A Multi-objective Two-layer Collaborative Optimal Configuration Method for Ship Hybrid Energy Storage System Based on NSGA II

To solve the problems of power quality degradation of ship power grid and power allocation of hybrid energy storage system (HESS) under complex operating conditions, a multi-objective two-layer collaborative optimization method based on the non-dominated sorting genetic algorithm (NSGA II) for all-electric ship hybrid energy storage system is proposed. The method first uses low-pass filtering(LPF) and variational modal decomposition (VMD) in the lower-layer operation model to realize the initial allocation and reallocation of the shipload power, and then takes into account the coupling characteristics between the energy management strategy and the capacity allocation of the HESS, and establishes a multi-objective optimal configuration model of the HESS that takes into account both the economy and technology in the upper-layer fixed-capacity model and then employs the NSGA II to solve the optimal power allocation strategy and the optimal capacity allocation. The optimal power allocation strategy and optimal capacity allocation are solved using NSGAII. The simulation results show that compared with two typical multi-objective algorithms, the proposed method realizes a reasonable power allocation between the diesel generator unit and the energy storage unit, and effectively suppresses the power fluctuation of the diesel generator unit under the premise of cost reduction.