Affiliations: [a] School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing, China
Correspondence:
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Corresponding author: Zhaoping Xu, School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China. E-mail: [email protected]
Abstract: Free-piston engine coupled with linear generator is a new type of thermoelectric energy converter, which has the advantages of high efficiency and simple structure. In this paper, a novel moving-coil linear generator with dual axial-magnetized stator is proposed for this kind of short-stroke high frequency oscillation generating applications. Finite-element (FE) model of the generator is created, the static and transient characteristics are analyzed, and the losses in different components are compared. A full-bridge power converter is designed to meet the control requirements of reversible operation. A 540 W experimental prototype is developed and tested to validate the FE analysis. According to the tested and simulated results, the generator has advantages of high efficiency and fast response. The generating efficiency of 92% can be obtained at the rated generating power. The average inductance of the proposed generator is about 0.7 mH, which benefits from the low armature effect and ensures a very quick electromagnetic response.
Keywords: Electromagnetic characteristics, free-piston engine, moving-coil linear generator, power converter
