Electrodynamic Analysis Of Mechatronics-Electro-Hydraulic Power Coupling System(MEH-PCS)

MEH-PCS realizes the arbitrary mutual conversion of mechanical power,electric power and hydraulic power.It has the advantages of high torque as low speed,rapid dynamic response,self-cooling,self-lubrication,highly integrated structure and compact structure,and has a wide range of application scenarios.In this paper,the equivalent magnetic circuit analytical model,parametric modeling and simulation,the relationship between structure and electrodynamic force and other issues of MEH-PCS are studied,which provides a theoretical basis for electrodynamic structure design and performance improvement of MEH-PCS.The main research contents are as follows.The electromagnetic field working principle of the MEH-PCS is analyzed,and the electrodynamic analytical model based on the equivalent magnetic circuit is given,and then the synchronous reactance,main flux and leakage flux are calculated respectively.The motor performance under the combined influence of the Q axis and the D axis is obtained by using the double reaction theory.The motor equation is transformed from A-B-C coordinate system to d-q coordinate system by power invariant coordinate transformation,and the parameterized model of MEH-PCS is build,then the field-path combination analysis is carried out according to the parameterized model of MEH-PCS.The finite element model of MEH-PCS structure is established by using Ansys Maxwell,and the validity of the finite element model is verified by considering the comparison of the air gap magnetic induction intensity between the analytical solution and the simulation results when the air gap length varies,and the comparison of the electromagnetic torque between the analytical solution and the simulation results when the work angle varies,respectively.In view of the more complex stator and rotor structures,different structural arrangement forms,different structural parameters and some other factors have important effects on the electrodynamic force of the MEH-PCS,the electrodynamic performance of the MEH-PCS is analyzed by using a parametric model to study the EPH and IPH,different stator slot types,air gap length,permanent magnet thickness,RIB,plunger hole diameter,plunger hole distribution radius,the excitation amplitude and core material,etc.,to explore the influence of each parameter on the output torque and torque fluctuation of the electric drive system,and to obtain the degree of influence of each parameter on the MEH-PCS electrodynamic performance,which becomes a discipline analysis tool for the subsequent optimization design.The torque magnitude is most influenced by the stator slot type and air gap length in terms of structural arrangement and structural parameters,in addition to the permanent magnet thickness and excitation amplitude.The torque fluctuation is most associated with the plunger hole arrangement and air gap length.Since the optimization of some of the influencing factors will be constrained by the structure or another performance,the optimized design solution still needs to be considered comprehensively.