Control of Flywheel Energy Storage Systems for wind farm power fluctuation mitigation

This paper proposes a new method to regulate the output power of offshore wind farms in presence of variable wind speed using Flywheel Energy Storage Systems (FESS). A novel configuration FESS-integrated offshore wind farm is presented. A hierarchical control structure was developed to handle the complexity of the FESS. Multi-Input Multi-Output Quantitative Feedback Theory (MIMO QFT) and Feedback Linearization were used to designed the controllers such that robust performance is achieved in presence of nonlinearities. A new current coordinating algorithm was developed to extend the operating speed of the FESS resulting in an increase in the energy storage capability.