SELECTIVE PROTECTION EARTH FAULT CIRCUIT FOR A HIGH-VOLTAGE CABLE LINE

摘要

1. A selective earth protection circuit arrangement for a high-voltage cable section (HKS) having at each end a power circuit breaker (LS, LS') with tripping means (S, S') and current transformers (Iw , Uw , Iw' , Uw' ) detecting the neutral current and the neutral voltage, characterised in that each power circuit breaker (LS, LS') has associated with it a signal-processing facility (ESV, ESV') in the form of a logic gating circuit arrangement having two inputs connected to the outputs of an earth fault direction relay (OER, OER') energized from the current transformers (Iw , Uw , Iw' , Uw' ), while a third input of the logic gating circuit arrangement is connected, by way of means (UST, UST') for detecting the measured value of the voltage transformer, to the current transformer (UW, UW') detecting the neutral voltage, and two connections are provided for an information channel (HAV) common to the two signal-processing facilities (ESV, ESV').