Design of Compensation Topology for IPT System Considering Coils’ Parameters and Load Variations for CC or CV Output

Abstract

The inductive power transfer (IPT) technology is drawing increasing attention. Variations in the height of the secondary coil are inevitable due to the fluctuations in the height of the electrical equipment or the pressure of the tires, which leads to variations in the coils’ parameters (self-inductances and mutual inductance). The coils’ parameters and load variations can dramatically affect the performance of the IPT system. In this paper, a unified mathematical model which can describe multiple compensation topologies is established. A design method is proposed to obtain suitable topology and component parameters based on the unified mathematical model and the non-dominated sorting genetic algorithm II. In addition, not only the stable output voltage/current is achieved, but the efficiency and cost are also improved. Finally, two experimental prototypes were built to verify the effectiveness, which has the output characteristics of constant current (3.5A/600W) and constant voltage (72V/100W), respectively. The results show that the output fluctuations are less than 5.63%, and the maximum efficiency is above 94.69% when the coils’ parameters (the primary self-inductance change from 85.76μH to 102.2μH, the secondary self-inductance change from 86.26μH to 102.35μH, and the mutual inductance change from 38.2μH to 72.1μH) and load (double change) vary.