Extending Feasible Load-Independent Voltage Gain Range in Wireless Power Transfer Links

Fixed-frequency constant-coupling series (capacitor) - series (capacitor) compensated inductive wireless power transfer links (SS(CC)-IWPTL) may be designed to operate with certain load independent voltage gain (LIVG), constrained by parameters of the loosely coupled transformer (LCT). Due to the fact that LCT parameters values are not arbitrary in practice, targeted LIVG value may not reside within attainable region. This may require for an additional power conversion stage, reducing power density and reliability of the system while increasing size and cost. This work reveals that employing an inductor instead of a capacitor as one of the two series compensation elements allows to extend the feasible LIVG range for given LCT parameters, followed by corresponding compensation elements sizing guidelines. The revealed methodology is validated by means of simulations and experiments.