Comprehensive Design Method and Experimental Examination of an Electrical Machine for a Free-Piston Linear Generator

This article describes the design method for an electrical machine for a free-piston linear generator. As with other applications for linear machines, defining a steady-state operating point as the basis for the design proved infeasible. To overcome the challenge of optimizing for an alternating motion cycle with accelerations and dynamic load forces, a previously established design methodology was implemented. In addition to the experimental validation of the optimization approach, each research step was presented, beginning with the preliminary choices for the machine topology. This was followed by the optimization of the linear machine and lastly the measurements of its characteristics for comparison with the simulation. A control strategy was determined and a machine prototype constructed that achieved the desired operating cycle, matching the simulated behavior remarkably.