Toggle Main Menu Toggle Search

Open Access padlockePrints

The Newcastle University research output collection, currently available on ePrints, will shortly be moving to a new open repository platform, Figshare. To prepare for the data migration we have paused adding new content to ePrints, and will resume once the new repository is launched. During this time you will continue to have access to ePrints (but no new content will appear). We will share updates here when available.

A Review on the Control of Magnetless Inductive Rotary Transformer-Based Excitation Systems

Lookup NU author(s): Dr Saleh AliORCiD, Dr Farshid Mahmouditabar, Professor Volker PickertORCiD, Dr Shafiq OdhanoORCiD, Dr Muhammad Awan, Dr Zepeng LiuORCiD

Downloads

Licence

This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).

Abstract

Magnetless rotary transformer excitation systems enable fully brushless operation of electrically excited synchronous machines (EESMs) and offer a scalable alternative to permanent-magnet drives. This review presents a control-oriented synthesis of rotary-transformer-excited EESMs by linking machine topology, modeling methods, resonant compensation networks, inverter architectures, and excitation-control strategies within a unified framework. The paper outlines a complete modeling chain, from fundamental-harmonic approximation to dynamic direct-quadrature-axis and coupled electromagnetic-thermal analysis, to support accurate field-current regulation and efficiency optimization. Inverter and compensation networks that enable soft switching are compared in terms of controllability, voltage regulation, efficiency, and implementation complexity. Emerging self-excitation methods, including common-mode voltage injection, harmonic excitation, and carrier-phase modulation are also assessed with respect to implementation simplicity and control flexibility. The review concludes by identifying key challenges in sensorless excitation control, thermal coupling, and high-frequency operation, and by highlighting research directions that can further enhance the performance, reliability, and scalability of brushless EESM drives.

Publication metadata

Author(s): Ali SA, Mahmouditabar F, Pickert V, Odhano S, Awan M, Liu Z

Publication type: Article

Publication status: Published

Journal: IEEE Access

Year: 2026

Pages: epub ahead of print

Online publication date: 20/05/2026

Acceptance date: 14/05/2026

Date deposited: 01/06/2026

ISSN (electronic): 2169-3536

Publisher: IEEE

URL: https://doi.org/10.1109/ACCESS.2026.3695371

DOI: 10.1109/ACCESS.2026.3695371

Altmetrics

Altmetrics provided by Altmetric

Share