Speed and energy optimization method for the inland all-electric ship in battery-swapping mode

Zero-emission battery-powered ship is considered the ideal technical solution to achieve emission reduction and energy conservation in inland shipping. However, due to long charging time, limited onboard space, and initial investment cost, the all-electric ship in battery charging mode may not be suitable for inland long-distance navigation. Therefore, the all-electric ship in battery-swapping mode is proposed, and a joint optimization method is designed to acquire optimal voyage scheduling and energy management. First, considering the environmental factors of water speed and water depth and cargo amount, the energy consumption model for the all-electric ship in battery-swapping mode is established by analyzing its energy transfer process. Second, a speed and energy optimization model is established to minimize the battery-swapping cost, considering the constraints of sailing speed, sailing time, and battery energy use. Third, differential evolution with neighborhood search (NSDE) is adopted to solve this nonlinear and complex problem. Finally, a case study for the ship in the Yangtze River is studied to verify the effectiveness of the proposed method. The results show that the operation cost could be minimized by this method effectively.