Voltage detection of utility service disturbances
US5943246A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 29, 1997 |
| Grant date | Aug 24, 1999 |
| Priority date | — |
| Expiry date | Apr 29, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/207
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A digital voltage detector uses a running average to detect utility service disturbances in real time. An isolation transformer taps the main electrical AC power supply line and provides an analog voltage waveform to a system controller. The analog waveform is sampled digitally in real time, and the samples are squared to create respective instantaneous squared voltage values. A running average is kept of the instantaneous squared voltage values for a preselected period of time, preferably one half-cycle for the main power supply waveform. The running average is compared to a preselected under-voltage threshold value and a preselected over-voltage threshold value, and a disturbance detection signal is generated if the running average violates either threshold value. The disturbance detection signal is preferably used to activate a standby electrical AC power supply, and contemporaneously to disable the main electric AC power supply.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.