Modeling and design of virtual inertia based rooftop PV

With ever increasing Photovoltaic (PV) penetration in distribution level, they expected to respond for voltage and frequency deviations. It is also necessary to provide an uninterrupted supply to the local loads during grid interruption. In this paper, virtual inertia based single phase rooftop PV which responds to changes in the grid state, grid voltage and frequency is described, using instantaneous real and reactive power components. As the instantaneous real and reactive power components are used in controller, it is embedded with power limiters to avoid over currents and to safe guard inverter switches. The Small signal model analysis is carried out for the system developed to observe its stability under both isolated and grid connected modes. The performance of PV-battery system with proposed controller is tested by considering various operating points and perturbations in digital simulation environment.