Passive Shielding Design of an Inductive Power Transfer System for Railway Applications

In this paper, a proposed shielding design for the Inductive power transfer (IPT) system for railway applications to reduce the electromagnetic field leakage between the transmitter and the receiver coils is presented. For high power applications, a strong magnetic field generates through a large air gap, resulting in human body health and safety problems. To satisfy standard requirements, the reference level set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP), a shielding design is proposed to limit EMF emission. To demonstrate the effect of the coil structure with a conductive material and different geometry of the shielding design, the distribution of the magnetic field density is simulated by using Ansys Maxwell. Results show that the proposed design considerably reduces the leakage magnetic field density around the IPT system and complies with the ICNIRP standard at a certain distance. Based on the analysis and results, the IPT system has been shielded with an aluminum plate horizontally with the appropriate size on the receiver side. A 5-kW IPT system is developed in this paper, with a novel W-I coupler design according to the constraints on locomotives. The prototype of the IPT system is developed to validate the proposed design, with an air gap of 5 inches and an 85kHz operating frequency [1].