Adaptive Energy Storage System Management Considering State Coupling Characteristics for Dynamic Positioning

The electrification of ships is an irreversible development trend. Large-scale energy storage system (ESS) integration can effectively improve operational flexibility for addressing uncertain navigation conditions, especially in dynamic positioning (DP) scenarios with highly uncertain environmental disturbances. However, frequent swaying conditions and uncertain power requirements protrude the state coupling characteristics of ESSs, making it difficult to quantify their dynamic feasible operation ranges, and even affecting their power supply capabilities. To address this issue, an adaptive ESS management approach that considers state coupling characteristics is proposed in this article. First, a flexible propulsion power model considering the navigation inertia of a ship is proposed to reduce pulse loads. Then, based on a six-month battery cycling experiment, a three-stage state coupling model is proposed to capture the battery dynamics observed under swaying conditions, and an adaptive power control scheme is proposed to account for navigation uncertainties. The proposed method is proven via a laboratory-scale experimental system. Compared with four conventional methods, the pulse loads, voltage sags, and power mismatches of the proposed method exhibit reductions of up to 28.32%, 53.9%, and 80.24%, respectively, and the battery can always operate within a healthy power range.