A novel control scheme of NPC VSC based STATCOM to enhance the performance of wind farm with fixed and variable speed wind turbines

This paper presents a novel control scheme of neutral point clamped (NPC) voltage source converter (VSC) based static synchronous compensator (STATCOM) to enhance the performance of wind farms. A novel control strategy for the STATCOM is presented by introducing a voltage equalizer for dc link capacitor voltages and decoupled current controllers to produce appropriate d-q currents. The controllers for the wind energy conversion system and STATCOM are implemented in Matlab/SimPower. The performance of the proposed control scheme is compared with the traditional vector control scheme and results show that the proposed scheme for the STATCOM shows better performance. The STATCOM is also used to enhance the system performance during loss of generation, load change, three phase fault, voltage sag and swell. The simulation results show that the STATCOM with the proposed controller can improve the steady state and dynamic responses, and enhance the system performance during various disturbances