GE LPS-D, Инструкция по эксплуатации

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LPS-D Line Protection System GE Power Management
2.3 PROTECTION SETTINGS 2 CALCULATION OF SETTINGS
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2.3.14 SCHMTIMERS
1301: TL1PICKUP - Trip Integrator
• Step Distance Scheme
Timer TL1 is not used in a Step Distance scheme, therefore it is not necessary to make a setting because
any setting that is made will be ignored.
• Blocking Schem e
For a Blocking scheme, TL1 delays tripping at the local end until a blocking signal can be received from the
remote end for an external fault beyond the remote terminal. The setting is determined by two factors:
1. The worst-case time coordination between the remote blocking functions and the local pilot tripping
functions.
2. The total remote-transmitter-keying to local-receiver-output time delay, which is equal to the back-to-
back channel time plus the channel propagation time.
Based on the above, use the following setting:
TL1PICKUP = 3 + channel time + propagation time
where channel time and propagation time are entered in milliseconds.
• PUTT, POTT1, POTT2 and Hybrid Schemes
For these schemes, timer TL1 provides security against spurious channel output during external faults
within the reach of the overreaching trip functions. TL1PICKUP should be based on the maximum output,
if any, expected from the channel under these conditions.
1302: TL4PICKUP: POTT1 Coordination Timer Pickup
• POTT1 Scheme
For a POTT1 scheme, the pickup time delays of timers TL4 and TL1 provide transient-blocking coordina-
tion to prevent a misoperation for current reversals that can occur when a fault on a parallel line is cleared
sequentially. If there is no parallel line, set TL4PICKUP to 0 and set TL1PICKUP as described above
under TL1PICKUP. If there is a parallel line, then use the following settings:
TL1PICKUP = 4 ms
TL4PICKUP = 13 ms + channel release time
Channel release time is defined as the time for the receiver at one end to drop out (release) after transmit-
ter keying at the other end has stopped.
• PUTT Scheme
A PUTT scheme does not require a transient-blocking time delay. Since Zone 1 functions are used to key
the transmitter, the transmitter is not keyed to the TRIP frequency during an external fault, and there is no
race between the reset of the receiver and pickup of a local pilot overreaching function following current
reversals associated with sequential clearing of faults on a parallel line. As such, set TL4PICKUP to 0.
1303: TL4DROPOUT - POTT1 Coordination Timer Dropout
• PUTT and POTT1 Schemes
Set TL4DROPOUT to 0.
• Step Distance, POTT2, Blocking and Hybrid Schemes
Timer TL4 is not used in these schemes therefore any TL4DROPOUT setting that is made is irrelevant and
will be ignored.