As I finish my term as editor in chief of IEEE Electrical Insulation Magazine, I want to thank all the board members and past editors in chief; their significant contributions have made my job much easier this year. I am proud of the wide range of dielectric research topics we have covered, which showcases the progress and innovation in our field. Serving as editor in chief has been a privilege and a unique chance to contribute to a publication that fosters both innovation and collaboration. It has been inspiring to work with ideas and people shaping the future of dielectric research for high-voltage applications. Starting in January 2026, we are excited to welcome two new board members: Ruochen Guo from Hitachi Energy and Dipankar Ghosh from 3M.

This issue includes three articles, the first titled “New Categories for Phase-Resolved Partial Discharge Pattern Classification,” by Contin, Piccolo, and Cavallini. It presents a refined framework for analyzing phase-resolved partial discharge (PRPD) patterns in insulation diagnostics. The study questions the traditional one-to-one link between PRPD shapes and defect types, proposing three new categories: voltage-dependent, multiple, and ambiguous patterns. This is to better represent the changing nature of discharge phenomena. By testing insulation systems rated between 4 and 18 kV, including porous tape insulation and four-layer mica tapes, the authors show how PRPD patterns develop under different voltage levels, aging conditions, and stress factors. Examples include distributed micro-void discharges that change from “rabbit-ear” to rounded shapes, symmetric in polarity and phase. The article emphasizes the limitations of relying only on pattern shape for diagnosis and recommends additional localization techniques such as antenna probes and ultrasound detectors. This work is especially valuable for those seeking to improve the reliability of insulation evaluation and develop more advanced pattern-recognition systems for rotating electrical machines.

In 2021 I started my PhD at the University of Colorado (CU), researching spacecraft-plasma interactions, which involve both vacuum chamber experiments and complex simulations. I happened upon this research topic during my junior year at the University of Texas while pursuing an undergraduate research position. I was fortunate to receive an offer to study spacecraft-plasma simulations. Through this position, I uncovered a strong passion for the research. It was this passion that led me to decide to continue in that area in graduate school, as well as intern at the Kirtland Air Force Base Air Force Research Lab (AFRL) the summer before starting graduate school.

The 23rd edition of the 2025 IEEE International Conference on Dielectric Liquids (ICDL) took place for the first time in Poland, between May 18 and 22. The conference was held at the Ambassador Premium Hotel in Lodz. Prof. Pawel Rozga from the Institute of Electrical Power Engineering, Lodz University of Technology, was responsible for organization, serving as chair of the Scientific and Organizing Committee. He was supported by Filip Stuchala, PhD, vice chair of the Organizing Committee.

This issue features three articles, the first of which, by Chen, Liu, Jarman, and Wilson, titled “Application of Ester-Based Tracers for Diagnosing Tap Changer Switch Oil Leaks in Power Transformers,” presents a new diagnostic approach for identifying oil migration between compartments in high-voltage transformers. It proposes the use of synthetic ester liquids as tracers, which are fully miscible in mineral oil and detectable via Fourier-transform infrared spectroscopy because of their unique ester functional group. The study details the preparation of various mineral oil samples, unused, laboratory aged, and in-service aged, with synthetic ester and demonstrates a strong linear correlation between ester concentration and absorbance for the C=O ester functional group. The results show that the detection limit of the measurement procedure is between 0.02% and 0.01%. The methodology shows high repeatability and minimal interference from aging by-products, confirming the feasibility of a synthetic ester liquid as an identification marker for diagnosing tap changer oil leaks. This work is particularly relevant for engineers and asset managers seeking to enhance transformer reliability through improved leak detection and compartmental integrity assessment.

As power demand rises and global temperatures climb, over-heating of outdoor electrical equipment has become a growing concern—threatening the reliability and lifespan of vital grid infrastructure [1], [2].