A Newton-Type Current Injection Model of UPFC for Studying Low-Frequency Oscillations

This paper presents a Newton-type current injection model of the unified power flow controller (UPFC) for studying the effect of the UPFC on the low-frequency oscillations. Since the proposed model is a Newton-type one, it is conceptually simple and gives fast convergence characteristics. The model is applied to an inter-area power oscillation damping regulator design of a sample two-area power system. The damping achievable by the UPFC equipped with damping regulator is investigated in both frequency and time domains using the proposed model. The case study results in this paper show that the proposed model is efficient for studying the effects of the UPFC on the inter-area oscillations.