Alstom MiCOM P545 - 1.33 Overvoltage protection

P54x/EN OP/La4 Operation
(OP) 5-90 MiCOM P543, P544, P545 & P546
OP
The logic diagram for the first stage undervoltage function is shown in Figure 62.
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A Phase Start
B Phase Start
C Phase Start
C Phase Trip
B Phase Trip
A Phase Trip
IDMT/DT
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IDMT/DT
IDMT/DT
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&
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&
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VA</VAB<
Undervoltage
VB</VBC<
Undervoltage
VC</VCA<
Undervoltage
Fast VTS Block
All Poles Dead
Undervoltage Timer Block
(One stage)
P1636ENd
DDB 683 or
DDB 684 or
DDB 685 or
DDB 686 or
DDB 688 or
DDB 689 or
DDB 6901
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DDB 687
Setting: V<operate mode/Any Phase
Setting: V<operate mode/3 Phase
Figure 62 Undervoltage - single and three phase tripping mode (single stage)
Note: Undervoltage protection is phase segregated, but the operation of any
phase is mapped to 3 phase tripping in the default PSL.
Each stage of Undervoltage protection may be disabled by a DDB (471 or 472) Inhibit Vx<.
1.33 Overvoltage protection
Both the over and un
dervoltage protection functions can be found in the relay menu Volt
Protection. The measuring mode (ph-N or ph-ph) and operating mode (single phase or 3
phase) for both stages are independently settable.
The IDMT characteristic available on the first stage is defined by the following formula:
t = K/(M - 1)
Where:
K = Time multiplier setting
t = Operating time in seconds
M = Measured voltage/relay setting voltage (V> Voltage Set)
The logic diagram for the first stage overvoltage function is shown in Figure 63.