In this paper, a model for Unified Power Flow Controller (UPFC) is suggested with Newton-Raphson power flow program included. The main control of UPFC series element is realized as a combination of the four control functions. The supplementary control of UPFC is added for damping power oscillation. The integrated UPFC model is then incorporated into the conventional transient and small signal stability programs with the Nigeria 330kV network. The tests on the interconnected power system show that the suggested UPFC model method work effectively. The results also show that the suggested UPFC control strategy can realize power flow control fairly well and improve system dynamic performance significantly.