Design of Frequency Bounded IWPT Systems under Sub-Resonant Control for Improved Misalignment Tolerance

There exist numerous cases in which wireless power transfer (WPT) systems are required to operate with varying geometrical positioning (vertical distance, misalignment) between the transmitter and receiver sides, creating the need for robust systems that can operate over a range of coupling coefficients. Sub-resonant frequency controlled inductive WPT link (IWPTL), utilizing frequency variation to control system output, has proven to be an effective solution to this problem, however, frequency constraints introduced in practical applications such as the SAEJ2954 electrical vehicle (EV) charging protocol naturally limit the coupling variance range for which such a system can correctly operate. This paper introduces clear and concise guidelines for a modified sub-resonant controlled series-series (SS) compensated IWPTL with improved coupling tolerance under frequency constraints. A comparison is made to typical design methodology showcasing a 44.4% increase in coupling tolerance and system operation is validated by PSIM simulations.