Toshiba GR200 Series Instruction Manual page 216

(I ) for stage 1 with the setting [OCN1] and Forward can be set for the scheme switch [OCN1-
OCN
Dir]. Setting of the sensing angle (θ) is configured by the setting [OCN1-Angle] with the value
of θ in the range of 0–180°. Figure 2.7-2 shows an example of an angle and a characteristic
using the θ.
The operation decision of OCN uses the following equation:
where
I 2 = Negative phase sequence current
V 2 = Negative phase sequence voltage
−V 2 = reference voltage (or polarizing voltage)
Φ = lagging angle
θ = OCN setting angle ([OCN1-Angle])
I OCN = Setting value of OCN ([OCN1] and the others])
OCN_Vpol = Setting value of the polarizing voltage ([OCN1-Vpol])
Note: The phase angle in the event of an internal fault is equal to the angle of the zero-
sequence impedance of the system; this value ranges approximately from 50° to
90°. The θ of OCN can be set from 0° to 180°. The minimum voltage necessary to
maintain directionality can be set from 0.5 to 180 V.
Forward
Reverse
θ=0°
Reverse
Forward
θ=100°
θ=100°
Figure 2.7-2
�� ≥ ��
2
�� × cos (φ − θ) ≥ 0
2
�� ≥ ������_��������
2
Vpol
Reverse
θ=30°
Forward
Vpol
θ=170°
Examples of directional characteristic angle (θ)
- 195 -
������
Vpol
θ=30°
Forward
Reverse
Vpol
θ=170°
6F2S1915 (0.46)
(2.7-1)
(2.7-2)
(2.7-3)
Reverse
Vpol
θ=90°
Forward
θ=90°
GRZ200 (Soft 031 & 032)