A hybrid static/rotary UPS system

An uninterruptible power supply (UPS) system is proposed. It uses a simple square-wave inverter driving a synchronous or induction motor-generator set to produce low-distortion isolated power. This power was shown to have advantages over both static UPS and standard rotary UPS systems, including reduced output impedance, reduced distortion with nonlinear loads, higher reliability, and better isolation. A 200 kVA system of this type installed at a large computer facility has resulted in significantly improved power availability.<<ETX>>

[1]  Klaus Sachs,et al.  A Low-Impedance Uninterruptible Power Technology for Nonlinear Critical Loads , 1987, IEEE Transactions on Industry Applications.

[2]  M. Lockwood.  Simulation of unstable oscillations in PWM variable-speed drives , 1988 .

[3]  Phoivos D. Ziogas,et al.  Towards a zero-output impedance UPS system , 1989 .

[4]  R. Ueda,et al.  Stability problem in induction motor drive system , 1988, Conference Record of the 1988 IEEE Industry Applications Society Annual Meeting.

[5]  T. Kawabata,et al.  Three phase parallel processing UPS using multi-functional inverter , 1989, Conference Record of the IEEE Industry Applications Society Annual Meeting,.