ABB RELION REX640 - Page 1438

Figure 804: 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 338)
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 1359: Parameters for deadband calculation
Function Settings Minimum/maximum
Three-phase current measurement (CMMXU) A deadband 0.04/40
Three-phase voltage measurement (VMMXU) V deadband 0.004/4
Phase voltage measurement (VMHMMXU) V deadband 0.004/4
Single-phase voltage measurement (VAMM-
XU)
V deadband 0.004/4
Residual current measurement (RESCMMXU) A deadband res 0.04/40
Residual voltage measurement (RESVMMXU) V deadband res 0.004/4
Frequency measurement (FMMXU) F deadband 0.04/40
Table continues on the next page
Measurement functions 1MRS759142 F
1438 REX640
Technical Manual