Dynamic placement and signal selection for UPFCs in wide-area controlled power systems

This paper deals with the problem of damping inter-area oscillations in wide-area bulk power systems using unified power flow controllers. Dynamic placement and signal selection are two important issues when FACTS devices are deployed in the system. In the paper both problems have been investigated using a Most Dominant Branches table calculated based on modal analysis which shows the influence of active powers of the branches on inter-area modes of the system. First, dynamic placement has been explained in which the best placement candidates are selected based on their influence on inter-area modes. Next the paper deals with dynamic estimation of the states of the system based on selected global measurements. Estimation of the states is important in centralized control approaches since global feedback is not fully available. Simulations on the IEEE 118 bus test system show that the proposed approaches give valuable guidelines for dynamic placement and signal selection problems. Although the results of the discussed methods have been explored using UPFCs, applications can be extended to other series connected FACTS devices.