The Performance Study Of Active Magnetic Bearing Based On The600Wh Flywheel Energy Storage System

Active magnetic bearing (AMB) offers a novel way of solving classical problems ofrotor dynamics by suspending a spinning rotor with no contact, wear and lubrication, andcontrolling its dynamic behavior, which can be used to support the flywheel energy storagesystem with high speed. However, the mature index system of the design and application ofAMB has not been formed as the industry standard. The bearing characteristic index is in itsinfancy, and lack of the similar engineering examples for reference.This thesis mainly focuses on the study of the bearing characteristics for the AMB. Asthe600Wh energy storage flywheel prototype design for the application background, theeffects of the structure parameters and control parameters on the bearing capacity of theAMB has been analyzed. Combined with the model of the prototype’s rotor system, thestudy of the bearing characteristics for the AMB has been carried out, which can provide thedesign reference for the structure design and control system design of the AMB and theoptimization of the prototype.Firstly, the mathematical model of the electromagnetic force was built to analyze theeffects of the structure parameters and control parameters on the AMB.The result of theanalysis, which was the nonlinear characteristics with the adjustable stiffness and dampingwas obtained. In order to reduce the nonlinear factors of the electromagnetic force model,the effects of the structure parameters the electromagnetic force was study to obtain optimalrange of the electric magnetic linearization control, and provide the parameters range for thestructural design to realize electric magnetic linearization control.Secondly, based on the proportion integration differentiation (PID) control strategy, thesingle degree of freedom model of the closed loop control system for the AMB was built,and the controlled parameters range was obtained by the Routh criterion. The variationtrend of the bearing characteristics of the AMB with the variation of control parameters wasgained by the analysis the variation trend of the equivalent stiffness and equivalent dampingwith the variation of control parameters. Considering with parameter requirements of theoptimal linear control, the PID controller control parameters was finally confirmed. Thesingle degree of freedom model of the closed loop control system for the AMB was built.The single degree of freedom control model with deviation differential control mode was established by MATLAB/Simulink, the response of the input displacement to validate thecorrectness of the above analysis.At last, combined with600Wh energy storage flywheel rotor system mathematicmodel, the Campbell diagram of the rotor system was obtained by the calculation of thewhirl frequency under different parameters in MATLAB to analyze the effect of thecontroller parameter on the whirl frequency and to limit the operating speed and tartacceleration or deceleration of the rotor. The result of the analysis can be used to set thesupport position of the rotor system, limit the ratio of transverse moment of inertia and thepolar moment of inertia and direct the flywheel prototype future design.