Megger PQ2000, User Manual

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Overview of MPQ2000
MPQ2000-UG-EN Rev 8 October 2018
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Transient A sudden non-power frequency change in the steady state
condition of voltage or current.
Vars A unit which is the imaginary counterpart of the watt. The
relationship between a VAR and a watt in an alternating-current
electrical system is determined by the power factor.
Volt Amps A measurement of apparent power.
Watts A unit of energy equivalent to one joule per second.
Waveform
Capture A selection in the MPQ2000 setup file that allows the unit to
record waveforms based on timed intervals.
NOTE: The unit will always capture waveforms
when an out of limits event occurs.
Calculations
RMS Calculation:
Voltage and Current Waveform Data
Waveform Sample = Binary Value * Slope*Cal offset
Calculation of a sliding reference voltage (First-order filter with a 1-min time constant)
Usr(n) = 0.9967 x Usr(n–1) + 0.0033 x U(10/12)rms
Where:
Usr(n)
is the present value of the sliding reference voltage;
Usr(n–1)
is the previous value of the sliding reference voltage; and
U(10/12)rms
is the most recent 10/12-cycle r.m.s. value.