Open source Spice cable bundle modelling project
The software allows the generation of multi-conductor cable bundle models for inclusion in Spice circuit simulations for the purposes of EMC/ EMI studies. The models include the following features:
Multi-conductor cables
Shielded cables
Frequency dependent cable properties
Incident field excitation
Transfer impedance coupling through imperfect shields
A set of test cases is included in the project. These may be run automatically to provide a test of the installation and they also provide examples to aid the generation of new cable bundle models.
The project files and directory structure is summarised below:
license.txt, COPYING.txt, COPYING.LESSER.txt : License information version_information.inc: Current version tag clean_project: A script to remove all executable files, object files, module files and test case files to provide a clean structure before updating the project repository
SRC : source code
DOCUMENTATION : theory document and user guide
TEST_CASES : directory of test cases and a script to run these automatically
SOFTWARE_NOTES : Notes regarding the software developments, work log, knoown problems etc
bin : binary executable files
obj_mod : Object files and fortran module files
Compiling and runnning the code
Unix installation for ngspice
Prerequisites:
- ESA_SPICE_CABLE_MODELLING project obtained from the git repository
- fortran complier
- ngspice
- gmsh (mesh generator)
- gnuplot
- text editor (nedit, gedit or similar)
If the transmission line models are to be included in other circuits then you will need the following:
- gschem (schematic capture tool)
- gnetlist (tool to create a spice circuit file from the output of gschem)
- gspiceui (tool to create and run a spice simulation)
Compilation Process:
from the top level go into the SRC directory
cd SRC
edit the Makefile as required to set the fortran compiler name and flags as required (the system is set up for gfortran by default, some notes are included in the Makefile)
compile the code with the command
make
(Note that has been observered to fail when the software is installed in a path which contains spaces so please ensure that there are no spaces in the path...)
The executables will be put in the /bin directory in the top level of the project
Running the test cases
from the top level go into the TEST_CASES directory cd TEST_CASES
Edit the file generate_spice_cable_model if required to set the directory for the schematic circuit symbols created for the spice transmission line subcircuits, SYMBOL_DIR.
SYMBOL_DIR can be set to the local directory SYMBOL_DIR="./" or to a directory which is used by gschem for example SYMBOL_DIR="/usr/share/gEDA/sym/local/"
The script generate_spice_cable_model can be used to run one or all test cases, view the results, check the latest results against saved reference results etc.
Run using the following command:
generate_spice_cable_model action
action is the process to run:
action=run NAME : Generate cable models, bundle model and Spice bundle model and validation spice model as required for the test case NAME. Run ngspice on the validation model and compare the spice result against the analytic solution
action=plot NAME : Plot the results of the spice validation model and analytic solution to x11 terminal
action=plot_wxt NAME : Plot the results of the spice validation model and analytic solution to wxt terminal
action=plot_jpg NAME : Plot the results of the spice validation model and analytic solution to .jpg file
action=plot_ref NAME : Plot the spice validation model results against
reference results to x11 terminal
action=plot_ref_wxt NAME : Plot the spice validation model results against
reference results to wxt terminal
action=plot_ref_jpg NAME : Plot the spice validation model results against
reference results to jpg file
action=plot_bundle NAME : Plot the bundle cross section to x11 terminal
action=plot_bundle_wxt NAME : Plot the bundle cross section to wxt terminal
action=plot_bundle_jpg NAME : Plot the bundle cross section to jpg file
action=reference NAME : Update the reference results and the difference
between the spice model and validation model
with the current set of results
action=check_error NAME : Quick check that the difference between the spice model and validation model is the same as for the reference data set
action=clean NAME : Remove all files except those required to set up the problem and the reference results.
action=clean_all NAME : Remove all files including the reference results.
NAME can be one of the existing test cases or left blank to run all the test cases
(note that if there are problems running the generate_spice_cable_model script this may be due to the file not being an 'executable' file. This can be fixed with chmod +x generate_spice_cable_model note also that it is useful if the local directory is included in the search path, if it is not then you will need to use
./generate_spice_cable_model
instead of
generate_spice_cable_model
As an example, run all the test cases with
generate_spice_cable_model run
The result comparisons given in the STATUS at the end of the process give a measure of the difference between the Spice model result and the analytic solution for each of the test cases run.
plot the comparison between the analytic and spice validation model results for all test cases with
generate_spice_cable_model plot
(note: press RETURN to move from one plot to the next)
Acknowledgement:
This work was funded by ESA under contract number 4000112765/14/NL/HK