Current Controlled Transmitter for High Frequency WPT utilizing Non-Invasive PCB Integrated Rogowski Current Sensor

This paper introduces a current controlled transmitter for WPT based on a differential Class E inverter with dual symmetrical LCL resonant networks for the transmitter and the receiver. The current control loop is implemented using a digital controller that maintains constant transmitter circulating current by adjusting the inverter input voltage using a pre-regulation stage. High frequency accurate current measurement has been carried out by a non-invasive, PCB integrated Rogowski current sensor. Sensor optimization procedure, and design considerations for the PCB integrated current sensor has been demonstrated via ANSYS MAXWELL simulation and verified experimentally. The differential Class E inverter operates in real-time ZVS operation using dedicated high frequency ZVS sensors with only few nano-second delay. The current controlled transmitter operation has been tested on a 12MHz 100W experimental prototype with all the required peripherals and sensing circuitry, alongside a capacitive medium emulator. The experimental prototype achieves peak efficiency of 83% and superior thermal performance.