Performance improvement of wind turbine with squirrel-cage induction generator by static synchronous compensator and hybrid energy storage system

ABSTRACT. Wind turbines with squirrel-cage induction generators (SCIGs) face multiple challenges in power quality and fail-safe operation at grid failures, calling for a combination of reactive power compensation device and energy storage system. Therefore, this paper puts forward a novel control plan based on the static synchronous compensator (STATCOM) and hybrid energy storage system (HESS). Specifically, the STATCOM was combined with series dynamic breaking resistor (SDBR) to mitigate the voltage fluctuation and improve low-voltage ride-through (LVRT) performance; the four-level power allocation was adopted for a parallel hybrid energy storage system based on supercapacitor and LiFePO4 lithium battery, with the aim to rationally allocate the compensation power between the two energy storage devices and balance the fluctuating wind power. Matlab simulation results show that the proposed control plan can significantly reduce the voltage fluctuations, enhance the LVRT performance, and smooth the power fed into the grid. The research findings help to promote the application of STATCOM/ hybrid energy storage technology in wind farms.