Optimal scheduling strategy of the hydrogen-electric coupled system considering source-load uncertainty

Abstract

Hybrid energy storage systems are increasingly envisaged to be used in the construction of microgrids to alleviate the intermittency of renewable energy output and achieve large-scale penetration into the power grid. The hydrogen-electric coupled system (HECS) combines long-term hydrogen storage with short-term battery storage and realizes the conversion of multiple energy flows through power to gas and gas to power. However, the optimal scheduling of such a hybrid energy storage system is more complex than a single one. Faced with this issue, this paper proposed a HECS scheduling method based on the storage degradation cost to solve the power distribution problem. Furthermore, to reduce the impact of source-load uncertainty, the improved k-medoids method is used to extract representatively typical and extreme scenarios from the annual data to evaluate the economy and reliability of the system operation. According to the simulation result, we can conclude that the proposed method achieves cost-optimal scheduling by maximizing hydrogen production in the on-grid mode and reducing the battery cycle cost in the off-grid mode. Compared with the state machine control strategy, the proposed method has lowered the operation cost in all simulation scenarios and shows its effectiveness. Finally, the results show that the operation cost can be reduced by applying a demand response program, especially in the off-grid mode.