• The ratio between the calculated minum and maximum of the three-phase currents is below
the
I
set
ratio setting.
• The ratio between the negative sequence and the positive sequence exceeds the
I2/I1
ratio setting.
• The calculated difference (IL1+IL2+IL3+I0) exceeds the
I
sum
difference setting (optional).
• The above-mentioned condition is met until the set time delay for alarm.
The inputs of the function are the following:
• setting parameters
• measured and pre-processed current magnitudes.
The output signals can be used for direct I/O controlling and user logic programming. The
function generates general time-stamped ON/OFF events to the common event buffer from each of the
two (2) output signal. The time stamp resolution is 1 ms. The function also provides a resettable
cumulative counter for the CTS ALARM and BLOCKED events.
The following figure presents a simplified function block diagram of the current transformer supervision
function.
A
AQ
Q-F201
-F201
Instruction manual
Version: 2.04
164