METREL power master MI 2892, Instruction Manual

Page: 171 / 207

MI 2892 Power Master Theory and internal operation
171
Arithmetic average:



N
j
j avg
A
N
A
1
1
Where:
A
avg
– quantity average over given aggregation interval
A – 10/12-cycle quantity value
N – number of 10/12 cycles measurements per aggregation interval.
(74)
In the next table averaging method for each quantity is specified:
Table 5.7: Data aggregation methods
Group Value Aggregation method
Recorded values
Voltage
U
Rms
RMS average Min, Avg, Max
THD
U
RMS average Avg, Max
CF
U
RMS average Min, Avg, Max
Current
I
Rms
RMS average Min, Avg, AvgOn, Max
THD
I
RMS average Min, Avg, AvgOn, Max
CF
I
RMS average Min, Avg, AvgOn, Max
Frequency
f(10s) -
f(200ms) RMS average Min, AvgOn, Max
Power
Combined Arithmetic average
Min, Avg, AvgOn, Max
Fundamental
Arithmetic average Min, Avg, AvgOn, Max
Nonfundamental
Arithmetic average Min, Avg, AvgOn, Max
Unbalance
U
+
RMS Min, Avg, Max
U
-
RMS
Min, Avg, Max
U
0
RMS Min, Avg, Max
u- RMS
Min, Avg, Max
u0 RMS
Min, Avg, Max
I
+
RMS
Min, Avg, AvgOn, Max
I
-
RMS
Min, Avg, AvgOn, Max
I
0
RMS
Min, Avg, AvgOn, Max
i- RMS
Min, Avg, AvgOn, Max
i0 RMS
Min, Avg, AvgOn, Max
Harmonics
DC, Uh
0÷50
RMS Avg, Max
DC, Ih
0÷50
RMS Avg, AvgOn, Max
Interharmonics
Uh
0÷50
RMS Avg, Max
Ih
0÷50
RMS Avg, AvgOn, Max
Signalling U
Sig
RMS Min, Avg, Max
An active average value is calculated upon the same principle (arithmetic or RMS) as average value, but
taking in account only measurement where measured value is not zero:
RMS active average
N M A
M
A
M
j
j RMSact
 


;
1
1
2
(75)
Where: