A Study Of Unified Power-Flow Controller

It is highly significant to study about Unified Power-Flow Controller (UPFC), UPFC has become a new and important controller of Flexible AC Transmission Systems (FACTS), and it has been paid attention to widely in Power Industry of some countries.In this paper, a 2KVA experimental device of UPFC is designed, and some problems concerned in UPFC are put forward. The development, present status, principle and model of UPFC are explained detailed, and UPFC has been compared with other controllers of FACTS in function and structure. Besides, the key of achieving UPFC function rests with the control technique of UPFC, the technique of SPWM have been adopted to act as the control of UPFC, and the technique restraining harmonic of UPFC also have been analyzed in detail.Based on the above-all study, the design and experiment of UPFC device has been completed, including power circuit, control circuit, IGBT buffer circuit, sampling circuit and protecting driving circuit. DSP TMS320LF2407 has been selected as controller to control three-phase inverter. In this paper, the results of the experiment is given, it is shown that the experimental device meets the demand of keeping work-performance stabilization and better output waveforms.