Reconfigurable Inductive Power Transfer Scheme Across Reinforced Concrete Walls for Building Attached Photovoltaic Grid Connection

A building attached photovoltaic (BAPV) inductive power transfer (IPT) system is proposed in this paper. The coupling coefficient is significantly improved by the designed ferrite bridge (FB), which enables efficient wireless power transfer (WPT) across building walls. The influence of wall-embedded rebar on system performance is analyzed, and corresponding methods to overcome it are developed. The additional core loss caused by FB and rebar is analyzed. A multi-tap auto-coupling coil is proposed. The voltage conversion ratio of the system can be reconfigured by switching the taps of the coil. Based on this, an IPT system is proposed to enable wireless connection between the outdoor photovoltaic system and the indoor microgrid. The circuit model of the system is built, and the transmission characteristics of the system and the losses of each part are analyzed. A three-tap IPT system prototype is built to simulate the situation of passing through a 360 mm building wall. Experiments show that the IPT system has an efficiency of approximately 90%.