Flywheel Energy Storage System to fast-frequency response provision on insular power systems from a microgrid perspective

This paper discusses a flywheel study case assessment in one of the Galapagos Islands' power systems. This network is essentially a microgrid in islanding operation with high penetration of wind energy generation, therefore with intermittent power harvesting and low-inertia synchronous machines. This characteristic leads these systems to present some operational issues related to frequency stability whose mitigation is intended to be achieved by incorporating a Flywheel Energy Storage System (FESS) in the power system, which is modeled in detail and implemented in MATLAB - SIMULINK®. The frequency response evaluation considers two scenarios: a normal operation condition characterized by an actual wind speed input and a contingency scenario caused by a sudden load increase. The simulation results show, in both cases, a significant enhancement of the microgrid resilience in terms of frequency by incorporating a FESS-system, which is reflected in an important reduction of the frequency deviation and ROCOF.