DM for UPFC´s Active & Reactive Power Decoupled Control

In this paper, the mathematical model is introduced for UPFC system which models the interaction between series and shunt inverters completely, and is more comprehensive than previous introduced models. There is a strong dynamic interaction between the active and reactive power flow through a transmission line when they are controlled by a UPFC. This paper shows a multiplied controller, which its name is decoupling matrix (DM) compensator, in company with a proportional-integral (PI) controller, eliminates the dynamic interaction between the active and reactive power flow through the line. The proposed compensator allows the controller to independently control the active and reactive power flow. The performance of the proposed DM-PI controller is compared with the conventional PI controller. Further more a method is introduced for controlling the dc-link´s voltage (using a linear differential equation that shows the dynamic of the DC link), in the desired value when the references of series real power changed and finally, by using inverters in the simulation which their dc-link´s voltage are produced by obtained linear differential equation the effect of the dc-link´s fluctuations on the state variables is applied in to the simulation