A Wireless Selective Frequency Hybrid Compensation Network with Constant Power Profile against Pad Misalignment

Abstract

Wireless Power Transfer (WPT) becomes increasingly popular in both industrial and commercial applications due to its ability to deliver energy across a large airgap, providing physical isolation, freedom in spatial misalignment, etc. However, wirelessly movable objects can cause changes to system key parameters related to magnetic couplers, which will affect power losses and power throughput of WPT systems. This paper proposes a novel Selective-Frequency-hybrid (SF-Hybrid) WPT system that provides an approximately constant power profile under misaligned positions. Four series parallel LC sub-tuning branches are connected in a way that can exhibit inductive, capacitive, short circuiting, or open circuiting characteristics at different frequencies. Hence, the SF-Hybrid system can be designed to be equivalent to either series- or parallel-compensation networks when operating at different frequencies. If the input voltage is a combined two or multiple sinusoidal voltages at integer times of the frequencies, the system can provide a relatively constant power profile against pad misalignments. Theoretical analysis shows the feasibility of an example SF -Hybrid system operating at 20 kHz and 60 kHz, and it is further validated by a simulation study based on a 1.3 kW system.