Realization Assessment of Coaxial Symmetrical Coils for Two-to-One Inductive Power Transfer in Rail Charging Applications

This paper proposes the placement of coaxial symmetrical coils for inductive power transfer that is suitable for rail charging applications. It was known that the third rail of mass rapid transit (MRT) is often connected to voltage source so as to supply power to the surface-current collector of subway trains. However, considering that the third rail is directly connected to voltage source that needs to be insulated in order to avoid any unexpected consequence, the study of inductive power transfer hence becomes one of alternatives to improve the safety of power delivery. Therefore, by adding the merit of inductive power transfer for rail charging applications with realization assessment, this paper starts with the design of induction coils based on the analysis of mutual coupling characteristics. It is followed by the two-to-one inductive power transfer along with the appropriate completion of resonance circuit in order to ensure a high-efficiency and stable power transmission. To assess the practical value of the proposed method, both hardware realization and software simulation are made and investigated under different test scenarios. Test results are anticipated to be useful for transportation electrification development.