Switching Loss Reduction of AC-AC Converter using Three-level Rectifier and Inverter for UPS. Kazuki Yoneda, Hiroki Takahashi and Jun-ichi Itoh Dept. of Electrical, Electronics and Information Engineering Nagaoka University of Technology Nagaoka, Niigata, Japan

Abstract— This paper proposes an AC-AC converter, which consists of T-type three-level rectifier and inverter, for an on-line UPS. The switching loss of the proposed AC-AC converter is drastically reduced because the proposed converter is driven at a very low switching frequency which is six times of input side frequency. The T-type rectifier separates the maximum phasevoltage, medium phase-voltage and minimum phase-voltage from the input voltage. Next the output waveform is built by the T-type inverter from each maximum phase-voltage, middle phasevoltage and minimum phase-voltage. The proposed circuit can achieve not only high efficiency, but also short instantaneous interruption time. Furthermore, the proposed AC-AC converter compensates a voltage dip with changing an operation mode of a rectifier. In this paper, the fundamental operation of the proposed converter is confirmed by simulations and experiments. In addition, the power loss of the proposed converter is compared to a conventional on-line UPS and the efficiency of the proposed converter is 97.1% at rated load in an experiment.

FULL PAPER  LINK ORIGINAL NA WEB
http://itohserver01.nagaokaut.ac.jp/itohlab/paper/2014/141105_peac2014/yoneda.pdf
LINK ALTERNATIVO
https://copy.com/LkWFpaxB26DaKPAI