雷击配电变压器的电磁融合仿真分析

Electromagnetic Fusion Simulation Analysis of Lightning Strike Distribution Transformer

用户用电的大部分问题都与配电网相关。配电变压器是配电网的末端设备,数量众多且绝缘水平低,容易受到雷击的侵害,进而引发配电网故障。针对这一现状,建立配电变压器的雷击模型并对其遭受雷击时的特性进行研究具有重要意义。为确保仿真结果的真实、可靠,创新性地利用直流电磁瞬套电力系统计算机辅助设计(PSCAD/EMTDC)、ANSYS MAXWELL平台,分别建立了雷击发生模拟器和配电变压器有限元模型。通过多平台融合仿真,对配电变压器遭受直击雷、感应雷两种雷击形式时的电磁过程进行研究分析。仿真结果表明,遭受雷击时,配电变压器各部件磁感应强度均会显著提升,雷电从高压侧进入时对磁感应强度的影响远大于低压侧,直击雷对磁感应强度的影响大于感应雷。因此,提升配电变压器的防雷性能,尤其是配电变压器高压侧防雷和直击雷防雷,应是后续研究的重要方向。

Most problems of users'electricity consumption are related to distribution network.Distribution transformers are the terminal equipment of distribution network.They have a large number and low insulation level,and are vulnerable to lightning strike,which leads to distribution network failure.In view of this situation,it is of great significance to establish the lightning strike model of distribution transformer and study its characteristics when it is struck by lightning.In order to ensure the authenticity and reliability of the simulation results,the power systems computer aided design/electromagnetic transients including DC(PSCAD/EMTDC)and ANSYS MAXWELL platforms are used to establish the lightning simulator and distribution transformer finite element model respectively.The electromagnetic process of distribution transformer under direct lightning and inductive lightning is studied and analyzed through multi-platform fusion simulation.The simulation results show that the magnetic induction intensity of distribution transformer components will be significantly increased under lightning strike,the impact of lightning from the high voltage side on the magnetic induction intensity is much greater than the low voltage side,direct lightning on the magnetic induction intensity is greater than the impact of induction lightning.Therefore,improving the lightning protection performance of distribution transformers,especially the high voltage side lightning protection and direct lightning protection,should be the important direction of subsequent research.