Method for detecting a fault or also the direction of a fault in electric lines and means for executing this method
US4618933A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 21, 1983 |
| Grant date | Oct 21, 1986 |
| Priority date | — |
| Expiry date | Jun 21, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H7/265
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for detecting a fault and also the direction of a fault in electric lines, wherein voltage (Su) and current step signals (Si) corresponding to the transient components in the line voltage and line current are derived; the instantaneous values of these step signals (Su, Si) define, in a co-ordinate system formed by the step signals (Su, Si) themselves, a point which passes through a line of motion (B) after the occurrence of a fault; and if the point transgresses a triggering boundary (AI, AII, AIII, AIV) in the co-ordinate system the fault is detected. In this event the direction of the fault is found from the quadrant (QI, QII, QIII, QIV) in which the transgression takes place. At a predetermined time after entry of the point into a boundary zone provided in one quadrant, located in the line of motion ahead of a triggering boundary in next adjacent quadrant, a triggering boundary in at least the next adjacent quadrant is adjusted to a greater distance from the origin of the co-ordinate system which is located in the same semicircular space bounded by the axis of the voltage step signal (Su). This measure considerably increases the reliability of detection wi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.