| Currently,the world resourses and environmental wreck issues are getting worse and worse.The new-energy cars,for example the battery-based electric vehicle(Battery-Based EV)and hybrid electric vehicle(HEV),have come into being.Battery-Based EV is the ultimate goal of the future development of the automotive industry.Due to the imperfection of element and charging installations,HEV is needed as a transitional stage.The HEV is more mature than battery-based EV as it has the advantages of high driving force,strong endurance,high fuel economies,and less demand for external facilities.The HEV uses a compound-structure dual-rotor motor(CSDR Motor)as a power distribution device to simplify the structure of vehicle.By reasonably matching with the internal combustion engine(ICE)and the storage battery,coupling with the appropriate control strategies of torque and speed,to realize the power,comfortalble,energy saving and environmental protection of HEV under different working condition.Therefore,the HEV based on CSDR motor will become the mainstream vehicle to alleviate the issues of future resource,energy and environmental.By analyzing the power splitting mode of HEV based on CSDR Motor,it can be seen that although the coupling effect between electromagnetic fields improves the fuel economies and reduces exhaust emissions of the vehicle,it also causes serious electromagnetic coupling problem in CSDR Motor.It greatly reduces the power factor and power density of the system,and leads to the increase of electromagnetic loss,which is one of the difficult problems for CSDR Motor to be solved.This paper mainly focus on the electromagnetic coupling mechanism and structural optimization design of the two kinds of CSDR Motor used in HEV,i.e.electric variable transmission(EVT)and compound-structure permanent-magnet motor(CSPM Motor),the specific work is as follows:Firstly,the system composition of HEV based on CSDR Motor is introduced,and its working principle is also analyzed.At the same time,the different working mode of HEV based on CSDR Motor is studied,which can be switched under different road condition to realize idle parking,power compensation,braking energy feedback and other functions.However,the complex energy flow leads to the saturation of magnetic field,which will affect the performance of CSDR Motor.To research on the electromagnetic coupling problem and structural optimization design of CSDR Motor,the parameters matching has been carried out between the CSDR Motor and the Toyota hybrid system(THS)of Toyota Prius series HEV,which obtaines the power design parameter of CSDR Motor as well as makes the two systems have the same dynamic driven performances.Next,the electromagnetic structurals of EVT and CSPM Motor used in HEV are optimized.The internal equivalent magnetic circuit models of the two motors are proposed to analyze the the coupling factors under the hybrid excitation sources to improve the decoupling effect.The state equations of EVT and CSPM Motor under three-phase stationary coordinate system are established to study the torque characteristic of them.The finite element method(FEM)models are established,then the internal magnetic field distribution disciplines of EVT and CSPM Motor are studied according to the coupling factors.The 2D-FEM is exploited to study and optimize the electromagnetic structures of EVT and CSPM Motor.The influence of different structure sizes on the torque characteristics is obtained,and the electromagnetic parameters are reasonably selected to reduce the torque ripple.The rationality of the electromagnetic structural optimization design is verified by establishing the FEM model of EVT and CSPM Motor according to the optimum parameters.Ultimately,the article principles are induced.It provides the research thoughts and theoretical references for optimizing the design of EVT and CSDR Motor,in order to improve its dynamic performance and promote its further application in HEV and other fields. |
PDF Full Text Request