Wireless Power Transfer for E-mobility

Abstract

Wireless Power Transfer (WPT) is the process of transferring power from one circuit onto another without passing through any manmade conductive elements interconnecting them. Several schemes for wireless power transfer exist – Inductive, Capacitive, Laser, Microwave etc. Of these, Inductive Power Transfer (IPT) is the most popular and is being extensively studied particularly from the last two decades. The first part of this thesis is dedicated to an extensive theoretical study of the basic compensation topologies so as to understand their operation and hence aid the design of a generic IPT system depending on the criteria to be optimized. The idea of resonance so developed can also be used to characterize any complex resonant circuit from an engineering approach. This understanding later evolved into a search for understanding the physics of magnetic fields, inductances etc. The state-of-art for IPT in E-mobility is the powering while driving scenario or dynamic charging. The second part of this thesis is dedicated to enhancing the understanding of the fundamentals of dynamic charging. This scheme is characterized by a major limitation apart from its inherent poor coupling, that being -“Misalignment”. Misalignment hampers effective power transfer as the mutual inductance would fall badly as a result of the same. To tackle the issue of misalignment, modifications can be made to both the secondary as well as the primary of the IPT. Modifications to the secondary in the form of introducing a new set of inductors referred to as “Quadrature Coils” has been studied. Also, a novel primary that could yield potentially higher power transfer, referred to as “Double Lane Model” has been proposed.