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Development of a high‐efficiency flywheel UPS using a 3‐arm inverter/converter
Author(s) -
Andoh Itaru,
Moriyama Akira,
Takahashi Isao
Publication year - 1997
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/(sici)1520-6416(19970715)120:1<77::aid-eej11>3.0.co;2-s
Subject(s) - flywheel , inverter , uninterruptible power supply , windage , flywheel energy storage , engineering , electrical engineering , rotor (electric) , power (physics) , cycloconverter , automotive engineering , mechanical engineering , energy storage , voltage , physics , quantum mechanics
A single‐phase high‐efficiency flywheel (FW) uninterruptible power supply (UPS) with a rating of 5 kW and 200 V‐1 min is described. The UPS has the following characteristics: (1) Batteryless system, which makes it maintenance free and results in long life (about three times that of a battery UPS). (2) Simple power conversion circuit of 3 arm configuration which can realize high efficiency and small size. The new flywheel unit, rotating at 1500 rpm, is vacuumized to eliminate windage losses by means of a zirconium getter pump. The flywheel rotor is made contact‐free by a pivot bearing in high‐speed states so as to assure long life. Charging or discharging of the mechanical energy of the FW is achieved by simply controlling the instantaneous slip frequency of the induction machine. The power conversion circuit consists of a three‐arm bridge which has a common arm of the inverter and converter bridges. All control of the UPS is realized by simple programs in a single‐chip floating point DSP. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 120(1): 77–84, 1997