SettSendMin = 0.1 s (0 s in parallel line applications)SetUnblock =OffSettSecurity = 0.015 s13.2 Current reversal and Weak-end infeed logic fordistance protection 3-phase ZCRWPSCH IP15751-1 v413.2.1 IdentificationM15073-1 v5Function description IEC 61850identificationIEC 60617identificationANSI/IEEE C37.2device numberCurrent reversal and weak-end infeedlogic for distance protection 3-phaseZCRWPSCH - 8513.2.2 Application IP15023-1 v113.2.2.1 Current reversal logic M13895-4 v6To avoid this kind of disturbances, a fault current reversal logic (transient blockinglogic) can be used.The unwanted operations that might occur can be explained by looking intoFigure 122 and Figure 123. Initially the protection A2 at A side will detect a faultin forward direction and send a communication signal to the protection B2 atremote end, which is measuring a fault in reverse direction.L1L2A1A2B1B2IEC9900043-2.vsdIEC99000043 V3 EN-USFigure 122: Current distribution for a fault close to B side when all breakers areclosedWhen the breaker B1 opens for clearing the fault, the fault current through B2 baywill invert. If the communication signal has not reset at the same time as thedistance protection function used in the teleprotection scheme has switched on toforward direction, we will have an unwanted operation of breaker B2 at B side.1MRK 505 393-UEN B Section 13Scheme communicationLine differential protection RED650 2.2 IEC 285Application manual
