Application Of Magnetorheological Fluid Damper In Vibration And Noise Reduction Of Frequency Conversion Permanent Magnet Motor

With the wide application of frequency conversion permanent magnet motors in various fields,their vibration noise has attracted more and more attention.Vibration and noise reduction technique of the frequency conversion permanent magnet motor is of great significance to environmental protection,the normal operation of the motor and improvement of the work efficiency.Kinds of smart vibration and noise reduction materials are favored by many scholars.Among them,the magnetorheological fluid damper(MRD)has excellent performance of fast response,wide adjustment range,low power loss and adjustable damping coefficient,which can be used to reduce vibration and noise of the structure.In this paper,magnetorheological fluid damper is used to the vibration and noise reduction of the frequency conversion permanent magnet motor.The main contents are as following:1.Vibration of the frequency conversion permanent magnet motor is studied by theoretical analysis and experimental search.The vibration acceleration waveform of the motor is obtained and its vibration characteristics are analyzed,which provides a theoretical basis for vibration and noise reduction of the frequency conversion permanent magnet motor.2.Through analyzing the magnetic field of the magnetorheological fluid damper by the finite element,we get the influence of the structure parameters and the excitation current to the magnetorheological fluid damper magnetic field distribution,as well as magnetic induction intensity variation tendency with different structure sizes and excitation currents.Then,introduce the magnetic circuit optimization principle,i.e.the damping force of the magnetorheological fluid damper reaches a maximum and adjustment,magnetic saturation reaching both in the magnetic cores and damping channels at the maximum magnetizing current.Damping force curves with piston and cylinder relative velocity at different excitation currents are obtained by using the finite element method,which verifies that the designed magnetorheological fluid damper meet the requirement.3.According to vibration characteristics of the frequency conversion permanent magnet motor,a new structure with elastic connection at the bottom of the piston rod is presented.Its performances are analyzed from transfer coefficient,modal displacement,natural frequency and mechanical property.4.This paper also designs a vibration control system of the magnetorheological fluid damper for the frequency conversion permanent magnet motor.The desired damping of the system controller is obtained by making the vibration acceleration response mean square value minimum,and control voltage of the current driver in the damper controller is adjusted by combining fuzzy with PID control.The fuzzy-PID damping control system of the magnetorheological fluid damper is simulated,too.And the simulation results show that the system has good damping effect.