Abstract: A modern power system is becoming more complex power flows from generating centre to load centre. Bus voltage flow from of active power & reactive power in transmission line for different loading conditions. Flexible ac transmission system (FACT) controller includes unified power flow controller (UPFC) , Static synchronous compensator (STATCOM). It should be consider real power and reactive power compensation. It able to controlling voltage, phase angle. It enhances the power transfer capability. When no UPFC installed in transmission line then real and reactive power cannot be controlled. Performance of UPFC is investigated to minimize the power loss in the transmission line. Improving the systemís reactive power handling capacity via FACTS device is ready for preventing of voltage instability and hence voltage collapse. It has been performed on IEEE 14bus system to minimize the transmission losses and improve the Voltage profile. This project shows the result in Mat lab Sim link when UPFC implement in transmission system. It compare with STATCOM results.

Keywords: UPFC, STATCOM, Power electronics device, IEEE 14 bus data sheet, MATLAB/SIMULINK.