ABB RELION 670 Series Technical Manual page 332

Section 7
Impedance protection
Y
Value Reported
(1st)
IEC99000529 V2 EN-US
Figure 169: Magnitude dead-band supervision reporting
After the new value is reported, the ±ΔY limits for dead-band are automatically set around it. The
new value is reported only if the measured quantity changes more than defined by the ±ΔY set
limits.
Integral dead-band reporting
The measured value is reported if the time integral of all changes exceeds the pre-set limit
XDbRepInt ), figure 170, where an example of reporting with integral dead-band supervision is
(
shown. The picture is simplified: the process is not continuous but the values are evaluated with a
time interval of one execution cycle from each other.
The last value reported, Y1 in figure
difference is calculated between the last reported and the newly measured value and is multiplied
by the time increment (discrete integral). The absolute values of these integral values are added
until the pre-set value is exceeded. This occurs with the value Y2 that is reported and set as a new
base for the following measurements (as well as for the values Y3, Y4 and Y5).
The integral dead-band supervision is particularly suitable for monitoring signals with small
variations that can last for relatively long periods.
326
Value Reported
Y3
Y
Y2
Y
Y
Y
Y1
Value Reported
Y
Y
170 serves as a basic value for further measurement. A
1MRK 502 066-UUS B
Value Reported
t
IEC99000529-2-en.vsdx
SEMOD54417-167 v4
Technical manual