CET PMC-592, User Manual, Page: 97 / 177

96
CET Electric Technology
4.4 Power Quality Parameters
4.4.1 Unbalance
The PMC-592 measures the Voltage and Current Unbalances based on the following:
100%
V
Unbalance Voltage
1
2
V
 
100%
I
I
Unbalance Current
1
2
 
Where
U₁ is Positive Sequence Voltage and U₂ is Negative Sequence Voltage.
and
I₁ is Positive Sequence Current and I₂ is Negative Sequence Current.
Under 1P3W wiring mode, the calculation method is listed below:
100% Unbalance Voltage
Ub) (Ua
| Ub - Ua |
 

100% Unbalance Current
Ib) (Ia
| Ib - Ia |
 

4.4.2 Harmonics
The PMC-592 provides the following Harmonic parameters:
Mains-I/II Inputs

U & I THD/TOHD/TEHD

U & I Individual Harmonics up to the 31st order

Current K-factor

Current TDD, TODD and TEDD since Firmware Version V1.00.05

U & I Crest Factor since Firmware V1.00.05
Branch Inputs

Current THD
All Harmonic parameters are available through communications, the built-in Web Interface and the
optional HMI Display.
The following equations illustrate how to calculate the individual harmonic distortion:
Fundamental Method:
Voltage K
th
Harmonic Distortion=
100%
1
K
V
V

Current K
th
Harmonic Distortion=
100%
I
I
1
k 
Where
V
1
/ I
1
are the Fundamental Voltage/Current RMS and
V
k
/ I
k
is the k
th
Harmonic Voltage/Current RMS
The PMC-592 provides the following Harmonic measurements:
Mains-I Mains-II Branch
Harmonics-Voltage
Uan/Ubn/Ucn THD (WYE)
Uab/Ubc/Uca THD (Delta)
Uan/Ubn/Ucn THD (WYE)
Uab/Ubc/Uca THD (Delta)
SM1 to SM84 THD
Uan/Ubn/Ucn TEHD (WYE)
Uab/Ubc/Uca TEHD (Delta)
Uan/Ubn/Ucn TEHD (WYE)
Uab/Ubc/Uca TEHD (Delta)
Uan/Ubn/Ucn TOHD (WYE)
Uab/Ubc/Uca TOHD (Delta)
Uan/Ubn/Ucn TOHD (WYE)
Uab/Ubc/Uca TOHD (Delta)
Uan/Ubn/Ucn Crest-Factor Uan/Ubn/Ucn Crest-Factor
Uan/Ubn/Ucn HD02 (WYE)
Uab/Ubc/Uca HD02 (Delta)
Uan/Ubn/Ucn HD02 (WYE)
Uab/Ubc/Uca HD02 (Delta)