Uninterruptible power supply and ferroresonant transformer for use therewith
US6218744A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 2000 |
| Grant date | Apr 17, 2001 |
| Priority date | — |
| Expiry date | Mar 22, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M7/797
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A line-interactive single conversion uninterruptible power supply (UPS) utilizing a multiple tapped ferroresonant transformer and a square wave PWM inverter is presented. During normal utility line operation, the line voltage is not modified in any way, except for ferroresonant filtering and regulation. Tap control circuitry insures proper tap selection based on the utility input voltage. During tap transitions in utility out of specification operation, a second power source, such as an inverter, is operated to provide output power to the connected loads. The control of the inverter switching angles may be accomplished through a look-up table. This look-up table contains the converter pulse widths for monitored battery voltage. No output voltage feedback is required. Based on the inherent regulation provided by the ferroresonant transformer, the PWM control may be accomplished in course steps.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.