Robust Wireless Power Transfer by Self-Oscillating Controlled Inverter and Double-D Pads

Inductive wireless power transmission (IWPT) for mobile devices like electric vehicles (EVs) requires high efficiency and power stability. A resilient IWPT system is demonstrated in this paper with double-D pads (DDP) serving as the transmitter (Tr) and receiver (Re) with a self-oscillating controlled inverter to maintain constant output power and transmission efficiency regardless of variation in inductive coupling within a defined region, with no communication or control circuitry on the Re side. The proposed compact DDP-DDP inductive coupler with a single identical coil on both the Tr and Re pads provides a resilient IWPT system with up to a 20 cm transmission distance, up to 12 cm horizontal offset at a 20 cm transmission distance, and limited degrees of angular offset around the Z-axis between the Tr and Re that can tolerate coupling variations and achieve stable 1-kW output power with 92% steady transmission efficiency.