Experimental verification of virtual inertia in diesel generator based microgrids

The dynamic frequency stability issues in microgrids with large penetration of low inertia and intermittent photovoltaic (PV) systems can be improved by using virtual inertia (VI). A VI is the combination of energy storage system, power electronics converter and a proper control algorithm. This paper presents design and experimental verification of the VI in a PV-diesel generator based remote microgrid system. Firstly, the VI was designed and tested in simulation using MATLAB/Simulink. Later, a hardware prototype of 1 kW inverter for the VI was designed and tested with a 13 kW diesel generator test system. The VI unit was able to reduce the frequency variations from a minimum value of 57.39 Hz to 58.03 Hz for a step change in the system load. The frequency deviations can be further reduced with a larger VI unit or multiple VI units in a real microgrid scenario.