ABB RELION Series Technical Manual page 460

Section 4
Protection functions
454
U1
I1
BLOCK
GUID-98A9A06F-278C-41CD-9E01-BF2D059CC931 V1 EN
Figure 230: Functional module diagram
Directional detector
The Directional detector module compares the angle of the positive-sequence current
I1 to the angle of the positive-sequence voltage V1. Using the positive-sequence
voltage angle as reference, the positive-sequence current angle is compared to the
Characteristic angle setting. If the angular difference is within the operating sector
selected with the Directional mode setting, the On signal is sent to Timer.
The operating sector is defined by the setting Min forward angle, Max forward angle,
Min reverse angle and Max reverse angle. The options that can be selected for the
Directional mode setting are "Forward" and "Reverse".
The sector limits are always given as positive degree values.
The Characteristic angle setting is also known as Relay
Characteristic Angle (RCA), Relay Base Angle or Maximum Torque
Line.
Timer
Directional
t
detector
Low level
blocking
Blocking
logic
1MRS758755 A
RELEASE
REC615 and RER615
Technical Manual