System and method for ground fault detection and fault type evaluation
US9134354B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 2012 |
| Grant date | Sep 15, 2015 |
| Priority date | — |
| Expiry date | May 15, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The embodiments disclose a circuit for detecting and determining a type of ground fault in a security system. An operational amplifier (OA) having positive and negative inputs and an output may receive AC input signals having different frequencies, f1 and f2 at a positive input and provide an AC output signal at the output. An OA feedback loop may comprise a ground fault equivalent impedance connected at the OA negative input and a feedback resistor connected between the OA output and the OA negative input. A rectifier may convert the AC output signal to a DC signal and a filter to obtain a steady DC voltage from the rectified DC signal. A steady DC voltage for two different AC input signals may be obtained and converted to a relative voltage with respect to a constant input voltage amplitude. The relative voltages may be compared to detect and determine a type of ground fault condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.