ERL tesla lite, User Manual, Page: 177 / 288

10 Graphing Records
D03283R01.10 TESLA LITE User Manual 10-43
Impedance
View
Impedance View is an R-X plot. The R-X quantities are calculated over the en-
tire data range from the recorded analog voltage and current channels. R-X plot
is useful in analyzing the performance of L-PRO relays and swing disturbances
from the TESLA recorders. Since the information to be displayed involves
time as a third dimension, this view provides meticulous cursor and zoom con-
trol over the data points being viewed. Optionally it supports superposition of
the relay characteristics (Zone 1, Zone 2, Line, Blinders, etc.) from L-PRO re-
cords or files generated from any L-PRO
Offliner settings program.
The following table summarizes the types of channels from which impedance
(R and X values) is derived along with the supported product. RecordGraph
displays these channels on the left hand side in the tree view. Depending on the
product, the following basic quantities are used the respective impedance chan-
nels.
In an impedance calculation, a threshold limit is used based on the fundamental
rms value of the current to include or exclude the R and X values for plotting.
For 1A CT model or unit, 0.02 A is the limit whereas for a 5A CT model or
unit, 0.1 A is used as the limit. When the data is copied to the clipboard, the
discarded values of R and X values are not exported.
To add an Impedance view select View>Add. or the Add a View tool bar but-
ton. From the dialog box select Impedance View.
Table 10.3:
Sl. No. Channel Types Quantities Supported Products
1 High Speed (HS) Voltage and Current L-PRO, TESLA,
COMTRADE
2 High Speed (HS) Positive Sequence Voltage
and Current TESLA
3 Low Speed (LS) Voltage and Current TESLA
4 Low Speed (LS) Watts, Vars and Voltage
(Phase and Sequence) L-PRO, TESLA
5 Low Speed (LS) Positive Sequence Voltage
and Current L-PRO, TESLA
6 Low Speed (LS) Impedance (Phase and
Sequence) L-PRO, TESLA