Abstract
This paper describes considerations on a Voltage Source Inverter based Reactive Power Compensator, especially load balancing control by symmetrical coordinates frame. Analytical expressions are derived to design the current controllers. With the designed controllers, fast response to the step changes in the reference current values can be obtained. This results in the improvement of the overall system performance. The improved current tracking capabilities of the inner controllers and better performance characteristics of dc voltage and reactive power loops are demonstrated for steady state and transient conditions. Besides this, the required additional loops for load balancing property of the VSI based SVC are investigated by using the positive - negative sequence decomposition calculated in α - β reference frame which gives a faster response than the separation in d-q frame. Simulation results have shown that with the use of simple additional loops, VSI type SVC can also achieve load balancing besides VAR compensation and dc voltage regulation.
