E-Mon E-PS-A-RTU-N - Manual (Page 92)

Chapter 4 Power
S O F T W A R E E N 5 0 1 6 0 E V A L U A T I O N A N D
R E C O R D I N G
92 PowerSmart+ Advanced Power Quality Meter
Harmonic Voltage
Method of Evaluation
The basic measurements are the individual harmonic voltage distortion factors (HD) and
the total harmonic distortion factor (THD) over a period of 10 minutes under normal
operating conditions.
Harmonic voltages are evaluated by instrumentation complying with IEC 61000-4-7. All
calculations are made relative to the nominal voltage.
The THD is evaluated including all harmonics up to the order 40. Harmonic voltages are
evaluated up the order 25 since the EN50160 provides target values for individual
harmonic voltages only for orders up to 25. The highest harmonic order for evaluating
individual harmonic voltages and THD can be changed in the meter in the range of 25 to 50
via the EN50160 Advanced Setup.
Harmonic voltages are not evaluated if the supply voltage crosses a voltage tolerance limit
(±15% Un).
Target Values
The ranges of harmonic voltages given in the EN50160 are:
THD ≤ 8 % for 95% of a week
Individual harmonic voltages shall be less than or equal to the values given in Table 1 in
Clause 2.11 of the EN50160 for 95% of a week.
The THD compliance limit can be changed in the meter via the EN50160 PQ Recorder
setup. The individual harmonic voltage limits can be adjusted via the EN50160 Harmonics
setup.
Interharmonic Voltage
Method of Evaluation
Since the EN50160 does not specify target limits for interharmonic voltages, this feature is
normally disabled in your meter. You can enable evaluation of interharmonic voltages via
the EN50160 Advanced Setup.
The basic measurements are the individual interharmonic voltage distortion factors (HD)
and the total interharmonic distortion factor (THD) over a period of 10 minutes under
normal operating conditions.
Interharmonic voltages are evaluated by instrumentation complying with IEC 61000-4-7. All
calculations are made relative to the nominal voltage.
The highest harmonic order for evaluating individual interharmonic voltages and
interharmonic THD can be selected in the meter in the range of 25 to 50 via the EN50160
Advanced setup.
Interharmonic voltages are not evaluated if the supply voltage crosses a voltage tolerance
limit (±15% Un).
Target Values
The EN50160 does not provide target limits for interharmonic voltages. The ranges of
interharmonic voltages selected in the PowerSmart+ Advanced PQM are:
Interharmonic THD ≤ 2 % for 95% of a week
Individual interharmonic voltages shall be less than or equal to the values given in the
following table for 95% of a week.
Interharmonic order Relative Voltage
2 0.2
3-15 1.0
16-25 0.5