Load-Independent Voltage-Gain Design Method for Domino-Resonator Wireless Power Transfer Systems

This letter proposes a novel voltage-gain design method for domino wireless power transfer (WPT) systems that can achieve load-independent zero-phase-angle and constant voltage conditions simultaneously. In the proposed method, only three compensation capacitors are tuned to achieve the design goals without changing the structures of identical domino coils, which increases the interface flexibility and stabilities of domino WPT systems to match the voltage difference between the power source and the load in various applications. A new character that the compensation capacitors in certain coil loops have monotonic influences on the input and output is revealed. Based on the transfer coefficient model, this character is modeled and explained in detail, resulting in an explicit capacitor design flowchart. The validity and accuracy of the proposed method are demonstrated using a five-coil experimental prototype to achieve three different voltage gains.