Adaptive quadrilateral characteristic distance relay
US5796258A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 30, 1997 |
| Grant date | Aug 18, 1998 |
| Priority date | — |
| Expiry date | Jan 30, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H7/26
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A quadrilateral characteristic relay system for determining a fault associated with a multiple-phase electric power transmission system is disclosed. The system dynamically adapts one line of the quadrilateral trip region to account for the interaction of load current and fault resistance. As a result of the adaptation, the system exhibits better overreach and underreach performance characteristics. The system employs impedance and voltage plane quadrilateral characteristics using negative sequence current as a proxy for fault current. In the voltage plane, the fault determination is made through a series of comparisons, avoiding computationally inefficient mathematical divisions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.