Research And Design On The Receiving System Of Wireless Power Transmission Based On Coupled Magnetic Resonances

As one of the most concern of technology by the international community in twenty-firstCentury, the wireless power transmission (WPT) has begun to enter people’s life. Because ofthe characteristics about energy efficient transmission in distance, wireless power transfertechnology via magnetic resonant coupling attracts a lot of researchers to research andexplore.According to the coupled-mode theory, this paper analyzes the transfer principle andrelated properties of wireless power transmission using magnetic resonant couplingtechnology. The formulas are derived to calculate the transmission efficiency, couplingcoefficient, quality factor and other parameters of magnetic resonant coupling wireless powertransmission system. Then it gives the design basis of the transceiver coils, fabricates severalgroups of transceiver coils, and verifies the rationality of the design basis through the actualtest.In the paper, the transmission characteristics of magnetic resonant coupling wirelesspower transmission system are validated by experiments. The experiments show that thetransceiver coils has good directivity. The system can obtain high transmission efficiencywhen the transmission coil and receive coil work at a same resonance frequency. Thefrequency splitting phenomena is observed, that is to say, the system has two resonantfrequencies, which are symmetrical about the central frequency. And the system can obtainthe maximum transmission efficiency at the two frequencies. The studies also show that thetwo resonant frequencies gradually move closer to the center frequency with the increase ofthe propagation distance, and the transmission efficiency at the high resonant frequency pointincreases first and then decreases, and at the low resonant frequency point, transmissionefficiency decreases gradually.The paper propose a receive circuit design scheme of magnetic resonance couplingwireless power transmission system. The design uses diodes to build bridge rectifier circuit torealize RF to DC conversion. Then this paper designs a low-pass filter based on the normalized low-pass filter parameters. Finally, the paper tests the receive circuit and lights upa3W bulb in the transmission distance of1m.