The following figure shows the logic diagram for underexcitation protection.
Figure 2-21
2.11.2 Setting Notes
General
The underexcitation protection is only effective and available if this function was set
during protective function configuration (Section 2.2, address 130, UNDEREXCIT. is
set to Enabled. If the function is not required Disabled is set. The address 3001
UNDEREXCIT. serves to enable the function ON and OFF or to block only the trip
command (Block relay).
The correct power system data input according to Section 2.3 is another prerequisite
for the parameterization of the underexcitation protection.
7UM61 Manual
C53000-G1176-C127-3
2.11 Underexcitation (Loss-of-Field) Protection (ANSI 40)
Logic diagram of the Underexcitation Protection
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