Full wave electromagnetic modelling of lightning discharge through complex power systems

电力系统界非常需要通过复杂的3D电力装置（如支持输电线路的塔、变压器变电站等）对雷击放电进行精确的电磁分析。目前现有的工具在这种分析过程中进行各种近似，导致在许多实际场景中建模不准确。这样的错误最终会对系统的故障率做出不可靠的预测，由于更高的系统故障率和由此导致的停电，造成数百万美元的经济损失。在这个研究项目中，曼尼托巴大学的Okhmatovski博士和Kordi博士的研究小组将开发新一代全波电磁建模能力，这将大大提高闪电放电模型的准确性。具体地说，矩量法（MoM）公式将不受目前可用模型中所具有的近似的影响。MoM公式将基于混合电位积分方程（MPIE）的全波三维Rao-Wilton-Glisson离散化，该方程严格考虑了宽带闪电放电时塔导体中土壤效应和电流的一般三维流动。通过创建准确的格林函数模型并将其纳入相关的MPIE，将严格地解释土壤的分层介质。新的MoM框架还将纳入塔导体中与频率相关的欧姆损耗。为了对包括多塔输电线路在内的输电系统在雷击时进行暂态分析，利用所建立的精确MoM模型提取的宽带网络参数将采用vectfit算法以极点残差形式拟合。创建的宏模型将集成到PSCAD/EMTDC系统中。包括加拿大在内的全球70个国家的10,000多名工程师将受益于PSCAD/EMTDC软件的新功能。作为拟议研究项目的结果，新模块集成到PSCAD/EMTDC中，预计将为马尼托巴HVDC中心提供新的工作岗位，并为其带来可观的年收入增长。

There is a significant need in the power systems community for accurate electromagnetic analysis of lightning discharge through complex 3D power installations such as towers supporting transmission lines, transformers substations, and others. Currently existing tools make various approximations in the process of such analysis causing modelling inaccuracies in many practical scenarios. Such errors ultimately make unreliable predictions about the failure rates of the systems costing millions of dollars in economic losses due to higher systems failure rates and resulting power outages. In this research project research groups of Dr. Okhmatovski and Dr. Kordi at the University of Manitoba will develop new generation of full-wave electromagnetic modelling capabilities which will significantly improve the accuracy of lightning discharge models. Specifically, Method of Moments (MoM) formulation free of the approximations featured in the currently available models will be developed. The MoM formulation will be based on full-wave 3D Rao-Wilton-Glisson discretization of the Mixed-Potential Integral Equation (MPIE) which rigorously accounts for the soil effects and general 3D flow of the current in the tower conductors as the broadband lightning discharge occurs. The stratified medium of the soil will be rigorously accounted for through creation of accurate Green's function models and their inclusion into the pertinent MPIE. The new MoM framework will also incorporate frequency dependent Ohmic losses in the tower conductors. To perform transient analysis of the power transmission system including multiple towers and transmission lines during lightning strike the broadband network parameters extracted using the developed accurate MoM model will be fitted with pole-residual form using VECTFITing algorithm. Created macro model will be integrated into PSCAD/EMTDC system. Over 10,000 engineers in 70 countries around the world including Canada will benefit from the new capabilities in PSCAD/EMTDC software. The new module integrated into PSCAD/EMTDC as a result of the proposed research project is expected to open new jobs at Manitoba HVDC Centre and bring it substantial increase in annual revenue.