ABB RELION REX640 Technical Manual page 829

1MRS759142 F
clockwise sector, a measurement from the
been rotated 180 degrees.
Relay characteristic angle (RCA) is set positive if the operating current lags the
polarizing quantity and negative if the operating current leads the polarizing
quantity.
Figure 469: Configurable operating sectors
The angle difference ANGLE between the negative-sequence current and the
polarizing quantity is calculated as shown below and is available in the Monitored
data view.
ANGLE
Based on the ANGLE value, the direction information DIRECTION is evaluated and is
made available in the Monitored data view.
Table 745: Momentary direction value for monitored data view
Criterion for direction information
ANGLE_X is not in any of the defined sectors,
or the direction cannot be defined due too
low amplitude
ANGLE_X is in the forward sector
ANGLE_X is in the reverse sector
REX640
Technical Manual
( ) ( )
φ U φ I φ
= − − −
RCA
2 2
Protection functions
Characteristic angle setting that has
Value for DIRECTION
0 = unknown
1 = forward
2 = backward
(Equation 235)
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