Multilevel energy storage based frequency regulation in remote area power supply systems

The penetration of renewable power generation in remote area power supply systems (RAPS) can be at a significant level, and the frequency support from renewable power generators is crucial to maintain the system stability under the imbalance between generation and load demand. However, the stochastic nature of renewable energy resources such as wind, and the power electronics based interface between the grid and the generator constrain the capability of permanent magnet synchronous generator (PMSG) to participate in frequency regulation. This paper proposes to integrate hybrid storage system including lead-acid batteries (LAB) and ultracapacitors (UC) into the PMSG based wind energy generation system (WECS) to provide frequency support. Furthermore, the power reserved in using suboptimal maximum power point tracking strategy (SOPPT) in WECS is utilized to provide secondary frequency response along with LAB. The proposed multilevel energy storage can regulate the system frequency effectively.