Research On Wireless Inductive Charging Key Technology Of Portable Electronic Products

Wireless inductive charger can eliminate the friction, arc and otherdisadvantages of traditional contact power supply system. Improving the securityand flexibility of power supply has a good prospect of application. Because of therequirement of different portable electronics users have different use habits andconvenience to use, separable transformer which use in wireless inductive chargerare different from Non-contact charging system, it’s primary and Secondary have notonly poor coupling, but also place corresponding position randomly. This make theseparable transformer have the characteristics of large equivalent leakage inductance,small magnetizing inductance and inductance value change randomly, all of thisaffect the efficiency and stability of the system. In this paper, some wirelessinductive charging key technology of portable electronic products will be researched.(1) The paper has introduced the current status and the developing trends of thecontactless inductive electric energy transferring technique and studied in portableelectronic products of new wireless charging platform in details.(2) The paper has analysis the reasons of high leakage inductance and lowmagnetizing inductance of separable transformer. This paper proposed a newcore structure which can increases the coupling coefficient by increasing the corecrossing area.(3) The paper has analysis the work mechanism of series resonant and parallelresonant converter and pointed out that the series resonant is more suitable forapplications in wireless inductive charging. When the series resonant converteroperating in natural resonant frequency, the circuit transporting the maximumpower.(4) The paper proposed a novel wireless inductive charging topology and controlscheme. In the new program: the primary side of detachable transformer adoptsthe asymmetrical half bridge series resonant which leakage inductance is used asresonant inductance and apply frequency tracking adaptive control to ensure thatthe circuit can work at resonant frequency even circuit parameter changes toimprove system efficiency and stability.The secondary side of detachable transformer adopts current chopper converter by controlling current conductiveangle to regulate the output voltage. The switches of the asymmetrical halfbridge series can achieve ZVS turning which power feedback to the primary side.Saber modeling and simulation verify the feasibility of new program areeffective.(5) This paper has designed, debugged a principal machine which adopts the novelwireless inductive charging topology and control scheme, verifying the correct ofthe new scheme. The adaptive frequency tracking circuit varies with the inductor,and work stability in the vicinity of the inherent resonant point. Meanwhile. Thecurrent chopper at the secondary side can achieve the stability of the outputvoltage...