LaTeX source of the STEPSS documentation of models and user guide.
This repository holds the LaTeX sources, figures, and compiled PDF of the official user documentation: a models reference and user guide covering the PFC, RAMSES, and CODEGEN modules, part of the STEPSS power system simulation platform.
There is no Makefile or latexmk configuration. Compile with two passes of pdflatex (the second pass resolves cross-references):
pdflatex stepss_doc.tex
pdflatex stepss_doc.texRequirements: any LaTeX distribution providing pdflatex and the packages times, epsfig, bm, hyperref, enumitem, algorithmic, fontawesome5, amsmath, and mdframed. The custom page style A4.STY is included in the repository.
Two pre-built PDFs are committed, and they are kept identical:
stepss_doc.pdf: the build output ofstepss_doc.tex, and the source of the copy published at stepss.sps-lab.org.userguide.pdf: the same document under the file name the Java GUI expects. It is bundled, together with the companion notes inmodels/, intoDOC.zipin stepss-java-ui and extracted at run time.
After rebuilding, refresh both copies, then regenerate DOC.zip in stepss-java-ui and update public/stepss_docs.pdf in stepss-docs so the GUI and the website ship the current guide.
The main entry point is stepss_doc.tex, which organises the guide in four parts:
- Part I (All modules):
overview.tex,install.tex,files.tex,network.tex - Part II (Power Flow, PFC):
pfc-data.tex - Part III (Dynamic Simulation, RAMSES):
ref_and_init.tex,sync_thev_impload.tex,disturbances.tex,solvsett.tex,disc_cont.tex - Part IV (User-defined models, CODEGEN):
user_models.tex,library_blocks.tex, pluscodegen/(one.texfile per modelling block, with block-diagram PDFs)
Other notable files: legal.tex (the software license printed at the front of the guide), models/ (companion PDF notes for specific device models, bundled with the GUI).
STEPSS (Static and Transient Electric Power Systems Simulation) is a power system simulation tool for dynamic studies of electrical grids. It performs power flow computations and simulates the dynamic response of power systems to disturbances under the phasor approximation.
STEPSS consists of three tightly integrated modules:
| Module | Full Name | Description |
|---|---|---|
| PFC | Power Flow Computation | Determines the initial operating point using the Newton-Raphson method in polar coordinates. Computes bus voltage magnitudes and phase angles, with optional transformer ratio adjustment. |
| RAMSES | RApid Multithreaded Simulation of Electric power Systems | Simulates the dynamic evolution of the power system. Supports Backward Euler, Trapezoidal, and BDF2 integration methods. Exploits OpenMP parallelism (up to 2 cores in the free version). |
| CODEGEN | CODE GENerator | Translates user-defined models from text descriptions into Fortran 2003 code for compilation and linking. Supports excitation controllers, torque controllers, injectors, and two-port components. |
The Java GUI documented in this guide comes two ways, both on the releases page:
- an installer (
.msi,.dmgor.deb) that carries its own Java, so nothing else is needed stepss.jar, which needs a 64-bit Java Runtime Environment, version 11 or later already installed, and self-extracts at startup
To compile user-defined models (CODEGEN), the toolchain is GNU Fortran, because the URAMSES kit STEPSS carries is a gfortran build:
- Windows: MSYS2, then
pacman -S mingw-w64-x86_64-gcc-fortran mingw-w64-x86_64-openblas make - Linux (Debian, Ubuntu):
sudo apt install gfortran make libopenblas-dev - macOS:
brew install gcc openblas
Intel oneAPI (ifx) and the Visual Studio environment it needs are no longer part of this. Every RAMSES binary distributed today, on all three platforms, is a gfortran build.
STEPSS is not Windows-only. RAMSES also builds on Linux and macOS with gfortran, and stepss installs with pip on Windows and Linux. See stepss.sps-lab.org.
- Maximum 1000 buses/nodes
- Maximum 2 processor cores for parallelisation
- Published guide (PDF): stepss.sps-lab.org/stepss_docs.pdf
- Documentation website: stepss.sps-lab.org, the same content published as a website, built from the stepss-docs repository
This guide (the LaTeX sources, the figures, and the built PDF) is licensed under the Creative Commons Attribution 4.0 International (CC BY 4.0) license. See LICENSE. Share and adapt it freely, including commercially, with appropriate credit.
The software it documents is not, and it is not under one licence. STEPSS is an umbrella over components licensed separately: the two user interfaces are Apache 2.0, while the engines are not. RAMSES is the property of the University of Liège (Belgium) and is proprietary, free for non-commercial use; Helios and CODEGEN are under Academic Public Licenses. The free-of-charge terms limit a model to 1000 buses and parallelisation to 2 cores, lifted by a $LICENSE record in the data files rather than by a different build.
Licensing on the documentation site is the single owner of these facts, and the terms printed at the front of the guide come from legal.tex. Summarising them here beyond the paragraph above only creates a second copy to drift: this file previously described the whole of STEPSS as Academic Public License, which is one component's terms applied to the platform.
See NOTICE.
Developed and maintained by the Sustainable Power Systems Laboratory (SPS-L) at the Cyprus University of Technology, under the direction of Dr. Petros Aristidou.
The guide is authored by:
- Dr. Petros Aristidou: [email protected]
- Dr. Thierry Van Cutsem: [email protected]