IEEE/PES presentation: Importance of modeling Transmission and Distribution as one integrated model

At the recent IEEE/PES annual conference, Jason Bank (Principal Engineer at EDD) and Himanshu Jain (PHD candidate at Virginia Tech) presented the paper: “Three-phase Dynamic Analysis of a Hybrid Transmission & Distribution Model: Impact of PV on Dynamics.”

As state regulators push utilities to install more renewable generation, the state of Hawaii has set the high water mark with a goal of 100% energy delivered from renewable resources by 2045. To achieve this goal, on the island of Oahu all rotating machines with the exception of one biomass plant will be shuttered.

Jason and Himanshu used the DEW/ISM software from EDD to build an Integrated System Model that included an unbalanced three-phase transmission model and a detailed distribution system model. The combined model included all electrical components at voltages ranging from 345 KV to 120 volts. The simulation analysis ran across the entire integrated system.

Running simulations on the combined T&D model, they were able to document the significant differences in analysis results that are achieved using the more detailed combination of models. They were able to validate the hypothesis: “Hybrid models enable evaluation of scenarios and reveal insights about the impact of PV that cannot be obtained with the traditional approach that uses positive sequence transmission models.”

Dr. Robert Broadwater is Chief Technical Officer at EDD, Professor of Electrical Engineering at Virginia Tech, and he provided mentoring for this work. According to Robert, “DEW analysis is based on a different paradigm for power flow software called Graph Trace Analysis. This paper is yet another result of the additional insights utility engineers and researchers can realize when they expand their modeling and analytics beyond traditional methods.”

View the presentation  …


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EDD staff contributes major authorship to NREL’s just-released PV Handbook

The “High Penetration PV Integration Handbook for Distribution Engineers” has been released and is available for free download from the NREL website at:

The PV Handbook was written as part of a DOE Sunshot project. Lead authors were Barry Mather of NREL, and Rich Seguin, Jeremy Woyak, Dave Costyk, and Josh Hambrick of EDD. An industry peer review team included representatives from leading US. utilities and universities. Southern California Edison provided circuit models and data for the project.

The PV Handbook is a reference manual for practicing distribution engineers working in North America. It is written to provide engineers with a framework for quantifying the impacts of PV that is being interconnected to the electric distribution system. The handbook will be applicable for utility engineers, PV developers, researchers, and customers when trying to study how to add PV to the distribution system. The PV Handbook is agnostic in regards to which modeling and analytics tool an engineer is using.

EDD is a software and engineering services company headquartered in Blacksburg, Virginia. They are the exclusive owner of the DEW/ISM modeling and engineering analysis software. EDD has developed a full suite of analysis tools within our DEW/ISM software that engineers can use to analyze the impact of connecting PV to the grid. Clients of EDD are using DEW/ISM for PV analysis in the following areas:

  • DER Interconnection Studies
  • DER Hosting Capacity Analysis
  • DER Screening
  • DER Data Mapping and Tracking
  • DER Service Transformer and Secondary Analysis
  • DER Analysis of Meshed Networks

To learn more about EDD products and services, please contact John Federowicz at or visit our website at


Our Article in the e-Publication “Utility Horizons”

Our CTO, Dr. Robert Broadwater, recently wrote an article about EDD’s model-centric approach and Integrated Systems Model for Utility Horizons. We are proud of the work our team has put into not only this article, but the software and philosophy that at the center of our company.

Check out the article here: is an online publication dedicated to electric, gas, and water markets.