Method and device for locating a fault point on a three-phase power transmission line
US4559491A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 31, 1983 |
| Grant date | Dec 17, 1985 |
| Priority date | — |
| Expiry date | Aug 31, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H7/26
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A fault point in a line section of a three-phase power transmission line, is determined by measuring currents and voltages at a measuring point arranged adjacent the near end of the section. The type of fault (single-phase/multi-phase ground fault/phase-to-phase fault) is determined and the parameters in a quadratic equation are determined using the relative distance (n) from the measuring point to the fault point as a variable. The equation is derived in advance from the electrical relationships between the complex values of the line impedance, the source impedances of the networks located ahead of and behind the fault, and measured currents and voltages following elimination of the fault resistance and possible zero sequence components. The parameters in the equation are determined by the type of the fault, by the measured voltages and currents and by said impedances. The equation is solved directly by means of a numerical square root method. When calculating the parameters, the fundamental frequency components of the measured values are used, which components are obtained by digital filtering of the measured values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.