1:00 p.m. – Transformer Overloading: A Necessary Evil, But at What Cost

Speaker: Mike Kockott, Hitachi Energy

In certain operational situations, it can be required to overload transformers for a limited time. Utility general philosophy has been that the operators are responsible for operating the system and have the freedom to deal with overloads and transformer heating as they see fit, in accordance with procedures. Operators are given the chance to address any overloads and take the necessary action, rather than have the transformer automatically trip-out and potentially make the situation worse.

However, today’s power grid is evolving to a distributed source/load architecture as distributed energy resources replace traditional centralized generation. The causes of transformer overloading, and their mitigation procedures, will become more complex. Loss-of-life monitoring can provide a needed tool to monitor the status of a transformer during its in-service life. Although thermal overload protections have typically not been used, insight is provided on how these protections can be applied to safeguard the transformer from loss of life due to an overload exceeding a predetermined amount.

1:45 – As Distributed Generation Increases, Does the Grounding Challenge Get Easier?

Speakers: Michael Gabriel and Dan Holm, nVent ERICO

High voltage (HV) electrical installations require appropriately designed grounding systems to provide the necessary levels of safety and operational security. In the years up until about 2020 in North America, the essential problem of managing HV fault energy had become more and more challenging as fault levels increased, substation footprints became smaller, and legal obligations become ever more stringent. The importance of safety in regards to proper grounding and bonding practices cannot and should not be overlooked in any electrical system, regardless of the application. As the power system generation mix changes across the entire utility industry over the coming ten years, what will be the challenges for HV grounding systems? Fault levels may well go down at many points on the network once the decommissioning of coal-fired generators begins, so does that mean we’ll need less focus on grounding designs—will "the problem" become less of a beast to wrangle? Can we expect wholesale simplifications of HV grounding designs, arriving at a position more akin to how LV earthing systems are designed, with less need for engineers? Or alternatively, will the complexity of the problem increase, even if the hazard level and overall cost of installation and management decreases? The following presentation aims to empirically explain how the design for grounding and bonding systems can adapt to the ever-changing environment that the utility industry experiences.

3:00 – Avoiding Structural Pitfalls when Scoping Substation Physical Upgrades

Speaker: Adane Teferi, HDR

This presentation will attempt to provide guiding points to avoid pitfalls for cases when extensive substation physical upgrades are likely to entail structural alterations of existing systems. The aim is to provide scoping professionals and others an additional set of tools to help foresee the likely pitfalls that bear significant project impact, including structural integrity and strength, and eventually impacting the project scope, schedule, and budget.

3:45 – Applying Digital Secondary Systems to Optimize Power System Reliability

Speakers: Josh LaBlanc and Shawn Westervelt, Schweitzer Engineering Laboratories

This paper is written to engage the reader to think about merging unit intelligence in IEC 61850 9-2 and IEC 61869 applications and to consider the electric grid of the future when making selections, particularly heavy IBR penetration environments and increasing asset health data requirements.


1:00 p.m. – Megahertz-Sampled Observations of AC Level 2 Onboard Electric Vehicle Charging

Speaker: Chad Kennedy, Schweitzer Engineering Laboratories

A waveform from a time-domain line protection relay is captured while charging an electric vehicle. Through the waveform, power quality analysis is performed in the time domain and includes voltage, current, harmonics, instantaneous power, average active power, average returned nonactive power, and time-domain energy.

1:45 – Do AMI Meters Cause Power Quality Problems?

Speaker: Dan Nordell, Xcel Energy

New so-called Smart Meters have been accused of a plethora of negative side-effects in the public view. These include supposed RF radiation, Power Quality issues, and concerns about metering accuracy. This presentation will seek to set the record straight and will illustrate how Smart Meters can, in fact, enhance the quality of service experienced by electric utility customers.

3:00 – Utilization of Features of an AMI Deployment

Speaker: Jason Christoff, Minnesota Power

An overview of Minnesota Power’s Sensus Flexnet AMI meter deployment from pilot to the current start of AMI 2.0. This presentation will also explore what Minnesota Power has done with the addition data from the AMI meters beyond billing.

3:45 – Leveraging AMI Data for Improved Grid Resiliency and Performance

Speaker: Bryan Ehrlich, Utilismart Corporations

AMI systems are delivering data, not only on energy consumption but about the health of the distribution grid. We will explore how optimizing the grid using AMI Data Analytics will improve outage times, help with asset loading, and improve the resiliency and reliability of your distribution system—all while accelerating the ROI for your AMI system in the same process.

Transmission Systems

1:00 p.m. – High-Altitude Electromagnetic Pulse Mitigation for Electric Transmission Systems

Speaker: Scott Adams, American Transmission Company, LLC

EPRI and the industry have been collaborating with DOE and the National Labs to study the effects of a nuclear weapon exploded in the atmosphere, causing an electromagnetic field on the surface of the earth and shifting the magnetic field of the earth. This presentation will summarize the EMP test results of the relay fleet actually deployed in the field today, how these relays have demonstrated resiliency in their current applications and how to further improve relay system performance and resiliency. Equipment testing has demonstrated that the transmission system is quite resilient to a HEMP event.

1:45 – Lessons Learned and Challenges Modeling of Large Loads for Positive Sequence and EMT studies

Speakers: Sibin Mohan, Ramsey Ayass, and Timothy Kopp, Electric Power Engineers

This presentation discusses the lessons learned and the existing challenges with modeling of large loads on the transmission system. This could include crypto mining facilities, hydrogen production facilities, and data centers. These facilities vary in size from a few hundred MWs to a few GWs. Loads of this size had previously been reserved for large cities and small countries, but we are now witnessing their presence as one facility with a single point of delivery (POD). Due to their enormous size and unique composition, detailed load modeling is needed to capture the dynamics of these plants. Since large load modeling is still evolving, there are several challenges to overcome such as modeling requirements and limited information from developers.

3:00 – Power Quality Degradation: Harmonics and Voltage Flicker Issues on Transmission and Subtransmission System

Speaker: Jeff McKeever, Otter Tail Power Company

This presentation will walk through the process used to investigate and respond to power quality problems due to harmonics and flicker in the transmission system. What were the complaints, how we investigated the reports, installation of power quality metering, data evaluation, temporary mitigation efforts, collaboration with field personnel and customers, mitigation plans and continued monitoring.

3:45 – Assessing System Strength

Speaker: Christian Winter, Minnesota Power

Minnesota Power’s System Strength Report describes wide-ranging investigations and technical analyses undertaken to better understand anticipated system strength, voltage support, and reactive power issues that will arise as the system support provided by local baseload generators becomes less available during the clean energy transition. The report discusses industry perspectives, detailed analysis of local system impacts, and potential long-term solutions.

Relaying I

Moderator: Dave Bisel
Co-moderators: Emily Riggs and Pete Malamen

1:00 p.m. – Cite Your Sources: An Analysis of Ground Sources and Impacts on Design for Inverter-Based Generation Resources and Collector Substations

Speaker: Joshua Hill, Black & Veatch

Ground sources are critical for fault detection and system voltage stability of Inverter Based Generation Resources and collector substations during faults involving ground. Careful considerations to limit the strength of ground sources to a “Goldilocks” region can minimize material cost impacts while ensuring adequate stability and detectability during these events.

1:45 – Improving Ground Fault Sensitivity for Transmission Lines Near Inverter-Based Resources

Speaker: Yash Shah, Schweitzer Engineering Laboratories, Inc.

In this paper, we will review considerations specific to the application of 32V in conjunction with sensitively set 67G elements in communications-assisted tripping schemes near IBRs.

3:00 – Optimization of Distance Protection Performance Used in Wind Farms' Collection Networks

Speaker: Mike Kockott, Hitachi Energy, USA

Distance protection is used on the cable feeders of wind farms' collection networks that have resistive grounding. Due to the extensive network of cables, large capacitive ground fault currents are contributed from all parallel healthy feeders for a single line to ground fault. This can cause the distance protection on the faulted cable to fail to see the fault as forward. The solution is to add directional ground fault protection supervising non-directional distance protection, plus other checks verifying the presence of a single line to ground fault.

3:45 - Getting Lines Crossed: How a Three-Phase Series Fault Caused a Sequence of Relay Operations

Speaker: Ryan McDaniel, Schweitzer Engineering Laboratories, Inc.

This paper provides insight on distance relay and transformer differential relay behavior for three-phase cross-connect faults. The paper also offers solutions with event analysis showcasing advancements in relay technology.