Grid-connected control strategy of GFM inverter in solar-powered ship photovoltaic system

Objective  The paper aims to solve the problem of the overall stability of the ship's power system being reduced due to the use of grid-following (GFL) control for grid connection in existing solar ship photovoltaic (PV) power generation systems.

Methods Based on the characteristics and operational characteristics of marine power systems, four inverter control methods, including GFL PQ control and grid-forming (GFM) droop control, as well as virtual synchronous generator (VSG) control and virtual oscillator control (VOC), were selected to construct photovoltaic grid-connected control strategies for solar-powered marine power systems. Finally, Matlab/Simulink is used to establish a simulation model of a solar ship power system in order to verify the effectiveness of the GFM control concepts and ideas.

Results Compared to the GFL control strategy, the utilization of GFM under load switching conditions can lead to an average reduction of 26.86% in frequency fluctuation amplitude and 37.85% in voltage regulation time.

Conclusions The utilization of the GFM control strategy is capable of effectively mitigating the stability deterioration of the ship's power system triggered by the grid-connected photovoltaic system. This approach enables the PV system to proactively uphold the stability of the power parameters of the ship's power system while fulfilling the energy supply, resulting in the substantial enhancement of the power system's stability.