GE ALPS Instruction Manual page 51

1 PRODUCT DESCRIPTION
For the fault conditions shown in Figure 1–22: INTER-CIRCUIT FAULT EXAMPLE, the ALPS relay on the protected line at
the S substation will sent detect an AG fault and send channel 1 to the remote terminal. The ALPS relay at Substation R will
detect an ABG fault, and will send both channels 1 and 2 to the relay at S. The ALPS relay at Substation S will issue a sin-
gle pole phase A trip via the operation of the Zone 1 ground distance function. The ALPS relay at the R substation will issue
a single pole phase A trip per the logic of Table II (Local fault type is ABG, and only channel 1 is received).
Table 1–8: SINGLE POLE PHASE A TRIP LOGIC
LOCAL FAULT TYPE
AG
BG
CG
AB, ABG, 3PH
AB, ABG, 3PH
AB, ABG, 3PH
BC, BCG
BC, BCG
BC, BCG
CA, CAG
CA, CAG
CA, CAG
· AND; + OR;! NOT
Combination of Local Fault type and Receiver not listed above will not allow a permissive trip output.
NOTE
b) ZONE 1 TRIPPING
Faulted phase determination for zone 1 tripping is the same as in the existing ALPS relay. This is to allow the Zone 1 ele-
ments to maintain their high speed operation and their independence from the channel.
c) WEAK INFEED TRIPPING
The standard ALPS faulted phase determination algorithm has been supplemented by undervoltage units for Weak Infeed
trips. The phase identified channel logic scheme will use the information in the received signal as well as the undervoltage
units. If there is a local determination of the fault type, the previous table will be used to determine which phases to trip; if
there is no local fault type determination, then the undervoltage functions will be used as in the existing ALPS Hybrid
scheme.
d) REPEAT (ECHO) KEYING
If no local tripping functions have operated, the repeat keying will be determined by the local fault type determination logic
and the received channels as noted below. If any local trip functions have operated, the channel repeat logic will be blocked
and the local fault type determination will control the keying outputs. If the fault type can not be determined locally, the
received channel(s) will be repeated as received.
Table 1–9: REPEAT KEYING LOGIC
LOCAL FAULT TYPE
AG
BG
CG
Any LL or LLG
GE Power Management
RECEIVER
RCVR #1·(!RCVR #2)
(!RCVR #1)·RCVR #2
RCVR #1·RCVR #2
RCVR #1·RCVR #2
RCVR #1·(!RCVR #2)
(!RCVR #1)·RCVR #2
RCVR #1·(!RCVR #2)
(!RCVR #1)·RCVR #2
RCVR #1·RCVR #2
(!RCVR #1)·RCVR #2
RCVR #1·(!RCVR #2)
RCVR #1·RCVR #2
RECEIVER
RCVR #1 + RCVR #2
RCVR #1 + RCVR #2
RCVR #1 + RCVR #2
----
ALPS Advanced Line Protection System
1.9 PHASE IDENITIFIED CHANNEL SCHEMES
PHASES TO TRIP
A
B
C
3 Phase
A
B
3 Phase
B
C
3 Phase
A
C
REPEAT KEYING
XMTR #1
XMTR #2
XMTR #1·XMTR #2
Repeat as received
1
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