真及保护算法

针对变压器事故有所增加及保护正确动作率普遍偏低的现状,在研究电力变压器励磁涌流和故障电流特性的基础上,利用仿真软件Saber,建立了变压器的精确仿真模型;并对变压器的空载合闸和包括匝间短路的多种故障情况进行了全面系统的仿真计算.最后,基于小波分析理论,利用其对突变信号的强大检测能力,提出了实现变压器保护的新方法,该方法能有效地区分变压器的内外部故障,对匝间短路也同样能精确检测.数字仿真结果验证了所提算法的有效性.

Simulation and Protective Algorithm of Power Transformers Considering Hysteresis Effect

Based on the study on the properties of Magnetic Inrush Current and Fault Current of power transformers, Saber is applied to realize the simulation of such conditions as no-load closing and all the fault conditions including turn-to-turn fault and turn-to-earth fault. Grounded on the wavelet analysis theory, a new method is proposed which can differentiate effectively the internal and external faults and detect the turn-to-turn fault. The simulation result shows its effectiveness.