Run-Time Model - ABB Relion 670 Series Technical Reference Manual

Section 4
Basic IED functions
4.2.2.2
82
Name of signal
SETCHGD
SETGRPCHGD
FTFERROR

Run-time model

The analog signals to the A/D converter is internally distributed into two different
converters, one with low amplification and one with high amplification, see
IEC05000296 V3 EN
Figure 23: Simplified drawing of A/D converter for the IED.
The technique to split the analog input signal into two A/D converter(s) with different
amplification makes it possible to supervise the A/D converters under normal
conditions where the signals from the two A/D converters should be identical. An
alarm is given if the signals are out of the boundaries. Another benefit is that it
improves the dynamic performance of the A/D conversion.
The self-supervision of the A/D conversion is controlled by the ADx_Controller
function. One of the tasks for the controller is to perform a validation of the input
signals. This is done in a validation filter which has mainly two objects: First is the
validation part that checks that the A/D conversion seems to work as expected.
Secondly, the filter chooses which of the two signals that shall be sent to the CPU, that
is the signal that has the most suitable signal level, the ADx_LO or the 16 times higher
ADx_HI.
Reasons for activation
This signal will generate an Internal Event to the Internal Event list if
any settings are changed.
This signal will generate an Internal Event to the Internal Event list if
any setting groups are changed.
This signal will be active if both the working file and the backup file
are corrupted and can not be recovered.
ADx
ADx_Low
x
1
u
1
x
2
ADx_High
x
1
u
1
x
2
1MRK505222-UUS C
Figure 23.
ADx
Controller
IEC05000296-3-en.vsd
Technical reference manual