Hitachi Relion 670 Series Applications Manual page 63

1MRK506375-UEN Rev. N
3)
4)
5)
4.2.4.4 Example on how to connect a residually connected IED
Figure 20
noted that this type of VT connection presents a secondary voltage proportional to 2U0 to the IED.
The primary rated voltage of an open Delta VT is always equal to U
secondary windings gives a secondary voltage equal to the sum of the two phase voltages. Thus the
secondary windings of open deltaVTs may have a secondary rating of 110/2V.
Figure 20
to the built-in protection and control functions within the IED as well.
132 kV
2
100
132 kV
2
100 V
2
IEC16000152 V1 EN-US
Figure 20: Residually connected VT in two-phase power system
Railway application RER670
Application manual
are two connections made in Signal Matrix Tool (SMT), which connect these two voltage inputs to first
two input channels of the preprocessing function block 5). Depending on the type of functions which
need this voltage information, more than one preprocessing block might be connected in parallel to these
VT inputs.
shows that in this example the fourth (that is, residual) input channel of the preprocessing block is not
connected in SMT tool. Thus the preprocessing block will automatically calculate 2Uo inside by vectorial
sum from the two phase to earth voltages connected to the first two input channels of the same
preprocessing block. Alternatively, the fourth input channel can be connected to open delta VT input, as
shown in Figure 20.
is a Preprocessing block that has the task to digitally filter the connected analog inputs and calculate:
• fundamental frequency phasors for all input channels
• harmonic content for all input channels
• positive and zero sequence quantities by using the fundamental frequency phasors for the first two
input channels (channel one taken as reference for sequence
These calculated values are then available for all built-in protection and control functions within the IED,
which are connected to this preprocessing function block in the configuration tool. For this application
most of the preprocessing settings can be left to the default values. However the following settings shall
be set as shown here:
UBase=132 kV (that is, rated Ph-Ph voltage)
gives an example about the wiring of a residually connected VT to the IED. It shall be
gives overview of required actions by the user in order to make this measurement available
L1
L2
V
2
+2Uo
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IED
2
3
1
Analog inputs
. Two series connected VT
Ph-E
5
SMAI2
BLOCK
^GRP2L1
^GRP2L2
^GRP2L1L2
^GRP2N
4
IEC16000152-1-en.vsdx
Section 4
SEMOD55055-163 v9
AI2P
AI1
AI2
AI3
AI4
AIN
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