Figure. 5.3.1 - 77. Principle diagram of the protection relay platform.
In the following chapters the common functionalities of protection functions are described. If a
protection function deviates from this basic structure, the difference is described in the corresponding
chapter of the manual.
Pick-up
The
X
set
parameter defines the pick-up level of the function, and this in turn defines the maximum or
minimum allowed measured magnitude (in per unit, absolute or percentage value) before the function
takes action. The function constantly calculates the ratio between the pick-up parameter set by the
user and the measured magnitude (
X
m
). The reset ratio of 97 % is built into the function and is always
relative to the
X
set
value. If a function's pick-up characteristics vary from this description, they
are defined in the function section in the manual.
Figure. 5.3.1 - 78. Pick up and reset.
The pick-up activation of the function is not directly equal to the START signal generation of the
function. The START signal is allowed if a blocking condition is not active.
A
AQ
Q-F215
-F215
Instruction manual
Version: 2.04
94
