Calculation and Experiment of Electromagnetic Force of the Axial AMB used in HTR-PM Main Helium Blower Prototype and its Dual Material Selection Method

摘要

The Active Magnetic Bearing (AMB) is usedin the main helium blower in the High TemperatureReactor-Pebble-bed Modules (HTR-PM) which is beingconstructed in Shandong province, China. The axialAMB is very large and works under extreme conditions.The calculation deviation of the electromagnetic force ofthe axial AMB was studied experimentally. Throughmeasuring B-H curve of the material in large range ofmagnetic field intensity, considering flux leakage incalculation, and considering residual magnetism and thechange of the gas gap in measurement, the calculationdeviation reduces to 10%, with most values less than 5%.The material selection method of the axial AMB workingunder extreme conditions was studied experimentally.Through measuring the electromagnetic force when thestator and the thrust disc are made of different materials,it’s found that the force mostly depends on the stator.Combined with the analysis of the stress distribution ofthe stator and the thrust disc under working condition,the dual material selection method is proposed. That is,the stator material should have good magnetic propertiesand its mechanical properties are not very important,however, the thrust disc material should have goodmechanical properties, and its magnetic properties arenot very important.