Objective  Aiming at the problems of the power quality degradation of the power grid and the power distribution of energy storage devices when the load power of a ship power system fluctuates sharply, a power fluctuation control strategy based on the hybrid energy storage of batteries and supercapacitors is proposed.

  Methods  First, based on the low-pass filtering algorithm, the power fluctuation of the ship's power system is initially allocated to the corresponding energy storage unit according to its fluctuation frequency. Then, based on the droop control strategy, the output current of each energy storage unit is adjusted according to the allocated power. Finally, based on the state of charge of each energy storage unit, the charge and discharge control of the hybrid energy storage system is conducted to smooth out the power fluctuations.

  Results  The simulation results show that this power distribution strategy realizes the reasonable distribution of power between energy storage units and the charge and discharge power control of the energy storage system, which can effectively smooth out the load power fluctuations of the ship's power system.

  Conclusion  The results of this study can provide valuable references for the optimal power quality design of a ship's power grid.