A current-based model of an IPFC for Newton-Raphson power flow

In this paper a new approach to modeling an interline power flow controller (IPFC) for power flow calculations by applying the Newton-Raphson method is presented as a continuation of the ideas already applied to static synchronous series compensator (SSSC). The presented approach differs from the methods proposed by other authors in terms of the interpretation of the device's branches. They are considered on the basis of their currents, and so it can, therefore, be denoted as a current-based model of an IPFC. First, the basic features of the IPFC are presented; as this is the basis for the current-based model that is incorporated into the Newton-Raphson load-flow model. Next, the basic equations are derived from the generic IPFC model. Further handling of the constraints is then discussed. The derived model was tested on the IEEE 57, IEEE 118 and IEEE 300 bus systems. The effectiveness of the proposed model's iteration procedure is compared with other models. The comparison is based on data available in the references. We have shown that the proposed model exhibits a faster convergence than other models, and in addition, the number of iterations needed to achieve the prescribed accuracy is almost constant, regardless of the location, a consideration of the constraints or the selection of the controlled variable. (C) 2009 Elsevier B.V. All rights reserved.