Patent · US Expired

Back-up uninterruptible power system

US5315533A · kind A · utility

182Cited by
34References
48Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 17, 1991
Grant dateMay 24, 1994
Priority date
Expiry dateMay 17, 2011

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH02J9/062
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A back-up uninterruptible power system has a power supply path from input terminals connected to AC power system lines to normally supply power to a load. Upon the occurrence of a line fault, a static switch in the power supply path interrupts the connection between the AC power lines and the load and an inverter is turned on to provide power derived from an auxiliary battery through a transformer to the power supply path to supply AC power to the load. By using the static switch, switching from line connection to backup power can be done quickly, within a half cycle, so that substantially no interruption of the output waveform is observed. The inverter can be operated to provide a commutation pulse to the SCRs in the static switch to commutate an SCR which might otherwise continue conducting after the triggering signals to the gates are cut off and before the inverter supplies the AC power to the load. A relay connected between the input terminals and the static switch is controlled to open relay contacts after the static switch has interrupted the current flow to the load, thereby providing positive electrical isolation of the AC power system from the uninterruptible power system…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.