ABB RELION Series Technical Manual page 289

1MRS758755 A
REC615 and RER615
Technical Manual
If the Enable voltage limit setting is set to "True", the magnitude of the
polarizing quantity is checked even if Directional mode is set to "Non-
directional" or Allow Non Dir to "True".
The Characteristic angle setting is used in the "Phase angle" mode to adjust the
operation according to the method of neutral point earthing so that in an isolated
network the Characteristic angle (φ
= 0°. In addition, the characteristic angle can be changed via the control signal
RCA_CTL. RCA_CTL affects the Characteristic angle setting.
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.
The polarity of the polarizing quantity can be reversed by setting the Pol reversal to
"True", which turns the polarizing quantity by 180 degrees.
For definitions of different directional earth-fault characteristics, see
the Directional earth-fault characteristics
For definitions of different directional earth-fault characteristics,
refer to general function block features information.
The directional calculation module calculates several values which are presented in
the monitored data.
Table 319: Monitored data values
Monitored data values
FAULT_DIR
DIRECTION
ANGLE
ANGLE_RCA
I_OPER
Protection functions
) = -90° and in a compensated network φ
RCA
section in this manual.
Description
The detected direction of fault during fault
situations, that is, when START output is active.
The momentary operating direction indication
output.
The angle difference between the operating angle
Characteristic angle , that is, ANGLE_RCA =
and
ANGLE – Characteristic 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).
Operation mode setting is "IoCos", I_OPER
If the
is calculated as follows I_OPER = Io x
cos(ANGLE).
Section 4
RCA
283