Design of Novel Electrical Machines
The design of novel generator topologies for direct drive wave energy wind energy and tidal current energy converters is my main area of research.
There are both electrical and mechanical challenges to overcome. Low speed machines will be physically larger and heavier than conventional high speed generators. Novel machine topologies using permanent magnets (PM) have been developed which exhibit high power density such as the transverse flux machine and the vernier hybrid machine.
I have done work with both of these machine topologies. However these machines suffer very large magnetic attraction forces requiring a significant mechanical structure to maintain a physical airgap.
Air-cored machines eliminate the unwanted magnetic attraction force leading but exhibit a much lower force density. However the elimination of the attraction force has the potential to lead to a lighter mechanical structure. An air-cored tubular permanent magnet machine has been designed and currently a novel air-cored machine which makes more effective use of the magnetic material in the machine compared to the tubular machine.
The influence of the electrical design on the mechanical design and vice versa forms the main thrust of my research into low speed electrical machines. In order to generate the optimum machine design such an integrated approach must be adopted.