Effective Grounding in DER Integration


Inverter-based resources (IBRs) are proliferating in distribution and transmission systems. These resources have been driving changes in industry paradigms, grid codes, standards, and recommended practices. One established utility system design is effective grounding for ground fault overvoltages (GFOV). This was derived entirely on the premise of a traditional grid, with utilities conforming their practices over the decades with the expectation of this topology to continue. As IBRs proliferate, traditional practices are becoming ineffective in depicting expected behavior. As a result, management of GFOV becomes critically dependent on IBR control algorithms and on the negative sequence impedance of the aggregate load of a distribution feeder. This requires a shift in direction for transmission and distribution operators. These controls also affect Load Rejection Overvoltage (LROV). This presentation includes an electric utility’s lessons learned in the interconnection of a range of large scale IBRs to its distribution grid. Simulation and measurement case studies are presented to illustrate the drawbacks of conventional practices. It also exemplifies how utilities can manage the problems and presents a forward-looking perspective on the evolution of rules, standards, and practices.

  Date and Time




  • Date: 18 Apr 2022
  • Time: 12:00 PM to 01:30 PM
  • All times are (UTC-04:00) Puerto Rico
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Hybrid. In-person attendance is limited. Location and link will be provided the morning of the event. 

  • San Juan, Puerto Rico
  • United States
  • Building: TEAMS
  • Room Number: Remotely Accessible

  • Contact Event Host
  • Starts 07 April 2022 12:48 PM
  • Ends 18 April 2022 12:00 PM
  • All times are (UTC-04:00) Puerto Rico
  • No Admission Charge


Alex Nassif, PhD Alex Nassif, PhD


Alexandre Nassif obtained a B.Sc. degree in electrical engineering in 2001, after conducting 18 months of undergraduate research in estimation methods of load composition models (P, Z, I). Upon graduation, he joined the then GE Hydro and worked in designing hardware and PLC software for hydro generation AVRs. He simultaneously obtained his M.Sc. degree with a thesis on transmission system voltage stability and generation angular stability, as well as the modeling and analysis of FACTS devices using modal analysis. Alex then embarked to Canada to pursue his Ph.D. in power system harmonic modeling, measurement and mitigation at the University of Alberta. Upon obtaining his Ph.D. in 2009, Alex joined Hydro One as a protection engineer and subsequently transitioned to the special studies department, conducting research in improving dependability and security of transformer differential relays and modeling the impact of GIC on line distance relays. He simultaneously worked at Ryerson University as a post-doctoral research fellow developing models for Type III and Type IV wind generators for integration in transmission and distribution load flow studies. In 2012 Alex joined ATCO electric as the SME in Power Quality and DER integration and he managed the DER and microgrid integration team until 2020, often leading other projects related to voltage optimization, grounding, protection, electromagnetic compatibility, conductor rating, and other technical issues. In 2020 Alex joined LUMA energy and led the strategy development of the UT Distribution programs and projects allocating a portfolio of nearly $5B during FET as well as shaping the Planning team. Since commencement, Alex has been the technical lead of special projects.


Throughout his career, Alex focused on emerging problems faced by utilities, driving industrial research solutions that resulted in over 100 scientific journal and conference papers with nearly 1,200 citations as of March 2022. He consistently participates in expert technical panels and is an Editor of IEEE Transactions on Power Delivery and of the IET Generation, Transmission and Distribution. Alex held many leadership roles with IEEE and PES and was the General Chair of two IEEE Canada Flagship conferences (IEEE CCECE 2019 and IEEE PES EPEC 2020), and is the General Chair of the 2023 ISGT-Latin America.


12:00 - event begins

13:00 - Q&A