Road-Embedded IPT Systems for Charging In-Motion Electric Vehicles

The transition to electric vehicles (EVs) represents a major step toward achieving sustainable transportation. Among the emerging technologies facilitating this shift, wireless charging systems for in-motion EVs offer a particularly promising solution. Road-embedded inductive power transfer (IPT) enables dynamic wireless charging while vehicles are in motion, addressing some limitations of conventional plug-in EV charging methods. This technology not only enhances user convenience but also extends EV driving range, making these vehicles more attractive to consumers and accelerating their adoption. Despite the advantages of dynamic wireless charging, the practical implementation of road-embedded IPT systems presents several challenges. These include cost, complexity, system modularity, and thermal management in a large-scale implementation. Moreover, integrating IPT systems into existing road infrastructure demands careful evaluations of economic viability and scalability. Addressing these challenges is crucial for the successful adoption of road-embedded IPT systems and the widespread use of wireless charging for in-motion EVs. This thesis explores the development of a modular, scalable, and cost-effective IPT framework for dynamic EV charging, addressing some of the limitations in conventional systems, such as complexity, cost, and reliability. The first contribution is a push-pull coupler array (PPCA) configuration, which reduces system complexity by minimizing the number of switches required to energize multiple in-road couplers. Specifically, this configuration requires only $N+1$ switches to independently energize $N$ primary IPT couplers. Additionally, the design enables multiple couplers to operate simultaneously without significantly increasing the current stress on the switches, thereby streamlining the overall system performance. Another contribution of this thesis is a modular IPT roadway layout centered around a semi-loosely coupled planar transformer integrated into the in-road coupler, referred to as the switchable inductively coupled connector (SICC). This design addresses installation and maintenance challenges while reducing the amount of magnetic material required in both the power converters and the in-road couplers compared with conventional designs. By combining the PPCA and SICC, this thesis introduces a unified framework called the PPCA-based SICC, which integrates the advantages of both approaches. The SICC ensures galvanic isolation between the in-road couplers and the power converters, while the PPCA minimizes the number of required power switches. The framework also explores interleaved configurations to allow controlled current phase shifts between the in-road couplers, and evaluates input filter requirements to achieve an optimal performance. This thesis also conducts an initial investigation into the thermal behavior of internal components within an IPT module and the surrounding roadway materials through experiments performed under various scenarios, with measurements and observations documented. Tests on a 10 kW IPT system compare asphalt-embedded and non-embedded setups, demonstrating that the thermal mass of asphalt slows the temperature rise of internal components, thereby improving thermal management and enhancing system reliability. In conclusion, the key findings and contributions are summarized, along with a list of publications. Suggestions for future work are also provided to further investigate the thermal challenges in dynamic wireless power transfer systems.

Name thesis:degree_name

PhD

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Electrical and Computer Engineering

Grantor dc:publisher

ResearchSpace@Auckland

Year dc:date.issued

2024

Author dc:creator

• Zahiri Barsari, Vahid

Advisors dc:contributor.advisor

• Thrimawithana, Duleepa
• Covic, Grant
• Kim, Seho

• Wireless Charging
• Wireless Power Transfer
• Inductive Power Transfer
• EV Dynamic Charging
• In-motion Charging
• IPT
• WPT
• DWPT

Statement dc:rights

• Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Licence dc:rights.uri

• https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm

Handle dc:identifier.uri

https://hdl.handle.net/2292/74488

OAI identifier oai:identifier

oai:researchspace.auckland.ac.nz:2292/74488