BLOCK
Voltage
unbalance
detector
MN_UNB_AL
PCT_UNB_AL
OBS_PR_ACT
Percentile
calculation
Recorded
data
V_A
V_B
V_C
Average
calculation
V
1
V
2
V
0
GUID-69B09FFB-8F8F-49AE-BEC7-42CB7272C224 V1 EN
Figure 541: Functional module diagram
Average calculation
PQVUB calculates two sets of measured voltage unbalance values, a three-second and a
ten-minute non-sliding average value. The three-second average value is used for
continuous monitoring. The ten-minute average is used for percentile calculation for a
longer period.
The Average calculation module uses five different methods for the average calculation.
The required method can be selected with the Unb detection method parameter.
When the "Neg Seq" mode is selected with Unb detection method, the voltage unbalance
is calculated based on the negative-sequence voltage magnitude. Similarly, when the
"Zero Seq" mode is selected, the voltage unbalance is calculated based on the zero-
sequence voltage magnitude. When the "Neg to Pos Seq" mode is selected, the voltage
unbalance is calculated based on the ratio of the negative-sequence voltage magnitude to
the positive-sequence magnitude. When the "Zero to Pos Seq" mode is selected, the
voltage unbalance is calculated based on the ratio of the zero-sequence voltage magnitude
to the positive-sequence magnitude. When the "Ph vectors Comp" mode is selected, the
ratio of the maximum phase voltage magnitude deviation from the mean voltage
magnitude to the mean of the phase voltage magnitude is used for voltage unbalance
calculation.
The calculated three-second value and ten-minute value are available in the Monitored
data view through the outputs 3S_MN_UNB and 10MN_MN_UNB.
For VT connection = "Delta", the calculated zero-sequence voltage is
always zero, hence, the setting Unb detection method = "Zero Seq" is not
applicable in this VT configuration.
1MAC059074-MB A Section 10
Power quality measurement functions
615 series ANSI 1063
Technical Manual
To Next Page
Loading...
