Dynamic reactive power compensation during fault conditions for wind farms with the consideration of wind turbine protection effects

This paper analyses the model of Doubly Fed Induction Generation (DFIG) and the feasibility to improve its dynamic voltage level by using reactive power compensation devices during fault conditions. MATLAB/SIMULINK has been used to analyse the dynamic characteristics of Static Var Compensator (SVC), and simulation results show that SVC can achieve the best compensation effect within 100ms whether the system voltage is low or high. In order to study the further ability of SVC to support wind farms during fault conditions, a 45MW wind power system model, with the consideration of wind turbine protection effects, such as the AC overvoltage protection, AC undervoltage protection and DC overvoltage protection, etc., has been established. Two scenarios have been used to compare active and reactive output of DFIG unit during the grid voltage sag, and the important role for dynamic support played by SVC is verified.