1kW Resonant Wireless Charging Technology

Magnetic Coupled Resonant Wireless Power Transfer technology has attracted more and more attention due to its advantages of long distance transmission,high power,and strong penetrability.It has become a research hotspot in the field of wireless charging.In this thesis,aiming at wireless charging of electric vehicles,a wireless charging device with output power of 1.33 kW and transmission efficiency of 82.1% under a transmission distance of 20 cm is developed by using magnetically coupled resonant wireless charging technology.This thesis firstly introduces the classification of wireless charging technology.Through comparative analysis,it is found that the magnetic coupling resonant wireless charging technology is more suitable for wireless charging of electric vehicles.The research status and achievements at home and abroad are summarized and the key problems of wireless charging for electric vehicles are proposed.Second,the principles of series resonance and parallel resonance are studied.The voltage relationship and frequency characteristics of series resonance are mainly studied.High voltage can be obtained by using series resonance.The four resonant topologies of magnetic coupling resonant wireless charging are analyzed,and the series-series structure is selected as the resonance structure of this subject;through the analysis and derivation of the transmission system equivalent model,the calculation formula of the system transmission efficiency is obtained.For system design requirements,design the system charging coil and charging circuit,The whole system adopts the scheme of dual-resonant solid-state Tesla coil.The calculation formulas for each parameter of the charging coil are given and the influence of each parameter on the transmission performance is studied.The wireless charging coil suitable for electric vehicles is designed.The design of the charging circuit includes rectifier filter circuit design,full-bridge inverter circuit design,drive circuit design,and control circuit design.The primary coil feedback signal is used to realize the full-bridge self-excited operation,and a full-bridge zero-current switch is realized.The arc extinguishing signal is used to control the turn-on and turn-off of the full bridge.Finally,the wireless charging device is powered on,its output waveform is analyzed,and calculated to achieve system output power and transmission efficiency requirements,and the system horizontal offset,vertical offset and angular offset characteristics are experimentally studied,the results show that the system has a certain anti-dislocation ability.