ABB RED650 - Page 150

IEC99000530-2-en.vsdx
Y
t
Value Reported
(1st)
Y1
Value
Reported
A1Y2
Value
Reported
Y3
Y4
A
Value
Reported
A2
Y5
A3
A4
A5
A7
A6
Value
Reported
A2 >=
pre-set value
A1 >=
pre-set value
A >=
pre-set value
A3 + A4 + A5 + A6 + A7 >=
pre-set value
IEC99000530 V2 EN-US
Figure 64: Reporting with integral dead-band supervision
Measurement ZMMMXU
GUID-2DB6F5A4-A3C2-4BBA-8327-393B7F89EDC6 v4
The magnitude and angle of the impedance for each phase-to-earth and phase-to-
phase loop are available on local HMI, monitoring tools within PCM600 or to the
station level, for example, via IEC61850.
Phase-to-earth impedance measurement is calculated based on
U
L1
/
IL1
,
UL2
/
IL 2
,
UL3
/
IL3
and phase-to-phase impedance is calculated based on
   
1 2 1 2/L L L LU U I I
,
   
2 3 2 3/L L L LU U I I
,
   
3 1 3 1/L L L LU U I I
, where
ULX
and
ILX
are phase-to-earth voltage and phase current.
When the operating current is too low, the impedance measurement can be
erroneous. To avoid such error, minimum operating current will be checked. For
phase-earth currents or phase-phase currents lower than 2% of IBase, the resistance
and reactance of the impedance are forced to 99 999 ohm, corresponding to a
magnitude at 141419 (99 999*√2) ohm and an angle at 45 degree.
Section 7 1MRK 505 394-UEN A
Impedance protection
144 Line differential protection RED650 2.2 IEC
Technical manual