Performance analysis of unified power flow controller (UPFC) by using different controllers

Nowadays, high voltage transmission networks met enormous power demands are very expensive investments in terms of their costs. Because of this, the importance of effective using the existing transmission lines is increasing. In order to benefit more efficiently from the existing transmission lines, the new methods are being developed and applied by making studies related to this area.The rapid developments on the area of power electronics have enabled the development of new equipments to be able to benefit more efficiently from the power systems. The equipments based on the power electronics have been improved under the name of Flexible Alternating Current Transmission Systems (FACTS) in the last years. FACTS devices, are quite efficiently at the power control of the transmission lines and increasing their current capacity, and have rapidly developed. FACTS technology has been used extensively at power control, voltage regulation, increasing the transient stability, and decreasing system oscillations. Unified Power Flow Controller (UPFC) is the more efficient among the FACTS equipments which have the potential to increase the power flow and the stability of the transmission line.In this thesis, the modeling and the developing of UPFC were studied in order to make better the steady state works of the power systems. The effect of UPFC on the power flow of transmission lines were analyzed mathematically and graphically in details. The performances of UPFC were examined by using different controllers.Keywords: FACTS, UPFC, Power Quality.