Hydrogen energy storage

as a long-term energy storage technology

can effectively promote the local consumption of high-proportion distributed renewable energy within microgrids and further enhance the autonomous operation capability of microgrids. To address the imbalance between renewable energy and load across different time scales

this paper focuses on an electric-hydrogen coupling microgrid and proposes a coordinated optimal configuration method for hybrid energy storage based on multi-time scale feature extraction. According to the coupling characteristics and regulation capability of electricity and hydrogen

a three-level energy storage system is established and a two-stage hybrid energy storage configuration model is constructed. Considering the switch between grid-connected and off-grid modes and the need for long-term autonomous operation

a 168-hour off-grid safety check is included in the configuration model

and extreme scenarios of continuous low renewable energy output are considered. Seasonal-trend decomposition and variational mode decomposition algorithms are employed to extract features from the annual imbalance power sequences. The hydrogen energy storage charge-discharge actions are determined by the long-term unbalance quantity to reduce the number of binary variables in the mixed-integer nonlinear programming problem. Finally

a case study of an actual electric-hydrogen coupling microgrid in Zhejiang Province is conducted to validate the effectiveness of the proposed method.