Frequency control - the new fundamental concept of “complex frequency”

The complex frequency (CF) concept provides novel definitions of frequency of electrical voltages and currents. This definition extends the domain of the frequency to the complex domain allowing for a complete and consistent formulation of the rate of change of power (RoCoP) at the buses in electric grids. The newly developed concepts of CF and RoCoP are fundamental tools that allow for the implementation of novel and efficient frequency controllers of distributed energy resources. They also constitute the theoretical tools building blocks enabling the implementation of the VPP 2.0 concept and of the most advanced services envisaged by edgeFLEX.

The edgeFLEX frequency control algorithms were tested in a realistic lab environment using state-of-art simulation tools developed at UCD. In the final stage of the project, UCD has initiated a collaboration with EirGrid (Irish TSO) to validate the concept of complex frequency. This collaboration is ongoing and will be carried out through on a detailed model of the Irish transmission system. The objective is to test the applications of the CF concepts in real-world scenarios and showcase the ability of such an approach to improve the transient response of low-inertia systems with high shares of non-synchronous resources following severe contingencies.