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 real and reactive power flow control through a transmission line by placing UPFC at the sending end using computer simulation. When no UPFC is installed, real and reactive power through the transmission line cannot be controlled. This paper presents control and performance of UPFC intended for installation on that transmission line to control power flow. A control system which enables the UPFC to follow the changes in reference values like AC voltage, DC voltage and angle order of the series voltage source converter is simulated. In this control system, a generalized pulse width modulation technique is used to generate firing pulses for both the converters. Installing the UPFC makes it possible to control an amount of active power flowing through the line. Simulations were carried out using MATLAB and PSCAD software to validate the performance of the UPFC.

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DC voltage regulation Flexible AC Transmission Systems (FACTS) feedback control high power PWM converters real and reactive power Unified Power Flow Controller (UPFC)