Hydraulic Transients and Thermal Dynamics Embedded Contingency Analysis of Integrated Electricity and Heating Systems

Intensified coupling between electricity and heating systems increases the risk of cascading failure, necessitating the contingency analysis in integrated electricity and heating systems (IEHS). However, current studies assume steady hydraulics and focus on the malfunctions caused by thermal fluctuations without justifying the simplification of hydraulics. Thus, this paper proposes a combined hydraulic transients and thermal dynamics modelling and simulation framework for IEHS contingencies, laying the basis for a more realistic electric-heating fault propagation analysis. First, we first present the detailed contingency models in IEHS across different timescales, including static power flow, dynamic thermal flow, and transient hydraulic flow. Then, a novel contingency simulation algorithm is tailored for heterogeneous partial differential equations (PDEs) of hydraulic and thermal systems in contingency analysis. Finally, we developed a comprehensive framework to evaluate the impact of cross-system contingencies and identified the crucial role of the hydraulic transient system (HTS) in security analysis. Case studies verify the accuracy and efficiency of the proposed simulation and modelling framework and reveal that the hydraulics could escalate the severity of faults more than assumed in the literature.