Patent · US Expired

Source quality monitoring system

US5555182A · kind A · utility

23Cited by
12References
20Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 4, 1995
Grant dateSep 10, 1996
Priority date
Expiry dateMay 4, 2015

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01R25/00
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A digital signal processor implemented monitoring circuit for detecting phase and magnitude disruptions in multi-phase alternating current input signals. A phase lock loop receives multi-phase alternating current input signals and provides one set of alternating current output signals in phase with a time average of the multi-phase alternating current input signals and provides a second set of alternating current output signals phase shifted in relation to the first set of output signals. In a three phase system the phase lock loop provides six alternating current signals. A demodulation circuit multiplies the first set of output signals from the phase lock loop circuit with the multi-phase input signals to produce demodulated sets of signals. An output circuit coupled to the demodulation circuit sums the first set of demodulated signals to provide a first source quality signal. The second set of demodulated signals is also summed to provide a second source quality signal. By comparing the first and second source quality signals with predetermined quality thresholds the output circuit produces a source quality indication.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.