Design and Optimization of a Planar Omnidirectional Wireless Power Transfer System for Consumer Electronics

Recently, omnidirectional wireless power transfer (WPT) has gained increasing popularity due to its capability to charge in arbitrary positions and directions. However, existing solutions still face several challenges, including coupled coils, non-optimized structure, non-uniform magnetic field, and poor misalignment tolerance. This work proposes an omnidirectional WPT system with three fully decoupled coils consisting of one square coil and two perpendicular DD coils. Comprehensive modeling and Pareto optimization for the transmitter coil structure are conducted for improved tolerance to both lateral and angular misalignment. Experimental results are provided to validate the system performance in terms of the output voltage and efficiency under different lateral and angular misalignments. With a 12 V input, the efficiency of the system exhibits a <10% variation, ranging from 69% to 78%, with 50 mm misalignment in the x and y axes and a 90-degree angular misalignment. At the same time, the output voltage remains within the range of 11.5 V to 14.5 V.