Control Method Research Of Contactless Power Transfer System

Inductive contactless power transfer(ICPT)technology is a newly developed power transfer technology using electromagnetic induction and resonant technology.These years,the research about ICPT's topology construction,transfer performance,and control method is highly discussed,making it possible to implement engineering practice of ICPT technology.ICPT system transfers power by electromagnetic induction,but the transfer capability and efficiency can be extremely low because of the little mutual inductance and big leakage inductance.In order to improve the transfer capability and efficiency,capacitor compensation is wildly used in ICPT system.The compensated capacitance and winding inductance forming a complex resonant system,which requests a lot more to the control methods.This paper will first introduce the research status of ICPT in the loosely coupled transformer,transfer performance and control method,then the significance and contents of this paper,principle and composition of this paper,and simple introduction of the composed construction.This paper introduces the four kinds of capacitor compensation of ICPT system,builds models of the four compensation systems based on the mutual inductance model of the loosely coupled transformer,analyzes the four resonant system in system impedance and input-output relationship,introduces the frequency bifurcation and frequency splitting phenomenon.This paper also deduces winding resistance's influence on transfer capability and efficiency,and based on which,the system parameters are deduced.In terms of the control methods of the ICPT system,this paper proposed a phase-shift control method and a Bang-Bang Charge Control method for the contactless DC-DC converter.The two control methods are compared by PSIM simulation.The simulation result shows that phase-shift method possesses obvious advantages in transfer efficiency when the transferred power is relatively large.For contactless AC-DC converter,this paper proposed a single stage AC-DC converter realizing input unity power factor using variable frequency-phase shift control,and the relationship between output power and mutual inductance is also deducted.This paper builds a experiment platform for ICPT system,including a loosely coupled transformer and printed circuit boards for main circuit and control circuit.Experiments are performed on the platform,and the feasibility of the proposed control methods is proved.