A Dynamic Wireless Power Transfer System Using DC-Controlled Variable Inductor for Segment Transmitter Automatic Switching

Segmented transmitter coils are commonly employed in dynamic wireless power transfer, and automatic switching is a preferred function to limit the transmitter current. This letter proposes a method for segment transmitter automatic switching utilizing a dc-controlled variable inductor (DCCVI), where the dc current can change the ac side's self-inductance. When the coils are decoupled, the dc current is small, so the inductance of the DCCVI is relatively large, leading to the suppression of the transmitter current. When the coils meet certain coupling conditions, the dc current becomes large, leading to a significant reduction in the ac inductance of the DCCVI, resulting in higher transmission power, thereby enabling segment transmitter automatic switching. The proposed method is straightforward and does not need additional position feedback. The experimental results demonstrate that the proposed system can automatically limit the coil current within the range of [0, 0.15] and achieve higher power transmission with higher efficiency within the coupling range of [0.165, 0.3].