Optimal operation strategy for a supplementary electric heating system in a heat-exchange station considering virtual thermal energy storage

To enhance the flexibility and economic performance of integrated thermoelectric energy systems, this study develops an optimal operation strategy for supplementary electric heating in heat-exchange stations by explicitly exploiting the virtual thermal energy storage (VTS) potential of district heating networks (DHNs) and buildings. The VTS of the pipe network is modeled based on adjustable supply water temperature, while that of buildings is modeled based on allowable indoor temperature variation, enabling unified scheduling within the heat–electric coupling framework. A coordinated operation model is established for the combined heat and power (CHP) system with supplementary electric heating under time-of-use electricity pricing, aiming to minimize the total operating cost while satisfying thermal comfort and operational constraints. The model is expressed as a mixed-integer linear programming (MILP) problem and solved with the CPLEX optimizer. Case studies demonstrate that the proposed strategy achieves significant cost and carbon-emission reductions: compared with the scenario without VTS, the energy purchase cost decreases by ∼14%, and carbon-emission-related costs are also reduced. Further analysis reveals that the DHN provides a more substantial storage effect (reducing electricity purchases by 1.1%) than buildings (0.1%), highlighting the need to prioritize network heat storage in practical applications. These results confirm the effectiveness, economic advantages, and low-carbon potential of the proposed approach, providing a viable pathway for clean heating systems to reduce dependence on fossil fuels.