Energy storage management for MVDC power system of all electric ship under different load conditions

Considering the issues of high electric power demand of various loads including propulsion load and pulsed load, energy storage system has become a vital part of the electric shipboard. In order to meet the transient and steady power demand of the medium voltage direct current (MVDC) power system of the all electric ship (AES), a hybrid energy storage system (HESS) consisting of a battery as high energy density storage and a supercapacitor as high power density storage is used to support the MVDC power system of the AES. In this paper, a Fuzzy Logic (FL) controller based energy storage management (ESM) system is designed which manages energy storages under different loading conditions. For maintaining the AES's bus voltage within the limit and keeping pace with the load power demand, the ESM system provides reference power for controlling the operations of the energy storages. To demonstrate the effectiveness of the energy storages and load management program, a 12kV MVDC power system of AES is designed with gas turbine based generators, modular multilevel converters (MMC), propulsion systems, service loads, pulsed load, energy storages (battery and supercapacitor), and dual active bridge (DAB) converters in SimPowerSystem. Simulation results are provided to show that the operation of the energy storages. FL control can perform effectively even with variation in the load demand.