Kyung-Hun Shin

Design and Analysis of Interior Permanent Magnet Synchronous Motor Considering Saturated Rotor Bridge using Equivalent Magnetic Circuit

This paper considers the design and performance evaluation of interior permanent magnet synchronous motors (IPMSMs). The initial design such as the sizing and shape design of the stator and rotor is performed for a given load condition. In particular, the equivalent magnetic circuit (EMC) is employed both to design the mechanical parameters of the rotor while considering nonlinear magnetic saturation effect and to analyze the magnetic characteristics of the air-gap of the motor. The designed motor is manufactured and tested to confirm the validity of the design processes and simulated results.

Characteristic Analysis of Interior Permanent-Magnet Synchronous Machine With Fractional-Slot Concentrated Winding Considering Nonlinear Magnetic Saturation

This paper presents the characteristic analysis of interior permanent-magnet synchronous motors (IPMSMs) considering magnetic saturation. In IPMSM with magnetic saturation, the individual flux from the permanent magnet (PM) and current exists, and the linear combination is not maintained. A nonlinear finite-element analysis, wherein the PMs and current are excited simultaneously, is performed. Then, the flux linkage data in each armature current and current angle are recorded, which are calculated by using the dynamic equation. Based on the analyzed results from electromagnetic field characteristic analysis, the equivalent circuit parameters are derived, and the modeling of both IPMSM and controller system is performed to predict its operating characteristics. Finally, the analysis results of the designed IPMSM are compared with measured results, and the validity of the analysis considering magnetic saturation of the IPMSM is confirmed.

Detent Force Minimization of Permanent Magnet Linear Synchronous Machines Using Subdomain Analytical Method Considering Auxiliary Teeth Configuration

This paper presents electromagnetic modeling and analysis of the detent force in a permanent magnet linear synchronous machine (PMLSM) according to auxiliary teeth configuration. Analytical solutions for magnetic fields generated by PMs are derived based on the Maxwell equation in terms of a 2-D Cartesian coordinate system. The magnetic vector potential of each subdomain (PM, air-gap, slot, and end region) is derived, and the field solution is obtained by applying the boundary and interface conditions between the subdomains. Based on the analytical solution, the magnetic force is derived by using the Maxwell stress tensor. All the analytical results were extensively validated using nonlinear finite-element analysis and experimental results. Using the proposed method, we investigated the influence of the machine parameters on the detent force. Therefore, the proposed method can be very useful in the initial design and optimization process of PMLSM for detent force analysis.

Armature Reaction Field and Inductance Calculations for a Permanent Magnet Linear Synchronous Machine Based on Subdomain Model

This paper proposes an analytical technique to calculate the armature reaction field and inductance of permanent magnet linear synchronous machines (PMLSMs) based on a subdomain analytical model. The analytical expressions can be used for PMLSMs with any armature current waveform and any number of slots. The analytical solutions based on the subdomain model, in terms of a two-dimensional Cartesian coordinate system, are obtained using boundary conditions. The analytical results of the magnetic field are validated extensively with finite-element (FE) analyses. Based on these solutions, the inductance is also determined analytically. Finally, the predictions are compared with the three-dimensional FE analyses and the measured data to confirm the validity of the analysis methods presented in this paper.

Analysis on the Pitching Moment in Permanent-Magnet Linear Synchronous Motor for Linear Motion Stage Systems

This paper presents the characteristic analysis and experiment of pitching moment in a high-precision permanent-magnet linear synchronous motor. The pitching moment is analyzed according to suggested strategy; therefore, analytical solutions for magnetic fields generated by PMs are derived based on the analytical magnetic field calculation in terms of a 2-D polar coordinate system. The analytical solution of each subdomain (PM, air gap, slot, slot opening, and end region) is derived, and the field solution is obtained by applying the boundary and interface conditions between the subdomains. The magnetic force is determined based on the magnetic field analysis results. Finally, the predictions are compared with the measured data to confirm the validity of the analysis methods presented in this paper.

Analytical Calculation and Experimental Verification of Cogging Torque and Optimal Point in Permanent Magnet Synchronous Motors

In this paper, an exact analytical solution based on Fourier analysis is proposed to compute the cogging torque in a surface-mounted permanent magnet synchronous machine. The analytical solutions are derived by solving the field-governing equations in each simple and regular subdomain, i.e., permanent magnet (PM), air, slot opening, and slot, and then by applying the boundary conditions to the interfaces between these subdomains. Based on these solutions, the cogging torque is also determined analytically. In order to verify the analytical results of the proposed method, an experimental system was implemented on a servomotor and a torque sensor. All analytical results were extensively validated using nonlinear 2-D finite-element analysis and experimental results. Using the proposed method, we investigated the influence on the cogging torque, according to the machine parameters. Therefore, the proposed method should be very useful in the initial design and cogging torque optimization of PM machines.

Comparative Study of Armature Reaction Field Analysis for Tubular Linear Machine with Axially Magnetized Single-sided and Double-sided Permanent Magnet Based on Analytical Field Calculations

This paper presents a comparative study of a Tubular Linear Machine (TLM) with an Axially Magnetized Single-sided Permanent Magnet (AMSPM) and an Axially Magnetized Double-sided Permanent Magnet (AMDPM) based on analytical field calculations. Using a two-dimensional (2-D) polar coordinate system and a magnetic vector potential, analytical solutions for the flux density produced by the stator windings are derived. This technique is significant for the design and control implementation of electromagnetic machines. The field solution is obtained by solving Maxwell’s equations in the simplified boundary value problem consisting of the air gap and coil. These analytical solutions are then used to estimate the self and mutual inductances. Two different types of machine are used to verify the validity of these model simplifications, and the analytical results are compared to results obtained using the finite element method (FEM) and experimental measurement.

Experimental Assessment of Unbalanced Magnetic Force according to Rotor Eccentricity in Permanent Magnet Machine

The manufacturing errors of machine tools are usually due to the imperfect of bearings, stiffness of spindle, assembly errors, and so on. In addition, the rotor eccentricity of the permanent magnet (PM) machine affects to the constant torque and speed characteristic of mechanical loads. The errors due to rotor eccentricity is caused by manufacturing process and rotor eccentricity generate unbalanced magnetic force (UMF). The sources of UMF are generated by the interaction between the rotor magnets and the stator core. Firstly, we suggested that the characteristic analysis results due to rotor eccentricity are calculated by using finite-element (FE) analysis. Moreover, we proposed experimental set to measure the UMF on the PM machines. Finally, we verified the validity of the proposed UMF measurement system by comparison with the measured results and simulation results due to the rotor eccentricity in the PM machine.

Parametric analysis and optimized torque characteristics of a coaxial magnetic gear based on the subdomain analytical model

This paper presents the torque calculation and parametric analysis of a coaxial magnetic gear (CMG). We obtained analytical magnetic field solutions produced by permanent magnets based on a magnetic vector potential. Then, the analytical solutions for magnetic torque were obtained. All analytical results were extensively validated with nonlinear two-dimensional finite element analysis. Finally, using the derived analytical magnetic torque solutions, we carried out parametric analysis to determine the influence of the design parameters on the CMG’s behavior.

Analytical prediction for electromagnetic performance of interior permanent magnet machines based on subdomain model

This paper presents an analytical model for the computation of the electromagnetic performance in interior permanent magnet (IPM) machines that accounts for the stator and the complex rotor structure. Using the subdomain method, we propose a simplified analytical model that considers the magnetic properties of the IPM machine. The analytical solutions are derived by solving the field-governing equations in each simple and regular subdomain, i.e., magnet, barrier, air gap, slot opening, and slot, and then applying the boundary conditions to the interfaces between these subdomains. The analytical model accurately accounts for the influence of the interaction between the slots, the relative recoil permeability of the magnets, and the boundary conditions. The magnetic field and electromagnetic performance obtained using the analytical method are compared with those obtained using finite element analysis. Finally, the analytical predictions are compared with the measured data in order to confirm the validity of the methods proposed in this paper.This paper presents an analytical model for the computation of the electromagnetic performance in interior permanent magnet (IPM) machines that accounts for the stator and the complex rotor structure. Using the subdomain method, we propose a simplified analytical model that considers the magnetic properties of the IPM machine. The analytical solutions are derived by solving the field-governing equations in each simple and regular subdomain, i.e., magnet, barrier, air gap, slot opening, and slot, and then applying the boundary conditions to the interfaces between these subdomains. The analytical model accurately accounts for the influence of the interaction between the slots, the relative recoil permeability of the magnets, and the boundary conditions. The magnetic field and electromagnetic performance obtained using the analytical method are compared with those obtained using finite element analysis. Finally, the analytical predictions are compared with the measured data in order to confirm the validity o...