NREL's Reference OpenSource Controller (ROSCO) toolbox for wind turbine applications

NREL's Reference OpenSource Controller (ROSCO) for wind turbine applications is a toolset designed to ease controller use and implementation for the wind turbine researcher. Some primary capabilities include:

• A reference controller with industry-standard functionality
• Generic tuning of NREL's ROSCO controller
• Simple 1-DOF turbine simulations for quick controller capability verifications
• Parsing of OpenFAST input and output files

Part of the WETO Stack

ROSCO is primarily developed with the support of the U.S. Department of Energy and is part of the WETO Software Stack. For more information and other integrated modeling software, see:

• Portfolio Overview
• Entry Guide
• OpenFAST Workshop

Introduction

The NREL Reference OpenSource Controller (ROSCO) provides an open, modular and fully adaptable baseline wind turbine controller to the scientific community. The ROSCO toolbox leverages this architecture and implementation to provide a generic tuning process for the controller. Because of the open character and modular set-up, scientists are able to collaborate and contribute in making continuous improvements to the code for the controller and the toolbox. The ROSCO controller is implemented in FORTRAN, while the remainder of the toolset is a mostly-python code base with a number of functionalities.

• ROSCO - the fortran source code for the ROSCO controller.
• Examples - short working examples of the capabilities of the ROSCO toolbox.
• Tune_Cases - example generic tuning scripts for a number of open-source reference turbines.
• Test_Cases - numerous NREL 5MW bases cases to run for controller updates and comparisons. A "test-suite", if you will...
• Matlab_Toolbox - MATLAB scripts to parse and plot simulation output data.
• ofTools - A number of scripts to facilitate usage of OpenFAST and manage OpenFAST input and output files.
• linear - Scripts to aid with the use of linear models for controller tuning and simplified simulation.

Documentation

All relevant documentation about the ROSCO toolbox and ROSCO controller can be found at through ROSCO's readthedocs webpage. Here, users can find the information on installing the ROSCO tools for control purposes. Additionally, there is information on the standard workflow, details of the input files, use cases for the ROSCO tool-chain, and more.

Issues and Discussion

If you find issues with any of the code that resides in this repository, it is encouraged for you to open a GitHub issue. If you have general questions or comments regarding the code, please start a discussion via GitHub. We encourage you to use these resources for all ROSCO-related questions and comments, rather than other resources such as the FAST forums. This helps us keep ROSCO-related items centralized, and provides a singular place for the community to look when they have questions that might arise. Please keep in mind that we will do our very best to respond in a timely manner, but may take a few days to get back to you if you catch us during a busy time.

Compatibility

The ROSCO control library should be compatible with any multi-physics simulator that uses the Bladed-style avrSWAP; this includes any version of OpenFAST. OpenFAST (after version 3.5.0) has an extended avrSWAP with additional sensors and actuators that can be enabled in the DISCON.IN file using Ext_Interface.
Simulators other than OpenFAST should have Ext_Interface set to 0.

The python-based ROSCO toolbox for tuning control inputs reads an OpenFAST input file during that process. The openfast-io package is now used for input file reading and writing.
The currently compatible version can be found in the environment.yml file. OpenFAST inputs used in the controller tuning process should be consistent with that version.

Precompiled ROSCO Libraries (No Compilation Required)

If you do not want to compile the ROSCO controller from source, you can extract precompiled shared libraries from the ROSCO conda package on conda-forge.

Finding the Package

1. Go to the ROSCO conda-forge page and find the version you need.
2. Select the .conda file for your platform:
   • Linux: linux-64
   • macOS (Intel): osx-64
   • macOS (Apple Silicon): osx-arm64
   • Windows: win-64

Extracting the Library

A .conda file is a ZIP archive. To extract the shared library:

# Download the .conda file (example for linux-64)
# Unzip the outer .conda archive
unzip rosco-*.conda -d rosco_conda

# Inside, unzip pkg-rosco-*.tar.zst (or use tar if available)
cd rosco_conda
tar --use-compress-program=unzstd -xf pkg-rosco-*.tar.zst

# The shared library will be located under lib/
# Linux:   lib/libdiscon.so
# macOS:   lib/libdiscon.dylib
# Windows: Library/bin/libdiscon.dll

On macOS or Linux, you may need to install zstd to decompress the inner archive:

# conda
conda install zstd
# or brew (macOS)
brew install zstd

On Windows, tools like 7-Zip can open both the .conda (ZIP) and .tar.zst archives directly.

Usage

Once extracted, point your OpenFAST ServoDyn input file's DLL_FileName to the path of the extracted libdiscon library.

Contributing

If it wasn't obvious from open-source being in the title of the tool-set, this is an open-source code base that we would love for the community to contribute to. If you find yourself fixing any bugs, writing new routines, or even making small typo changes, please submit a pull request.

Survey

Please help us better understand the ROSCO user-base and how we can improve rosco through this brief survey: ROSCO toolchain survey

Referencing

To reference the ROSCO source code directly, please use the following DOI:

If the ROSCO Toolbox played a role in your research, please cite it. This software can be cited as:

NREL: ROSCO. Version 2.4.1, https://github.com/NREL/ROSCO, 2021.

For LaTeX users:

@misc{ROSCO_toolbox_2021,
    author = {NREL},
    title = {{ROSCO. Version 2.4.1}},
    year = {2021},
    publisher = {GitHub},
    journal = {GitHub repository},
    url = {https://github.com/NREL/ROSCO}
    }

If the ROSCO generic tuning theory and implementation played a roll in your research, please cite the following paper

@Article{wes-2021-19,
AUTHOR = {Abbas, N. and Zalkind, D. and Pao, L. and Wright, A.},
TITLE = {A Reference Open-Source Controller for Fixed and Floating Offshore Wind Turbines},
JOURNAL = {Wind Energy Science Discussions},
VOLUME = {2021},
YEAR = {2021},
PAGES = {1--33},
URL = {https://wes.copernicus.org/preprints/wes-2021-19/},
DOI = {10.5194/wes-2021-19}
}

Additional Contributors and Acknowledgments

Primary contributions to ROSCO have been provided by researchers the National Renewable Energy Laboratory and the University of Colorado Boulder. Additionally, the ROSCO controller was built upon the foundations of the Delft Research Controller. Much of the intellect behind these contributions has been inspired or derived from an extensive amount of work in the literature. The bulk of this has been cited through the primary publications about this work.