Enhanced Frequency Response of Inverter Dominated Low Inertia Power Systems

This paper addresses the problem of frequency stability of power systems highly penetrated by distributed energy resources interfaced through power electronics inverters. The integration of asynchronously connected generation to the grid results in an overall system inertia reduction, which as a consequence, deteriorates the system frequency response by increasing the system's sensitivity to sudden changes in generation-load balance as is recorded by the RoCoF and frequency nadir characteristics. This study proposes a novel design of a Synthetic Inertia control scheme equipped on the wind turbine generators (WTGs) that dynamically alters the inertial response provision of the WTGs to the system, assisting this way into a fast system frequency stability recovery. The feasibility of the proposed control scheme is validated on the IEEE 68 bus power system model accommodating solar and wind generation installations. All simulation studies were performed within the DIgSILENT PowerFactory 2018 simulation environment.