MI 2883 Energy Master
Theory and internal operation
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5 Theory and internal operation
This section contains basic theory of measuring functions and technical information of
the internal operation of the Energy Master instrument, including descriptions of
measuring methods and logging principles.
5.1 Measurement methods
5.1.1 Measurement aggregation over time intervals
Standard compliance: IEC 61000-4-30 Class A (Section 4.4)
The basic measurement time interval for:
Voltage
Current
Power
Harmonics
Interharmonics
Signalling
Unbalance
is a 10/12-cycle time interval. The 10/12-cycle measurement is resynchronized on each
Interval tick according to the IEC 61000-4-30 Class A. Measurement methods are
based on the digital sampling of the input signals, synchronised to the fundamental
frequency. Each input (4 voltages and 4 currents) is simultaneously sampled.
5.1.2 Voltage measurement (magnitude of supply voltage)
Standard compliance: IEC 61000-4-30 Class S (Section 5.2)
All voltage measurements represent RMS values of the voltage magnitude over a
10/12-cycle time interval. Every interval is contiguous, and not overlapping with adjacent
intervals.
L1
L3
L2
N
GND
U
1
U
2
U
3
U
N
U
1
2
U
2
3
U
3
1
Figure 5.1: Phase and Phase-to-phase (line) voltage
Voltage values are measured according to the following equation:
Phase voltage:
M
j
j
p
p
u
M
U
1
2
1
[V], p: 1,2,3,N
(1)
