Implementation of a Fuzzy Logic Controller for Virtual Inertia Emulation

Any inequality in the overall system's power balance causes a variation in the kinetic energy of the rotating masses and thus a change in frequency. The inertia stored in all the rotational parts of the system is defined as a resistance to change and impedes sudden frequency variations. In general, synchronous machines consist of large and heavy rotating parts which serve as an obstacle against abrupt frequency deviations. This paper investigates the application of various designs of frequency control that support frequency stability. At a second phase, for improving the performance of frequency control, an additional controller is implemented, employing a fuzzy structure controller with virtual inertia response. It is shown that during step load changes and after the implementation of a continuous fluctuation in the system, the lower the total system's rotational inertia is, the more the frequency stabilization deteriorates. Nevertheless, through the aforementioned control strategies, frequency stability is enhanced. This study presents the results from the Researcher Exchange Program within the FP7 ELECTRA IRP European project.