Research And Implementation Of Magnetic Coupled Resonant Wireless Power Transmission System

Wireless power transfer is a non-contact power transmission.The main transmission methods are electromagnetic induction,microwave,laser,and magnetic coupling resonance.Magnetic coupled resonant wireless power transmission is a hot topic in the research and development in modern electrical technology.It can achieve high power,long range wireless power transfer.It is currently the most likely means of power transmission for portable appliances and implantable medical devices and smart wearable devices in real time and flexible power supply.This article is based on the above research background and the recent studies in our laboratory on exploration.According to the design specifications of the system,the IRF510MOS transistor is used as the basis.The wireless power transmission system with E/F₃ power amplifier as its core module is designed and implemented,and the theoretical analysis of the receiving system is carried out.According to the physical parameters and electrical parameters of the coil,a hollow copper wire transceiver coil with a height of 20 cm,a diameter of 60 cm and a 5.25 inch was designed and wound.The transmission characteristic test of the coil shows that the coil has good directivity.The coil frequency characteristic test shows that there is frequency splitting when the coil resonates,and the two resonant frequencies increase with the transmission distance,and eventually tend to the same frequency of 8 MHz.According to the design index of the system,the IRF510MOS tube is selected as the switching tube of the power amplifier;An 8 MHz duty cycle adjustable power amplifier gate control signal is analyzed and designed by using a 16 MHz active crystal oscillator and a74LS74 dual D flip-flop.In order to achieve the maximum power output of the power amplifier,the matching network of the output of the power amplifier is analyzed and designed.In order to eliminate the third harmonic component of the transmitting end,a low-pass filter with the harmonic frequency as the cutoff frequency is designed.Finally,the ADS software is used to simulate the whole circuit of E/F₃ power amplifier.The simulation results show that the power amplifier meets the design requirements.The key of the wireless energy receiving system is the high-frequency rectifier circuit and the filter circuit.An improved bridge-type RF to DC conversion circuit is designed.In order to make the unidirectional pulsating DC become a more stable DC,a T-type low-pass filter is designed according to the normalized filter design parameters.The results show that the designed bridge RF to DC conversion circuit and T-type low-pass filter reach the design index.The theoretical efficiency of the transmitting system power amplifier is 100%,the simulation result is 92.5%,and the measured efficiency is 90%.The measured data of the E/F₃power amplifier circuit shows that when the output power is 4.6 W-5 W,the power amplifier efficiency is above 85%,so the power amplifier achieves high efficiency output.The comparison between the measured waveform and the simulated waveform of the power amplifier shows that the designed E/F₃ power amplifier circuit has reached the design index.Finally,build and test the entire magnetically coupled resonant wireless power transmission system,when the DC input power of the transmitting system is 5 W and the RF signal is 8 MHz,the 3W bulb is lit at 6 meters from the Launch system.The maximum transmission distance of the geometrical size of the transmitting coil of the coupled mode of the magnetically coupled resonant wireless power transmission is realized.The voltage waveform at the receiving end measured by digital oscilloscope is 8 MHz sinusoidal wave,which indicates that the magnetically coupled resonant power transmission is realized.