Patent · US Expired

Phase sequence detector for three-phase AC power system

US3976919A · kind A · utility

63Cited by
3References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 4, 1975
Grant dateAug 24, 1976
Priority date
Expiry dateJun 4, 1995

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH02H11/004
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

The phase sequence of the phase currents supplied by a three-phase AC power supply to a phase-sensitive load (such as a three-phase AC motor) is monitored by developing three phase-displaced, rectangular shaped logic signals, respectively representing the three phase currents, and applying these logic signals to respective ones of the J, C and K inputs of a J-K flip-flop. When the load is correctly connected to the power supply, the phase relationship of the three logic signals will be appropriate to trigger the flip-flop to its set operating state. Any other sequence actuates the flip-flop to its reset state which, in turn, disconnects the load from the power supply.

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