Operation Manual

MI 2092 Power Harmonics Analyser Section VI Theory of operation
49
When measuring Power and Power Factor, values can be calculated for each individual
cycle or averaged over a period (the ‘Power sub IP’) which can be set at any value
between 1 and 20 cycles (a 400 ms window at 50Hz).
If the Instrument is recording a power, it automatically calculates and records the
energy of the selected power in an IP.
Values used for the calculation of maximum and minimum Powers and Power
Factors are the average values calculated on power sub IP values (see fig. 35
below).
Recording of voltage or current THD is automatically enabled if one or more individual
voltage or current harmonics are selected.
20 ms @ 50Hz
P
P
1
P
2
P
3
P
4
P
5
P
6
P
7
P
8
P
9
P
10
P
11
P
12
P
13
P
14
P
15
P
16
P= P
min5
P= P
mina
P avg
P
avg
P= P
max6
P= P
maxb
P
P
t
t
t
P=(P+P+P+P+P)/ 5
a12345
P=(P+P+P+P+P)/ 5
b678910
P=(P+P+P+P+P)/ 5
c1112131415
Sub IP=1
Sub IP=5
Examples of calculation of Maximum & Minimum values for various ‘Power sub
IP’ periods
fig. 41