Wireless power transmission technology based on coil coupling has been widely applied in various fields. However, the performance of the system is affected by the malposition of the transmission coil-couple, which is inevitable in the wireless power transmission system (WPTS). In this study, a multi-transmitter coil array is proposed to build a more uniform magnetic flux density for the WPTS, intending to enhance the performance of the WPTS in the case of coil-couple malposition. The model of the transmission system is built and different coil arrangement methods are analyzed. Then, the magnetic field distributions of the proposed WPTS with different coil arrays are compared using numerical simulations. Experiments are conducted to investigate the performances of the designed WPTS. The results show that WPTS with a seven-coil array can provide a more uniform magnetic field for the WPTS, whose relative deviation of output power is less than 28.55%. This study provides some clues for improving the performance of the WPTS through different arrangements of the transmitter coils.

This article presents a coil couple-based transcutaneous energy transmission system (TETS) for wirelessly powering implanted artificial hearts. In the TETS, the performance of the system is commonly affected by the change in the position of the coupling coils, which are placed inside and outside the skin. However, to some extent, the influence of coupling efficiency caused by misalignment can be reduced by optimizing the coil. Thus, different types of coils are designed in this paper for comparison. It has been found that the curved coil better fits the surface of the skin and provides better performance for the TETS. Various types of curved coils have been designed in response to observed bending deformations, dislocations, and other coupling variations in the curved coil couple. The numerical model of the TETS is established to analyze the effects of the different types of coils. Subsequently, a series of experiments are designed to evaluate the resilience to misalignment and to verify the heating of the coil under conditions of severe coupling misalignment. The results indicated that, in the case of misalignment of the coils used in artificial hearts, the curved transmission coil demonstrated superior efficiency and lower temperature rise compared to the planar coil.