Wireless charging of the EVs offers a convenient, reliable, and automatic charging of the autonomous vehicles without user interference. The focus of this thesis is the design and optimization of new structures for stationary EV wireless charging applications.
The fundamentals of the Wireless Power Transfer (WPT) system and its main components including the magnetic couplers, transmitter and receiver power converters, and control methods are studied in depth. The requirements of the EV wireless charging application and design criteria are discussed in detail. The advantages and disadvantages of each topology are highlighted, and possible candidates for EV wireless charging applications are selected.
Optimization of the resonant networks in terms of maximum efficiency and misalignment tolerance is studied. Different resonant topologies are studied in detail and their sensitivity functions are extracted. For each topology, an efficiency model is presented that includes the inverter, resonant capacitors, resonant inductor, diode-bridge, and core and conduction losses. Each topology is optimized with two different objective functions and the results are compared through the simulation and experiments. According to the optimization results, suitable topologies for the EV wireless charging application are selected.
In order to increase the power density of the wireless charging system, and save ferrite material, integrated inductors into the magnetic couplers are proposed. In this structure, the DC-DC inductor is integrated into the receiver main coil and the resonant inductor is integrated into the transmitter coil. This integration introduces new challenges to the design of the resonant network and magnetic coupler due to the unwanted cross-coupling effect. To address this issue, the fully integrated magnetic structure is optimally designed to have minimum cross-coupling. Moreover, the resonant network is designed based on an optimization problem that includes the cross-coupling into the system equations to ensure maximum efficiency. The proposed fully-integrated magnetic structure is built and experimental tests are presented to validate the performance of the proposed magnetic structure and its optimization method.
To reduce the implementation cost, size and weight a PCB-based magnetic coupler is proposed to replace the Litz wire in the magnetic coupler of the WPT system. Moreover, the proposed PCB-magnetic coupler increases the repeatability of the design and reduces manufacturing errors. The PCB-based magnetic coupler is studied through Finite Element Analysis (FEA) to minimize the AC resistance of the coil. Different parameters such including the number of the PCB layers, copper cross-section, and layer thickness are studied in detail to evaluate their effect on the coil resistance. Thermal analysis is performed to ensure the feasibility of the design under different loading conditions. A 3.3 kW/85 kHz wireless charging system is built and experimental tests are presented.
A novel modular resonant topology for fast wireless charging is proposed. A modular structure offers reliability, scalability, and better thermal management. The proposed topology is made by multi-parallel inverter legs connected to an LCC resonant network. The outputs of the resonant networks are connected in parallel to feed the transmitter coil with a high excitation current. The proposed modular system is compared with a conventional system and it showed superior performance in different aspects. / Thesis / Doctor of Philosophy (PhD)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/26371 |
| Date | January 2021 |
| Creators | Ramezani, Ali |
| Contributors | Narimani, Mehdi, Electrical Engineering |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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