Objective Shipboard power systems (SPS) are vulnerable to attacks, often resulting in a degraded or partially damaged state. In this state, the system exhibits low inertia, and the connection of critical loads, mainly high-power impulse loads, may cause severe frequency instability or even system collapse. This poses a significant challenge to the stable operation of the shipboard and the accomplishment of its intended tasks. Therefore, the SPS must be reconfigured.

Method To address the challenge of ensuring frequency security, a novel configuration approach is proposed. First, a flexible load switching strategy is developed based on the power adjustability of flexible loads. During the connection or disconnection of the impulse loads, flexible loads are dynamically disconnected or re-engaged in a timely manner. This helps maintain system frequency within a safe range by balancing power demand and supply, thereby enhancing the SPS's frequency stability. Second, the frequency security boundary of the SPS is derived based on the flexible load switching strategy. This boundary is then transformed into a set of constraint conditions. By integrating these conditions with other system-related constraints, a reconfiguration strategy for the shipboard power system that can adapt to the connection of impulse loads is formulated.

Results  The simulation results across various scenarios involving the connection of power impulse loads show that the proposed strategy effectively maintains frequency security in all cases. By comparing with other reconfiguration strategies, it is found that the strategy presented in this paper maximizes the power capacity of critical impulse loads, demonstrating its superior performance in ensuring the stable operation of high-power impulse loads.

Conclusion In conclusion, the proposed strategy not only maximizes the recovery of vital load power but also effectively leverages flexible loads and the battery energy storage system (BESS) to maintain the safe operation of impulse loads. It successfully ensures the connection of critical impulse loads, which are essential for the ship's operational safety. However, it should be noted that this strategy imposes specific requirements on the communication infrastructure of the energy management system. Future research should focus on engineering validation to further verify the strategy's advantages and effectiveness, especially as SPS evolves toward DC-integrated shipboard power systems.