Toshiba GR200 Series - 2.27.1 Operation characteristic

6F2S1914 (0.49)
GRL200 (Soft 033 & 037)
- 351 -
2.27.1 Operation characteristic
Two elements are provided to detect an out-of-step condition. Figure 2.27-1 shows the operation
principle of the OSTV function. Reference voltage (V
A
) is acquired in IED A at terminal A; and
a corresponding voltage (V
B
) is acquired in IED B at terminal B. Using the telecommunication
1
voltage data at both terminals are provided to the respective opposite terminals. Electrical
center is located at which the respective impedances for respective terminals are equal.
Figure 2.27-1 Typical impedance and electrical center
1
Note: The data is transferred by the function of ‘Communication application’. For more
information, see Chapter Relay application: Communication application .
Figure 2.27-2 is the characteristic of the OSTV-1 element. Phasor V
B
will exist in the
second quadrant (α-zone) or the third quadrant (β-zone) if the out-of-step state is appeared.
This is because a reference voltage is obtained at terminal A.
Figure 2.27-2 Voltage phase comparison between terminal A and terminal B (OSTV-1)
IED A
V
A
V
B
Data of V
B
Telecommunication
Electrical center
Terminal A
Terminal B
Z
A
Z
B
Z
L
(Z
A
+Z
L
+Z
B
)/2
(Z
A
+Z
L
+Z
B
)/2
IED B
Left impedance
Right impedance
Data of V
A
-zone
V
B
-zone
V
A
1V