Electricity: electrical systems and devices – Safety and protection of systems and devices – Feeder protection in distribution networks
Patent
1989-05-05
1990-07-03
DeBoer, Todd E.
Electricity: electrical systems and devices
Safety and protection of systems and devices
Feeder protection in distribution networks
361 68, 361 83, H02H 300
Patent
active
049396170
ABSTRACT:
The invention is directed to an improved method and apparatus for monitoring the status of an AC electrical transmission line connected between first and second locations. In a disclosed embodiment of the method of the invention, first signal parameter values are generated, for the first location, by time integrating between zero-crossings of an AC signal parameter measured at the first location. Second signal parameter values are generated, for the second location, by time integrating between zero-crossings of the AC signal parameter measured at the second location. The second signal parameter values are transmitted to the first location. In a form of this embodiment, the second signal parameter values transmitted for each of the three phases are transmitted only for time periods between successive zero-crossings beginning with a zero-crossing of one sense (e.g. positive-going zero-crossings), and the second signal parameter value for the ground reference return is transmitted only for time periods between successive zero-crossings beginning with a zero-crossing of an opposite sense (e.g. negative-going zero-crossings) to said one sense. This technique can provide a further saving of bandwidth without substantial compromise of tripping response time.
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Hinman Walter L.
Hoffman Gary R.
Deboer Todd E.
Dowty RFL Industries Inc.
Novack Martin M.
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