Model-based protection system for fault detection and location in converter-fed networks

电力供应的脱碳导致以可再生能源为基础的馈电系统大规模扩展到电网。可再生能源系统依赖于足够的能量储存和能量传输能力。从今天的角度来看，这只能用电力电子转换器来实现。因此，功率转换器越来越多地决定着未来网络的运行和故障行为。在配电网中，将出现完全由功率变流器主导的局部化网络结构。变流器控制的高灵活性潜力，特别是在故障行为方面，以及电网的高结构变化，给传统的网络保护概念带来了无法解决的问题，从而危及网络安全。这一致地将基于模型的设备保护的已知方法发展到基于模型的电网保护。在这种情况下，首次使用卡尔曼滤波作为状态估计器和参数估计器，与以前基于模型的方法相比，改进了所开发方法的功能性和灵活性，并增加了必要的鲁棒性。变流器的保护和预测控制程序的紧密联系保证了在检测难以识别的故障情况方面的协同效应。新方法将在实验室样机上实现，并在实时网络模拟器(RTDS)上进行测试，该研究项目的实施将为未来以变流器为主的网络中更多的网格安全做出重要贡献。

The decarbonization of the electrical energy supply leads to a massive expansion of infeed-systems based on renewable energies into the electrical grid. Regenerative energy systems are dependent on sufficient energy storage and energy transport capacity. From today's perspective, this can only be implemented with power electronic converters. Power converters are therefore increasingly determining the operating and fault behavior of future networks. In the distribution grids, localized network structures will emerge that are completely dominated by power converters.The high flexibility potential of the converter control, particularly in terms of fault behavior, as well as the high structural variance of the grids, pose insolvable problems for classic network protection concepts and thus endanger network security.In the proposed research project, we pursue a fundamentally new approach to model-based protection systems. This consistently develops the known approaches of model-based equipment protection to model-based grid protection. The first-time use of Kalman filters in this context as both state and parameter estimators improves the functionality and flexibility of the developed method compared to previous model-based approaches and increases the necessary robustness. A close interlinking of protection and predictive control procedures of the converters promises synergy effects with regard to the detection of fault scenarios that are difficult to identify. The new approach is to be implemented on a laboratory sample and tested on a real-time network simulator (RTDS).With the implementation of this research project, an important contribution can be made to more grid security in future converter-dominated networks.