This article investigates the effect of coordinated control of variable frequency transformer and fuzzy based flywheel energy storage system for frequency stabilisation of wind penetrated two area power system. Wind turbine generator and fuzzy based flywheel energy storage system are incorporated in two different areas. Variable frequency transformer, set up in series with the tie-line near wind-embedded area, is modelled as a tie-line power flow controller between interconnected areas. Variable frequency transformer introduces the phase angle shift between interconnected areas in accordance with the power demand on account of load and wind speed variations in wind-embedded area, while actual power is supplied from fast acting flywheel energy storage system incorporated in other area. Fuzzy controller for flywheel energy storage system is designed in such way that frequency deviations are mitigated continuously during disturbances and nominal storage capacity of flywheel energy storage system is restored on incessant basis, after every load and wind disturbance is tackled.
Robust PI controller design for frequency stabilisation in a hybrid microgrid system considering parameter uncertainties and communication time delay
