A Design of Magnetic Load Simulator for the Rotor Dropping Protection Experiment System of Helium Circulator in HTR

The rotor of helium circulator in High Temperature Reactor (HTR) is supported by magnetic bearings, but the auxiliary bearings of the magnetic bearings are easy to be broken if the rotor touched down the bearings at the full speed. If the rotor touched down more than a few times, the auxiliary bearings must be changed, which will bring huge economic losses to the HTR. Therefore, we designed a rotor dropping protection system which can reduce the impact when the touching down happened and protect the auxiliary bearings from more damages. We designed an experiment system to validate the reliability of the protection system. For simulating the impact of the auxiliary bearings when the rotor dropped, a magnetic load simulator was designed, which can exert axial load to the motor directly by electromagnetic force though a similar technology to the magnetic bearings. The design axial load of the magnetic load simulator is 110kN with a clearance of 1mm. By analyzing and calculating the parameter of the magnetic load simulator, we thought it can meet the loading requirements of this test. And the design of the magnetic load simulator will open up a new way of application for the magnetic bearings.