Small-signal Stability Evaluation of DFIG Wind Farms with On-site Battery Energy Storage

Standalone battery energy storage systems (BESS) have widely been integrated to wind turbines recently to enhance the power quality and reliability of wind generation systems. This research analyzes the stability of a doubly fed induction generator (DFIG)-type wind turbines with stand alone battery storage using small-signal analysis. For the wind turbine, the induction generator model, grid side converter (GSC) controller, AC dynamics, and rotor side converter (RSC) controller are considered. For the BESS, the AC filters, and BESS controller are considered in the modeling. Eigenvalue analysis is performed to study the sensitivity of parameters of the system and control parameters on the stability of the combined wind turbine+BESS system. MATLAB/Simulink is used to analyze the system and validate the design.