CYMDIST 4.7
A self-contained study file (.sxst) to
use with this tutorial is provided. The
explanations below are based on the
use of that file.
Tutorial
4. Voltage Drop and Short Circuit
CYMDIST includes Voltage Drop Calculation and performs per-phase voltage drop calculations on balanced or
unbalanced radial and meshed distribution systems. The results include voltage profiles, power flows and losses.
The short-circuit analysis calculates maximum and minimum fault currents according to either one of the following
three methods:
•
•
•
Conventional shorts circuit methods.
North American ANSI Standards ANSI C37.5, ANSI C37.010, ANSI C37.13 for all duty types, namely: Time
Delayed, Contact Parting, Closing / Latching and Low Voltage Circuit Breaker.
International IEC-60909 guidelines and supports all four types of fault currents, namely: Initial Short-Circuit
Current (I"k), Maximum Asymmetrical Fault or Peak Current (Ip), Breaking Fault Current (Ib) and Steady State
Fault Current (Ik)
n
Running the Analyses
1.
Load circuit GA04 from the tutorial file Tutorial Part 4-.sxst.
2.
Use one of the following options to run voltage drop and/or short-circuit analysis.
(a) Select the Analysis > Calculation menu option.
(b) Use the Run Simulation button from the Simulation toolbar.
(c) In the Simulation toolbar, select “Voltage Drop”, “Short-Circuit”
or “Voltage drop and Short-Circuit” depending on the
simulation(s) to be ran, and click the Run Simulation button.
3.
In the Network Calculation dialog
box, select:
(a) The networks on which the
analysis is to be performed on.
(b) The analysis to be run: voltage
drop, short-circuit, or both.
(c) Through the different tabs, set
the calculation parameters.
4.
Once all parameters are set, click on
Run.
© CYME International T&D, September 2007
CYMDIST 4.7 Tutorial – Voltage Drop and Short-Circuit Analyses
5.
The results are displayed in the Voltage Drop
Box and Short-circuit Box.
Use Ctrl-V and Ctrl-S, respectively, to display
them.
o
Result Boxes
To customize the result boxes in order to display results as
desired, double-click in the box so it becomes editable, or go
to Customize > Result Box > Voltage Drop Box or Short
Circuit Box.
Increase or decrease the number of rows and/or columns to
change the size of the result box.
To add new keywords, select a cell and click on the Select
key button.
p
Graphs
Graphs can also be plotted. CYMDIST always plot graphs
from the source to a point selected in the network.
First select a node in the network and click on the Chart
Selection button in the result box or in the toolbar.
Select the graph(s) desired by checking the check-boxes.
© CYME International T&D, September 2007
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CYMDIST 4.7 Tutorial – Voltage Drop and Short-Circuit Analyses
q
Reports
1.
Select the Report > On Calculation
menu option to display the list of reports
available. Mark the check box(es) of the
report(s) to be displayed. To customize
their content, click on the Properties
hyperlink next to the name of the
report(s).
2.
While customizing the reports, (1) the
file type can be changed (ex: Excel); (2)
the devices to be included in the report
can be chosen; (3) if results are only to
be displayed for abnormal conditions;
and also (4) which results are to be
seen in the reports.
© CYME International T&D, September 2007
Page 3