Experimental Results on Contact-less Power Transmission System for the High-speed Trains

Historically the contact type power delivery system has been employed for the trains, the advantages of which might be the high reliability and the low cost, however the metal contact essentially results in the abrasion, which in turn inevitable causes the frequent maintenance, the audible noise generation and the contamination to the environment. This paper proposes a contact-less power transmission system with a wide air gap transformer for the high speed trains. We describe the proposed basic concept, problems and our approach for the proposed wire-less system. The magnetic coupling is influenced by the structure of the transformer. Since the wide gap type transformer results in the less coupling between the primary and secondary windings, the analysis on the magnetic coupling and power delivery efficiency are performed based on the magnetic circuit. Authors have proposed the simple C core type wide air gap transformer. In this paper the experimental data on a low power prototype of the contact-less power transmission equipment are reported, in which the air gap control is installed, and the primary and secondary move at the relative speed up to 25 [m/s]. The power transmission efficiency 70[%] was achieved.