A current regulated converter: design and limitations as a VAr controller and an active filter

This paper introduces the mathematical model of a current regulated switched capacitor static volt ampere reactive compensator. It is based on simulating the differential equations, relevant to different operating modes of the compensator, by difference equations. The model is used to compute power converter losses and analyze its limitations. Experimental results from a reduced scale prototype are presented to verify the accuracy of the model and show its versatility of operation as a reactive power exchanger at the fundamental frequency and as an active filter. The control philosophy of the compensator is suitable also for controlling real power exchange between the AC source and the DC link to make it function as an active power line conditioner.