Harmonic Brushless Field Excitation Methods for Electrical Machines

Project Information

HARMFIX

Grant agreement ID: 101108122

DOI

10.3030/101108122

Project closed

EC signature date 20 June 2023

Start date 1 November 2023

End date 30 November 2025

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 215 534,40

Coordinated by

TAMPEREEN KORKEAKOULUSAATIO SR
Finland

Periodic Reporting for period 1 - HARMFIX (Harmonic Brushless Field Excitation Methods for Electrical Machines)

Reporting period: 2023-11-01 to 2025-11-30

Summary of the context and overall objectives of the project

Electrical machines are central to the global energy transition and electrification. They currently consume over 45% of the world’s electricity, and their numbers are expected to double by 2040. Conventional high performance machines often rely on rare earth permanent magnets, whose extraction is environmentally harmful, economically volatile, and geopolitically risky. Wound field machines, although free of permanent magnets, typically require brushes, slip rings, or auxiliary exciters that increase cost, size, and maintenance needs while reducing long term reliability.
To address these limitations, harmonic field excitation methods have emerged as promising alternatives that enable brushless operation of wound field machines. However, existing approaches still face major challenges: complex dual armature winding configurations, dual inverter requirements, large torque ripple, and unbalanced magnetic pull. These drawbacks hinder practical deployment, especially in electric vehicles, household appliances, and other cost and size critical applications.
Against this backdrop, the Harmonic Brushless Field Excitation Methods for Electrical Machines (HARMFIX) project was conceived to develop a simple, compact, magnet less, and truly brushless excitation method using only a single armature winding and a single current controlled voltage source inverter. This innovation significantly reduces system complexity, dependence on rare earth materials, and manufacturing costs while enabling high performance and high material efficiency.
The main objectives of HARMFIX were as follows:

RO1 – Research Training and Knowledge Transfer
Objective: Develop the researcher’s scientific, technical, and complementary skills to reach full professional maturity and independence.

RO2 – Development of Modelling and Optimization Techniques for Electrical Machines with Harmonic Field Excitation Systems
Objective: Build a computationally efficient finite element-based modelling and optimization tool to achieve high performance and material efficiency for electrical machines with harmonic field excitation methods.

RO3 – Development and Implementation of a Single Inverter, and Single Armature Winding Based Field Excitation Method
Objective: Design, implement, and validate new self-excited brushless wound field synchronous and vernier machine topologies based on the proposed armature winding configuration.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Across all three work packages, the HARMFIX project delivered technical, scientific, and professional outcomes as discussed below:

Under Work Package - 1, the Fellow completed comprehensive research training and knowledge transfer activities, including two international secondments, end-to-end management of an in-house machine prototype manufacturing process, formal pedagogical training, university level teaching, and active participation in project and financial administration.

Work Package - 2 achieved the full development and optimization of harmonically excited electrical machine topologies. Advanced modelling tools, a MATLAB based parameter computation script, and a multi-objective genetic algorithm were used to design efficient stator and rotor harmonic windings. The optimized configurations were integrated into a finite element-based solver, leading to the identification of high-performance wound field synchronous and vernier machine topologies and resulting in one journal publication and one conference publication.

Work Package - 3 focused on implementing the proposed single inverter, single armature winding based harmonic field excitation method in both machine types through extensive finite element simulations in JMAG Designer, with prototypes now in the final stages of construction. Although experimental validation is ongoing, two conference papers have already been published, with journal submissions planned following prototype testing. Overall, the project successfully advanced the modelling, optimization, and preliminary implementation of compact, magnet less, brushless excitation methods while fulfilling nearly all milestones and generating significant scientific and professional achievements.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The HARMFIX project delivered substantial scientific, technological, and career advancing outcomes by achieving its major research and training objectives. The Fellow successfully completed intensive scientific training, two international secondments, pedagogical certification, and hands on in-house manufacturing of an electrical machine, resulting in strong professional growth and leading to positions as a Lead NPI Engineer at GE Finland and University Instructor at TAU.

Scientifically, the project developed a complete modelling, optimization, and simulation framework for harmonically excited wound field machines, including a dedicated MATLAB tool, a multi objective genetic optimization process, and integrated finite element based solvers. These advances enabled the optimized design of armature and harmonic windings for both synchronous and vernier machines. The project also validated the proposed single inverter, single armature winding based brushless field excitation method in finite element based tools and advanced the fabrication of prototypes toward final testing. These achievements have generated multiple high quality publications and conference contributions, strengthened collaboration with University of Vigo, Spain and Newcastle University, UK, and established a foundation for future joint research and intellectual property development.

In terms of impact, the project positions Europe to reduce dependency on rare-earth materials by providing efficient, cost-effective, rare-earth free electrical machines capable of replacing permanent magnet based technologies, potentially lowering production costs by up to 30%. This supports key EU priorities including the European Green Deal, European Raw Materials Alliance (ERMA) raw material security, industrial competitiveness, and strategic autonomy in energy and mobility sectors. The developed modelling tools, optimized topologies, and brushless excitation concepts offer immediate relevance for electric vehicles, renewable energy systems, and industrial drives, thereby accelerating the green transition.