Low Loss Online Capacitor Tuning Method for Reactive Power Reduction of Inductive Wireless Power Transfer System Under Misalignment

In an inductive wireless power transfer system, unavoidable lateral misalignment between the transmitter and the receiver leads to reactive power, which reduces the power-transfer- efficiency and limits the maximum output power under given input voltage. A tunable capacitor provides access to achieve low reactive power and maintain high power-transfer-efficiency. In this paper, the effects of misalignment on power transfer performance is investigated. A conventional capacitor tuning method is analyzed, and its limitations are identified. An innovative low loss online capacitor tuning method is proposed to automatically achieve low reactive power and maintain high power-transfer-efficiency under misalignment. The proposed designs are evaluated via simulation.