Investigating the Capability of Power Flow Regulation by UPFC in a Single-Machine-Infinite Bus System

The capability of regulating power flow in Nigerian Grid System using UPFC is the main focus in this paper. Consequently, three control methods, namely, voltage control through shunt compensation, real power flow control through quadrature voltage injection and reactive power flow control through in-phase voltage injection for the UPFC were examined in order to improve the transient stability of the power system. The quadrature voltage control was found to be effective in reducing the transient swings whereas in-phase voltage control was effective in improving the transient stability margin. Finally, the overall performance of the UPFC was evaluated in a single-machine infinite bus system by nonlinear simulations, and results obtained showed the effectiveness of the controller in improving the dynamic stability of the system and provide better damping to electromechanical oscillations