Hioki PW3390 - Calculation Formula Specifications

10.6 Calculation Formula Specifications
210
1. Calculation Formulas for Basic Measurement Items
(i)
: Measurement channel
M : Number of synchronous samples
s : Sample (data point) number
10.6 Calculation Formula Specifications
1P2W 1P3W 3P3W2M 3P3W3M 3P4W
Voltage RMS
Voltage MEAN
Voltage AC
component
Voltage simple
average
Voltage
fundamental wave
component
Harmonic voltage U1(i) for harmonic calculation formulas
Peak voltage
THD Voltage
Percentage
Uthd(i) in harmonic calculation formulas
Voltage ripple rate
Voltage unbalance
factor

Items
Phase
System
Urms
i
1
M
-----
U
is

2
S0=
M1–

=
Urms
12
1
2
---
Urms
1
Urms
2
+=
Urms
34
1
2
---Urms
3
Urms
4
+=
Urms
123
1
3
---Urms
1
Urms
2
Urms
3
++=
Umn
i

22
----------
1
M
-----
U
is
S0=
M1–

=
Umn
12
1
2
--- Umn
1
Umn
2
+=
Umn
34
1
2
--- Umn
3
Umn
4
+=
Umn
123
1
3
--- Umn
1
Umn
2
Umn
3
++=
Uac
i
Urms
i

2
Udc
i

2
–=
Udc
i
1
M
-----U
i
s
s0=
M1–

=
Maximum M value
pk sU (i) U(i)  
Minimum M value
pk sU(i) U(i)  
()
100
(2 ( ) )
pk pk
dc
U(i) U(i)
Ui
  


Uunb
123
136  ––
136
 –+
----------------------------- 1 0 0=

U
12
4
U
23
4
U
31
4
++
U
12
2
U
23
2
U
31
2
++
2
-------------------------------------------------=
U
12
, U
23
, and U
31
are fundamental rms volt-
ages (between lines) obtained from harmonic
calculations. For 3P4W systems, voltage bal-
ance is detected from phase voltage, but is
converted to voltage between lines for calcu-
lations.