Frequency control using Vanadium redox flow batteries on wind farms

Vanadium redox flow batteries offer many advantages over other energy storage technologies. In the context of wind farm operation, these batteries could greatly enhance the interaction of intermittent renewables with the power system and can provide ancillary services such as frequency control. This allows renewable sources to behave more like conventional plant. In this paper a novel power system model of a Vanadium redox flow battery is introduced and validated, demonstrating the importance of round trip efficiency modelling. It is then proposed to use such batteries as energy storage on a large wind farm, connecting through an IGBT SVC. It has been clearly demonstrated that such an implementation enables fast active power regulation that permits both the wind farm and storage to provide frequency regulation services. Several methods of controlling the energy storage to provide a power reserve response to large frequency deviations are also analysed, including a critical evaluation and analysis of the associated losses from such schemes.