Thermal Dynamic Embedded Contingency Analysis for Heat-Electrical Integrated Energy System

To address security challenges in Heat-Electrical Integrated Energy Systems (HE-IES), this paper introduces a simulation-based contingency analysis method aimed at identifying potentially threatening faults. We begin by modeling common faults in HE-IES and outlining a comprehensive procedure for simulation-based contingency analysis. Next, we analyze the factors determining temperature drop in the heat medium transfer process and propose a novel analytical-numerical method for thermal dynamic simulation. Real-world experimental results demonstrate that, compared to existing methods, the proposed approach stands out in eliminating numerical dispersion and reducing simulation time by 81.7% while maintaining accuracy, making it particularly effective for HE-IES contingency analysis where solution efficiency is crucial. Subsequently, the proposed contingency analysis method is applied to a 49-node testbed to explore fault propagation mechanism across subsystems. The result reveals that faults originating from the power system and combined heat and power units can cause cascading effects, leading to severe impacts on power supply and heating temperatures. In contrast, faults from the heating system tend to propagate in a less complicated manner but pose a greater risk to the hydraulic system. To mitigate fault propagation, we recommend enhanced monitoring of the operational status of coupling equipment, which plays a critical role in ensuring HE-IES security.