Power Electronics, Machines and Drives
-- key capabilities --
- Design for manufacturing
While developing new products, companies struggle with the fact that there are significant gaps between design tool predictions (even with virtual prototyping 3D). These gaps are typically addressed by including empirical ‘build factors’ in modelling tools. This requires prototyping for calibration of the models. Induced emf, iron loss, AC losses, end-winding length, equivalent contact thermal resistance and impregnation goodness are some of the properties which are difficult to predict. These unknowns expand dramatically development time, costs and risks.
Our vision is that electric machine design tools should optimally include manufacturing processes influence. WMG has a unique position of understanding how materials, manufacturing and design interact to affect electric machine performance. Our activities aim at suppressing the need of complete motor prototyping to identify design tool build factors.
Our current focus is the effect of manufacturing on e-steel and e-machine performance. With a portfolio of projects, we investigate electric steel properties and the impact of stress on local characteristics. We consider a wide range of manufacturing processes (cutting and assembly processes) and develop specific experiments to validate models from materials to samples with simple shapes, parts, sub-assemblies and electric machines. These activities are carried on in collaboration with steel processes research group, led by Professor Claire Davis.
We have also started activities to increase our understanding of the impregnation goodness build factor for a wide range of manufacturing processes.
- Electric machines modelling
We aim to be at the state-of-art in modelling of electric machines. We have experience in developing dedicated modelling tools for design purposes (research and teaching activities) as well as advanced multi-physics 2D and 3D modelling of electric machines and associated devices/test rigs. We have a partnership with Motor Design Limited allowing us to use MOTORCAD and help developing new capabilities. Our team has experience using FLUX, and COMSOL for FEA analysis but we would welcome opportunities to widen our portfolio of simulation tools.
Our modelling capability is used to perform design of electric machines (conventional and new topologies), investigate and understand influence of material properties as well as conducting system studies. The latter includes typically power train simulations, vehicle low voltage 12-48V systems or electric drives investigations focusing on inverter-electric machine interactions.
- Experimental characterisation of electric machines
Our research group has the capability to run traditional experimental characterisation of electric machines and drives using dynamometer test rigs in the Vehicle Energy facility. We are also developing our ability to perform loss measurements of high precision using calorimetry.
Our research team develops specific experimental setups to investigate the impact of manufacturing processes. With these test rigs, we can then run design of experiments to improve the processes and obtain improved performance at part and electric machine level.
These activities are supported by the collaboration with the metrology research group, led by Professor Mark Williams.
Our hallmark in Power Conversion is a systems level perspective.
For EVs we cover all aspects of on vehicle power conversion, including the propulsion inverter, DC to DC converters associated with battery systems and converters between different system voltages. As well as the converters themselves using the advanced facilities of the Energy Innovation Centre and the Energy Research Accelerator we are able to test systems up to high powers of 500 kW. In addition, we work on power conversion for key sub-systems – such as electric power steering and power quality issue in EVs.
We have worked on wireless charging systems (inverters, coils, electro-magnetic modelling etc.) for several years and have a unique capability for testing within the Energy Research Accelerator.
Linked to vehicle charging, and the integration of renewables into the electricity network, is the deployment of static energy storage. We are focusing on commercial and domestic storage using a range of battery chemistries.