Inverter and battery testing for uninterruptible power systems
US5182518A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 1991 |
| Grant date | Jan 26, 1993 |
| Priority date | — |
| Expiry date | Apr 11, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/40
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The inverter of an uninterruptible power system is tested by turning on switches in the inverter at a selected test phase in each half-cycle of the AC input waveform so that the inverter provides a voltage which opposes the AC input voltage waveform during part of each half-cycle of the waveform. The resulting current drawn from the inverter battery, if any, is measured and its peak may be found. The peak battery current during each half-cycle is compared to maximum allowable peak currents to determine if an inverter failure has occurred. If the peak currents are lower than a maximum acceptable value, the test is repeated on a subsequent AC input waveform at a decreased test phase (a shorter time delay from the zero crossing of each half-cycle of the waveform) until the peak current in the first half-cycle is at a selected value, at which time the peak in the second half-cycle is checked to determine if it is within an acceptable range. If not, an inverter test failure is indicated. Inverter test failure is also indicated if repeated cycles during which the test phase is reduced fail to cause the first peak to reach the proper value and the test phase is finally reduced to a minimu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.