Study of radial and axial magnets for linear alternator — Free piston engine system

The use of linear alternators are increasing daily with the usage in hybrid vehicles, Stirling power engines, free piston engines and other renewable energy technologies. Detailed study on the usage of radial or axial magnets in the linear alternator has not been performed so far. This paper attempts to study the effects of the radial magnets and axial magnets under the same conditions using ANSYS Maxwell for a tubular linear alternator used in free piston engines. For the study, a linear alternator is designed, modeled and tested with radial and axial magnets. For the sake of comparison, the EMF, flux density, power, efficiency have been evaluated for the axial and radial field machines. Later the results obtained from the simulations were analyzed and studied. It shows that the axial magnets provide more efficiency and output power compared to the radial magnets.