A New Methodology for SVC Modeling in the Power Flow Problem Based on Sigmoid Functions

Abstract

This paper presents a new methodology for static VAr compensator (SVC) modeling in the power flow problem. The proposed formulation applies sigmoid functions to model the control equations that describe SVCs' steady-state behavior, including their limits consideration. In addition, an improvement to the SVC firing angle model is also proposed to include the droop characteristic in the linear region. The main objective is to develop a power flow formulation considering the full Newton approach. One of the main advantages of the proposed method is that no alternating adjustments are required, even in dealing with boundaries and backoffs procedures. The implementation of a power flow program has been tested using both small-scale tutorial systems and the medium-scale IEEE Nordic system. The results presented validate and indicate the effectiveness of the proposed methodology.