Research Theme: Machines

• Wang J, Baker NJ. (2018) A Linear Laminated Cylindrical Transverse Flux Machine for use with a Free Piston Engine. IEEE Transactions on Energy Conversion 33(4) pp1988-1997. https://doi.org/10.1109/TEC.2018.2877502
• Baker NJ, Raihan MA, Almoraya A. (2018) A Cylindrical Linear Permanent Magnet Vernier Hybrid Machine for Wave Energy. IEEE Transactions on Energy Conversion https://doi.org/10.1109/TEC.2018.2879405

Contact

• Dr Nick Baker

Soft Magnetic Composite (or SMC) is a material consisting of individually insulated iron particles. They can be pressed together to form components. These components are capable of transmitting and suppressing flux in three dimensions. In this way, it is possible to build machines that have a 3D flux path.

As the particles are so small, SMC is a material known for its low iron losses, especially at high electrical frequencies.

We are the only UK university to work directly with suppliers of Soft Magnetic Composites, as we have done for almost 20 years. We have demonstrated SMC machines belonging to transverse flux, axial and linear machine topologies.

For example, the Yokeless and Segmented Armature – the YASA machine – is easily fabricated from SMC. The soft magnetic composite material carries the flux in its non-planar path. It does this without incurring excessive losses. It does not need an impractical lamination design that is difficult to manufacture. We have done work on the design, build and thermal aspects of the YASA machine.

Contact

• Dr Glynn Atkinson

We constantly strive for increased power density. We work at the edge of material capability in terms of mechanical stress, temperature and tip speed.

We have demonstrated machines significantly beyond the power density published publicly anywhere in the world.

Contact

• Prof Barrie Mecrow

As part of our strive towards low cost machines, we have worked with a variety of switched and synchronous reluctance topologies. These machines have the potential to offer low or zero magnet machines with inherent fault tolerance.

We are working on segmented and more conventional machines within both the aerospace and automotive sectors. Their performance rivals that of the more common permanent magnet topologies.

Contact

• Prof Barrie Mecrow

Over the last three decades, we have analysed, designed and tested many new electrical machine topologies. These all satisfy industrial need: axial, double rotor, transverse flux and modular pole machines.

See for example:

• Baker NJ, Jordan S. (2018) Comparison of Two Transverse Flux Machines for an Aerospace Application. IEEE Transactions on Industry Applications 54(6) pp5783-5790. https://doi.org/10.1109/TIA.2018.2849737

Contact

• Dr Nick Baker
• Dr Glynn Atkinson

Using Halbach arrays instead of conventionally magnetised magnets offers the potential of a reduced coreback. Hence, they can provide higher torque density in some applications.

Demagnetisation, physical air-gap and torque capability at both continuous and overload operation are all affected. In one fixed volume application, we found that using one transition per pole increased rated torque by 5% and overload torque by 3%. Using three transitions per pole, we found that this topology gives an increase in the overload torque of 4%.

We are presently investigating a novel trapezoidal Halbach array arrangement. This will reduce the demagnetisation of the transition magnets. It will also increase their permeance coefficient.

• Contact: Dr Nick Baker