An energy management strategy for fuel cell ships considering endurance and operating cost

To optimise the service life and operating cost of the hydrogen fuel cell ship energy system and improve the ship’s endurance, a two-layer energy management strategy (EMS) is proposed in this paper. The first layer of the EMS is based on nonlinear model predictive control (NMPC), which combines the analysis of the load demand of the multi-fuel cell stack (MFCS) with the battery to minimise the operating cost and maximise the endurance. The dynamic programming (DP) is used to provide an initial reference and an optimisation range for NMPC to further enhance its convergence speed and optimisation quality. The second layer addresses the power allocation to each fuel cell (FC) in the MFCS and based on the MFCS optimal efficiency range (MER) and considering power generation characteristics and performance degradation of FC, the MFCS optimal power allocation curve (MOC) is proposed to improve the fuel efficiency of the MFCS while decreasing the performance degradation rate of the FC and promoting the consistent performance degradation of the MFCS. The experiment demonstrates that the EMS proposed in this paper can effectively reduce the operating cost, extend the system service life, promote consistent FC performance degradation, and enhance the endurance of the ship.