Electricite De France - Service National

Areva T&d Sa

Patrick Bastard

Jean-Pierre Dupraz

Houria Siguerdidjane

Volker Leitloff

Michael Nassaeur

Farah Boudaoud

A method for determining the reclose time of a circuit breaker on a three-phase high-voltage electric network after separation of contactsA,A,B,B,C,C in the presence of a fault on one of the three phases A, B or C includes measuring voltages UL, ULand UL, measuring voltage US,determining the voltage US, US, and US, calculating the differences UL, ULand UL, calculating the differences US, US, and US. From these measurements and calculations, a determination of the reclose time is made on the basis of the voltage differences.

Method for determining the moment of closure of a circuit breaker on a high voltage line

This device for protecting a line ( ) of a network of supply lines comprises two protective relays ( ) furnished with means for detecting faults and a circuit breaker adapted so as to disconnect the line from the network of lines in the presence of a fault, each relay being adapted so as to monitor a first zone (Z ) of the line corresponding to a zone of certain detection of a fault ( ) and at least one second zone (Z ) juxtaposed with the first zone and corresponding to a zone of uncertain detection of a fault. At least one of the relays comprises means for detecting the opening of the circuit breaker associated with the other relay in response to a detection, by the latter, of a fault in the first zone in such a way as to cause the opening of the circuit breaker associated with the said at least one relay ( ). The means for detecting the opening of the circuit breaker comprise means for calculating a characteristic representative of the variation of a measurement value of the impedance of the line and means for comparing this characteristic with a threshold value.

Device and process for protecting a line of a network of electricity supply lines

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Gif sur Yvette, France

Patrick Bastard