A Dual-Frequency Dual-Load Multirelay Magnetic Coupling Wireless Power Transfer System Using Shared Power Channel

Aiming at the power supply solution of online monitoring equipment for high-voltage transmission lines, a dual-frequency dual-load multirelay magnetic coupling wireless power transfer (MC-WPT) system using a shared power channel has been proposed. The proposed MC-WPT system provides the selective power distribution for different loads and has the constant current output characteristic. First, a dual-frequency inverter is introduced to provide the ac voltage of two frequencies. The compensation network that includes the band-stop filter can reduce the cross interference of the nontarget frequency from another power channel. Second, the system is modeled and analyzed based on the quadratic eigenvalue problem. Considering the cross-coupling mutual inductance, operating frequencies that make the system have constant current output characteristics are obtained. Finally, three evaluation indices are proposed: average current gain, load-independent index, and average sensitivity index of operating frequencies. Optimized operating frequency is selected according to these evaluation indices. The experimental results verify constant current output characteristics and the selective power distribution of two power channels.