Impact of Grid Forming Converters on Power System Stability

包括英国在内的大多数国家都在促进可再生能源（RES）的普及，以减少碳排放和应对气候变化，国家电网的预测显示，到2024年，可再生能源发电量有可能满足60%的年度电能需求，高于目前的26%。大多数可再生能源通过电力电子设备连接，与传统发电厂相比，具有显着不同的动态行为。随着我们转向电力电子接口单元渗透率接近100%的电力系统，电力电子接口单元的当前控制结构已经开始显示出局限性的迹象。出于这个原因，电网形成转换器被提出作为一个潜在的解决方案，以确保稳定的操作。然而，在具有多个发电机的电力系统中，这种电网形成转换器的动态相互作用尚未得到充分研究。此外，并网变流器、并网变流器与传统常规发电厂之间可能出现新的动态相互作用。本项目旨在开发具有多个并网变流器的大型电力系统模型，并研究动态相互作用及其对系统稳定性的影响。这种模型的详细程度，以充分代表这种转换器的大规模系统研究的动态行为也将进行调查。除了研究工作点附近的线性化模型（电力系统小信号稳定性研究的常用方法）外，该项目还将重点研究非线性动力学，从而建立模型，以确保捕获更复杂的动态相互作用。

Most countries, including the UK, promote the increased penetration of Renewable Energy Sources (RES) to reduce carbon emissions and combat climate change with forecasts from National Grid showing the potential for renewable generation output to meet 60% of annual demand for electrical energy in 2024, up from the present level of 26%. Most RES are interfaced through power electronics and have significantly different dynamic behaviour compared to conventional power plants. Current control structures of power electronic interfaced units already started showing signs of limitations as we move towards power systems with close to 100% penetration of power electronic interfaced units. For this reason, grid forming converters are proposed as a potential solution to ensure stable operation. However, the dynamic interactions of such grid forming converters in a power system with multiple generators has not been yet adequately investigated. Moreover, new dynamic interactions between grid forming converters, grid following converters and tradition conventional power plants might appear. This project will aim at developing large scale power system models with several grid forming converters and investigate dynamic interactions and their impact on system stability. The level of detail needed for such models to adequately represent the dynamic behaviour of such converters for large scale system studies will also be investigated. Apart from investigating linearised models around an operating point, a common approach in power system small signal stability studies, the project will also focus on nonlinear dynamics and consequently models to ensure more complex dynamic interactions are captured.