Magnetic and thermal characteristics analysis of inductive power transfer module for railway applications

As a new concept of energy transmission systems out of the existing catenary and pantograph method, Inductive Power Transmission System (IPTS) has been studied on a variety of applications in the field of railway systems recently, but there are still a lot of technical issues to solve in order to apply the IPTS system to a large system such as high-speed railway system. For railway applications, the IPTS will transfer energy while train stops at a station for around 30 seconds. The airgap of IPTS for railway system is larger than one of the home appliance and the coupling coefficient will decrease due to the large airgap ; consequently capability of the power transfer will decrease compared with the direct current collector. Therefore, equivalent circuit parameters and coupling coefficient of Inductive Power Transmission Module(IPTM) are an important design factor for the high energy transfer efficiency. This paper investigates the properties of equivalent circuit parameters and coupling coefficient of U-U type IPTM and U-I type IPTM using an analytical method and experimental method. In addition, it is important to predict the temperature property of the IPTM during power delivery operation because the primary part of the IPTM should be buried in the ground track. Therefore, The thermal analysis is performed using FEM for the prediction of temperature property during operation of the IPTM in this study.