Research On Integrated Motor Driving And Onboard Charging System Based On Flux-switching Machines

The integrated onboard motor driving and charging system is a new type of vehicle charging system for electric vehicles that has received widespread attention.In this system,only the original motor driving system in the electric vehicle is employed to constructs the onboard charger by reconfiguring the motor windings and multiplexing the power converter with no additional power devices.However,the existing integrated onboard charging systems still have problems such as the need of additional devices,the start and pulsation torque during charging,and the voltage matching problem of the grid voltage and the battery voltage,which limit their large-scale application in electric vehicles.Therefore,based on summarizing and sorting out the bottlenecks and demands of the integrated onboard charging system,this thesis proposes an integrated onboard motor driving and charging system based on multi-phase HEFS motors that can simultaneously solve multiple bottlenecks of the integrated system,and conducts an in-depth study on it.The main contents can be divided into the following parts:1)On the basis of analyzing the advantages and bottlenecks of the integrated vehicle charging system,from the perspective of several key bottlenecks of the integrated onboard charging system,the solutions of the existing integrated system to the key bottlenecks are summarized,and some of the most necessary characteristics and features for the motors used in the integrated charging system are analyzed.2)A generic topology for an integrated onboard motor driving and charging system based on a multi-phase HEFS motor is proposed,relying on the unique characteristics of the multi-phase HEFS motor.3)An integrated onboard charging system based on a five-phase HEFS motor is proposed,and its working principle of single-phase/three-phase charging mode,calculation method of winding connection in both modes,current balance control strategy and PFC solution without PLL are comprehensively analyzed,and simulation verification and quantitative analysis are carried out.4)An integrated vehicle charging system based on a six-phase HEFS motor is proposed,and its operating principle,winding connection method and control method are also discussed,and simulation verification and quantitative analysis are carried out.5)A comprehensive optimization method for motor winding parameters is proposed,and the constraints of the HEFS motor armature and excitation winding are established,the calculation of the system output power and operating efficiency are discussed,and finally a general procedure for the optimization method is given.6)Taking a five-phase HEFS motor as an example,the original winding parameters are optimized using the proposed optimization method,which greatly improves the output power and steady-state operating efficiency of the system while maintaining the performance of the electric mode motor,and the simulation verification is carried out.7)A general purpose scalable three-phase motor drive controller is built.The functional modules,mechanical structure and hardware circuits are designed,manufactured and tested.8)An experimental platform for the integrated onboard charging system is built,and the feasibility of the proposed integrated charging system and the effectiveness of the optimization method for winding parameters are verified by experimental methods.