ABB RELION REX640 Technical Manual page 537

1MRS759142 C
REX640
Technical Manual
+90 deg.

Tilt angle
-90 deg.
GUID-A7DE7E6B-6170-4805-A126-F9F94196ECAE V1 EN
Figure 289: Directional characteristic of MFADPSDE
The residual current should be measured with accurate Core Balance
Current Transformer (CBCT) to minimize the measurement errors,
especially phase displacement. This is especially important when high
sensitivity of protection is targeted.
The characteristic Tilt angle should reflect the measurement errors,
that is, the larger the measurement errors, the larger the Tilt angle
setting should be. A typical setting value of 5 degrees is
recommended.
The maximum value for characteristic Tilt angle depends on the ratio
of the resistive and reactive component in the measured residual
current Io. The operation point moves away from the operation sector
mid-point; the lower is the ratio of the resistive and reactive
component in the measured residual current Io. The phase angle of
operation point in the faulted feeder can be approximated with
equation
+45 deg.

0 deg.


Section 4
Protection functions
531