Enhancing Misalignment Tolerance in Hybrid Wireless Power Transfer System With Integrated Coupler via Frequency Tuning

DOI link: 10.1109/TPEL.2024.3416172

Keywords: Wireless Power Transfer (WPT), Hybrid Wireless Power Transfer (HWPT), Integrated Coupler, Frequency Tuning, Misalignment Tolerance.

What - Clarification of the Core Content:

• This study proposes a hybrid wireless power transfer (HWPT) system with an integrated coupler that combines capacitors and coils in a coaxial arrangement to enhance misalignment tolerance and system integration.
• The HWPT system leverages the complementary characteristics of electric field coupled power (EFCP) and magnetic field coupled power (MFCP) to achieve synergistic power transfer under a wide range of coupling conditions.
• The paper introduces a method to regulate the transfer ratio of the two types of coupled powers by adjusting the system’s working frequency, ensuring optimal resonance even when the coupler is misaligned.
• The study aims to provide a new approach to improve the misalignment tolerance and overall performance of WPT systems by integrating the coupler into the main circuit without additional compensation components.

Why - Analysis of the Purpose:

• Traditional WPT systems face challenges in maintaining high efficiency and stable power transfer when the coupler is misaligned, limiting their practical applications.
• The HWPT system addresses this issue by integrating the coupler into the main circuit, reducing the system’s size and complexity while enhancing its tolerance to misalignment.
• The goal is to achieve a high level of misalignment tolerance and system integration, making WPT systems more practical and reliable for various applications, such as electric vehicle charging and industrial automation.

How - Description of the Methods Used:

• The HWPT system utilizes an integrated coupler with capacitors and coils overlapping in a coaxial arrangement, enabling the transfer of power through both electric and magnetic fields.
• The system’s working frequency is adjusted to maintain resonance and optimal power transfer, even when the coupler is misaligned.
• A field-circuit coupling model is developed to analyze the system’s performance under different misalignment conditions and to verify the feasibility of the proposed method.
• Experiments are conducted on a 500-W HWPT platform to validate the effectiveness of the proposed method and to demonstrate the system’s enhanced misalignment tolerance.

Key Findings and Insights:

• The HWPT system demonstrates a significant improvement in misalignment tolerance compared to traditional single-coupling WPT systems, achieving 82.7% system efficiency (DC-DC) at 40% unidirectional misalignment.
• The integrated coupler design allows for the synergistic transfer of EFCP and MFCP, enhancing the system’s overall performance and efficiency.
• The system’s working frequency adjustment method ensures that the HWPT system remains in resonance under various misalignment conditions, maintaining high efficiency and stable power transfer.
• The HWPT system’s output power remains stable even when the coupler is misaligned, due to the complementary effects of the two types of coupled powers.

Examples of Critical Solutions Proposed:

• The HWPT system integrates the coupler into the main circuit without additional compensation components, reducing system size and complexity.
• The system’s working frequency is dynamically adjusted to maintain resonance and optimal power transfer, enhancing misalignment tolerance.
• The use of an integrated coupler with capacitors and coils in a coaxial arrangement enables the synergistic transfer of EFCP and MFCP, improving the system’s overall performance.

Research Gaps and Future Work:

• While the study demonstrates the effectiveness of the HWPT system in enhancing misalignment tolerance, further research is needed to explore other potential coupler designs and materials that could further improve system performance.
• The impact of different environmental conditions (e.g., temperature, humidity) on the HWPT system’s performance should be investigated in future work.
• The study’s results provide a foundation for further exploration into the optimization of system control strategies and the development of more advanced HWPT systems for various applications.

Recommended citation: Fengxian Wang, Qingxin Yang*, Xian Zhang*, Ting Chen, Guangyao Li. Enhancing Misalignment Tolerance in Hybrid Wireless Power Transfer System With Integrated Coupler via Frequency Tuning. IEEE Transactions on Power Electronics. 39(9).
Download Paper | Download Slides