ABB RED615 Technical Manual page 400

Section 4
Protection functions
394
faults. When the operation of the biased low stage is blocked by the second
harmonic blocking functionality, the BLKD2H output is activated.
When operation of the biased low stage is blocked by the fifth harmonic blocking
functionality, the BLKD5H output is activated. Correspondingly, when the
operation of the biased low stage is blocked by the waveform blocking
functionality, the BLKDWAV output is activated according to the phase information.
When required, the operate outputs of the biased low stage can be blocked by the
BLK_OPR_LS or BLOCK external control signals.
I [%Ir]
d
300
200
100
I
d1
Low operate value
Section 1
End section 1
GUID-EAAB6851-B6A9-4A69-B962-1725A4928D54 V3 EN
Figure 210: Operation characteristic for biased operation of TR2PTDF
The Low operate value of the biased stage of the differential function is determined
according to the operation characteristic:
Low operate value = Id1
Slope section 2 is determined correspondingly:
Slope section 2 = Id 2 / Ib 2 100
GUID-D1C2CAED-3D58-4405-A79D-17B203A8D3A9 V3 EN
The second turning point End section 2 can be set in the range of 100 percent to
500 percent.
The slope of the differential function's operating characteristic curve varies in the
different sections of the range.
I
b2
I
d2
100 200
Section 2
End section 2
× %
1YHT530004D05 D
I
b3
I
d3
300 400 500
Section 3
Technical Manual
I [%Ir]
b
(Equation 50)
615 series