Hierarchical Real-Time Wavelet-ECMS for Hybrid Energy Management: A Case Study of Wing-Sail-Assisted Electric Propulsion Ship

Wing-sail-assisted electric propulsion systems are susceptible to intermittent wind factors, which can affect the ship stability. This study proposes a wind condition adaptive constant speed mode. By comparing it with the conventional constant power mode, the control effectiveness and energy-saving potential are evaluated. To mitigate the impact of wind energy on the power grid, a real-time wavelet-equivalent consumption minimization strategy (ECMS) energy management strategy (EMS) is designed based on a hierarchical architecture. This approach aims to improve the energy quality, economic efficiency, and real-time performance under the constant speed mode. Taking a small-scale experimental platform as a prototype and matching it with the target ship through scaling theory, a model of the micro wing-sail-assisted electric propulsion system is established using MATLAB/Simulink. The hardware-in-the-loop verification of the strategy is implemented based on the dSPACE. The results show that the proposed constant speed mode can respond quickly to changes in ship speed and can save 9.66% of fuel consumption compared to the conventional constant power mode, demonstrating better overall performance. Compared with extended Kalman filter (EKF)-model predictive control (MPC) strategy, the real-time wavelet-ECMS strategy under the constant speed mode can suppress 2.45% of voltage fluctuations and reduce fuel consumption by 2.27%. This strategy can provide reference for the greenization of ships with abundant wind resources.