METREL MI 2792 PowerQ4 Plus, Instruction Manual

Page: 114 / 138

MI 2792 PowerQ4 Plus
Theory and internal operation
114
Q Arithmetic
S Arithmetic
PF Arithmetic
DPF (cos
φ ) Arithmetic
U
+
RMS
U
-
RMS
U
0
RMS
u- RMS
u0 RMS
I
+
RMS
I
-
RMS
I
0
RMS
i- RMS
Symmetry
i0 RMS
Uh
1÷50
RMS
Harmonics
Ih
1÷50
RMS
Uh
1÷50
RMS
Interharmonics
Ih
1÷50
RMS
Signalling U
Sig
RMS
Parameter which will be recorded during recording session depends on Connection and
Synchronization channel, as shown in Table 4.6. For each parameter:

minimum,

average,

maximum,

active average,
value is recorded per time-interval.
Note: In EN 50160 recording only average values are stored. In order to perform
EN50160 recording with minimum and maximum values, use general type of recording
and later convert it into EN50160 type of record by using Powerview v2.0 software.
An
active average value is calculated upon the same principle (arithmetic or RMS) as
average value, but taking in account just measurements with “active” attribute set:
RMS active average
N M A
M
A
M
j
j RMSact
 


;
1
1
2
(30)
Where:
A
RMSact
– quantity average over active part of given aggregation interval,
A – 10-cycle quantity value marked as “active”,
M – number of 10 cycles measurements with active value.
Arithmetic active average:


 
M
j
j avgact
N M A
M
A
1
;
1
(31)
Where:
A
avgact
– quantity average over active part of given aggregation interval,
A – 10-cycle quantity value in “active” part of interval,
M – number of 10 cycles measurements with active value.