Unbalanced current detector for three phase electrical system
US4423374A · kind A · utility
6Cited by
2References
9Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Sep 21, 1981 |
| Grant date | Dec 27, 1983 |
| Priority date | — |
| Expiry date | Sep 21, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R29/16
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An unbalanced current detector for a three phase electrical system of the type including a current transformer (4, 6, 8) for each phase (.phi.A, .phi.B, .phi.C) and a burden resistor (16) which receives a rectified output of the current transformer is disclosed. The harmonic content of a rectified ripple voltage developed across the burden resistor (16) is applied to a filter (20) for extracting desired frequencies and rejecting other frequencies, and the filter output is applied to a level detecting and amplifying circuit (54) the output of which is applied to an indicator (77) to indicate an unbalanced current condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.