State feedback controller for current source inverter Based STATCOM used for unbalance compensation in high voltage power grid

This paper presents a new approach to the dynamic control of a current source inverter based STATCOM. The state model in the dq-frame is proposed as the basis for control design. The use of a traditional PID controller led to a high frequency oscillation with low damping between the inductance and capacitance of the output filter CSI. The new approach includes a state-feedback control which reduces system instability due to the oscillations introduced by the output filter. Simulations are performed on MATLAB/Simulink to compare the results obtained by traditional PID control and the state-feedback control.