CYG PRS-7367 - Application Scope; Settings; Under Voltage Protection CUB_27; CUB_27 Overview

Protection Functions
100 PRS-7367
block the start signals. The binary input 27P_Blk_Op can be used to block the operation signals.
3.16.3 27P Application Scope
27P can be applied for protecting a power station used for embedded generation when network
faults like short circuits or phase-to-earth faults in a transmission or a distribution line cause
potentially dangerous situations for the power station.
27P complements other loss-of-grid protection principles based on the frequency and voltage
operation.
Motor stalling and failure to start can lead to a continuous under voltage. The positive- sequence
under voltage is used as a backup protection against the motor stall condition.
3.16.4 27P Settings
Table 3.16-3 27P settings
No.
Name
Values(Range)
Unit
Step
Default
Description
1
27P_Vol_Str
0.00 -120.00
V
0.01
110
Positive sequence under
voltage start value
2
27P_Op_T
0.04 - 120.00
s
0.01
0.04
Operate delay time
3
27P_Vol_Blk
18.00 - 100.00
V
0.01
30
Internal blocking voltage level
4
27P_Vol_Blk_Ena
0-1
-
-
1
Enable Internal Blocking
5
27P_Ena
0-1
-
-
1
Operation Enable/Disable
3.17 Under voltage protection CUB_27
3.17.1 CUB_27 Overview
The under voltage protection function CUB_27 is used to disconnect capacitor from the system
when the voltage of capacitor is less than setting value.