GE F650 Instruction Manual page 199

5.4 PROTECTION ELEMENTS
Figure 5–8: OVERCURRENT ELEMENTS BLOCK CONFIGURATION BY THE DIRECTIONAL ELEMENT
Directional elements can also be blocked with signals coming from other relays, PLCs, or through signals configured in the
relay PLC Editor (Logic configuration tool). The signal used in that case is PHASE DIR BLK INP. Figure 5–9: shows an
example of the default block configuration of directional elements by digital input. There is one block signal per input for
5
each setting group.
Figure 5–9: DIRECTIONAL ELEMENT BLOCK CONFIGURATION BY INPUT
The main component of the phase directional element is the angle comparator with two inputs: the operation magnitude
(phase current) and the polarization magnitude (phase-to-phase voltage rotated the angle set in MTA setting), which is the
torque angle.
The Polarization type used in the directional element is crossed, this means that in case of a fault in phase A, the Operation
magnitude will be Ia, and the polarization magnitude will be Vbc, rotated by the torque angle. In case of a fault in phase B,
the operation magnitude will be Ib, and the polarization magnitude will be Vca rotated by the torque angle. Finally, in case
of a fault in phase C, the operation magnitudes will be Ic, and Vab.
Table 5–44: OPERATION AND POLARIZATION MAGNITUDES FOR DIRECTIONAL UNITS
PHASE
A
B
C
5-52
OPERATING SIGNAL ABC PHASE SEQUENCE
IA angle VBC angle x 1 MTA
IB angle VCA angle x 1 MTA
IC angle VAB angle x 1 MTA
F650 Digital Bay Controller
POLARIZING SIGNAL VPOL
ACB PHASE SEQUENCE
VCB angle x 1 MTA
VAC angle x 1 MTA
VBA angle x 1 MTA
5 SETTINGS
GEK-106310AB