KMB NOVAR 2600, Руководство по эксплуатации

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NOVAR 2600 Operating Manual
• harmonic components, THD and unbalance – the last measurement cycle values are
displayed (no averaging)
• temperature – the value is refreshed each temperature measurement cycle (see above)
Actual values, read from an instrument via a communication link for monitoring purposes are
evaluated from one – the last – measurement cycle only.
Neither maximum nor minimum of cosφ values are evaluated due to special character of the
quantity. Similarly, these extreme values are not evaluated at frequency, harmonics&THD
and temperature values either due to a specific measurement method.
5.3.3.1.1 Harmonics and THD Presentation
Harmonic components in both numeric and graphic format can be
viewed at
Actual data
group. At the numeric format – a table – a value of
Total Harmonic Distortion ( THD ) is displayed too. You can list through
all measured phase voltage and current signal harmonics with the ▲and
▼buttons.
With the ►button you can switch between :
• voltage and current signals using
U↔I
switch
• absolute ( volts, amps ) or relative (percentual) harmonic values
expression using
V,A↔% switch
• graphic and numeric representation using ↔123 switch
• odd and event harmonics ( at numeric format only ) using 2-4-
6↔1-3-5 switch
If current harmonics are displayed in numeric format and expressed in amperes, their values are
extended with a sign. The sign indicates if a current phasor of appropriate harmonic is delayed after its
voltage phasor ( positive value ) or if the current phasor foreruns the voltage one ( negative value ).
This information can be useful for a harmonic distortion source location.
5.3.3.2 Average Values Evaluation
From measurement cycle values, average values of all basic quantities are calculated. Following
parameters can be set to control the way of averaging :
• averaging method, which can be set to one of :
• fixed window
• floating window
• averaging period in range from 1 second to 1 hour
When the fixed window averaging is set, values are calculated from fixed block intervals. The values
are updated at the end of every interval. Beginnings of the intervals are synchronized to the nearest
whole time ( for example, when averaging period is set to 15 minutes, the average values are updated
four times per hour in xx:00, xx:15, xx:30 and xx:45 ).
When
the floating window averaging method is applied, an exponential function simulation is used to
get the thermal dependence. Unit step time response depends on the preset averaging period –
during this period, an average value reaches about 90 % of unit step amplitude.
Average values processing can be set independently for two groups of quantities : so called
U/I
-group
and P/Q/S -group. Following table lists processed quantities of both groups.
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Fig. 5.13 : Harmonics