Droop and Adaptive Virtual Inertia Controller of PV Inverters for Frequency Regulation in Microgrid

In this renewable energy era, the power from the solar PV arrays increasing. The world is reducing the power from fossil fuels to reducing carbon emissions. Hence the concept of microgrid with support form solar PV power and energy storage is significant. A local microgrid can reduce the losses as well as use effectively the generated power. In this paper, the two PV inverters are operated in parallel, with support from the battery. PV inverters are used to supply the critical load in a microgrid environment. The control algorithm of the PV inverters includes the implementation of virtual synchronous generator concept and droop controller. It is necessary to implement such control algorithms in a high penetration of solar power into the grid to maintain the stability of the system and operate along with conventional generators. A dual inertia adaptive controller is used to calculate the virtual inertia constant based on the system dynamics in this paper. A comparative analysis is made in this paper to verify the effectiveness of the proposed dual adaptive controller. It is a decoupled methodology which makes a compromise between the frequency response and power output.