Parameter Matching And Performance Research Of Field Modulated Brushless Electrical Variable Transmission With Halbach Permanent Array

In the face of the enormous challenges posed by global energy and environmental systems,the car-driving approach ushered in a revolutionary change.At present,the global development of new energy vehicles has reached a consensus,and the future long-term new energy vehicle technology's direction is mainly driven by the pure electric,fuel cell technology,including pure electricity.In the short term,oil-electric hybrid,plug-in hybrid power will be an important transition route.Nowadays,the hybrid power system includes series,parallel and mixed type,the mixed hybrid power system based on the planetary gear structure dynamic coupling device synthesizes.The advantages of the former two has a larger development foreground,which can realize the speed coupling and torque coupling between the internal combustion engine and the motor,and optimize the working range of the engine.However,the planetary gear structure of the system is a pure mechanical device,which is unavoidable in the aspects of noise,efficiency,vibration and so on,and it needs to be maintained on a regular basis.In recent years,a dual mechanical port electric machines based on the principle of electromagnetic energy conversion has been proposed.Dual mechanical port electric machines as a power coupler used in hybrid vehicles not only replaced the planetary gear transmission,but also to the motor,generators,clutches and other components,greatly reducing the vehicle quality,not only save space,and the vehicle power density and energy transmission efficiency has been greatly improved.Based on the dual mechanical port electric machines,a new type of field modulated brushless electrical variable transmission with Halbach permanent array is presented in this paper,the brushless motor is realized with magnetic gear effect,and the coupling phenomenon between magnetic field is effectively reduced by using Halbach Permanent Magnet array,and the efficiency of the device is improved,and the main research contents are as follows:First of all,in order to study the principle of dual mechanical port electric machines and its application in hybrid electric vehicle,this paper analyzes the structure and working principle of the hybrid power system based on dual mechanical port electric machines and the internal power flow and distribution in different working modes,and develops the performance test of the principle prototype,and carries out no-load and load experiments on the prototype.Secondly,based on the analysis of the problems of the dual mechanical port electric machines,this paper presents a dual mechanical port electric machines structure scheme using the Halbach permanent magnet array and the integrated magnetic field modulation principle combined with the planetary gear mechanism.Its topological structure is integrated in the same diameter,which avoids the problem that the split-type structure occupies too much space,while the permanent magnet on the outer rotor adopts the Halbach array to reduce and even eliminate the magnetic coupling by using the unilateral magnetic shielding of the structure.It is closed to the sinusoidal air gap magnetic density effectively improve the performance of the motor,using planetary gear mechanism to effectively solve the device internal parameter matching unreasonable problem;The structure and working principle of each part of the device are analyzed.The coupling magnetic density is analyzed theoretically,and a field modulated brushless dual mechanical port electric machines with radial magnetizing and Halbach magnetizing mode is established respectively,from magnetic field distribution,air-gap magnetic density,inductive potential,the influence of different magnetizing modes on the performance of the motor is compared and analyzed by the torque.Then,the key electromagnetic dimensions of field modulated brushless electrical variable transmission with Halbach permanent array are determined by the finite element method.The inner field modulated motor and the outer motor are designed,and the performance characteristics of the dual mechanical port electric machines and the field modulated brushless dual mechanical port electric machines are compared,and their advantages and disadvantages are analyzed.Then,in order to give full play to the performance of field modulated brushless electrical variable transmission with Halbach permanent array,the working mode of the device and the power flow in different working modes are analyzed,the dynamic distribution strategy is determined,including the mode switching condition,the smooth handoff between the modes is ensured,and the development of the correlative Hybrid dynamic coordinated control strategy is completed.Finally,in order to rationally match the internal combustion engine,field modulated brushless dual mechanical port electric machines with Halbach permanent array,power battery and other components,a hybrid electric vehicle model of field modulated brushless dual mechanical port electric machines with Halbach permanent array is established.Based on the actual operating condition of the vehicle,the working points of each part of the hybrid power system are analyzed,the design indexes of the internal combustion engine,the inner field modulated motor and the outer motor are determined.Moreover,the influence of the ratio of the planetary gear drive on the hybrid power system is discussed.By selecting the optimum transmission ratio,the working range of the inner field modulated motor is better.Finally,under the condition of satisfying the power requirement of the vehicle,the whole vehicle fuel consumption is reduced by the design of the hybrid power system's parameters.