Recent Blog Posts

In today’s rapidly evolving energy landscape, the reliability and efficiency of the power grid are more crucial than ever. An increasing penetration of inverter-based resources (IBR) to meet clean energy targets will also mean an IBR-dominated dynamic behavior of power systems. It is extremely important that a usable power system model representation of IBR, conventional machines, loads, and other components is submitted to utilities to support the analysis of the reliability of the transmission system.

In a significant move for the U.S. energy sector, a proposed settlement filed with the Federal Energy Regulatory Commission (FERC) promises to resolve a long-standing dispute over how costs for critical transmission upgrades are shared within PJM Interconnection, one of the nation’s largest regional grid operators. This agreement, detailed in filings from the Indicated PJM Transmission Owners (ITOs), Long Island Power Authority (LIPA), Neptune Regional Transmission System, LLC, and supported by technical analysis from Pterra, addresses fairness in cost allocation while paving the way for a more reliable grid. Here’s a deep dive into what this settlement means and why it matters.

Meet Pterra’s Francis Luces & Yifu Li at Texas A&M University during the IEEE TPEC 2025 event on Feb 10-11, 2025! Pterra will be presenting our technical paper, “dqBOT: An Automation Tool for Benchmarking Dynamic Quality in Generator Interconnections.” We look forward to…

By Ric Austria (This Blog presents the salient points of a presentation made to the North Carolina Utilities Commission in 2022 on the subject. A redacted version of the presentation can be found at this link. The author is Executive…

Introducing Our Principal Engineers’ Talk at PSCAD UGM 2023, Boston!   Join us at PSCAD UGM 2023 in Boston, where our Principal Engineers will unveil a compelling case study. A load break switch’s unexpected failure during a vital task led…

In December 2022, the New York State Energy Research and Development Authority (NYSERDA) published a report on the Great Lakes Wind (GLW) energy feasibility based on a study conducted by the National Renewable Energy Laboratory (NREL), Advisian Worley Group, Brattle Group and Pterra Consulting.

By Francis Luces, Ric Austria Power projects planning to participate in the wholesale market are required to undergo impact studies as part of the interconnection application process. The studies, as a minimum, evaluate the performance of the projects under instantaneous,…

By R. Austria, M. Gutierrez, F. Luces Very popular pre-2000, when computer processing bandwidth was at a premium and engineers had more time to put together study information on the desktop (the wooden one, not the one filled with integrated…

Pterra was engaged by the New York State (NYS) Department of Public Service (DPS) to provide some insight into technical issues associated with battery energy storage systems (BESS) interconnecting into distribution feeders. This work was part of ongoing support Pterra…

By R. Tapia, M. Gutierrez and M. Infantado Introduction Independent System Operators (ISO) constantly face the challenge of assessing the impact of facility additions to the power grid. They normally require a system impact study for any proposed interconnection of…

By R. Austria, R. Tapia, K. Dartawan, M. Gutierrez, M. Infantado For a company to have made it through its 14th year is not much to crow about. After all, businesses do this all the time. For a boutique consulting…

By Ketut Dartawan (This topic was presented at the PSCAD Users group Meeting held in Atlanta, GA on Sept. 20-21, 2018. For the full presentation, please see this link.) Many interconnection challenges exist when connecting photovoltaic (PV) resources to the…

by  Ketut Dartawan,  Amin M. Najafabadi Pterra is presenting a paper on the above subject at the IEEE General Meeting 2017- Chicago 16~20 July.  Abstract of the paper follows: IEEE updated its recommended practice and requirement for harmonic control in electric…

By Francis Luces, Ric Austria, Cherry Bautista, Ted Garcia The undesired outages of generating units during the July 1996 Outages in the Western Interconnection and the August 2003 blackout in the Eastern Interconnection have resulted in updates to reliability standards…

In recent work performed by Pterra, the issue of ground fault overvoltage (GFOV) was raised in relation to integration of distributed generation (DG).  In particular, can inverter-based photovoltaic systems, connected in distribution feeders, induce GFOV on the high -side of…

A 200 MW DFIG wind farm is experiencing nuisance tripping. These occur during switching of power factor correction cap banks comprising of 4×12 MVAR connected to the farm’s 34.5 KV collector buses. Trip signals recorded by WTGs indicate power quality issues. Harmonic distortion study of the Project did not indicate potential violations. A more detailed analysis indicated presence of interharmonics.

by Francis Luces Introduction                                                                For developers of power plants, one of the important factors to consider is where and how to interconnect a plant to an existing transmission network in order to reliably deliver its full output. For conventional power…

Pterra has been a fan of the General Electric PSLF transmission planning software product almost ever since our little boutique consulting company was established in 2004. Aside from its robust analytical engines that improved on PSSE’s capabilities, PSLF also had…

Circuit breaker nameplates sometimes indicate only rating on symmetrical short circuit current. In such cases, the rating only reflects the AC component of the short circuit current. A common misinterpretation occurs when one compares the symmetrical short circuit current against…

How to integrate a long-term view to the development of transmission systems? This is the challenge of transmission planning: to take into account future uncertainty, new power technologies and economic and operating realities in order to come up with a…