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.
