Virtual Inertia in a Microgrid with Renewable Generation and a Battery Energy Storage System in Islanding Transition

This paper focuses on the islanding transition of an AC microgrid equipped with a doubly-fed induction generator wind turbine, a photovoltaic unit, a battery energy storage system (BESS) and local loads. It is well known that the islanding transition put at risk system stability, especially for the systems with low inertia. This paper has explored the combined contribution of virtual inertia support schemes applied to the BESS and to the DC-link capacitor of the back-to-back inverter of the wind power generator in order to ensure a smooth islanding transition by preserving the microgrid stability. For this purpose, we analyse the frequency/inertia support provided by two virtual inertia control schemes: i) a virtual synchronous generator technique on the BESS and ii) a DC-link capacitor control. The analysis is carried out by using time domain simulations in the DIgSILENT PowerFactory environment.