Apparatus and method for filtering current sensor output signals
US7304829B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 16, 2005 |
| Grant date | Dec 4, 2007 |
| Priority date | — |
| Expiry date | Mar 15, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/0935
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electronic filter for filtering the output signal of a current sensor of a circuit breaker is disclosed. The current sensor has an output signal characteristic similar to that of a Rogowski coil output signal characteristic that includes a third harmonic noise component in response to a switching primary current of the circuit breaker, and the circuit breaker has an electronic trip unit with an instantaneous pick-up setting responsive to the output signal of the current sensor. The electronic filter includes a first stage and a second stage. The first stage has a first transfer function that defines first characteristic poles and permits passage of the third harmonic noise component. The second stage has a second transfer function that defines second characteristic poles and filters the third harmonic noise component.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.