A novel energy management strategy of hydrogen-SMES hybrid storage for high-speed railway traction power system

Hydrogen storage enables long-duration energy storage, while superconducting magnetic energy storage (SMES) can rapidly smooth power fluctuations. A hybrid energy storage system (HESS) combining both is highly suitable for enhancing the reliability and stability of the high-speed railway (HSR) traction power supply system (TPSS). A novel energy management strategy of HESS for HSR TPSS was proposed. Firstly, the representative daily power curves were extracted by a clustering method, and an improved moving average filter and amplitude limiting filter (IMAF-ALF) algorithm was employed to limit the change rate of net power. Then, the remaining fluctuating power was adaptively decomposed by adaptive variational mode decomposition (VMD), which assigned the high-frequency components to SMES and the low-frequency components to hydrogen storage. In addition, a mixed integer linear programming model was developed to optimize capacity allocation, minimizing annual system cost while satisfying power and energy constraints. Results showed that the proposed energy management strategy can effectively mitigate the intermittency and volatility introduced by grid-connected renewable energy generation, suppress traction load surges, reduce system losses and investment costs.