Hitachi Relion 670 Series Applications Manual page 58

Section 4
Analog inputs
CT 600/5A
Star Connected
IEC16000137 V1 EN-US
Figure 15:
In the example, everything is done in a similar way as in the above described example (Figure 14).
The only difference is the setting of the parameter CTStarPoint of the used current inputs on the
TRM (item 2 in Figure
• CTprim=600A
• CTsec=5A
• CTStarPoint=FromObject
The ratio of the first two parameters is only used inside the IED. The third parameter as set in this
example will negate the measured currents in order to ensure that the currents are measured
towards the protected object within the IED.
A third alternative is to have the residual/neutral current from the two-phase CT set connected to the
IED as shown in Figure 16.
CT 600/5A
Star Connected
IEC16000138 V1 EN-US
Figure 16:
52
L1 L2
IN
IL2
IL1
Protected Object
Star connected two-phase CT set with its star point away from the protected
object
14 and 15):
L1 L2
IN
IL2
IL1
Protected Object
Star connected two-phase CT set with its star point away from the protected
object and the residual/neutral current connected to the IED
© 2017 - 2023 Hitachi Energy. All rights reserved
IED
2
1
3
BLOCK
^GRP2L1
^GRP2L2
^GRP2L1L2
^GRP2N
IED
3
1
4
5
2
1MRK506375-UEN Rev. N
4
SMAI2
AI2P
AI1
5
AI2
AI3
AI4
AIN
IEC16000137-1-en.vsdx
6
SMAI2
BLOCK AI2P
^GRP2L1 AI1
5
^GRP2L2 AI2
^GRP2L1L2 AI3
^GRP2N AI4
AIN
IEC16000138-1-en.vsdx
Railway application RER670
Application manual