WIRELESS POWER TRANSFER FOR RAILWAY APPLICATIONS

The United States trains have the highest energy demands in rail transport in the world. More than 90% of the trains are powered by diesel, which aggressively impacts climate change. In addition, the current procedure of charging an electric locomotive is more complicated compared with charging an electric vehicle. Thus, Inductive power transfer (IPT) technology has a huge potential for charging locomotives wirelessly. IPT technology has been extensively studied for EV application in the past decades. However, it has not drawn much attention to railway applications. Due to the unique requirements of the railway system, most of the EV coupler designs are not directly compatible with wireless charging applications for a train. To fill this technical gap, this dissertation discusses the design considerations for railway application and introduces a design of a modular 5-kW IPT system for rail locomotives. A novel W-I coupler is proposed for the 5-kW IPT system, and the system is optimized via ANSYS Maxwell, to achieve high power transfer capability and lower cost. The optimized LCL-S compensated IPT system is also proposed for the railway IPT system to improve the system efficiency. Besides, the factory manufacturing tolerance effect on the power transfer capability was also investigated. A 10% coil tolerance can lead to a power reduction of up to 61.3%. The dissertation proposed a frequency modulated maximum power point tracking method to adjust the inverter frequency to achieve its maximum power point. The simulation and experimental results are demonstrated and analyzed to validate the feasibility of the design.