Delayed WiFi Communications Feedback Control Primary-Side Buck Converter for CC-CV Inductive Wireless EV Charging

This paper aimed to study the delayed WiFi communications for constant current and constant voltage (CC-CV) inductive wireless EV charging coupled to the primary side (PS) buck converter through the ESP 32 feedback controllers on the secondary side (SS). The results show that the cascade PI controller achieved the transient response, non-steady state error, stability, and reliability for the wireless charging system with a delayed time feedback signal of 30 ms based on the step-resistance load and lithium battery charging for 20% to 90% SOC. Ultimately, the system's current and voltage gains produced cascade feedback signals from the SS and the primary side buck converter output, outperforming the battery unit's single-stage feedback current and voltage signals. The system achieved 88% efficiency during charging with 380 W to 800 W.