GridDyn is a power system simulator developed at Lawrence Livermore National Laboratory. The name is a concatenation of Grid Dynamics, and as such usually pronounced as "Grid Dine". It was created to meet a research need for exploring coupling between transmission, distribution, and communications system simulations. While good open source tools existed on the distribution side, the open source tools on the transmission side were limited in usability either in the language or platform or simulation capability, and commercial tools while quite capable simply did not allow the access to the internals required to conduct the research. Thus the decision was made to design a platform that met the needs of the research project. Building off of prior efforts in grid simulation, GridDyn was designed to meet the current and future research needs of the various grid related research and computational efforts. It is written in C++ making use of recent improvements in the C++ standards. It is intended to be cross platform with regard to operating system and machine scale. The design goals were for the software to be easy to couple with other simulation, and be easy to modify and extend. It is very much still in development and as such, the interfaces and code is likely to change, in some cases significantly as more experience and testing is done. It is our expectation that the performance, reliability, capabilities, and flexibility will continue to improve as projects making use of the code continue and new ones develop. We expect there are still many issues so any bug reports or fixes are welcome. And hopefully even in its current state and as the software improves the broader power systems research community will find it useful.

Documentation

The current user documentation is hosted on Read the Docs, including installation, quick start, Python API, and build guidance. The C++ API reference is generated separately with Doxygen; see the build guide for instructions.

The repository also includes background presentations:

• Intro
• Execution Flow
• Objects
• Object Construction and properties
• States and offsets
• Validation and Performance

Installation

For Python, install the package from PyPI with python -m pip install griddyn (Python 3.13 or newer). See the installation guide.

Quick Start

Start with the quick start guide.

Python package

The griddyn Python package provides simulation control, network inspection, and PYPOWER/MATPOWER power-flow case export. Install it on Python 3.13 or newer:

python -m pip install griddyn

from pathlib import Path
import griddyn as gd

sim = gd.load(Path("network.xml"))
sim.PFlow.run()
warnings = sim.save_pypower_case(Path("network.py"))

See the Python interface guide for setup, available methods, case-export limits, and four runnable examples covering power flow, OPF, load changes, and dynamic recorder time series. For example, run python -m griddyn.examples.power_flow after installing the package.

Get Involved!

GridDyn is an open source project. Questions, discussion, and contributions are welcome. Contributions can be anything from new packages to bugfixes, or even new core features. We are actively working on improving it and making it better, as well as development related to specific projects.

Contributions

See CONTRIBUTING.md for the current contribution process and development guidance. Please include tests for new behavior where practical.

Authors

GridDyn was originally written by Philip Top, top1@llnl.gov. A number of other people have contributed, see CONTRIBUTORS for more details

Source Repo

The GridDyn source code is hosted on GitHub: https://github.com/LLNL/GridDyn

Release

GridDyn is distributed under the terms of the BSD-3 clause license. All new contributions must be made under this license. LICENSE

SPDX-License-Identifier: BSD-3-Clause

portions of the code written by LLNL with release number LLNL-CODE-681053