Research on Power Flow Algorithm of Power System with UPFC

The Unified Power Flow Controller (UPFC) is the most complex and powerful FACTS device, which can provide full or independent control of line transmission parameters, such as voltage, line impedance and phase angle. In this paper, steady-state model of unified power flow controller (UPFC) and power flow algorithm of power system with UPFC were studied. The parallel and series sides of UPFC were equivalent to separate power injections, and an alternating iteration algorithm of power flow for power system with UPFC was presented. In order to improve the convergence of the algorithm, this paper analyzes the impact of UPFC’s various control strategies on the convergence of power flow calculations, and proroses a control strategy for converting constant power control to constant variable control during the iterative process. Based on the actual project of Nanjing Western UPFC, the correctness and effectiveness of the model and algorithm are verified.