Date of Award:


Document Type:


Degree Name:

Doctor of Philosophy (PhD)


Electrical and Computer Engineering

Committee Chair(s)

Regan Zane


Regan Zane


Hongjie Wang


Abhilash Kamineni


Jacob Gunther


Chris Winstead


David Geller


Electric vehicles (EVs) are going mainstream due to the increased awareness about climate change and lower total cost of ownership. Due to the rapidly falling battery prices, EVs are inching towards price parity with internal combustion engine (ICE) vehicles. However, long recharging time is still a significant roadblock to EV adoption. The traditional conductive charging solution requires the user to plugin the bulky high-voltage and high-current connector into the EV. Inductive wireless charging has evolved as a safe and convenient alternative to conductive charging as it allows hands-free charging. Static and in-motion wireless charging methods for EVs are increasingly explored these days to alleviate range anxiety. In addition to automobiles, wireless charging finds its application in Autonomous Underwater Vehicles (AUVs), personal mobility vehicles, and consumer electronics. Firstly, a review of the state-of-the-art wireless charging technologies for AUVs with an emphasis on the effect of the marine environment on the wireless power transfer is presented in this thesis.

Secondly, the system-level design of a smart 1 kW wireless charging system for a power wheelchair is also presented. The smart device-operated wireless charging system provides more freedom to wheelchair users by reducing their dependence on the caregiver. Various elements of the charging system including the hardware design, software architecture, system integration, and safety aspects are discussed. The wireless power transfer (WPT) system developed for the power wheelchair utilizes a conventional two-stage AC-AC conversion approach which suffers from low efficiency. Single-stage AC-AC topologies based on a 3-ϕ unfolder have mostly been explored for conductive charging applications and are proven to achieve higher efficiency and power density. However, these solutions cannot be directly applied to the WPT systems due to challenges like a lack of high-speed wireless communication and synchronization between the primary and secondary sides of the WPT system, essential for implementing high bandwidth dual-side control.

Finally, different unfolder-based AC-AC conversion topologies for WPT systems have been explored in this thesis. The topology comparison and modularity concepts for realizing a high-power wireless charging system are presented. A novel modulation strategy for a 3-ϕ unfolder and T-type-based single-stage AC-AC conversion topology has been developed. T The hardware results of a 16 KW hardware prototype of the proposed single-stage ACAC converter topology demonstrating a grid-to-battery efficiency of 93.2% are provided. Furthermore, the practical considerations for extending the proposed topology to a 1 MW wireless charging system are provided.

Available for download on Wednesday, December 01, 2027