Non-linear stability of inverter-dominated power grids

逆变器主导电网的非线性稳定性

• 批准号: 2767353
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2767353
• 关键词: Non; linear; stability; inverter; dominated

The continuous drive towards the decarbonisation of existing power systems is directly connected with the increasing installation of renewable energy resources in them. These renewable resources require power electronic inverters in order to interface them to the existing power networks. The power electronic inverters are dominated by control algorithms and despite the fact that they can offer increased flexibility in operation and control of the network compared to the traditional synchronous generators, they also introduce new and unprecedented dynamics to the network that are threatening the stability of the power systems. It is of vital importance for the smooth operation of future power networks to be able to guarantee the stability of the networks and avoid in this way interruption of services to the public. My PhD research focuses on investigating the stability of the power networks under high penetration of power electronics. More specifically it concentrates on studying and analysing their transient stability, which is the stability of the system after large disturbances, such as short circuit faults, line disconnections and phase jumps, take place in it. The power electronic inverters that are used are distinguished into two main types of inverter depending on their method of synchronisation with the grid and their operation. These two types are the Grid-Following inverters, which inject power to the grid by forming the current and following the grid's voltage and the Grid-Forming inverters which form a voltage source from which power can be drawn. These types of inverters utilize different synchronisation controllers to sustain their synchronisation with the network and therefore their interaction with the network under different disturbances from the grid differs. My research aims to provide insights into their individual behaviours after disturbances take place in the network and deduce valuable conclusions on how they should be configured and used in the network to reduce as much as possible potential instabilities to the system. The approach includes analytical derivations of differential equations describing the behaviour of the inverters under different circumstances and in a range of network configurations. These configurations will include different number of inverters connected to several example grids, covering grids of different strengths and structures aiming to cover a large range of possible scenarios and derive comprehensive results on how these inverters affect the system's stability. The derived analytical equations will be used to perform Phase Plane analysis of the systems and gain visual insights on their behaviours as well as employ other techniques and methods that are used for investigating the stability of non-linear systems. This analysis will be followed by time-domain simulations of the examined systems in simulation software for validation of theoretical results obtained. It is anticipated that the analysis will be useful to grid system operators in choosing how to plan and configure their power grids.

现有电力系统脱碳的持续推动与可再生能源安装量的增加直接相关。这些可再生资源需要电力电子逆变器，以便将它们连接到现有的电网。电力电子逆变器以控制算法为主，尽管与传统同步发电机相比，它们可以提高网络运行和控制的灵活性，但它们也给网络带来了前所未有的新动态，威胁着电网的稳定性。电力系统。能够保证网络的稳定性并避免对公众的服务中断，对于未来电力网络的平稳运行至关重要。我的博士研究重点是研究电力电子高渗透率下电力网络的稳定性。更具体地说，它集中研究和分析其暂态稳定性，即系统发生短路故障、线路断线、相位跳变等大扰动后的稳定性。所使用的电力电子逆变器根据其与电网同步的方法及其操作分为两种主要类型的逆变器。这两种类型是并网逆变器和并网逆变器，前者通过形成电流并跟随电网电压向电网注入电力，后者形成可从中获取电力的电压源。这些类型的逆变器利用不同的同步控制器来维持与网络的同步，因此在来自电网的不同扰动下它们与网络的交互是不同的。我的研究旨在深入了解网络中发生干扰后它们的个体行为，并就如何在网络中配置和使用它们以尽可能减少系统的潜在不稳定性得出有价值的结论。该方法包括微分方程的分析推导，描述了逆变器在不同情况下和一系列网络配置中的行为。这些配置将包括连接到多个示例电网的不同数量的逆变器，覆盖不同强度和结构的电网，旨在覆盖大量可能的场景，并得出这些逆变器如何影响系统稳定性的综合结果。导出的解析方程将用于对系统进行相平面分析，获得对其行为的直观了解，并采用其他用于研究非线性系统稳定性的技术和方法。该分析之后将在仿真软件中对所检查的系统进行时域仿真，以验证所获得的理论结果。预计该分析将有助于电网系统运营商选择如何规划和配置其电网。