In an integrated electricity-gas system (IEGS), load fluctuations affect not only the voltage in the power system but also the gas pressure in the natural gas system. The static voltage stability region (SVSR) method is a tool for analyzing the overall static voltage stability in a power system. However, in an IEGS, the SVSR boundary may be overly optimistic because the gas pressure may collapse before the voltage collapses. Thus, the SVSR method cannot be directly applied to an IEGS. In this paper, the concept of the SVSR is extended to the IEGS-static stability region (SSR) while considering voltage and gas pressure. First, criteria for static gas pressure stability in a natural gas system are proposed, based on the static voltage stability criteria in a power system. Then, the IEGS-SSR is defined as a set of active power injections that satisfies multi-energy flow (MEF) equations and static voltage and gas pressure stability constraints in the active power injection space of natural gas-fired generator units (NGUs). To determine the IEGS-SSR, a continuation MEF (CMEF) method is employed to trace the boundary point in one specific NGU scheduling direction. A multidimensional hyperplane sampling method is also proposed to sample the NGU scheduling directions evenly. The obtained boundary points are further used to form the IEGS-SSR in 3D space via a Delaunay triangulation hypersurface fitting method. Finally, the numerical results of typical case studies are presented to demonstrate that the proposed method can effectively form the IEGS-SSR, providing a tool for IEGS online monitoring and dispatching.

中文翻译：

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考虑电压和气压的电-气一体化系统静态稳定区域

在电-气一体化系统（IEGS）中，负荷波动不仅影响电力系统的电压，还影响天然气系统的气压。静态电压稳定区域（SVSR）方法是分析电力系统整体静态电压稳定性的工具。然而，在 IEGS 中，SVSR 边界可能过于乐观，因为气压可能会在电压崩溃之前崩溃。因此，SVSR方法不能直接应用于IEGS。本文将 SVSR 的概念扩展到 IEGS 静态稳定区域（SSR），同时考虑电压和气压。首先，基于电力系统中的静态电压稳定性准则，提出了天然气系统中的静态气压稳定性准则。然后，IEGS-SSR被定义为一组有功功率注入，满足天然气发电机组（NGU）有功功率注入空间中的多能流（MEF）方程以及静态电压和气压稳定性约束。为了确定IEGS-SSR，采用连续MEF（CMEF）方法来跟踪一个特定NGU调度方向上的边界点。还提出了一种多维超平面采样方法来均匀地采样NGU调度方向。获得的边界点进一步用于通过 Delaunay 三角剖分超曲面拟合方法在 3D 空间中形成 IEGS-SSR。最后，通过典型案例的数值计算结果表明，该方法可以有效地形成IEGS-SSR，为IEGS在线监测和调度提供工具。