A Loss Separation Method of a High-Speed Magnetic Levitated PMSM Based on Drag System Experiment Without Torque Meter

Varieties of loss should be optimized to be as little as possible for the stability of the permanent magnet in a high-speed magnetic levitated permanent magnet synchronous motor (HSMLPMSM) rotor and ensure the high efficiency and low temperature of the motor. First, this paper analyzes loss distribution in a motor, whose power and rated speed are 100 kW and 32 000 r/min, by a calculation method. Then, separation of losses of the HSMLPMSM is implemented based on a drag system without torque meter accounting for its particularity of high-power and high-speed level. In all kinds of losses, core loss and coil loss can be separated by a traditional calculation method with related parameters being tested. Besides, windage loss and magnetic bearing loss can be obtained by a deceleration test. Resulting from power balance equations deduced by the relationship of the drag system's power input and output, eddy current loss of the rotor can be separated, compared to its finite-element analysis results and analytical results. In the end, with thermal-electromagnetic coupled analysis, loss separation results are validated via temperature rise experiment indirectly.