5-228 D30 Line Distance Protection System GE Multilin5.8 INPUTS AND OUTPUTS 5 SETTINGS5EXAMPLE 2: PILOT-AIDED SCHEMESConsider a three-terminal line protection application shown in the figure below.Figure 5–121: THREE-TERMINAL LINE APPLICATIONAssume the Hybrid Permissive Overreaching Transfer Trip (Hybrid POTT) scheme is applied using the architecture shownbelow. The scheme output operand HYB POTT TX1 is used to key the permission.Figure 5–122: SINGLE-CHANNEL OPEN-LOOP CONFIGURATIONIn the above architecture, Devices 1 and 3 do not communicate directly. Therefore, Device 2 must act as a ‘bridge’. The fol-lowing settings should be applied:UR IED 1: DIRECT OUT 2 OPERAND: " HYB POTT TX1 "DIRECT INPUT 5 DEVICE ID: "2"DIRECT INPUT 5 BIT NUMBER: "2" (this is a message from IED 2)DIRECT INPUT 6 DEVICE ID: "2"DIRECT INPUT 6 BIT NUMBER: "4" (effectively, this is a message from IED 3)UR IED 3: DIRECT OUT 2 OPERAND: " HYB POTT TX1 "DIRECT INPUT 5 DEVICE ID: "2"DIRECT INPUT 5 BIT NUMBER: "2" (this is a message from IED 2)DIRECT INPUT 6 DEVICE ID: "2"DIRECT INPUT 6 BIT NUMBER: "3" (effectively, this is a message from IED 1)UR IED 2: DIRECT INPUT 5 DEVICE ID: "1"DIRECT INPUT 5 BIT NUMBER: "2"DIRECT INPUT 6 DEVICE ID: "3"DIRECT INPUT 6 BIT NUMBER: "2"DIRECT OUT 2 OPERAND: " HYB POTT TX1 "DIRECT OUT 3 OPERAND: " DIRECT INPUT 5 " (forward a message from 1 to 3)DIRECT OUT 4 OPERAND: " DIRECT INPUT 6 " (forward a message from 3 to 1)842713A1.CDRUR IED 1 UR IED 2UR IED 3842714A1.CDRUR IED 1TX1RX1UR IED 2RX2TX2RX1TX1UR IED 3RX1TX1
