Time-domain modeling of electromagnetic interactions in power-system transmission line networks

可靠和高质量的电力分配对社会和加拿大经济至关重要。在配电系统中，输电线路是配电系统的关键部件，其良好的性能对实现配电网的预期运行至关重要。电力仿真软件工具，如PSCAD/EMTDC，由马尼托巴水电HVDC研究中心开发，并在世界各地使用，在电力系统的设计和维护中发挥着至关重要的作用。这些仿真工具需要准确、高效的输电线路模型。在本研究计划中，我们解决了如何准确建模频率相关和/或非均匀多导体传输线的问题，如何将它们纳入时域仿真代码中，以及如何模拟传输线的外部场耦合和电磁辐射的影响。为了实现这一目标，将开发一种基于时域有限差分方法的新模型，并将其集成到电力系统模拟器中。该模型将能够模拟具有频率相关参数的多导体传输线。它还将具有能够包括外部场耦合的固有特征，例如来自闪电的耦合。为了补充这一能力，将开发一种精确确定闪电回击瞬态场的算法。该模型和现有模型的无源性问题也将得到解决，以及单位长度参数提取方法，这对埋地电缆的研究很重要。这些方面的结合将提供一类新的电力系统传输线模型，可以集成到PSCAD/EMTDC框架或其他时域电路模拟器中。

Reliable and high quality electric power distribution is of paramount importance to society and the Canadian economy. In a power distribution system, transmission lines are key components and their proper performance is essential to achieve the desired expectations of the power distribution network. Power-simulation software tools, such as PSCAD/EMTDC which is developed by the Manitoba Hydro HVDC Research Centre, and used throughout the world, play a crucial role in design and maintenance of a power system. These simulation tools require accurate and efficient models for transmission lines. In this research proposal, we tackle the problem of how to accurately model frequency-dependent and/or non-uniform multiconductor transmission lines, how to incorporate them within a time-domain simulation code, and how to model the effects of external-field coupling to and electromagnetic radiation from transmission lines. To accomplish this, a novel model based on a finite-difference time-domain approach will be developed and integrated within the power-system simulator. This model will be capable of simulating multiconductor transmission lines with frequency-dependent parameters. It will also have the intrinsic feature of being able to include external-field coupling, such as that from lightning. To complement this capability, an algorithm for accurate determination of the transient fields from a lightning return stroke will be developed. The issue of passivity for this model and existing models will also be addressed, as well as methods for per-unit-length parameter extraction, which is important for buried-cable studies. The combination of these aspects will provide a new class of power-system transmission line models that can be integrated into the PSCAD/EMTDC framework or other time-domain circuit simulator.