Loss and thermal estimation method of a magnetic bearing system considering electromagnetic and temperature coupling

The stability of magnetic bearings will seriously affect the overall operation of the motor. Magnetic bearing temperature is closely related to the performance of magnetic bearing (MB) system. Therefore, loss calculation and thermal estimation are very important in the design of MB system. A MB system including a pure radial magnetic bearing (RMB) and a combined radial and axial magnetic bearing (CRAMB) was designed for a high-speed permanent magnet motor. An approach of loss and temperature field calculation considering electromagnetic and temperature coupling was proposed. Two electrical machines supported by this MB system, whose power is 30kW and related speed is 36000rpm have been developed for experiment. The experimental results verify the validity and accuracy of this method.