FPGA Based High Frequency PWM Generation for H-Bridge Inverter in Wireless EV Chargers

Recent trends have indicated that high frequency power inverters are an integral part in the wireless charging applications especially in the EV industry space. Pulse Width Modulation techniques have been at the center of such designs in order to achieve the required high switching frequency. This paper proposes the design and development of such PWM signals utilized in Power Inverters for Static Wireless Charging application. The design utilizes the Xilinx Spartan-6 XC6SLX9 which is a low-cost field programmable gate array [FPGA] to develop and deploy the RTL logic needed to drive the inverter for the wireless power transfer at a switching frequency of 85kHz. The added advantage is that the techniques used here are also readily applicable to other FPGA chips offered by Xilinx. The digital logic developed via VHDL language will generate four pulse signals which are fed to the full H-bridge inverter comprised of Silicon-carbide (SiC) based MOSFET switch devices. Experimental results are presented to verify the FPGA-based inverter operation at 85 kHz.