Unlike diesel generators or energy storage systems, photovoltaic (PV) arrays lack inherent rotational inertia and have output limitations due to their operational environmental dependencies. This characteristics restricts their suitability as primary microgrid (MG) backbone components. This study proposes a grid-forming (GF) control strategy for PV inverters in MGs using a model predictive control (MPC) approach. First, a modified predictive model incorporating PV capacitor dynamics is developed to enable simultaneous AC-side output voltage and DC-side voltage prediction. Secondly, a modified P-V droop curve is implemented instead of frequency adjustment to achieve DC/AC power balance and multi PV source power sharing. Furthermore, to possess the ability of regulating PV operating region between limited GF mode (MPPT operation) and GF mode (power reserve operation), based on DC-side voltage prediction, a modified cost function is proposed. Simulation and experimental tests are carried out to validate the effectiveness of the proposed strategy.

PV inverter,grid-forming,predictive control