Modeling and Design of a Tubular Linear Generator for Direct-Drive Free-Piston Engine

This paper focuses on the sizing approximation and parameter estimation of a Linear Generator (LG) to be driven by a direct drive free-piston engine. The modeled and designed LG is of tubular topology comprising of an outer stator with a 3-phase winding configuration and inner slider having layers of axially magnetized PMs and spacers. Two design approaches have been used for the linear generator sizing approximations based on initial requirements. Equations for determining geometrical parameters have been derived. Finite Element Analysis (FEA) simulation and a MATLAB model were developed highlighting the inputs and outputs of the designed LG.