Figure. 5.3.5 - 93. Simplified function block diagram of the I2> function.
Measured input
The function block uses analog current measurement values and always uses calculated positive and
negative sequence currents. In the broken conductor mode (I2/I1) the function also uses the RMS
values of all phase currents to check the minimum current. Zero sequence and component sequence
angles are used for fault registering and for fault analysis processing. A -20 ms averaged value of the
selected magnitude is used for pre-fault data registering.
Table. 5.3.5 - 73. Measurement inputs of the I2> function.
Signal
Description
Time base
I1
Positive sequence current magnitude
5 ms
I2
Negative sequence current magnitude
5 ms
IZ
Zero sequence current magnitude
5 ms
I1 ANG
Positive sequence current angle
5 ms
I2 ANG
Negative sequence current angle
5 ms
IZ ANG
Zero sequence current angle
5 ms
IL1RMS
Phase L1 (A) measured RMS current
5 ms
IL2RMS
Phase L2 (B) measured RMS current
5 ms
IL3RMS
Phase L3 (C) measured RMS current
5 ms
General settings
The following general settings define the general behavior of the function. These settings are static i.e.
it is not possible to change them by editing the setting group.
Name
Description
Range Step Default
Measured
magnitude
Defines whether the ratio between the positive and the negative sequence currents
are supervised or whether only the negative sequence is used in detecting
unbalance.
1: I2pu
2: I2/I1
-
1: I2pu
A
AQ
Q-C213
-C213
Instruction manual
Version: 2.04
118