Research on the Evolution Risk of Urban Power Supply Imbalance Under Extreme High-Temperature Events

Global climate change has led to frequent and intensified extreme high-temperature disasters, severely challenging the operational resilience and sustainable operation of urban power energy systems. Extreme heat triggers a dual risk of surging cooling electricity demand and weakened power generation capacity, easily inducing regional power supply–demand imbalance and staged power rationing. Nevertheless, most existing studies fail to systematically characterize the coupled dynamic mechanisms of climate shock transmission on both power supply and demand sides and lack quantitative comparative evaluation of diverse regulatory strategies for risk mitigation. This paper constructs a system dynamics (SD) model to simulate the interactive response mechanism of urban power systems under extreme high-temperature shocks, fully incorporating temperature-driven demand load growth and generation capacity degradation of hydropower and thermal power units. Eight regulatory scenarios with differentiated response delays and regulation intensities are designed, and their mitigation effects are comprehensively evaluated from economic, social and energy system dimensions based on economic loss, public well-being and power imbalance degree indicators. The model is validated against the 2022 Sichuan-Chongqing extreme high-temperature power crisis event, achieving excellent simulation accuracy with a mean absolute percentage error (MAPE) of 3.3% across the 92-day daily series, a peak-load error of +0.6%, and a Pearson correlation coefficient of 0.965 between simulated and observed daily load sequences. Scenario simulation results demonstrate that the coordinated supply–demand regulation strategy with short response delay and high regulation intensity can effectively suppress excessive cooling load growth, reduce economic losses and significantly alleviate power supply–demand imbalance, which is far superior to single-sided and low-intensity regulatory schemes. Holding regulation intensity at the maximum while prolonging the response delay (Scenarios 7 versus 8) shows that response timeliness is as decisive as regulation capacity itself. This study clarifies the coupling evolution law of urban power system risks under extreme heat, providing reliable theoretical support and practical decision-making references for climate disaster risk early warning, emergency dispatching and resilient optimization of regional power systems.