Analysis and Design of a High Frequency Wireless Power Transfer System Based on Bilateral Impedance Compression for Light Emitting Diode Driver

This paper designs a bilateral T-type circuit for the development of a Light Emitting Diode (LED) driver. Aiming at the impedance sensitivity of the high-frequency wireless power transfer (WPT) system, the impedance compression T-network is used for impedance transformation to realize the wide load range constant voltage characteristic of the power amplifier (PA). In view of the multi-load current balance and load pluggable requirements of the LED driver, the constant current characteristics and independent controllability of each LED ring are realized through the voltage-current conversion T-network. The optimal input resistance of the rectifier is deduced by using the coil parameters, and the design formula of the bilateral T-type circuit is given. An 18.43 W single-ring LED system and a 36.83 W double-ring system were built to verify the feasibility of the LED driver. In the end, the maximum efficiency of the single LED ring system can reach 92.85%, and the efficiency of the double ring system can reach 90%.