Novar 1xxx KMB systems
10
Pressing the M button switches to the relevant subbranch: to the branch of power factors, power, and
temperature while displaying COS (further as COS Branch), to the current branch while displaying Ieff
(further as A Branch) or to the voltage branch while displaying Ueff (further as V Branch). Again, you
can move up and down the branch using the ▲, ▼ buttons. Displaying values of the subbranches’
quantities is indicated with periodic flashes of the quantity symbol. To get back to the main branch of
instantaneous values press button M.
Tables 1.1 through 1.4 show descriptions of the measurement quantities.
1.9.1.2.1 COS Branch
Instantaneous power values as well as recorded average, maximum and minimum values of selected
quantities are shown in the COS Branch. Power is displayed as three-phase values (single-phase
power values multiplied by three). Reactive power values are prefixed with L for positive values and C
for negative values.
The values recorded can be divided by their nature into three groups:
1. Average values Acos, APac, APre
These are average values of power factor, active and reactive power. The depth of average
can be set in parameter 56 from 1 minute to 7 days.
Note: The average values of active and reactive power are rendered with the sign. If then, for
example, the reactive power value is changing its polarity (it has alternately inductive and
capacitive character), its average value, APre, may become zero even though the
instantaneous reactive power value was not zero at any point in time under evaluation. Also
the power factor average value, which is evaluated from the average active and reactive
power using the formula
Acos =
APac
22
+
may, in such an event, become 1 even though the instantaneous power factor was never 1
within the time evaluated.
2. Maximum and minimum values mincos, maxPac, maxPre, maxdPre
• mincos – evaluated as a ratio of fundamental harmonic active and reactive power
moving averages. The moving average window size can be specified in parameter
57 from 1 minute to 7 days. The minimum value is recorded and displayed.
Evaluation is conditioned by the corresponding average current being at least 5% of
the nominal load as determined from the metering current transformer turns ratio
primary value (parameter12) else the value is ignored (the value is not recorder for
minimum loads).
• maxPac, maxPre – the maximum values of fundamental harmonic active and
reactive power moving averages. The moving average window size can be specified
in parameter 57 from 1 minute to 7 days.
• maxdPre – the maximum value of fundamental harmonic absent reactive power
moving average. As opposed to the absent reactive power instantaneous value,
dPre, which is the difference between the actual and required reactive power,
irrespective of the instantaneous condition of the controller’s closed outputs,
maxdPre is only evaluated if the required reactive power exceeds the system’s
control capacity (that is the total power of all compensation banks, or sections), and
its value is determined as a difference between this control capacity and required
power (if the control capacity is sufficient, the maxdPre value is zero). The moving
average window size can be specified in parameter 57 from 1 minute to 7 days.
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