| The traditional wired power transmission gradually shows some disadvantage due to the limitation of the wire.And the wireless power transmission has more portable and practical performance because it is free from the constraint of the wire.The magnetic coupling resonant wireless power transmission has great advantages in terms of transmission distance,efficiency and power.It is the development trend of wireless power transmission in the future,and it is also a hot spot of current research.By analyzing the international research process of this technology at present,designed a set of high-power magnetic coupling resonant wireless power transmission system.The circuit parameters of the magnetically coupled resonant wireless power transmission system are analyzed by the circuit principle modeling way.The simulation analysis is carried out by MATLAB software and finite element analysis software,which proves its feasibility.Finally,I designed a experimental platform and verified this system.To achieve controllable and adjustable of power,In view of the current research hotspots of this technology,we have proposed and designed several solutions to overcome many technical difficulties of the technology.Through experimental verification,it has achieved a good result.The design work and innovation in the technology include the following aspects:(1)The front end of the system used rectification and voltage regulation circuits to limit the power of the system and protect the safety of the back end.At the load end,high-frequency rectification is achieved by a new SiC diode which has zero reverse recovery time.And used buck-boost circuit to achieve constant voltage,constant current and constant power controlon the output;(2)Used DSP combined with CPLD to realize the closed-loop adjustment of the resonant frequency,which not only realized frequency tracking,but also realized soft-switching control.At the same time,The high-speed driving chip which has a lowspeed delay is used to drive the SiC switching device,And combine with Class E inverter to realize high frequency inverter,which frequency up to several MHz,and the output voltage is sine wave;(3)Used specific planar spiral coils combined with the high-power adjustable capacitor to ensure that the resonant parameters of the coils at the transmitting end and the receiving end are completely consistent,which improved the transmission efficiency.and designed three sets of coils with different sizes,and done a lot of researches on the relationship between transmission power,efficiency and distance;(4)In order to prevent metal and living organisms from entering the transmission range,Desinged a function to detect foreign matter appearing between the resonance coils and to protect the System.And used wireless LAN for communication connection at the transmitting end and the receiving end to realize real-time monitoring of the transmission state;The system software can realize the closed-loop adjustment of voltage,current,frequency and power.At the same time,designed the humancomputer interaction interface,and the system setting and adjustment are directly realized through the operation panel.The resonant frequency of this design is up to 7.5MHz.The optimum efficiency is 92% when the system frequency 1MHz.the maximum transmission distance of this design is more than 28 cm.In this design,I also used the experimental platform to study the relationship between transmission distance and efficiency,power,and thetransmission effects of three different radius coils.In addition,I also verified other functions such as impedance matching and frequency tracking.The experimental results verify the correctness of the design. |
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