Department of Electrical Engineering, Jawaharlal Nehru Technological University, Hyderabad, India-500 085.
The Unified Power Flow Controller (UPFC) is the most versatile and complex power electronic equipment that has emerged for the control and optimization of power flow in electrical power transmission system. This paper presents the performance analysis of UPFC installed in transmission system consisting of two sets of three phase transmission lines in parallel, through computer simulation. When no UPFC is installed, interruption of either of three-phase line reduces the active power flow to half, because the line impedance becomes double after interruption. In stalling the UPFC makes it possible to control the amount of active power flowing through the transmission line. The performance of UPFC when a fault occurs in one transmission line is also studied. A generalized pulse width modulation switching technique is used to generate firing pulses for both the converters of the UPFC. Simulations were carried out using PSCAD software to validate the performance of the UPFC. Simulation results show that the presence of UPFC improves the transmission capability, stability and power oscillation damping of the transmission line.
DC voltage regulation, Flexible AC Transmission Systems (FACTS), High power PWM converters, Power swings, Power oscillation damping, Unified Power Flow Controller (UPFC)
