Design of tubular Moving Magnet Linear Alternator for use with an External Combustion - Free Piston Engine

The work presents a design methodology for a tubular Moving Magnet Linear Alternator for use with an External Combustion - Free Piston Engine (EC-FPE). Modelling and design of three alternative machines of 6 slots / 7 poles composed of feasible PM arrangements have been performed to react the same EC-FPE driving force. Demonstration of geometrical constraints and design methodology for the desired force is primarily presented, from which the Radial machine is found unsuitable for the application under the given design constraints. Then, performance comparison of the remaining designed machines is listed. Comparison using a weighted score system shows that the Quasi-Halbach machine has a lighter translator mass, yet the Axial machine has higher magnet utilisation as well as higher power densities.