A Novel Concept for Stabilization of AC/DC Network with UPFC

Abstract

This chapter discusses a novel concept for stabilization of AC/DC network with unified power flow controller (UPFC). The basic operational requirement of the high voltage direct current (HVDC) schemes is adequate control action, depending on the power order for damping the power network oscillations. The behavior of various components of the HVDC system should be appropriately represented in a linear domain. The HVDC-SVC (static VAR compensator) alone could not handle the perturbation of line to line voltage change after a certain value. The complete system model of HVDC-SVC-UPFC framework was developed in the discrete time domain and the system stability was examined, where it was observed that the variation of AC line-to-line bus voltage does not deteriorate the overall system stability. This was reflected so because the basic feature of UPFC in the AC network is to control the power flow dynamics very fast using VSC technology. The novel combination can effectively be utilized in situations when the ac system bus voltage undergoes the fluctuations due to changing P and Q requirements. © 2007 Elsevier Ltd All rights reserved.