Wind farms-fed HVDC system power profile enhancement using solid state transformer based flywheel energy storage system

The FESS is connected in parallel with the dc-link of the grid side converter; therefore during the healthy conditions, the excess wind energy can be stored in the flywheel and then restored during the energy-shortage periods. However, in faulty conditions, typically ac faults, the FESS will provide an alternating path for the wind energy instead of feeding the fault. Hence, excessive overvoltage across the DC-link capacitor due to trapped energy is avoided.. The proposed system including FESS with an interfacing SST is modeled, simulated, and analyzed in MATLAB/SIMULINK environment. The results verify the effectiveness of the proposed system.