Toshiba GR200 Series Instruction Manual page 198

Setting of the sensing angle (θ) is configured by the setting [EF1-Angle] with the value of θ set
in the range of 0–180°. Figure 2.6-2 shows an example of an angle and a characteristic using
the θ. The operation of the EF element is based upon the following equation.
where
3Io = residual current
3Vo = residual voltage
−3Vo = reference voltage (or polarizing voltage)
φ= lagging angle
θ = EF setting angle
I = Setting value of the EF element ([EF1-DT] and the others)
EF
EF_Vpol = Setting value of the polarizing voltage ([EF1-Vpol])
Note: In the case of an internal fault, the phase angle is equal to the angle of the zero-
sequence impedance of the system, in a directly-earthed system this value is in
the range of approximately 50° to 90°. The sensing angle θ of the EF element can
be set between 0° to 180°. The minimum voltage necessary to maintain
directionality can be set from 0.5 to 100.0 V.
Forward
Reverse
θ=0°
Reverse
Forward
θ=100°
θ=100°
Figure 2.6-2 Examples of directional characteristic angle (θ)
3�� ≥ ��
0 ����
3�� × cos (φ − θ) ≥ 0
0
3�� ≥ ����_��������
0
−3Vo
Forward
Reverse
θ=30°
Forward
−3Vo
θ=170°
- 177 -
−3Vo
θ=30°
Reverse
−3Vo
θ=170°
6F2S1915 (0.46)
(2.6-1)
(2.6-2)
(2.6-3)
Reverse
−3Vo
θ=90°
Forward
θ=90°
GRZ200 (Soft 031 & 032)