ABB RELION 620 Series Technical Manual page 208

Section 4
Protection functions
202
The Correction angle setting can be used to improve selectivity due the inaccuracies in the
measurement transformers. The setting decreases the operation sector. The correction can
only be used with the "IoCos" or "IoSin" modes.
When polarizing quantity (zero sequence voltage (-U
voltage measurement cables, the correction can be done by setting the Pol reversal to
"True" which turns polarizing quantity by 180 degrees.
For definitions of different directional ground-fault characteristics, see
the Directional ground-fault characteristics
The directional calculation module calculates several values which are presented in the
monitored data.
Table 154: Monitored data values
Monitored data values
FAULT_DIR
DIRECTION
ANGLE
ANGLE_RCA
I_OPER
Monitored data values are accessible on the LHMI or through tools via communications.
Timer
Once activated, the timer activates the PICKUP output. Depending on the value of the
Operating curve type setting, the time characteristics are according to DT or IDMT. When
the operation timer has reached the value of Trip delay time in the DT mode or the
maximum value defined by the inverse time curve, the TRIP output is activated.
)) is inverted because of switched
0
section in this manual.
Description
The detected direction of fault during fault situations,
that is, when PICKUP output is active.
The momentary operating direction indication
output.
Also called operating angle, shows the angle
difference between the VG (polarizing quantity) and
Io (operating quantity).
The angle difference between the operating angle
Characteristic angle , that is, ANGLE_RCA =
and
Characteristic angle .
ANGLE –
The current that is used for fault detection. If the
Operation mode setting is "Phase angle", "Phase
angle 80" or "Phase angle 88", I_OPER is the
measured or calculated residual current. If the
Operation mode setting is "IoSin", I_OPER is
calculated as follows I_OPER = Io x sin(ANGLE). If
Operation mode setting is "IoCos", I_OPER is
the
calculated as follows I_OPER = Io x cos(ANGLE).
1MAC504801-IB E
620 series ANSI
Technical Manual