Correction procedure of the phase difference introduced by a zero sequence toroid of leakage current and isolation monitor this procedure
US5066920A · kind A · utility
11Cited by
3References
14Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 22, 1990 |
| Grant date | Nov 19, 1991 |
| Priority date | — |
| Expiry date | May 22, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/33
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A digital isolation monitor comprises a signal processor operating in conjunction with a measuring circuit to perform a first no-load measurement and a second load measurement of a zero sequence signal delivery by a toroid of a differential transformer, followed by synchronous demodulation, A microcontroller computes the tangent of the angle of phase difference introduced by the toroid by computing the relationship between the load and no-load components, and determines the true values of the leakage resistance and stray capacitance of the power system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.