Open Loop Simulation of Unified Power Flow Controller

Flexible alternating current transmission system (FACTS) technology open up opportunities for controlling power flow and enhancing the usable capacity of present, as well as new lines. FACTS device uses power electronic component to maintain controllability and capability of electrical power system. FACTS controller includes UPFC, STATCOM, SSSC are capable to modify voltage, phase angle and impedance at particular bus in a power system. 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. The real and reactive power in transmission line cannot be controlled easily without FACTS devices. To control active and reactive power the UPFC is very attractive feature and it is a solid state controller which can be used to control active and reactive power flow in a transmission line. The basic control method is such that the shunt converter controls the transmission line reactive power flow and the dc-link voltage. The series converter controls the real power flow in the transmission line and the UPFC bus voltages. The simulation is performed using MATLAB Simulink power system toolbox.