Fault type classification algorithm
US5783946A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 5, 1997 |
| Grant date | Jul 21, 1998 |
| Priority date | — |
| Expiry date | Mar 5, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/44
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A process for identifying the type of fault detected by a protective relay includes measuring pre-fault and post-fault samples of current waveforms on the phase-A, phase-B and phase-C conductors of a transmission line. Next, increment currents DELIA1, DELIB1, and DELIC1 are calculated, where EQU DELIA1=(I.sub.ar -I.sub.apr).sup.2 +(I.sub.ai -I.sub.api).sup.2 EQU DELIB1=(I.sub.br -I.sub.bpr).sup.2 +(I.sub.bi -I.sub.bpi).sup.2 EQU DELIC1=(I.sub.cr -I.sub.cpr).sup.2 +(I.sub.ci -I.sub.cpi).sup.2. The increment currents are then employed to identify a two-phase to ground fault. In calculating the increment currents, I.sub.ar represents a post-fault value of the real part of the phase-A current, I.sub.apr represents a pre-fault value of the real part of the phase-A current, I.sub.ai represents a post-fault value of the imaginary part of the phase-A current, and I.sub.api represents a pre-fault value of the real part of the phase-A current. The phase-B and phase-C values are denoted accordingly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.