Instruction manual
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AQ G3x7 Generator protection IED
68 (211
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Figure 3-38: Wattmetric and varmetric operating characteristics.
In the in the figure above are presented the characteristics of the wattmetric and varmetric
operating principles in forward direction. For reverse operating direction the operating
vectors are turned 180 degrees.
Table 3-22 Setting parameters of the residual directional overcurrent function
Parameter
Setting value, range
and step
Description
Direction
NonDir,
Forward-Angle,
Backward-Angle,
Forward-I0*cos(fi),
Backward-I0*cos(fi),
Forward-I0*sin(fi),
Backward-I0*sin(fi),
Forward-I0*sin(fi+45),
Backward-
I0*sin(fi+45)
Direction mode selection of the function. By the
direction mode selection also the operating
characteristics is selected either non directional,
operating angle mode, wattmetric I0cos(fi) or varmetric
I0sin(fi) mode.
Uo min
1…10 %, by step of
1%
The threshold value for the 3Uo zero sequence voltage,
below this setting no directionality is possible. % of the
rated voltage of the voltage transformer input.
Io min
1…50 % by step of
1%
The threshold value for the 3Io zero sequence current,
below this setting no operation is possible. % of the
rated current of the current transformer input.
With 0.2A
sensitive current module 2 mA secondary current pick-
up sensitivity can be achieved. (ordering option)
Operating Angle
30…90 deg by step of
1 deg
Width of the operating characteristics in relation of the
Characteristic Angle
(only in Forward/Backward-Angle
mode).
Operating Angle setting value is
±
deg from the
reference Characteristic Angle setting. For example
with setting of Characteristic Angle = 0 deg and
Operating Angle 30 deg Forward operating
characteristic would be area 30 deg and -30
deg.