An Improved Maximum Energy Efficiency Tracking Control Method for Inductive Power Transfer Systems

A transmitting-side phase shift control strategy based on an improved perturbation and observation (P&O) method is proposed to achieve maximum energy efficiency tracking (MEET) for LCL-LCL compensated inductive power transfer (IPT) systems, which is based on minimizing the input dc current. In this method, the tracking process for the maximum efficiency point is divided into two stages (tracking and oscillation stage), and an adaptive perturbation step size is proposed. In the tracking stage, a large step size is set for the short time to reach the maximum efficiency point. The decreasing step size in the oscillation stage is introduced to reduce the steady state oscillation existed in the conventional method, and the corresponding state switching conditions are given. Hence, the trade-off for MEET between the convergence rate and the oscillation can be removed by adopting this method. Finally, simulation results are given to verify the effectiveness of the proposed algorithm.