GE C70 Instruction Manual page 209

5 SETTINGS
Example 3: Pilot-Aided Schemes
Consider the three-terminal line protection application shown below:
A permissive pilot-aided scheme could be implemented in a two-ring configuration as shown below (IEDs 1 and 2 constitute
a first ring, while IEDs 2 and 3 constitute a second ring):
Figure 5–21: SINGLE-CHANNEL OPEN LOOP CONFIGURATION
In the above application, the following settings should be applied. For UR-series IED 1:
DIRECT OUTPUT DEVICE ID:
DIRECT I/O CH1 RING CONFIGURATION:
DIRECT I/O CH2 RING CONFIGURATION:
For UR-series IED 2:
DIRECT OUTPUT DEVICE ID:
DIRECT I/O CH1 RING CONFIGURATION:
DIRECT I/O CH2 RING CONFIGURATION:
For UR-series IED 3:
DIRECT OUTPUT DEVICE ID:
DIRECT I/O CH1 RING CONFIGURATION:
DIRECT I/O CH2 RING CONFIGURATION:
In this configuration the following delivery times are expected (at 128 kbps):
IED 1 to IED 2: 0.2 of power system cycle;
IED 1 to IED 3: 0.5 of power system cycle;
IED 2 to IED 3: 0.2 of power system cycle.
In the above scheme, IEDs 1 and 3 do not communicate directly. IED 2 must be configured to forward the messages as
explained in the Inputs and outputs section. A blocking pilot-aided scheme should be implemented with more security and,
ideally, faster message delivery time. This could be accomplished using a dual-ring configuration as shown below.
GE Multilin
UR IED 1
Figure 5–20: THREE-TERMINAL LINE APPLICATION
TX1
UR IED 1
RX1
UR IED 3
"1"
"Yes"
"Yes"
"2"
"Yes"
"Yes"
"3"
"Yes"
"Yes"
C70 Capacitor Bank Protection and Control System
UR IED 2
UR IED 3
842713A1.CDR
RX1 RX2
UR IED 2
TX1 TX2
RX1
TX1
842714A1.CDR
5.2 PRODUCT SETUP
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