Design And Performance Research Of Electrodynamic Structure Of Permanent Magnet Piston Mechanical-electric Motor

The permanent magnet piston mechanical-electric engine is a new type of dualelement power device integrating the structural principles of traditional piston internal combustion engine and linear generator.This engine retains the crank-link mechanism of traditional internal combustion engine and adds the electromagnetic structure of linear generator,which solves the problems of large structure,long transmission route,uncoordinated work and only single energy output of traditional internal combustion generator set.In this paper,the electrodynamic structure and performance of the permanent magnet piston-mechanical electric engine was studied through simulation and test,and the theoretical basis was provided for the structural optimization and design.The whole dynamic model was constructed,and structure was matched to design.Based on the analysis methods of traditional internal combustion engine and linear generator,the system dynamics model,electrodynamics model and loss model of the permanent magnet piston mechanical-electric engine were established,the motion law and force equilibrium equation of the mover part and the electromagnetic equation of the motor were obtained,and five system performance indexes were proposed.The structure of this engine based on the structure of the 168 F gasoline engine was improved and designed.And its relevant dimensional parameters such as the mover part and the stator part were determined.Finally,the geometric modeling of this engine was completed.The three-dimensional finite element model of the electrodynamic structure is established and analyzed.Using ANSYS Maxwell electromagnetic simulation software,a three-dimensional finite element model of the permanent magnet piston mechanicalelectric engine was established.And based on the magnetic properties of the permanent magnet at 200℃,the electrodynamic simulation study of the linear generator part was carried out.The static magnetic field characteristics of different stator designs and different magnetization directions,and the electrodynamic characteristics of different magnetization directions under rated operating conditions(throttle opening of 100%,crankshaft speed of 3600r/min,load resistance of 5Ω)were compared and analyzed respectively.It was found that the structural design with core stator and axially magnetized permanent magnets had better electrical performance.Accordingly,the load characteristics were analyzed.And the time domain curves of load current,load voltage and electromagnetic thrust were obtained.When the load resistance was 5Ω,the load current RMS value was about 1A and the electrical output power was about5 W.Comparing the overall performance parameters of the 168 F gasoline engine,it was found that although the mechanical output power was reduced,the electrical energy output was increased.Therefore,the dual element power output of this engine was realized.The three-dimensional finite element modeling and analysis of the electric power structure was carried out.Parametric simulation analysis was carried out under different working conditions to obtain the influence law of load resistance and motion frequency on load current,load voltage and electromagnetic thrust.When further calculated,the regular curve of the system performance indexes was obtained.With the increase of load resistance,the electric output power increased at first and then decreased,while other system performance indexes increased.With the increase of movement frequency,the electric efficiency remained unchanged,the mechanical efficiency increased first and then decreased,while other system performance indexes increased.When the load resistance was 8Ω and the movement frequency was 60 Hz,the electric output power reached the maximum of 5.11 W,at which time the electric efficiency was 65.84%,the mechanical output power was 3698.33 W,the mechanical efficiency was 83.24%,and the thermal efficiency was 33.88%,which was only 0.04% less than the original engine.Based on the mathematical model,a test prototype of a permanent magnet piston mechanical-electric engine was designed.Using the mechanical energy of the motor for electrodynamic matching experiments,the load voltage signal was obtained,which is closer to the simulation data,verifying the accuracy of the finite element model and the feasibility of the structural principle.