Abstract: [Objectives] The fluctuation in output from renewable energy sources and frequent load shedding may cause frequent changes in the power flow direction within the energy storage system, which can affect the stability of bus voltage and the system's dynamic response performance. To address the issue of DC link bus voltage being vulnerable to load power fluctuations in low-inertia integrated energy systems, a virtual inertia control strategy for the DC bus voltage based on an electric-hydrogen hybrid energy storage system is proposed. [Methods] Virtual inertia control is introduced into the voltage outer loop, and model predictive control is introduced into the current inner loop. The virtual inertia parameters are combined with the voltage rate of change to establish an adjustment relationship between voltage and virtual capacitance. Based on this, a power coordination control method suitable for electric-hydrogen hybrid energy storage systems is designed, and the economic feasibility of different energy storage devices is compared. Simulation models are established using MATLAB/Simulink to verify the superiority of the proposed control method in suppressing voltage fluctuations and improving system dynamic characteristics. [Results] The proposed control strategy can reduce the voltage fluctuation range to 2.2%, ensuring the efficient coordinated operation of the electric-hydrogen hybrid energy storage system and improving the safety of the hydrogen storage tank. Compared with the single lithium battery energy storage scheme and the hybrid energy storage scheme of lithium battery and super capacitor, the cost of the electric-hydrogen hybrid energy storage scheme is reduced by 10.54% and 3.57% respectively. [Conclusions] The proposed control method effectively solves the bus voltage fluctuation problem caused by load power fluctuations, enhances the system's dynamic response capability, and contributes to the stable operation of the campus integrated energy system.

Key words: renewable energy, new energy, energy storage, power system, park-level integrated energy system, model predictive control, virtual inertia control, bidirectional DC-DC converter