A Design Approach for DC Voltage Controller of CHB-based STATCOM

In this paper, a novel parameter design approach of the PI controller used for individual DC voltage balancing control of cascaded H-bridge converter-based STATic synchronous COMpensator(STATCOM) is presented. By means of phase shift sinusoidal pulse width modulation, using two control loops(DC voltage control loop and phase angle shift control loop) to ensure DC voltage balance, the proposed approach can calculate parameters of the PI controller of the two control loops relative accurately by finding the relationship of the input and output of PI controller, The simulation and experimental results verify that the proposed method has good effects of balancing individual DC voltage, meanwhile, it makes the system a good dynamic performance. Key-Words: CHB inverter, Static synchronous compensator (STATCOM), DC voltage controller, parameter design, Sinusoidal pulse width modulation