Optimization of coils for magnetically coupled resonant wireless power transfer system based on maximum output power

Magnetically coupled resonant (MCR) wireless power transfer (WPT) technology is efficient and practical for mid-range wireless energy transmission. For the design of MCR WPT system, it is necessary to seek optimal transmission performance under different applications. This paper presented an equivalent analytical model for such system to incorporate spatial misalignments between the transmitting coils and receiving coils. According to the obtained model, the relationship among the output power, spatial misalignments and coil parameters were analyzed in detail. To achieve maximum output power and high stability of power transfer in a specific misalignments range, a normalization method was introduced, providing critical insight into the optimal design of coils. Relative design considerations and optimization procedures were further stated. Experiments had also been carried out to evaluate the accuracy of theoretical analysis and confirm the validity of the proposed method.