Arc detection by non-causal signal correlation
US6859042B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 7, 2002 |
| Grant date | Feb 22, 2005 |
| Priority date | — |
| Expiry date | Jun 14, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/44
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for detecting electrical arcs in an electrical system having a periodic power supply is disclosed. A method according to the invention compares instantaneous values of a monitored waveform both with (a) their past values at corresponding phases of the AC supply waveform, and (b) their future values at corresponding phases of the AC supply waveform. The monitored waveform is delayed or stored to allow such comparisons in near real time, to produce an output which is only slightly delayed behind the monitored waveform. An apparatus according to the present invention discloses a sampling circuit that samples electrical signals indicative of transient load conditions to produce a sampling circuit output. A storage device receives the sampling circuit's output and stores a time history of that output over an interval. A subtracting circuit receives the stored time history and subtract the time history from both of (a) a delayed version of the history, and (b) an advanced version of the history. An alarm circuit receives the output of the subtracting circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.