Functions
2.4 Load Restoration
SIPROTEC, 7RW80, Manual
C53000-G1140-C233-1, Release date 10.2010
61
2.4.2 Setting Notes
General
The load restoration is active, if Load Restore = Enabled has been set at address 155 during configuration.
If the function is not required Disabled is set.
The various elements of the load restoration are configured ON orr OFF at addresses 5520, 5540, 5560 and
5580.
Pickup- and Dropout Values
At addresses 5521, 5541, 5561 and 5581 you may configure the start frequency LRx Start for the elements.
The start frequency must be adjusted to a value equal or higher than the tripping frequency of the underfre-
quency element.
At addresses 5523, 5543, 5563 and 5583 may configure the pickup frequency LRx Pickup for the elements.
The pickup frequency and the start frequency add up to the pickup threshold of the load restoration element.
At addresses 5524, 5544, 5564 and 5584 you may configure the delay time LRx t pickup for the pickup of
elements.
At addresses 5525, 5545, 5565 and 5585 you may configure the dropout frequency LRx Dropout the ele-
ments. The dropout frequency and the start frequency add up to the dropout threshold of the load restoration
element.
At addresses 5526, 5546, 5566 and 5586 you may configure the dropout time LRx t dropout for the ele-
ments.
At addresses 5527, 5547, 5567 and 5587 you may configure the close command duration of the circuit
breaker
LRx t CB Close.
The following example illustrates the interaction of the pickup- and dropout values of the load restoration ele-
ments and underfrequency elements.
The pickup threshold of the underfrequency elements 81 U-1, 81 U-2 and 81 U-3 are set to the following fre-
quencies:
81-1 PICKUP 5403 = 49,5 Hz
81-2 PICKUP 5406 = 49 Hz
81-3 PICKUP 5409 = 47.5 Hz
Table 2-3 Settings Example
Parameter LR1 LR2 LR3
Start LR1 Start 5521 = 49,5 Hz LR2 Start 5541 = 49 Hz LR3 Start 5561 = 49 Hz
PICKUP LR1 Pickup 5523 = 0.25 Hz LR2 Pickup 5543 = 0.5 Hz LR3 Pickup 5563 = 0.5 Hz
Dropout LR1 Dropout 5525 = 0 Hz LR2 Dropout 5545 = 0.25 Hz LR3 Dropout 5565 = 0.25 Hz
Trip Time LR1 t pickup 5524 = 14 s LR2 t pickup 5544 = 13 s LR3 t pickup 5564 = 7 s
Dropout Time LR1 t dropout 5526 = 10 s LR2 t dropout 5546 = 10 s LR3 t dropout 5566 = 10 s
CB Close time LR1 t CB Close 5527 = 1 s LR2 t CB Close 5547 = 1 s LR3 t CB Close 5567 = 1s
Underfrequency ele-
ments
LR1 after 81-1 5528 = YES
LR1 after 81-2 5529 = YES
LR1 after 81-3 5530 = YES
LR1 after 81-4 5531 = YES
LR2 after 81-1 5548 = NO
LR2 after 81-2 5549 = YES
LR2 after 81-3 5550 = YES
LR2 after 81-4 5551 = YES
LR3 after 81-1 5568 = NO
LR3 after 81-2 5569 = YES
LR3 after 81-3 5570 = YES
LR3 after 81-4 5571 = YES
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