Method and apparatus for determination of battery run-time in uninterruptible power system
US5295078A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 1992 |
| Grant date | Mar 15, 1994 |
| Priority date | — |
| Expiry date | May 15, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02J9/062
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The run-time on battery power available from an uninterruptible power system is accurately determined both during supply of power from the battery through an inverter to the load and during the time where power is supplied directly from an AC power system to the load. During power outages where power is supplied from the battery through the inverter to the load, the output voltage of the battery is directly measured as is the output current supplied to the load. The remaining run-time is determined utilizing the measured battery voltage, the measured output current, and system specifications including the full charge open circuit voltage of the battery, the allowable lower limit of battery voltage, and constants which are characteristic of the uninterruptible power supply and the battery. When power is supplied from the AC power system to the load, the open circuit voltage of the battery is measured initially, and then during the time that the battery is being recharged the open circuit battery voltage is calculated based on the initial open circuit voltage adjusted by a factor porportional to the time that the battery has been charged. The calculated open circuit voltage is used t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.