System and method for calibration of data in an electric power monitoring system
US6639413B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 6, 2001 |
| Grant date | Oct 28, 2003 |
| Priority date | — |
| Expiry date | Jul 6, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/044
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The error compensating system and method is used in electric power monitoring systems, e.g. protective relays, and includes a test unit for applying a test signal to the front end of a data acquisition section of the power monitoring system and a phase reference module which converts the test signal to a square wave having falling and rising edges corresponding to transitions between the positive and negative portions of the test signal. A programmable logic device determines the zero crossings of the sampled digital signal from the data acquisition system and then determines the time difference between a falling edge of the module output signal and the zero crossing of the sampled digital signal. The time difference is representative of the phase shift produced by the data acquisition components. A compensation circuit adjusts the digitally sampled signals with the amount of the determined phase shift.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.