Distributed wireless power transfer based on secondary-side-direct-series topology for integration with building-attached photovoltaic system

Building-attached photovoltaic (BAPV) systems integrate photovoltaic (PV) technology with buildings, attracting increasing attention as a promising solution to advancing eco-friendly objectives. In BAPV systems, wireless power transfer (WPT) technology offers unique advantages; however, existing research faces challenges in effectively balancing cost, efficiency, and flexibility. This paper presents a distributed WPT system based on secondary-side-direct-series (SSDS) topology. The proposed system inherits the high flexibility of conventional distributed WPT systems, while removing the secondary rectifiers within each module, noticeably reducing cost and size compared to conventional distributed WPT systems. Furthermore, this paper presents a planar and integrated design for the power and detection coils, reducing volume, improving consistency and synchronization accuracy, and utilizing PCB litz wire in the power coil to enhance efficiency. In addition, this paper proposes a synchronization strategy based on detection coil, ensuring the stability and safety of the proposed SSDS distributed WPT system. The proposed system is validated through simulations, and an 850 W prototype system is developed for experimental verification, achieving an efficiency of over 85%.