OpenDSS and Open Source Software

EPRI
5 min readJun 18, 2020

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Mark McGranaghan

Back in the late 1990s, distributed generation (DG) was growing in importance, but our tools to study the integration of these systems as part of distribution planning were very limited. Essentially, the industry was representing this generation as negative loads and the Electric Power Research Institute (EPRI) was studying distribution systems based on specific conditions at a point in time, such as maximum or minimum load conditions. We needed tools that could represent the dynamic characteristics of DG systems and evaluate the impact on distribution system voltage management, load flows, and protection. We realized that existing tools were not adequate to analyze many of the impacts of these distributed resources — the time varying characteristics, control system interactions, voltage regulation impacts, harmonic interaction, losses, etc.

Roger Dugan and Tom McDermott and others put their heads together and developed a new tool called the Distribution System Simulator. It provided very fast, time-based simulations of distribution systems (e.g., solving for conditions over a whole year every 15 minutes, or over a day in one-second increments), with flexible models of distributed generation, distribution controllers, and load characteristics.

We used this tool internally at EPRI for a number of years and then decided that we could accelerate the pace of innovation if we were to make the tool open source, allowing open collaboration with researchers from around the world.

Wow! The response far exceeded our expectations. We released the open source version called OpenDSS in 2008, and 12 years later it is being used by universities, researchers and utilities around the world. In fact, it has just surpassed 100,000 downloads! The sharing of the code allows university researchers and other research organizations to innovate and develop new versions and advanced capabilities, which can be incorporated into new commercial products. Cool examples include:

· Xendee developed a web-based microgrid analysis platform.

· Davis Montenegro developed a real-time simulation version as a collaboration between Gustavo Ramos at the Universidad de los Andes in Bogota, Colombia and Raphael Caire at Université Grenoble Alpes in Grenoble, France. (Davis now is part of the research team at EPRI and developed the graphical user interface.)

· Nando Ochoa and Pielluigi Mancarella provided major advancements to the platform through the efforts of many graduate students at Manchester and now Melbourne.

· The Brazilian regulator (ANEEL) has standardized on OpenDSS for calculating technical distribution losses. As a result, videos providing OpenDSS training in Portuguese have become big hits in Brazil.

Masters and PhD research projects from around the world have used these open source tools to facilitate major advancements in numerous areas of distribution system analysis. Sharing of models such as the IEEE 8500 node example distribution system also helps new engineers better understand the complexity of distribution system modeling.

That’s the advantage of open source software — providing broad access to capabilities that don’t have to be reinvented so that researchers can focus on innovation and advancing the state of the art. This has been the mantra of the Silicon Valley community for many years and is much of the reason that software applications advance so quickly.

One small example from my personal experience comes from my nephew (coincidentally, also Mark McGranaghan) who has been part of that Silicon Valley open source community since he was in college. His latest project is a new app for the iPad called Muse that provides a multilayer white board for integrating and organizing information from your own writing or drawing, PDFs, web pages, etc. This is not an ad for the app (although it is great) — just watch Julia Roggatz, one of his codevelopers, talk about how they developed this platform and what they had to develop themselves compared to tools and code they were able to use from the open source community in this video..

Many government organizations are seeing the value of open source software. In the U.S., the Department of Energy has developed numerous open source platforms that provide a foundation for all kinds of industry advancements — GridLab-D, GridApps-D, and VOLTTRON are a few prominent examples from PNNL alone. (Check its software exchange catalog for a more complete list.) Entire companies, such as the Grid Protection Alliance, have formed to help develop, apply and support open source software.

And it is a worldwide phenomenon. In Europe, there is strong support for open source software. Research funded through programs such as Horizon 2020 and individual country research efforts use open source software as a way to facilitate broad sharing of research results. One of the problems with actual adoption of tools based on open source software is building a support infrastructure for the software that can use tools in the open source community and develop fully supported software systems. This happens in the commercial software community, but new approaches are also appearing as fully open source initiatives. In the power system community, LF Energy, a new organization under the Linux Foundation, is helping to organize open source software efforts into industry-driven projects. RTE (French TSO) gave this effort a great kickstart when it donated and provided support for a suite of software tools for transmission system operators (OperatorFabric project at LF Energy). EPRI is very excited to be a part of this community and helping to build value from open source software (see announcement). And we welcome your ideas and collaboration as new applications continue to emerge and evolve.

LF Energy Vision for Open Source Software Projects

Back to OpenDSS … What a milestone! I couldn’t be prouder of my association with Roger Dugan and the OpenDSS team, and the decision at EPRI to make this software a truly open source project. Check out this update from EPRI’s Technology Innovation team for more details — Unlocking Our Understanding of Distributed Energy Resources on the Power System: OpenDSS Hits 100,000 Downloads. And with the continued development and all the derivative works, it will be no time at all before we get to 200,000.

Thanks for listening. Share in the conversation by posting comments below.

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