UNIFIED POWER FLOW CONTROLLER CONTROL STRATEGIES for POWER FLOW

Abstract

In order to address power flow control issues, this study introduces the use of Unified Power Flow Controller (UPFC) models. These models are based on regulating the variables influencing the transmission line’s power flow, and they are capable of controlling the bus voltage, the line’s actual and reactive power, all at once and independently. The idea behind the UPFC technique proposed in this paper is to provide the unique functional capability of independently controlling both the real and reactive power flow in the line. The in-phase component of the series injected voltage dominates the reactive power while the quadrature component affects the real power. A conventional controlling steady-state analysis and dynamic stability analysis of the power system is developed based on the UPFC model. UPFC provides real-time controlling of all or any combination of the power system parameters which determine the transmittable power. UPFC can force and maintain strategically chosen values of the active power and the reactive power at a given point of the line by PI control.