Ground fault detecting apparatus and method for detecting ground fault of field circuit and exciting circuit by detecting ground fault current flowing from ground to neutral point of exciting circuit
US5691643A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1995 |
| Grant date | Nov 25, 1997 |
| Priority date | — |
| Expiry date | Oct 6, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/165
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus detects a ground fault of an exciting circuit and a field circuit of an AC exciting variable speed rotating machine. The exciting circuit outputs an excited voltage controlled a frequency and/or an amplitude, and the field circuit of the AC exciting variable speed rotating machine is applied a field current by the excited voltage of the exciting circuit. A ground resistance is connected between a neutral point and a ground. The apparatus detects a current flowing from a ground to a neutral point through the ground resistance, and detects the ground fault based upon the detected current. Therefore, the apparatus can detect a ground fault of a field circuit and an exciting circuit of an AC exciting rotating machine during the AC exciting rotating machine operation with certainty.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.