Integrating SCESS into a Ship-PV Power System to Mitigate Power Fluctuations and Improve LVRT Capability

Because of the intermittence of PV power generation and the peculiarities of the ship power system, the integration of a PV system into a ship grid must adopt an ESS or available control strategy to smooth the fluctuating grid-connected power and enhance the LVRT capability of the PV power system. This paper proposes a novel model to smooth the grid-connected power and improve the LVRT capability by using an SCESS. In addition, a comprehensive control strategy is designed to achieve the power scheduling between the PV and SCESS and to overcome the problems of DC-link overvoltage and AC overcurrent that may cause disconnection or damage to the inverter. The dynamic behaviours of the system are investigated by considering various scenarios, such as varying irradiance and different levels of voltage drop. The results confirm the effectiveness of the proposed model in limiting the DC bus voltage, smoothing the grid-connected power and enhancing the LVRT capability by PSCAD/EMTDC simulation of a 143-kW ship-PV power system.