A Tubular Single‐Phase Linear Generator with an Axially Magnetized PM Mover for Free‐Piston Engines.

A novel tubular single‐phase linear generator with an axially magnetized permanent magnets (PM) mover is proposed in this paper for the application of free‐piston engine, which is an alternative power generation system of next‐generation electric vehicle. The transient 3D with motion electromagnetic field finite element model is created to analyze the EMF and thrust force characteristics of the linear generator. A 1.4 kW prototype with the max stroke of 40 mm and the max thrust force of 1670 N is developed, and main performances of the prototype are tested and validated with the finite element simulation. The prototype generating efficiency of 84 and 91% can be obtained respectively when driving by the 35 and 50 Hz sinusoidal reciprocation motion. Compared with the existed moving coil linear generator with similar generating efficiency, the mass power density and the volumetric power density of the new linear generator increase by about 37 and 80%, respectively. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]