The Bearing Characteristics Study And Experiment Of Active Magnetic Bearing Based On E Structure

Flying wheel energy storage system store the energy in the form of kinetic energy in the high speed rotation of the flying wheel rotor, for the support system is needed highly quality. Because there is no contact and no mechanical friction between the Active magnetic bearing(AMB) and the supporting shaft, no lubricant, and the support of the active control and many other advantages of the flying wheel energy storage system is one of the key technologies. Currently, domestic and foreign still lack a mature theory and design methods for the development and application of magnetic bearing, and lack of research on supporting characteristics of magnetic bearing. In this paper, the lOkWh flywheel energy storage system is target for the application,analyze the influence of the structure parameters and control parameters on the bearing characteristics of AMB. According to trial prototype's system, experimental Study on the static bearing capacity and dynamic bearing characteristics of AMB, provide the design reference for the structure design ,control system design and the optimization of the prototype of the AMB.Firstly, this paper analyze the structure and working principle of AMB system, built the axial single degree of freedom mathematical model and the radial four degrees of freedom mathematical model of the electromagnetic force. According to trial prototype's system,analyze the function of the electromagnetic force with the structure parameters and control electric current.Secondly, this paper analyze the effects of different structures parameters on the bearing characteristics of AMB system. Conducted design Calculation of the E-type radial magnetic bearings and axial magnetic bearings. Point out that the gap is the main factors electromagnetic bearing structure size, estimate copper loss, iron loss and the stator temperature rise of the AMB system. By analyzing the relationship between the electromagnetic force and displacement under different initial gap, to determine the optimal linear range of the electromagnetic bearing, analyze the floating conditions when the rotor just started.Thirdly, this paper analyze the effects of different control parameters on the bearing characteristics of AMB system. From the characteristics and design requirements for AMB system, based on PID loop control strategy, build the model of the closed loop control system for the AMB. Points out the factors supporting the active magnetic bearing characteristics is equivalent stiffness, equivalent damping and dynamic stiffness, analyze its variation in different control parameters.At last,this paper conducted electromagnetic force test,dynamic response test and static suspension test. Testing the electromagnetic force in a single direction of the magnetic bearing on different electric current and air gap, get the electromagnetic properties curve of AMB system by analyzing the experimental data, and modified the theoretical calculation formula of electromagnetic force. Test the coil response on different frequency and duty cycle of the control currents. Completed the debugging of AMB system on the design and trial of the AMB system prototype, verify the feasibility of magnetic bearing system by collecting, analysis and research of the experimental data.