1. Eversource Substation Lightning Interference Study - Phase 2

Client:	Eversource Berlin Corporate Headquarters
Completion Date:	January 2020

Project Outline:

As a continuous study of Eversource Substation Lightning Interference Study Phase I, The Phase II study focus was to develop an accurate model of the relevant control cables to determine how the relays were impacted by the present control cable topology and interconnection philosophy and how to develop mitigation measures that will prevent control equipment failures from happening in the future. Several computer models were built and their lightning performance analysed. The results from various computer models show similar trends and maximum electrical stress values of the same order of magnitude for specific soil structure models. This study has shown that adequate mitigation measures can reduce stress voltages on control cables and associated equipment by an order magnitude. Appropriate company standards and mitigation measures have the potential to prevent all, except the most severe, lightning strikes in the future resulting in significant economical savings in outages avoidance and equipment damages.

2. Riel Converter Station Grounding System Field Testing

Client:	Manitoba Hydro
Completion Date:	November 2019

Project Outline:

Fall-of-potential, touch and step voltage tests were carried out at Riel Converter Station using multiple test frequencies to verify the predictions of the design study. Testing was carried out on this very large station (roughly 1.4 km in extent), with the station in operation. The fall-of-potential impedance measurements were found to match model predictions within roughly 10% and touch voltages within 7%.

3. Keewatinohk Converter Station - As-Built Grid Performance

Client:	Manitoba Hydro
Completion Date:	November 2019

Project Outline:

Final as-built station grounding study during 230 kV fault conditions, both within and outside the station, as a function of seasonal variations and for contingency conditions. Interactions between the station grounding system and an adjacent storage area were modeled. The effect of induced voltage from overhead lines and buswork on touch and step voltages throughout the grounding system was considered.

4. Keewatinohk Converter Station Grounding System Testing

Client:	Manitoba Hydro
Completion Date:	October 2019

Project Outline:

Fall-of-potential, touch and step voltage tests were carried out at Keewatinohk Converter Station using multiple test frequencies to verify the predictions of the design study. Testing was carried out in subzero temperatures on this very large northern station (roughly 0.7 km in extent), with the station in operation. The fall-of-potential impedance measurements were found to match model predictions very closely; touch and step voltages were well within the design limits and reproduced their anticipated relative magnitudes throughout the station. New test techniques were developed to contend with high resistivity of frozen surficial soil.

5. Eversource Substation Lightning Interference Study - Phase 1

Client:	Eversource Berlin Corporate Headquarters
Completion Date:	June 2019

Project Outline:

The Eversource 345/115/13.8kV substation, was struck on April 26, 2019 by a very strong cloud to ground (CG) strike (-146 kA). Multiple lightning strokes occurred during that time. The storm resulted in a lightning fault on the one of the 230 kV line terminals followed by a subsequent B-phase to Ground fault. The relays failed to operate and trip the line causing a major outage on Eversource power system network. Consequently, Eversource determined that a systematic design approach on the transient analysis of the event with mitigation measures and remedial actions was required to retrofit existing substations and design future substations where such events must be considered. Phase 1 study carried out by SES confirmed that voltage and current stresses consistent with the observed damages were possible because of the lightning strikes. The study revealed that potential differences along the control cables were sufficiently large to cause possible damage or disruptions of the protection system, due to dielectric breakdown of the cable insulation or electronic components located at the ends of the control cables and recommended further investigations in a Phase 2 follow-up study.

6. Electrical Shock Safety in MMTP Construction Zone at Riel Converter Station during 500 kV and 230 kV Fault Conditions

Client:	Manitoba Hydro
Completion Date:	May 2019

Project Outline:

Study of touch, step and equipment transfer voltages in construction zone, and assessment of safety precautions required in the absence of crushed stone surfacing, at Riel Converter Station. Both 230 kV and 500 kV fault conditions near the construction zone were studied.

7. ATCO Pole Ground Resistance Testing

Client:	Trans Mountain Corporation
Completion Date:	May 2019

Project Outline:

Quality control test developed to verify 69 kV transmission line pole ground resistances in areas close to the Trans Mountain pipeline, with the transmission line in operation.

8. Review of AEP Karl Road Station Grounding Study

Client:	AEP Ohio Transmission Company, Inc.
Completion Date:	July 2018

Project Outline:

Peer review by SES of a preliminary distribution station grounding study and further modeling by SES. The review included preparation of a detailed model of the substation grounding system, surrounding municipal water system, and adjacent neighborhood fences. The sensitivity of the results to the soil model chosen was illustrated and recommendations made with respect to the final grounding study.

9. Riel Station Grounding Study - As-Built Grid Performance

Client:	Manitoba Hydro
Completion Date:	May 2018

Project Outline:

Final as-built station grounding study during 500 kV and 230 kV fault conditions, both within and outside the station, as a function of seasonal variations and for contingency conditions. Variations in fill material thickness were considered using finite-volume soil models. Interactions between the station grounding system and adjacent towers and a railway spur were modeled.

10. Riel Station Grounding Study – As-Built Grid Performance: Construction Scenario

Client:	Manitoba Hydro
Completion Date:	October 2017

Project Outline:

Study of as-built station grounding during 500 kV and 230 kV fault conditions, as a function of seasonal variations, for construction conditions, during which final grading will not be present everywhere. Variations in fill material thickness were considered using finite-volume soil models. Areas of concern were identified and corrective measures proposed.

11. Los Azufres – Unit 18 Geothermal Plant Ground Grid Design

Client:	TSK
Completion Date:	August 2017

Project Outline:

SES was called upon to assist TSK in designing a satisfactory grounding system for a geothermal plant, in a high resistivity soil. By combining deep soil resistivity sounding with consideration of all grounded metallic infrastructure associated with the plant, including transmission lines, pipes and adjacent plants, SES was able to meet and exceed the owner’s design requirements.

12. Keewatinohk Converter Station Grounding Study

Client:	Manitoba Hydro
Completion Date:	May 2016

Project Outline:

Grounding study of 0.5 km x 0.5 km 230 kV AC / 500 kV DC converter station, connected to five 230 kV transmission lines and one 500 kV HVDC transmission line, in northern Manitoba. Used MultiFields software to simultaneously carry out fault current split calculation and grounding, accounting for inductive coupling between overhead lines and bus work in the station with grounding conductors, thus reducing computed touch and step voltages significantly. Induced currents in the soil were found to yield an apparent grid impedance with a capacitive reactance, due to very high soil resistivity at deep layers and low to moderate soil resistivity at shallow layers. Optimized grounding performance, accounting for soil freezing down to 4.5 m, difficulty driving ground rods much deeper than 12 m, need to meet IEEE Standard 80 limits in certain areas without an insulating layer of crushed stone, saving millions of dollars.

13. Wildcat Point Generation Facility Gas Yard Grounding Study

Client:	Hunt, Guillot & Associates, LLC
Completion Date:	Thursday, October 01, 2015

Project Outline:

Grounding design study for gas yard adjacent to Wildcat Point Generation Facility. Included modeling of interactions of cathodic protection system of gas yard with adjacent 500 kV switchyard and other plant grounding and identified locations with peak leakage current densities.

14. Wildcat Point Generation Facility, Plant & Switchyard Grounding - Phases I and II

Client:	Sargent & Lundy, LLC
Completion Date:	Tuesday, April 21, 2015

Project Outline:

Two-part grounding study, first to determine safety in area of plant being rebuilt, in the absence of grounding conductors, in the event of a 500 kV fault, and recommend required mitigation, next to evaluate the final conceptual design for the entire plant area, consisting of existing and new generation.

15. Napanee GS Grounding Study

Client:	Kiewit Power Engineers
Completion Date:	Monday, June 23, 2014

Project Outline:

Short-circuit study, fault current split calculation and grounding recommendations for TransCanada Napanee Generating Station. Included modeling of interconnected and interacting grounding systems of two power plants and one major adjacent 500 kV / 230 kV transformer station, two major three-winding, three-phase auto-transformers, six 500 kV circuits, four 230 kV circuits, local generators, 4 remote generators, 3 remote transformer stations and equivalent transfer impedances between them. Study demonstrated that consideration of all interacting system components made it possible to meet grounding design criteria without any need for deep wells or additional remote grounding electrodes outside the generating station, as would otherwise have been required.

16. AEP Sorenson Substation Grounding Study

Client:	American Electric Power
Completion Date:	September 5, 2013

Project Outline:

Grounding study of 2,300 ft long 765 kV / 345 kV / 138 kV substation. Faults studied at multiple locations throughout station, accounting for circulating currents. Demonstrated potential savings on the order of $1 M with cost-effective mitigation approach.

17. Grounding Study for LCRA Ferguson Replacement Project

Client:	Fluor Enterprises, Inc. (for Lower Colorado River Authority)
Completion Date:	July 30, 2012

Project Outline:

Grounding study of a large power plant next to a lake. Studied grounding performance with and without supplementary grid in lake, using finite-volume soil structures to represent water, soil and rock. Modeled 138 kV transmission line system up to 39 miles away (11 circuits), in order to find worst case fault location and benefit as much as possible from fault current split provided by conductive shield wires.

18. LADWP HVDC Sea Electrode Study

Client:	Burns & McDonnell (for Los Angeles Department of Water & Power)
Completion Date:	March 2012

Project Outline:

Study of the impact of an HVDC electrode in the sea and transferred potentials to nearby gas pipeline. The sensitivity of the results to the method used to represent the sea bed was examined: e.g., infinitely long sloped plane versus trapezoidal volumes.

19. BGE High Ridge Substation GIS Grounding Design and Substation Test & Analysis

Client:	Baltimore Gas & Electric Company
Completion Date:	May 2011

Project Outline:

Study of the optimal method to ground a 230 kV GIS to the grounding system of an existing air-insulated substation. Included the modeling of the phase conductors and bus enclosures and associated inductive coupling and provided training in field testing of the substation: soil resistivity measurements, fall-of-potential test, touch and step voltage measurements.

20. Habshan-5 Utilities & Offsites: Grounding and Lightning Shielding Study

Client:	Hyundai Engineering & Construction Co., Ltd.
Completion Date:	December 2010

Project Outline:

Lightning shielding design study for utilities & offsites areas of 2 km x 2 km Habshan-5 gas development project. Grounding study as well for the entire plant, for 132 kV and 220 kV faults at the 4 high-voltage substations on site. Study also of resistance versus solid grounding for 132 kV transformers at this site.

21. Riel Substation Grounding Study

Client:	Manitoba Hydro
Completion Date:	December 2010

Project Outline:

Riel Station is a 230kV/500 kV power station Manitoba Hydro is planning to build. In addition to several 230 kV and 500 kV AC power lines, 500 kV DC lines are also planned to be connected to the station. The station is extensive, about 1700m by 800m, and is located near an extensive system of water pipes, which must be considered in the calculation of earth potential gradients and transferred potentials. The objective of the study is to design a satisfactory grounding system, which will ensure the safety of personnel and the integrity of the equipment at the station under fault conditions, accounting for contingency conditions and seasonal variations (freezing and thawing of soil).

22. National Grid Underground Safety Analysis

Client:	National Grid USA Service Company, Inc.
Completion Date:	April 2009

Project Outline:

This study consisted of a detailed parametric analysis of underground cable systems and safety of personnel during load and fault conditions, for different contact situations, cable types, vault types and safety bonding scenarios. Different ground mat designs for switch handles of overhead distribution lines were also compared.

23. ABB Nobel Substation Grounding Study

Client:	ABB Inc.
Completion Date:	August 2009

Project Outline:

Two 500 kV series capacitor banks are to be installed midway along a pair of transmission lines, at a location where the soil resistivity is extremely high (on the order of 4,000 to 5,000 ohm-m). The size of the station is 244 m by 124 m. The first objective of the study is design a grounding system resulting in acceptable touch and step voltages. A second objective is to determine the GPR of the station, which is highly dependent on the ground impedance of the 500 kV transmission line shield wires. A specification to measure the equivalent ground impedance presented by the shield wires was developed by SES, which also participated in the testing.

24. EWCC – EnWin – Ford Composite Grounding System Analysis

Client:	East Windsor Cogeneration LP - EWCC
Completion Date:	February 2009

Project Outline:

This is an extensive grounding study involving the modeling of the two interconnected power plants, an associated switching station expansion, and two Ford motor plants, the objective being to investigate safety in the switching station expansion area and at the other facilities to which the substation is connected and to recommend any required mitigation.

25. Suncor Firebag Substation Grounding Study

Client:	Washington Group International
Completion Date:	January 2009

Project Outline:

This study involved detailed modeling of a system of two 260 kV/144 kV substations, three 144 kV substations, two large generating plants, and 5 well pad substations, along with the interconnecting 260 kV and 144 kV transmission lines (over 100 km), the objective being to evaluate safety at the substations and plants and make recommendations, as applicable, to meet IEEE Standard 80, Canadian Electrical Code, and Alberta Electrical and Communication Utility Code safety requirements. It was found that grounded plant infrastructure and the optical shield wires used for the transmission system had a major impact on the results.

26. Suncor Voyageur Upgrader Project (VUP) Grounding Study

Client:	Suncor
Completion Date:	January 2009

Project Outline:

Modeling of a 1 mile x 1 mile oil sands site and two offsites, with 15 substations ranging from 34.5 kV to 260 kV, two overhead 260 kV circuits, buried and overhead 34.5 kV circuits, cable/pipe racks and a good number of pipelines, whose through-earth and magnetic field interactions were studied, in designing a conceptual grounding system for the entire VUP meeting IEEE Standard 80. It was found that consideration of the grounding provided by supporting infrastructure (piles and interconnecting structures) tremendously reduced the need for any additional buried grounding conductors.

27. Marble River Wind Farm – Clinton/Ellenburg 230 kV/34.5 kV Substation Grounding Analysis

Client:	E/PRO Engineering & Environmental Consulting, LLC
Completion Date:	September 2008

Project Outline:

A wind farm with 109 turbines, 2.1 MW each, was studied. Conceptual grounding designs for the main 230 kV/34.5 kV substation and for the turbines were evaluated, accounting for collector line grounding and current return in the 230 kV transmission line static wires. A total of 74 representative faults were simulated on the 34.5 kV collector system and at wind turbines, in addition to faults at the main 230 kV/34.5 kV substation. Frozen, partially frozen and unfrozen soil conditions were considered. Recommendations were made with respect to the most cost-effective grounding, accounting for the interactions of all wind farm components.

28. Herblet Lake Performance & Measurements Analysis

Client:	Manitoba Hydro
Completion Date:	October 2007

Project Outline:

This study involved the verification of the grounding of a 230 kV substation located in an area with high soil resistivities (on the order of 3000 – 6000 ohm-m near the surface and 700 ohm-m below that). Detailed soil resistivity measurements were made in both winter and summer and considered in the analysis. Various contingencies, such as the loss of a line or loss of ground rods, were also examined. It was found that the high surface soil resistivities, while resulting in greater touch and step voltages, also resulted in allowable touch and step voltage limits, ultimately providing a satisfactory solution to an otherwise difficult problem.

29. Paca & Orchard Substation Grounding Study

Client:	Black & Veatch Corporation
Completion Date:	October 2007

Project Outline:

This study involved two urban 115 kV substations with GIS and 60 kA fault levels. SES demonstrated that the buried cable ground conductor/concentric pipe return paths and the metallic water system surrounding the substations reduced grounding requirements significantly despite the high fault current levels. SES also demonstrated the effectiveness of the unipolar Wenner method for soil resistivity testing.

1. Review of Atlantic Coast Pipeline AC Interference Mitigation Study

Client:	Duke Energy
Completion Date:	August 2019

Project Outline:

Detailed third-party review by SES of AC interference mitigation study of extensive exposure of Atlantic Coast Pipeline to 18 Duke Energy transmission lines ranging from 115 kV to 500 kV, including a continuous parallel exposure to roughly 24 miles of 500 kV line and close proximity to a major substation. The AC interference mitigation study report, associated computer models and new data collected by SES were reviewed. Key missed data (such as buried counterpoises crossing the pipeline) and modeling issues were identified.

2. Review of AC Interference Mitigation Assessment of PNG Line 99 and Proposed Pipes to New Receiver

Client:	Piedmont Natural Gas
Completion Date:	August 2019

Project Outline:

Detailed third-party review by SES of AC interference mitigation study of a PNG pipeline exposed to a Duke Energy 230 kV transmission line near a proposed new receiver station. Review included collection of additional power system and pipeline data, study of report and examination of computer model inputs and outputs. Approximate modeling by SES demonstrated that mitigation proposed along the PNG pipeline was in all likelihood unnecessary, increased pipeline potentials further away from the receiver station and did not address a potential hazard introduced by a transmission line counterpoise crossing that nobody had noticed.

3. Harmonic Voltages Induced in ITC Twisted Wire Pair Telephone Cables by Crocker Wind Farm Collector Cables

Client:	Geronimo Energy
Completion Date:	May 2019

Project Outline:

Computer modeling of induced voltages in twisted wire pair telephone cables by wind turbine harmonics in underground collector cables with ground cable. Worst case combination of positive and negative sequence components of harmonic noise from the first 50 harmonics was considered and translated into the expected noise metallic on three telephone circuit branches, applying a C-message filter and typical telephone circuit balance. The interference levels were also expressed in terms of Ground Return I*T. The report included attachments designed to make it easier for power engineers to understand the terminology, calculations and measurements used by telephone companies to assess noise levels.

4. AEP/ECSL Mottville Hydro – Pigeon River Railroad Induction Mitigation Study

Client:	ECSL
Completion Date:	May 2019

Project Outline:

Preliminary AC induction mitigation study between planned double-circuit 138 kV/69 kV transmission line with distribution underbuild and two railways, during fault and load conditions, including parametric analysis of interference levels versus load unbalance in transmission and distribution circuits, ballast resistance, locations of railroad insulated joints, installation of buried counterpoise mitigation, installation of a second distribution neutral, and extension of the distribution neutral along the transmission line beyond end of distribution underbuild. Need for most mitigation was found to be predicated upon load unbalance levels and integrity of one set of railroad insulated joints.

5. Review of AC Interference Studies of Impact of Sheridan 69 kV Substation on Trans Mountain Pipelines

Client:	Trans Mountain Corporation
Completion Date:	April 2019

Project Outline:

Third-party review by SES of studies by two consultants, each working for a different stakeholder, in order to reconcile major differences in recommendations between the two, with respect to the mitigation required to address the impact of the Sheridan 69 kV Substation upon nearby Trans Mountain pipelines during fault conditions. Work entailed study of the computer models used by both consultants, collection of additional data, and more detailed modeling of the transmission system, including substation transformers, for a wide range of modeling scenarios. SES identified the key differences in modeling assumptions made by the two consultants. The detailed modeling by SES found dramatically lower pipeline coating stress voltages than predicted by both consultants (by factors of roughly two and three, respectively) for all scenarios modeled and no need for the mitigation recommended by one of the two.

6. Review of BC Hydro Direct Arcing Calculations in Evaluation of Safety and Reliability Impacts of Planned Trans Mountain Pipeline on Existing BC Hydro Transmission System

Client:	Trans Mountain Canada Inc.
Completion Date:	March 2019

Project Outline:

Review of BC Hydro calculations of direct arcing risk to Trans Mountain pipeline from BC Hydro transmission lines and application thereof to further commentary on methodology used by a third party consultant to develop proposed mitigation on 69 kV wood poles. Found that premise of third party’s evaluation of direct arcing risk was flawed and certainly not carried out based on BC Hydro’s methodology. In review, SES provided detailed recommendations on more suitable protection of the pipeline from direct arcing from 69 kV wood poles.

7. Review of Aldene-Warinanco-Linden (AWL) Project 230 kV Overhead Transmission Line Encroachment Study

Client:	Public Service Electric & Gas Company (PSE&G)
Completion Date:	March 2019

Project Outline:

PSE&G Aldene – Warinanco - Linden (AWL) project plans to rebuild the existing aging five (5) miles 230 kV transmission infrastructure on the existing railroad ROW to accommodate higher thermal load requirements. Along the ROW, there is an existing high pressure gas pipeline with the separations less than 10 feet from the existing transmission structures in approximately 27 locations; there are also paralleling rail road tracks and several encroachments identified, including structures such as pools, garages, homes, and perimeter fences, buildings, etc. The proposed work has raised concerns associated with electrical interference, grounding effects, and personnel safety on the ROW. SES & technologies ltd. (SES) was asked by PSE&G to assist and support PSE&G engineers in carrying out the study at SES Offices, followed by remote project-specific support, then to provide an expert review on the report.

8. Review of Construction Tolerances: Required Clearance of ATCO Jasper 6L650, 69 kV Transmission Line Poles from Trans Mountain Canada Pipeline

Client:	Trans Mountain Canada Inc.
Completion Date:	February 2019

Project Outline:

Further study of the corridor shared by an existing Trans Mountain Canada pipeline and proposed ATCO 69 kV transmission line, in order to provide construction tolerances for areas where transmission line poles are to be installed in close proximity to the pipeline.

9. Review of AC Interference Study and Mitigation Design Assessment of PNG 12” Line 439

Client:	Piedmont Natural Gas
Completion Date:	January 2019

Project Outline:

Third-party review by SES of AC interference mitigation study, submitted by others to PNG, for a proposed PNG pipeline exposed to a Duke Energy 230 kV transmission line, over a distance of roughly 4.5 miles. Detailed critique with recommendation to correct study, following collection of extensive additional data from major stakeholders, review of the report and of the computer models.

10. Review of Arcing Concerns Due to ATCO Jasper 6L650, 69 kV Transmission Line on Trans Mountain Canada Pipeline

Client:	Trans Mountain Canada Inc.
Completion Date:	September 2018

Project Outline:

Further to an initial review by SES of studies carried out by two consultants initially retained by the two primary project stakeholders, design of alternative mitigation to address concerns of the two primary project stakeholders related to direct arcing, supported by the modeling of lightning strikes to the 69 kV transmission line under study.

11. Review of AC Interference Analysis & Mitigation System Design for Cardinal Lateral Pipeline

Client:	Duke Energy
Completion Date:	September 2018

Project Outline:

Detailed review by SES of AC interference mitigation study carried out by third party of exposure of Williams’ 24” Cardinal Lateral to Duke Energy 230 kV and 500 kV transmission lines over a distance of roughly 22 miles. The report, associated computer models and extensive new data were reviewed and considerable corrective action recommended by SES, resulting in a dramatic reduction in the required extent of pipeline mitigation and significant cost savings.

12. Review of Predictive AC Influence Assessment for T-001A Phase 3 – 12” Interconnect

Client:	Duke Energy
Completion Date:	June 2018

Project Outline:

Third-party review by SES of AC interference study of 12” high pressure natural gas pipeline connection to combined cycle plant supplying power to a network of 115 kV and 230 kV transmission lines. SES found transferred potentials from the plant to the pipeline during fault conditions had been overlooked.

13. Review of Third Party AC Mitigation Study for Trans Mountain Expansion Project

Client:	Kinder Morgan Canada Inc.
Completion Date:	January 2018

Project Outline:

Third-party review by SES of AC mitigation study of portions of the proposed Trans Mountain running in close proximity to BC Hydro transmission lines. In particular, SES was asked for an opinion on the expensive recommendation by the study under review to ground 69 kV wood pole lines, some located as far as 23 m from the pipeline, with ground rods placed 5 m away from the pipeline. A detailed report was submitted, calling into question the very premise of grounding the wood poles as a preventive measure against direct arcing.

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