Network protector relay and method of controlling a circuit breaker employing two trip characteristics
US6671151B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 3, 2001 |
| Grant date | Dec 30, 2003 |
| Priority date | — |
| Expiry date | Mar 27, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/385
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A network protector relay controls a circuit breaker connected between polyphase feeder and network busses. A circuit samples polyphase circuit breaker current and network voltage to generate digital polyphase current and voltage samples. A microcontroller generates positive sequence current and voltage vectors from the current and voltage samples. A first trip algorithm trips the breaker in response to the positive sequence current vector being in a first trip region of a first trip characteristic with respect to the positive sequence voltage vector. The first trip characteristic is defined by a reverse trip setpoint and a first positive angle. A second trip algorithm trips the breaker in response to the positive sequence current vector being in a second trip region of a second trip characteristic with respect to the positive sequence voltage vector. The second trip characteristic is defined by the reverse trip setpoint and a second negative angle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.