Magnetic Energy Estimation And Circuit Design Of Wireless Energy Transmission Based On Magnetic Resonance

Wireless energy transmission,as its term suggests,refers to the transmission of energy through electromagnetic means rather than wires.This technology has been deeply concerned by researchers for many years,and has broad application aspects in medical equipment,transportation,aerospace and other fields.According to its energy transmission distance,complexity of implementation,etc.Wireless energy transmission technology can generally be divided into two kinds:Near field magnetic coupling technology and far field transmission technology.The difference between the two technologies in energy transmission is that the former uses the transmitting antennas to transmit electromagnetic waves directionally,and the far-terminal receiving antenna receive the electromagnetic wave and supplies the converted energy to the load through the energy conversion device;The latter uses electromagnetic coupling to transmit energy from transmitting terminal to receiving terminal in the near field range.Far field transmission technology uses antennas to emit electromagnetic waves,so the energy transmission distance is long,the disadvantages are high equipment prices and radiation problems.Compared with far field transmission technology,near field magnetic coupling technology has the disadvantages that the energy efficient transmission distance is short,but the price is low,and the realization is easy.This paper mainly studies the wireless energy transmission between multiple coils,using the magnetic resonance method in the near field coupling technology,that is,the transceiver circuit works in the same frequency in the system,using beamforming to transmit the energy of multiple transmitting terminals with highest efficiency to the receiving terminal.In the actually working environment,wireless energy transmission technology is commonly used in wireless charging of intelligent electronic devices,and the state of electronic devices during charging changes with time.Therefore,this paper constructs a transmission circuit that can be adjusted in real time.In this paper,the main work are as follows:1)The basic principle of the wireless energy transmission system is analyzed and the basic influence parameters of wireless energy transmission system are studied.The key system parameters that affect the the transmission efficiency of the system are obtained from it;2)Two structure of magnetic resonance wireless energy transmission are studied,two-turn structure and four-turn structure.the system circuit model of two structures is established by using the mutual inductance coupling theory,and the transmission power,output power and transmission efficiency of wireless energy transmission system under these two structures are derived;3)A magnetic channel estimation method under MISO(multiple-input single output)wireless energy transmission circuit is proposed.In the near field range,the voltage and current on the partial transmitting coils are measured,and the mutual inductance between the partial transmitting coils and the receiving coil are estimated by the least squares estimation,and the according to the relationship between mutual and the position between the transmitting coil and the receiving coil,the position of the receiving coil is obtained.Finally,the mathematical relationship of the position between the partial transmission coils and the remaining transmitting coils is utilized to obtain an estimated value of the mutual inductance between all the transmitting coils and the receiving coil.4)A wireless energy transmission implementation scheme that can adjust energy distribution in real time is introduced.The system mainly includes the following modules:a single source module,a gain adjustment module,a power amplification module and other auxiliary circuits.This paper introduces the construction of SISO and DISO wireless energy transmission experimental demonstration system,and studies the relationship between the energy transmission efficiency and the relative distance between the transmitting coil and the receiving coil.The actual construction and programming can realize the real-time adjustment of energy distribution.In this paper,the wireless energy transmission system is deeply researched,and the wireless energy transmission circuit that can adjust the energy distribution in real time is built and tested.The results show that the wireless energy transmission circuit constructed in this paper can realize the real-time energy regulation and high energy transmission efficiency.