This paper proposes a 3-D omnidirectional WPT system with multiple loads to satisfy the multi-direction misalignment charging condition in the space. The theoretical analysis shows that there exists a set of current amplitude to maximize system efficiency. Moreover, the phase difference of current between transmitters should be set to 0° or 180° to improve efficiency. A current regulation method base on steepest descent algorithm is proposed to realize maximum efficiency point tracking. The simulation results based on Simulink/MATLAB show that the system efficiency is 90.9% with an improvement of up to 29.7% compared to that without the method.This paper proposes a 3-D omnidirectional WPT system with multiple loads to satisfy the multi-direction misalignment charging condition in the space. The theoretical analysis shows that there exists a set of current amplitude to maximize system efficiency. Moreover, the phase difference of current between transmitters should be set to 0° or 180° to improve efficiency. A current regulation method base on steepest descent algorithm is proposed to realize maximum efficiency point tracking. The simulation results based on Simulink/MATLAB show that the system efficiency is 90.9% with an improvement of up to 29.7% compared to that without the method.

current regulation,efficiency,multi-receiver,steepest descent algorithm,wireless power transfer (WPT)