配电变压器绕组短路电动力的暂态特征分析

Analysis of Transient Characteristics of Short Circuit Electromotive Force ofDistribution Transformer Winding

配电变压器低压侧三相出口短路故障危害大,不仅危及设备运行安全和供电可靠性,甚至还引发火灾事故。而在实际研究中,变压器出口短路试验既对被试设备造成绝缘损伤、遗留潜伏性隐患,又需付出高昂的试验费用。为探究出口短路故障对配电变压器绕组短路电动力的影响,采用Maxwell有限元仿真软件搭建“磁-路”耦合模型,仿真研究配电变压器突发低压侧三相出口短路时绕组电流、磁场及所受电动力的暂态特征,探寻其受力薄弱点,为配电变压器抗短路能力的提升措施实施提供参考。

The short-circuit failure of the three-phase outlet on the low-voltage side of the distribution transformer is harmful,endangering the safety of equipment operation and power supply reliability,and even cause fire accidents.The transformer outlet short-circuit test not only causes insulation damage to the tested equipment and leaves latent hidden dangers,but also needs to pay high test costs.In order to explore the impact of short-circuit faults on the electric power of the short-circuit of the distribution transformer windings,Maxwell finite element simulation software is used to build a"magnetic-circuit"coupling model to simulate the winding current and the transient characteristics of winding current,magnetic field and electric power when the three-phase outlet short circuit of distribution transformer occurs at the sudden low-voltage side is studied.Its weak point of stress is explored,and reference for the implementation of measures are provided to improve the short-circuit resistance of distribution transformer.