Delay Based Virtual Inertia Emulation for a Grid Forming System

Microgrids powered by inverter based resources require sources that mimic grid forming operation. These sources not only help in providing voltage and frequency reference for other inverters but also mimic the inertia of the synchronous generator. This paper proposes a control strategy for emulation of virtual inertia in inverters operating in islanded operation mode. A delay based control strategy is implemented and by varying the inertia constant it mimics the performance of a synchronous generator. Finally, to verify the above statement, similar loading is done on a synchronous generator with similar inertia constants and compared with the proposed grid forming inverter. Transient response parameters are compared in both the cases using EMTDC/PSCAD.