The basic setting of ranges of the circular areas of the 2 MB memory has been chosen
as follows:
–
recording of average RMS values of four voltages, four currents and three real
and three imaginary components of the power; the data memory will be suffi-
cient for recording during 30 days when the records are made with step 1 min
–
recording of the list of events with capacity of more than 910 events
–
recording of a detailed development of events for more than 180 last events
–
recording of compressed weekly data for the period longer than 52 weeks.
When extending the data memory to 4 MB it is possible to extend anyone of the
above-mentioned data areas, e. g. the area of recording the average values and the
area of recording the list of events.
3. Description of measuring functions and of input/output
functions of the PQ monitor
3.1 Function of monitoring (time recorder, type MDS)
Average RMS values from all periods within the chosen step are being recorded
when the monitor operates in this function. Average values of up to four voltages,
four currents and three active and reactive powers (U1, I1), (U2, I2), (U3, I3) are
being recorded according to setting. Basing on these recorded data, real power fac-
tors and energies are then calculated in the higher SW. When a suitable sensor is
installed, another physical quality, e. g. the temperature can be recorded instead of
the current I4.
3.2 Function of voltage quality (monitor, type QN)
The following ten-minute data can be recorded here:
–
average frequency, maximum and minimum 10 s frequency derived from U1,
–
numbers of overpassing the 10 s values of frequency of four limits defined by
ČSN EN 50160,
–
values of voltage unbalance calculated from the negative-sequence and the pos-
itive-sequence voltage component as well as from phase-to-phase voltages,
–
average and maximum RMS values of voltages U1 to U4 and currents I1 to I4,
minimum values of voltages U1 to U4 from the 0.2 s long intervals,
–
average values of five selected harmonic components of voltages U1 to U4 and
currents I1 to I4 in the range of the 2
nd
to 51
st
harmonic,
6
PQ monitor – MEg30, MEg31, MEg32, MEg33
