Power Swing Blocking Logic; Figure 122: Load Blinder Boundary Conditions - GE MiCOM P40 Technical Manual

Chapter 10 - Power Swing Functions
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Figure 122: Load Blinder Boundary Conditions

The area is defined by lines created with angles fixed at 10° closer to the resistive axis than those created by the
load blinder angle setting (Load/B Angle - 10°) and a circular arc with a radius concentric with, and equivalent
to 20% greater than, the load blinder impedance setting (Z< Blinder Imp + 20%).
This is clearly indicated with reference to the diagram.
Note:
This power swing conditions are completely independent of the slow swing associated with Zone 7 and Zone 8.
3.5

POWER SWING BLOCKING LOGIC

The Power Swing function follows the logic diagram below:
236
jX
Zone x
Blind Region
-jX
Operate Region
-10°
Blind Region
20%
Load blinder boundary
P446SV
Power Swing region
(shaded area)
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P446SV-TM-EN-1