The Wire

Energy news from Omaha Public Power District


New substation simulator offers fresh training option for OPPD apprentices

April 3, 2024 | Grant Schulte |
T&D_Substation Simulator simulator 1

Inside a lab office at OPPD’s Elkhorn Service Center is a boxy screen with big potential.

The device resembles a clunky laptop with a keyboard and touchscreen. On the screen are schematics – a diagram of the main electrical connections in a substation – highlighted in green, yellow, white and red.

It looks, and acts, just like the screens that OPPD substation electricians see in substations every day as they work to ensure a consistent, usable power supply. But the new machine is a simulator, with no connections to the grid or any substation.

The human machine interface (HMI) simulator provides a new way to give apprentice relay specialists, engineers, switch operators and apprentice substation electricians some hands-on experience with equipment, whenever it’s convenient, in addition to their regular on-the-job training.

“The HMI has been a vital tool for training all of the apprentices on substation switching scenarios,” said Brandon Parmer, manager of Substation & System Protection at OPPD. “Training with real-world simulators like this will help reduce switching mistakes in the field that could lead to large outages.”

How it works

HMIs allow people to control machines with digital buttons and switches on a screen. Imagine an app on your phone that lets you lower your thermostat or open your garage door.

In a real substation, HMI displays control core functions that can affect the grid, which is why new hires in training are closely watched and guided by more experienced journeyman substation electricians. The simulator provides an extra training option, with much lower stakes.

“You’re not at risk of interrupting anyone’s power,” said Rick Stava, manager of Protection and Automation engineering. “If you’re in the field and you make a mistake, it can have repercussions. The simulator provides a safe environment for people.”

Relay technicians build, install, program and maintain the relays (or switches) the protect OPPD’s vital substation and power plant equipment. Their work at substations is critical to keeping the electrical system healthy and reliable.

The importance for substations

Substations are a pivotal part of OPPD’s electrical grid, transforming voltages from high to low and vice versa. They also help isolate electrical faults that can cause outages. The electricity that runs through large transmission lines has a voltage far too high for most homes and businesses, so distribution substations reduce the voltage to a more suitable level and send electricity out to smaller, neighborhood distribution lines.

OPPD installed its first HMI unit in a substation about 20 years ago. The utility has 130-plus substations scattered throughout its territory. Most use HMI screens, although some still have traditional, mechanical switches and handles.

This is one of OPPD's substations.
Apprentices are working with a new substation simulator that provides realistic, hands-on training for working at substations. Photo by Jason Kuiper

In a substation, the HMIs open and close breakers. The simulator models that action by changing the color of icons on the screen when the user toggles a button.

OPPD has been adding touch-screens to its substations over the last two decades as part of routine upgrades. The HMI screen displays an engineering schematic of the substation – all the breakers, transformers, connections and other equipment that help the substation function.

The simulator, just a few months old, may have uses beyond training, as well. Because it acts just like the real thing, engineers could use it for testing and data-gathering for other projects. Experienced relay technicians could use it for practice.

Aaron Rasmussen, an OPPD principal engineer, said the project emerged from a desire to create a usable training tool. The simulator is based on a specific substation within OPPD’s grid, so that trainees can go out and see the real thing. In the future, the simulator may expand to resemble other substations in the utility’s service territory.

“We wanted to make something that closely resembles an HMI environment,” Rasmussen said. “You can have the HMI (simulator) screen here and it’s very similar to what people see out in the field.”

How it came about

Rasmussen said the idea came from a conversation with Brian Stone, a relay specialist work coordinator, shortly after Rasmussen joined OPPD. They tested the simulator with relay specialists to get feedback on its realism and usability.

“It’s huge,” Stava said. “You want to have a safe system, where people can practice comfortably. Screenshots aren’t very interactive, but you don’t necessarily want to teach on a live system with real repercussions. This is a happy medium.”

Rasmussen said he’s still gathering input from users and will continue to do so in quarterly meetings. He’s hoping for more information as they fine-tune the simulator. Do workers like the color? Are images too small, or not visible enough?

Already, he has made some changes in response to feedback. One user noted that clicking on an icon turned it blue, but said the blue tag wasn’t big and visible enough. Each box has a code behind it, making the simulation respond just as it would in real life.

“We’re really hoping to get that routine feedback for continuous improvement,” Rasmussen said.

Stava said the simulators could even have use for OPPD’s newly hired engineering co-ops, who spend their time learning about the utility and how it operates.

The simulator was built from spare parts, and Rasmussen coded its logic. Right now, the simulator is in a lab where specialists run system checks on substation equipment before it’s installed. But the simulator could theoretically go to a training center classroom at Elkhorn or some other facility. OPPD staff have already taken it to career fairs, showing potential hires some of what they might be doing on the job.

New hires in OPPD’s Substation and Protection Division start as helpers and receive on-the-job training through a 6-month probationary period and apprenticeship with more experienced specialists. The simulator could add to that experience.

“It’ll be really valuable,” said Karl Knobbe, a senior relay specialist.

Author Image

About Grant Schulte

Grant Schulte joined OPPD as a content generalist in 2022. He is a former reporter for The Associated Press, where he covered the Nebraska Legislature, state politics and other news for a global audience. He is a graduate of the University of Iowa and a proud Hawkeye. In his free time he enjoys running, reading, spending time with his wife, and all things aviation.

View all posts by Grant Schulte >

Leave a Comment


How Does That Work?


Leading the Way

Powerful Life


Working for You