Principles, Current Status, and Optimization of Multi-Device Wireless Charging Systems

Abstract

With the rapid proliferation of mobile electronic devices such as smartphones, earphones, and smartwatches, users are demanding more efficient and convenient charging methods. Traditional wired charging in public scenarios is hampered by incompatible connectors, inconvenience, and potential safety hazards. In contrast, wireless charging technology has gradually become a research and application hotspot due to its flexibility and safety. Existing wireless charging systems primarily focus on single-device-to-single-coil energy transfer models. However, when serving multiple devices simultaneously in public spaces, the systems face challenges such as magnetic field interference, uneven power distribution, and reduced efficiency. This paper reviews multi-zone and multi-device wireless charging systems. It outlines the fundamental principles of wireless charging and mainstream technical approaches. Particular emphasis is placed on multi-coil array structure design, regional circuit models, and management modules, as well as interference suppression and power regulation mechanisms. Furthermore, the paper examines the effects of device quantity and spacing on system coupling performance and energy transfer efficiency, and summarizes the major optimization methods based on representative research results. Additionally, it highlights the practical challenges faced in public applications, including electromagnetic compatibility and safety, system cost and complexity, and issues of standardization and interoperability. In conclusion, through a systematic review and comparative analysis of existing studies, this paper summarizes the current status and problems of multi-zone wireless charging systems. It also points out that future development will move toward smarter, more efficient, and standardized system implementations, providing useful references for large-scale applications in public environments.