路面材料磁化对无线电能传输的能量损失效应研究

A wireless charging pavement is a new type of intelligent pavement that combines wireless power transfer (WPT) technology with a pavement structure to enable the pavement to perform both driving and wireless charging functions. Practical wireless charging pavements require to bury devices inside the pavement materials such as asphalt concrete and Portland cement concrete. Wireless power transfer technology relies on inductive coupling resonance between primary coils in the pavement and secondary coils in electric vehicles. For existing wireless power transfer technology, the transfer medium is air. When pavement materials serve as an environmental medium, their electromagnetic properties can influence wireless power transfer, which needs to be investigated. In this study, AC-13 asphalt concrete and C30 Portland cement concrete were selected as pavement materials, and the impact of their magnetization properties and energy loss on inductively coupled resonant circuits were investigated. First, through a vibrating sample magnetometer, the magnetization properties of the components were quantified. The influence on the inductively coupled resonant circuits was then measured with an LCR meter. Finally, an actual 87 kHz WPT system was established to investigate the impact of factual energy loss. The results show that asphalt and Portland cement concretes contain components with very different magnetization properties. Portland cement concrete can be considered as a continuous magnetic medium, whereas asphalt concrete is discontinuous with many medium interfaces. The two kinds of pavement materials can decrease the inductive coupling factor, and magnetization can cause resonant circuit mismatch and reduce power output at the primary side by 12.7% and 14.2%, respectively. The resonant frequency was found to have decreased after adjusting the frequency of the power source. Therefore, to reduce the energy loss of wireless charging pavements, the electromagnetic properties of pavement materials should be considered as a key factor in the design process.