Effects of coil misalignment in a four coil implantable wireless power transfer system

Wireless power transfer (WPT) is the technology which enables transfer of electric power without wires. It is based on the principle of electromagnetic induction. There are two main modes of WPT, inductive and resonance based coupling. In either of these methods, for the highest possible efficiency to be achieved, the transmitter and receiver coil should be aligned perfectly with each other, but in real world WPT applications, there is always some amount of misalignment between the transmitting and receiving coils. Therefore, it is important to study the effects of coil misalignment to identify and make the necessary design changes to maintain the efficiency of power transfer. This paper presents a simulation analysis on the effect of coil misalignments in a resonance coupled four coil WPT system and the effects of lateral misalignment have also been analyzed and documented.