Toshiba GR200 Series Instruction Manual page 525

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