Investigation of dynamic controllers for a unified power flow controller

In this paper, a unified power flow controller (UPFC) model based on a d-q rotating frame is introduced The performance of the UPFC system with three different controllers, PI controller, PI controller with decoupling and cross-coupling controller, are investigated through simulation and implementation in an experimental laboratory model. It is found that the cross-coupling controller produces the best performance when the transmission line parameters are unknown. Furthermore the measures implemented to reduce the interaction between the series and shunt inverters an also introduced.