A surface-mounted permanent magnet synchronous motor (SPMSM) is an electric motor with a simple magnetic circuit design, fast responsiveness, linear torque–current characteristics, speed–voltage characteristics, and constant operating speed. SPMSMs use only magnetic torque; however, interior PMSMs (IPMSMs) have high power densities because they can use reluctance torque. In addition, when flux-weakening control is used, the operating range is wide compared with the SPMSM. This study presents a comparative analysis of the characteristics of SPMSM and bar-type IPMSM. Characteristic analyses are performed by setting the same stator shape, rated speed, number of turns, winding specifications, voltage limit, and magnet usage in a pole/slot combination of six poles and 27 slots. Next, we compare the no-load back electromotive force, cogging torque, and loss characteristics, and perform a characteristic analysis of each model while satisfying the design specifications. No-load and load tests are performed using a back-to-back system. The results of the analysis and experimental results are in good agreement, and the reliability of the analysis results is guaranteed. The SPMSM is approximately 8.5% superior to the IPMSM in terms of core loss, and the eddy current loss is greater than that of the IPMSM.

This study deals with the analysis of electro-mechanical characteristic analysis on permanent magnet synchronous machines (PMSMs) for electrically driven tools primarily used in industrial applications. This study compares the noise, vibration, and harshness (NVH) characteristic results generated by fractional pole/slot combinations. The electromagnetic (EM) analysis results of the PMSMs are derived using the finite element method (FEM), and the NVH analysis is performed by applying the EM analysis results. The analysis results and the effects of EM characteristics on the vibration of the PMSMs were analyzed. The effects of EM excitation characteristics on the rotor vibrations in the PMSM were compared and analyzed.

In this study, a 10 MW-class superconducting generator that can be applied to electric propulsion aircraft and large-capacity wind turbines is proposed. An active shielding air-core rotating armature-type superconducting generator was designed to minimize the weight and maximize the power density. A 10 MW 3000 rpm class (specific power: 13.7 kW/kg) generator for an electric propulsion aircraft and a 10 MW 500 rpm class (specific power: 4.3 kW/kg) generator for a large-capacity wind turbine were designed, respectively. In addition, to experimentally verify the armature rotating partial superconducting air-core-type superconducting generator, small experimental devices were manufactured, and preliminary experiments were performed on the force characteristics of the superconducting coil and the generating characteristics of the rotating armature-type generator to verify the feasibility of the study.

This study analyzes and verifies the electromagnetic performance and thrust characteristics of linear magnetic gears using subdomain-based analytical methods. By simplifying the analytical model, the governing equations of each domain are calculated based on the Maxwell equation. In addition, the undetermined coefficients of the governing equations are derived using four boundary conditions. In magnetic gears, where power transmission is important, force characteristics are also important. The force characteristics were calculated using the undetermined coefficients and the Maxwell stress tensor.

In this study, analysis of core-loss occurring in the magnetic flux modulation core of a linear magnetic gear and the core of each mover is presented, using an analytical method. Losses in electric machines were generally calculated and analyzed using the finite element method (FEM). However, in the case of core-loss, the exact loss value could not be calculated using FEM data. Therefore, we considered the harmonic component of the air-gap magnetic flux density waveform with the modified Steinmetz equation, and performed a more accurate core-loss analysis with magnetic behavior analysis. Thus, we performed a calculated core-loss characteristic comparison with the FEM and the modified Steinmetz equation.

In this study, to analyze the effects of electromagnetic factors that are affected by the eccentricity on vibration, an overall structural model of a motor was constructed, including the stator core, rotor structure, and the other parts. Thereafter, a mode analysis was performed to verify the dynamic stiffness of the constructed model using the finite element method. Vibration analysis was performed using a method that applied the electromagnetic characteristic analysis results to the mechanical system using the finite element model of the entire mechanical system, and the analysis results were obtained. To verify the validity of the proposed analysis method, a comparison of the test results obtained from the finite element analysis and fabrication model was performed. Finally, by analyzing the effect of changes in the electromagnetic characteristics due to eccentricity on vibration, it was confirmed that the change in electromagnetic characteristics was reflected in the vibration characteristics. In addition, the trend followed by the vibration characteristics derived from the analysis results agreed well with the measured vibration tendency, indicating that the vibration analysis could be performed by the method presented in this paper.