Simple Enhancement of Series–Series-Compensated Inductive Wireless Power Transfer Links Operating With Load-Independent Voltage Output at Fixed Frequency to Attain Zero Inverter Phase Angle

Abstract

It is well-known that series-series compensated resonant inductive wireless power transfer links (SS-IWPTL) may be designed to attain load independent voltage output (LIVO) for given operating frequency and coupling coefficient. Unfortunately, corresponding inverter output impedance is either highly-inductive or highly-capacitive (inductive region is typically preferred due to natural zero-voltage switching (ZVS) of inverter transistors), significantly increasing inverter volt-ampere (VA) rating. The letter demonstrates that designing the SS-IWPTL for operation in the capacitive region and then adding a shunt inductor across AC-side terminals of either inverter or rectifier while allows attaining inverter zero phase angle (ZPA) thus minimizing its VA rating.