Optimal Design And Experimental Verification Of High Power Density Electromagnetic Actuator

The active vibration control technology can adapt to the frequency change of external disturbance and the uncertainty of the controlled system structure parameters,and has a good control effect on the low frequency band.The actuator is key to the practical application of active control.In this thesis,combined with the production and research project of enterprise electromagnetic active actuator,a new high-power density electromagnetic actuator with compact structure and large output force is proposed from the perspective of structural innovation,in order to meet the control requirements of low-frequency and strong line-spectrum vibration of high-power diesel engines for vehicles,and its structural design,magnetic circuit optimization,multi-field coupling calculation,performance testing and other aspects are studied.Finally,an experimental bench simulating actual working conditions is designed to verify the actual vibration damping effect of the prototype.The main research contents of this thesis are as follows:Based on the magnetic field theory,the technical principle and the actuating mechanism of the electromagnetic actuator are analyzed and compared,and the type of the product is defined as the moving-magnetic electromagnetic actuator.The dynamics model and working circuit model of the inertial electromagnetic actuator are established,and the influence of system parameters and circuit parameters on the output force of the actuator are analyzed.The optimization direction of increasing the mass of the moving component,reducing the damping of the system,increasing the electromagnetic force constant,reasonably designing the spring stiffness and winding coil are proposed.A model of radial magnetized magnetic circuit is proposed.The average magnetic induction intensity of the air gap is taken as the evaluation index,and the factorial test is carried out by sensitivity analysis method to determine the influence degree of each structural parameter on the air gap magnetic intensity.The orthogonal test is designed to obtain the main structural parameters affecting the air gap magnetic intensity considering the coupling effect between the parameters.Based on the response surface analysis method,the proxy model of structural parameters and air-gap magnetic induction strength is established,and the particle swarm optimization algorithm is used to solve the optimal solution,and the magnetic circuit structural parameters are adjusted and determined considering the magnetic saturation of the magnet.The simulation results show that the air-gap magnetic strength optimized by the response surface particle swarm optimization algorithm is 23.2% higher than the initial design value.On the basis of magnetic circuit optimization,the design and selection of the key components of the electromagnetic actuator are completed.In view of the difficulty and high risk of permanent magnet assembly,the tile magnetic steel fixture is designed,and the machining and assembly of the actuator prototype is completed.The simulation model of the electromagnetic actuator is established,and the electromagnetic force calculation and temperature field simulation analysis of coupled electromagnetic heat are carried out.The simulation results show that the output force is greatly affected by the inductance,and the maximum temperature rise of the actuator will not affect the normal operation of the actuator.The performance test of the prototype is designed and carried out,and the results show that the output force of the actuator can still be maintained at about 280 N under the excitation frequency of 150 Hz,and the linearity of output force in each frequency band can reach more than 92%,which can meet the requirements of automotive diesel engine vibration reduction.In order to verify the actual active vibration control effect of the electromagnetic actuator,a double-layer vibration isolation test bench is designed and built to simulate the actual condition,and a dual-channel active vibration control experiment is carried out.The results show that both channels have good control effect under single frequency50 Hz,100Hz,150 Hz and multi-frequency 40 Hz and 60 Hz vibration conditions.The average damping capacity can reach 15～30d B.The designed electromagnetic actuator can be used for active vibration control and effective control of low frequency strong line spectrum vibration.