Improving inverter models for real-world grid applications
ACEP summer intern Manuel Gutiérrez gives a presentation on his inverter model project.
September 27, 2025
ACEP summer intern Manuel Alexis Gutiérrez López worked with ACEP researchers Glen Woodworth and Emilia Sakai Hernandez to develop quantitative methods of evaluating how well a computer model replicates actual behavior of an inverter.
An inverter is an electronic device that converts direct current (DC) electricity into alternating current (AC) electricity, allowing various electrical loads, such as appliances, to operate. Inverters are necessary for integrating energy sources such as solar and batteries that produce DC power to the AC power used on the grid.
Communities in Alaska and Puerto Rico are at the forefront of using high amounts of renewable energy on microgrids. They rely on accurate power system models to determine whether an inverter meets specific system requirements.
The models of the inverters are typically provided by manufacturers, and information about how these models are generated and validated is often not transparent. Reliability issues may arise during testing and commissioning when there is a mismatch between the modeled and experimental behavior of inverters.
ACEP summer intern Manuel Gutiérrez, left, shakes hands with his fellow intern Lucian Rodriguez as they start their internship.
For his project, Gutiérrez analyzed how inverters respond to complex electrical events. He compared grid-forming inverter behavior simulated in two power system modeling platforms to experimental data taken from a 313-kilovolt-amperes, or kVA, inverter in the ACEP Power Systems Integration Laboratory. “Grid-forming inverter” is a technology that allows inverter-based energy sources such as solar to restart and form the grid independently from a traditional baseload like diesel. He developed methods to filter and classify these data in a programming tool called MATLAB.
Gutiérrez analyzed data recorded during fault (defect in the electrical circuit) and load step (an increase in the demand to an electrical system) conditions. The data that was collected included many different channels that record important information on the state of the grid at the time of the events, including measurements of frequency, real power, reactive power and root mean square current and voltage.
Using all of these data sources, he then created a mathematical model to compare the accuracy of each inverter model to the experimental data.
“This internship has helped me apply many aspects of my degree to real-world challenges,” said Gutiérrez, a senior at the Polytechnic University of Puerto Rico studying electrical engineering with a focus on smart grid power systems.
ACEP summer intern Manuel Gutiérrez, second from right, poses for a photo with his fellow interns during a tour of the UAF heat and power plant.
He found that his MATLAB skills and general coding abilities significantly improved during his internship. But more importantly, he gained a deeper appreciation for fundamental concepts.
“I’ve learned that sometimes the simplest ideas of calculus or electrical engineering can be the key to progress,” Gutiérrez explained.
“I’ve also learned how you can accidentally work against yourself by overcomplicating or reinventing existing techniques,” he said.
Seeking feedback from people with different perspectives helped him solve many problems.
“That’s something I will continue doing in my future endeavors, thanks to this internship,” he said.
This internship was funded by the U.S. through ACEP’s Research Experiences for Undergraduates program. View the on ACEP’s YouTube channel. For more information on this project, contact Glen Woodworth at gwoodworth@alaska.edu.