ABB Relion SMU615, Technical Manual

Page: 187 / 272

Figure 121: Integral deadband supervision
The deadband value used in the integral calculation is configured with the X
deadband setting. The value represents the percentage of the difference between
the maximum and minimum limit in the units of 0.001 percent x seconds.
The reporting delay of the integral algorithms in seconds is calculated with the
formula:
t s
deadband
Y
( )
(max min) /
%
=
− ×
×
1000
100 ∆
(Equation 9)
Example for CMMXU:
A deadband = 2500 (2.5% of the total measuring range of 40)
I_INST_A
=
I_DB_A
= 0.30
If
I_INST_A
changes to 0.40, the reporting delay is:
t s s
( )
( ) /
. . %
=
− ×
− ×
=
40 0 2500 1000
0 40 0 30 100
10
Table 205: Parameters for deadband calculation
Function Settings Maximum/
minimum
(=range)
Three-phase current measurement
(CMMXU)
A deadband 40/0 (=40xIn)
Three-phase voltage measurement
(VMMXU)
V Deadband 4/0 (=4xUn)
Residual current measurement (RE-
SCMMXU)
A deadband res 40/0 (=40xIn)
Table continues on the next page
1MRS758407 C Measurement functions
SMU615
Technical Manual
187