BibTeX:

@article{IJIRSTV2I12161,
     title={Unified Power Flow Controller},
     author={Mihirkumar Chimanlal Rathod},
     journal={International Journal for Innovative Research in Science & Technology},
     volume={2},
     number={12},
     pages={393--396},
     year={},
     url={http://www.ijirst.org/articles/IJIRSTV2I12161.pdf},
     publisher={IJIRST (International Journal for Innovative Research in Science & Technology)},
}

The Unified Power Flow Controller (UPFC) is a power electronic controller which can be used to control active and reactive power flows in a transmission line by injection of (variable) voltage in series and reactive current in shunt. The main function of the UPFC is to control the flow of real and reactive power. Both the magnitude and the phase angle of the voltage can be varied independently. The two types of model are discussed here. One is static and second is dynamic. Static model is used to understand the basic concept. The dynamic model uses time domain differential and algebraic equations. The new control strategy based on p-q theory is implemented with a new concept in UPFC and also is used for controlling active and reactive power. The simple PI-controllers are used to control active-reactive power in UPFC model. The interaction is observed in simulation results.

UPFC, Unified Power Flow Controller