Performance comparison of analytical models for rotor eccentricity: A case study of active magnetic bearing

This paper applies two different analytical methods, i.e., the perturbation method and superposition method, to calculate the magnetic flux density distribution and the magnetic force of the active magnetic bearing (AMB) with the rotor eccentricity. These two methods are thoroughly analyzed, compared and validated by the finite element model ...

A New Rotor Structure for High Speed Flywheel Permanent Magnet Synchronous Machine

This paper presents a new rotor design with assembled permeable retaining sleeve (APRS) to improve performances of a high speed permanent magnet synchronous machine (PMSM). The APRS consists of equal number of permeable and nonmagnetic parts, which are alternately arranged and assembled together circumferentially via keyways. Electromagnetic and...

Sliding mode control with neural network for active magnetic bearing system

A novel controller design procedure is proposed for a 5-degree-of-freedom (DOF) active magnetic bearing (AMB) system, based on sliding mode control (SMC) and neural network (NN). The SMC is used to achieve high robustness and fast response while the NN can compensate unmodeled uncertainty and external disturbance by on-line tuning algorithm. The...

A New Hybrid Method for Magnetic Field Calculation in IPMSM Accounting for Any Rotor Configuration

In this paper, a new hybrid model is proposed for the prediction of air gap magnetic field distribution (MFD) in interior permanent magnet machines with any rotor configuration. The slotless magnetic field is first predicted by finite-element method (FEM) with automatic scripting in MATLAB to consider saturation in the rotor iron. Afterward,...

Investigation Study of the Influence of Pole Numbers on Torque Density and Flux-Weakening Ability of Fractional Slot Concentrated Winding Wheel-Hub Machines

Fractional slot concentrated winding machines (FSCWMs) with the low operation speed and large diameter usually have a large number of poles and slots; thus, numerous pole/slot combinations are feasible. The common practice to choose pole/slot combinations by multiplying the basic combinations may neglect some competitive candidates. Taking 36...

General Analytical Modeling for Magnet Demagnetization in Surface Mounted Permanent Magnet Machines

This paper proposes an analytical model for the prediction of airgap magnetic field distribution for axial flux permanent magnet (AFPM) machine with partial magnet demagnetization. The AFPM machine geometry is first converted to a polar representation. Consequently, the subdomain model based on current sheet technique is developed. Then...