Document Type

Article

Publication Date

8-16-2026

Department

Department of Mechanical and Aerospace Engineering

Abstract

This paper presents a novel approach for protecting transformers during an (Formula presented.) HEMP insult as well as the associated technology-agnostic voltage, power, energy storage, and bandwidth requirements of various control laws. The mitigation is performed by placing a controlled voltage supply in series with the primary winding of a transformer. The controlled voltage supply is subjected to four control laws: an integral controller (capacitor), a linear quadratic regulator (LQR), a nonlinear energy storage optimal feedforward control law, and a Hamiltonian feedback control law. The research gap addressed is that most (Formula presented.) mitigation discussions emphasize neutral-side blocking, whereas transmission-level (high-side) assets may offer a lower-upgrade pathway in some grids and require different actuator sizing and control structure. The results show that the Hamiltonian feedback control law performs the same as the energy storage optimized control law and requires the same specifications. Both of these control laws require less than 30 kV of control effort, 0 W of power, 0 kWh of energy storage, and 16 Hz of bandwidth. This suggests that the Hamiltonian feedback control law is an energy storage optimized feedback control law. These specifications should be considered bounds to the requirements, as power and energy storage requirements will change, depending on the efficiency of the actuator chosen to implement the control laws. These two controllers outperform the blocking capacitor and LQR solutions, despite having significantly less stringent specifications.

Publisher's Statement

Copyright: © 2026 by the authors. Licensee MDPI, Basel, Switzerland. Publisher’s version of record: https://doi.org/10.3390/en19163835

Publication Title

Energies

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Version

Publisher's PDF

Download

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.