The Structure Design Of Electromagnetic Bearing Based On 10kWh Flywheel Energy Storage System

Flying wheel energy storage system is to store 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 magnetic bearing 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. In this paper, the 10kWh flywheel energy storage system is target for the application, according to the energy storage flying wheel for technical indicators, size limits and other requirements of supporting system , design and analysis of the radial and axial electromagnetic bearing structure, and through the test bench to verify the performance of the electromagnetic bearings.Firstly, according to the distribution characteristics of the shaft of the 10kWh flying wheel energy storage system, the overall layout of the supporting system is designed,including the auxiliary support system. According to the basic mechanical model of the electromagnetic bearing, the magnetic force is deduced, and the basic principle of the differential controling. According to the performance of requirements of the energy storage flying wheel to support system, the selection of radial magnetic bearing ferromagnetic material and the number of magnetic poles are determined. Then establishing the mathematical model of electromagnetic force of 12 magnetic pole radial magnetic bearings,designed for the structure of the radial magnetic bearing,so as to analyzed of the electromagnetic characteristics of the magnetic bearings finally. The magnetic field distribution and eddy current loss of the radial magnetic bearings are analyzed by Maxwell ANSYS finite element software.Secondly, according to energy storage flywheel to the condition of the operation parameters and the size constraint of the axial suspension support system, designed for the structure of the axial magnetic bearing, including the parameters of the stator, the thrust plate and the winding and so on. Establishing the electromagnetic force mathematical model of the axial magnetic bearing in the rotor system off balance position, and designed for the electromagnetic force generated by the rotor shaft in the axial electromagnetic bearing,which is the maximum starting force, the design of the overall structure of the axial electromagnetic bearing, and the final determination of the structural parameters, and then through the structural parameters of the static feedback current. Finally, according to the analysis of the structural parameters of the design of the electromagnetic characteristics of the axial electromagnetic bearings, and analyzing the magnetic field distribution and eddy current loss through the finite element software.Finally, according to the structural characteristics of radial and axial magnetic bearings,the two performance test bench is designed, which can adjust the distance between the stator pole and rotor. After the calibration experiment of the force sensor is completed, the performance of the magnetic bearing is tested. Obtained for testing data to draw the electromagnetic bearing the electromagnetic force and the coil current and gas gap between electromagnetic characteristic curve for analysis and theory,data contrast,error analysis reasons, ultimately determine the structure design of electromagnetic bearings can meet lOkwh storage flying wheel requirements for supporting system, and for the follow-up control system research and development to provide data to support.