An improved PV system with auto-protection to inject active power into the power grid of marine ships

Photovoltaic (PV) system is turning into an ideal secondary power source for marine ships because of the ability to trap nature's green energy. In this paper, a ship's power grid connected PV system is proposed. The proposed system will help to inject the active power into the ship's electric power grid together with a protection scheme, which will prevent the PV system and ship's power grid from different faulty conditions. The proposed system has facility to track the maximum power point (MPP) of PV array by means of hybrid MPPT method and flyback DC-DC converter. Space vector pulse width modulation (SVPWM) technique controlled 3-phase full-bridge VSI is used to convert DC bus voltage into useful 3-phase AC output in order to feed the local load and transmit excess AC power into the ship's bus. Furthermore, an isolation transformer is used to provide galvanic isolation amid PV system and ship's power grid.