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.

朝着现有电力系统脱碳的持续驱动与在其中增加可再生能源的安装直接相关。这些可再生资源需要电力电子逆变器才能将其连接到现有的电力网络。电源电子逆变器以控制算法为主，尽管与传统同步发电机相比，它们可以在网络的运行和控制方面具有更高的灵活性，但它们还向网络引入了威胁性电源系统稳定性的网络。对于未来的电力网络的平稳运行，能够确保网络的稳定性并以这种方式中断向公众中断，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，它集中于研究和分析其瞬态稳定性，这是在大型干扰之后系统的稳定性，例如短路故障，线路断开和相位跳跃，发生在其中。使用的电源电子逆变器将其分为两种主要类型的逆变器类型，具体取决于它们与网格的同步方法及其操作。这两种类型是网格跟随逆变器，它们通过形成电流并遵循网格的电压和网格形成的逆变器来向电网注入功率，从而形成了可以从中汲取功率的电压源。这些类型的逆变器利用不同的同步控制器来维持其与网络的同步，因此在与网格不同的干扰下与网络的相互作用不同。我的研究旨在在网络中发生干扰后对其个体行为进行见解，并就应如何在网络中配置和使用它们来降低系统的潜在不稳定性，从而得出有价值的结论。该方法包括在不同情况下和一系列网络配置中描述逆变器行为的微分方程的分析推导。这些配置将包括连接到几个示例网格的不同数量的逆变器，涵盖了旨在涵盖各种可能场景的不同强度和结构的网格，并就这些逆变器如何影响系统的稳定性产生了全面的结果。派生的分析方程将用于对系统进行相位平面分析，并获得对其行为的视觉见解，并采用用于研究非线性系统稳定性的其他技术和方法。该分析将在模拟软件中对所检查系统的时间域模拟进行验证，以验证所获得的理论结果。可以预料，该分析对于网格系统运营商选择如何计划和配置其电网将是有用的。