Optimal resonant tank design considerations for primary track compensation in Inductive Power Transfer systems

In this paper, design of a primary resonant tank for resonant converters compensation in an Inductive Power Transfer (IPT) system is analyzed and some criteria for selecting its reactive components are established. The optimization goal is to maximize the transferred power, while limiting the number of compensation components to no more than two reactive components. Additionally, VA limits of the inverter are taken into consideration. Current track requirements are relaxed and instead of constant track current, small track load dependency is allowed, which is acceptable in practice. The theoretical investigations and calculations, as well as simulations for two important practical cases considered are presented in the paper. It is shown that LC compensation structure allows maximum delivered power, but not for the case when the impedances of compensation elements are the same as it would be expected. Additionally, the impact of converter ratings and allowed load dependent track current variation on the optimal design are investigated through the set of numerical simulations.