ABB RER670 Applications Manual page 63

1MRK 506 375-UEN A
Railway application RER670 2.2 IEC
Application manual
132 kV
2
110 V
2
132 kV
2
110 V
2
IEC16000140 V1 EN-US
Figure 17: A two phase-to-earth connected VT
Where:
1) shows how to connect two secondary phase-to-earth voltages to two VT inputs on the
IED
2) is the TRM where these voltage inputs are located. For these voltage inputs, the
following setting values shall be entered:
VTprim = 132 kV
VTsec = 110 V
Inside the IED, only the ratio of these two parameters is used. It shall be noted that the
ratio of the entered values exactly corresponds to ratio of one individual VT.
132 / 2

132 / 110 k
110 / 2
IECEQUATION16055 V1 EN-US
3) 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.
4) 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 18.
5) 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)
L1
IED
L2
1
k
Section 4
Analog inputs
2
3
SMAI2
BLOCK AI2P
^GRP2L1 AI1
5
^GRP2L2
AI2
^GRP2L1L2 AI3
^GRP2N AI4
AIN
4
IEC16000140-1-en.vsdx
(Equation 2)
57