Toshiba GR200 Series - (iv) Delay compensation

6F2S1914 (0.49)
GRL200 (Soft 033 & 037)
- 502 -
t
t
Master
IED_G
T
M
T
Slave
IED_H
T
d2
T
d1
T
F
T
A signal in downstream (IED_H to IED_G)
A signal in upstream (IED_G to IED_H)
(2) IED_G
receives the
signal.
(4) IED_H receives its own signal.
Sampling timing at IED_H
Sampling timing at IED_G
(1) IED_H
sends a signal
to IED_G.
(3) IED_G replay to IED_H with the signal received.
T
T
o
δ
Figure 2.36-7 Sampling address after synchronization
(iv) Delay compensation
Synchronized sampling allows compensating the differential protection calculation even if a
transmission delay exists. The compensation is shown in Figure 2.36-8.
t
t
IED G
IED H
4
3
2
1
0
i
B(1)
i
A(0)
i
B(0)
i
A(1)
4
3
2
1
0
Sampling address number
i
A(0)
Differential current calculation
i
B(0)
Figure 2.36-8 Calculation of differential current with transmission delay time
Suppose sampling synchronization is made between the IED_G and the IED_H, their
sampling timing and their sampling address is match between; and their instantaneous
current data and their sampling address are sent each other. Consequently, the IEDs between
can use instant data sampled at the same time and they can compute the differential current
irrelevant to large transmission delay.