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The Transmission Planning Process

  • September 27, 2023
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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…

Pterra at PSCAD UGM 2023

  • August 14, 2023
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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…

Benchmarking Phasor and EMT Models for Inverter-Based Energy Resources

  • October 28, 2020
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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,…

Network Equivalents for the Power System Engineer

  • February 19, 2019
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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…

A Second Retrospective

  • October 1, 2018
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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…

Utilizing PSCAD in Designing Detection Logic for Ground Fault Overvoltage

  • September 28, 2018
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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…

Ground Fault Overvoltage and Distributed Generation: Factors for Occurrence

  • January 18, 2017
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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…

Interharmonics Case Study: Nuisance Tripping in a 200 MW Wind Farm

  • October 18, 2016
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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.

Siting of Power Plants: A Thermal Capacity Assessment for Grid Interconnection

  • July 13, 2016
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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…

The New PSLF

  • March 18, 2015
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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…

Role of X/R Ratio in Circuit Breaker Short Circuit Duty Evaluation

  • January 30, 2015
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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…

Transmission Planning Course

  • November 27, 2013
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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…

Understanding Location-Based Energy Pricing

  • November 27, 2013
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Nodal pricing is the emerging method for determining the impact of transmission congestion and losses on the price of electric energy. The method involves an optimization solution of costs subject to transmission constraints. This method bears more resemblance to the…

Aspects of Underground Power Cable Systems Course

  • November 27, 2013
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Utilities, architect-engineers, developers and industrials are often faced with considering an underground cable option either as a portion of an otherwise overhead line, to connect nearby substations, as entry to an already congested substation, or in urban setting where underground…

Linear Power Flow Analysis and Applications

  • November 26, 2013
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In the accelerated environments of today’s electric energy markets, fast analyses of power flows are a must. Emerging real-time and day-ahead markets require that analysis of infrastructure capacity be performed in a compressed timeframe. In this context, approximate but fast…