Microgrid and Fleet to Grid Operation of a Hybrid Electric Ferry

The onboard renewable energy based hybrid electric ferry, which is an isolated marine microgrid can be an alternative for the conventional fossil fuel based marine microgrid in reducing greenhouse gas emission. The onboard energy storage of a marine microgrid can be utilized as FCAS (frequency control ancillary service) by regulating system voltage and frequency of shore side local grid. Like V2G (vehicle to grid), F2G (ferry to grid) can also support the local grid by feeding electricity from storage devices during peak demand when the electric ferry or vessel is at berth. In this paper, two simulated models are designed using MATLAB®/SIMULINK® for analyzing the system parameters like voltage, current and power at different sections of marine microgrid as well as for grid interactive F2G operation. In simulated model of hybrid ZED (zonal electrical distribution), the AC and DC loads of 28.32 kW and 775.7 W respectively consume electricity mainly from lithium-ion battery of 100 Ah, 300V, Proton Exchange Membrane Fuel Cell (PEMFC) of 50 kW, 625 V and 1-kW PV solar system whereas 5 kVA diesel generator acts as backup source. In simulated model of F2G operation, the coordinated charging of 4 MW BESSs (Battery Energy Storage Systems) of 40 electric vessels at berth provides FCAS. The maximum electricity consumption by 13 MW load (BESS and residential and industrial load) matches with the maximum electricity generation by steam turbine generator, wind park and solar PV farm of 15 MW, 4.5 MW and 8 MW respectively of SSP (shore side power) at that instant. The simulation results give an overview of applicability of hybrid marine microgrid with F2G operation of electric vessel.