Optimal Dispatch of Multi-Coupling Systems Considering Molten Salt Thermal Energy Storage Retrofit and Cost Allocation Under Rapid Load Variations

With the rapid growth of renewable energy generation capacity, integrating thermal power units and renewable energy units at the point of common coupling (PCC) as a coupling system (CS) can significantly enhance the operational reliability and economic efficiency of modern power systems. To better reflect the coordinated operational capability of thermal power units with molten salt thermal storage retrofit (TPUMSTSR) in multi-coupling system (MCS) scheduling, this study proposes a multi-stage optimization-based dispatch method for MCSs. First, rapid load variation (RLV) technology and thermal storage retrofitting are combined to establish a thermal power unit operation model incorporating molten salt thermal storage (MSTS) retrofits under RLVs. Based on this, a three-stage economic dispatch optimization method is proposed to maximize the daily comprehensive generation revenue of MCSs while dynamically allocating peak regulation (PR) revenue costs across different time periods to relax and simplify nonlinear objectives and constraints in the optimization process. Finally, a simulation study is conducted on an MCS in northeast China. The results demonstrate that the proposed flexibility retrofit scheme and optimization algorithm enable a more coordinated and economically efficient dispatch strategy.