FUNCTION CHARACTERISTICS
55
4.3
I/0 DESCRIPTION
—
Metering inputs
CT-VT input version
XMR-A
4I+1V/1A
XMR-V
4V
XMR-P
4I+4V
XMR-D
4I+4V
(4I+64F)
XMR-T
8I+1V
XMR-T PRO
11I+1V
2 windings
3 windings
Measuring inputs
Phase current
1/5A CT (x3)
-
1/5A CT (x3)
1/5A CT (x6)
1/5A CT (x6)
1/5A CT (x9)
Residual current
1/5A CT (x1)
-
1/5A CT (x1)
1/5A CT (x2)
1/5A CT (x2)
1/5A CT (x2)
Phase voltage
-
100/400V VT (x3) 100/400V VT (x3)
100/400V VT (x3)
100V VT (x1)
100V VT (x1)
or
or
Homopolar voltage
-
100V VT (x1)
100V VT (x1)
100V VT (x1)
100V VT (x1)
100V VT (x1)
Signal processing
Various processing levels are involved:
• Acquisition (base level).
• Direct measures of physical channels (first level).
• Calculated measures (second level).
• Derived (third level).
The measures concerning a level are based on data worked out in the previous level.
For each level the required resources concerning the priority for tasks (conditioning circuits, DSP
and CPU) are on hand.
ACQUISITION (base level)
The input signals are sampled 64 times per period::
-
i
L1
...
i
L3
Phase current instantaneous values
-
i
E
Residual current instantaneous value
-
u
L1
...
u
L3
Phase voltage instantaneous values
-
u
E
Residual voltage instantaneous value (traditional VT inputs only)
From the sampled quantities, several measures are computed for protection, monitoring and mete-
ring purposes.
• Direct
• Calculated
• Phase
• Sequence
• Power
• Harmonic
• Demand
• Energy.
sensors.ai
XMR-x
3 phase voltage inputs
3 phase current inputs
1 residual current input
1 residual voltage input
acquisizione.ai
≈
ACQUISITION
instantaneous measures
XMR-D EQUIPMENT MANUAL
Ed. 2.9 - 02/2021