Experimental Verifications of UPFC using Deadbeat Control with 3-phase Unbalanced Compensation

Unified Power Flow Controller (UPFC) is one of the Flexible AC Transmission System (FACTS). The UPFC has been developed to improve the power quality of the power systems in order to keep conditions of the power line without increasing the number of transmission branches. The UPFC is divided into two parts. One is the parallel system and the other is the series system. The parallel system can compensate the reactive power and 3-phase unbalance due to the load in the power line to improve the power factor. In addition, the active power is controlled to maintain voltage of the common DC capacitor and unbalance among 3-phase active power flow. The series system can control active and reactive power flow. In addition, the voltage drop at load side can be compensated to maintain proper line voltage. In both systems, Output current in parallel system and output voltage control in series side are reqired accurate and quick response in adopt to variable situations. The deadbeat (DB) control is applied to realize good performance. Experiment is demonstrated to investigate performance of the proposed method. The theory of the control are described and experimental results in same tipical situations are presented for verification of its characteristics .