Beyond the 4th industrial revolution, the beginning of the eco-friendly era has begun. Carbon neutrality with the last means regarding to climate change, has begun. In this reason, the electric motor industry rapidly emerged as the center of the industrial trend toward zero carbon. In particular, the eco-friendly automobile industry is the center of change for the automobile drive system. In other words, the driving core of automobiles is in a state of great transition from the internal combustion engine to the electric motor. In this paper, the development process of the motor drive system, which is the core technology of eco-friendly vehicles, and the design verification case of the motor system using CAE are described. Finally, the future technology development direction for the motor drive system of eco-friendly vehicles are introduced.

This paper deals with design technology trend of permanent magnet generators (PMGs) for wind turbines. First, the classification and characteristics of each type of PMGs were investigated, and then the characteristics, advantages and disadvantages for each PMGs type were compared and analyzed. In addition, the specifications and capacities of PMGs currently being developed at domestic and abroad are summarized. In particular, based on the papers published in the last 10 years, research trends related to design and analysis of PMGs were described. The results presented in this paper will be useful criteria in design and analysis of PMGs for wind turbines.

This paper deals with the magnetic field analysis of a magnetic gear. A simplified analysis model was presented through assumptions for applying the analytical method. Then, the governing equation and general solution for each analysis region were derived using definition of the magnetic vector potential, and the general solutions were transformed to obtain a more accurate analysis results. We derived the undetermined coefficients of the general solutions through appropriate boundary conditions. All analytical results were validated with two-dimensional finite element analysis.

The permanent magnet is an important component that determines the performance and cost of a synchronous motor. Also, the characteristic of the permanent magnet is a major factor in determining the performance of the electric motor. Therefore, to improve the performance of the permanent magnet synchronous motor and reduce the material cost, the permanent magnets having various characteristics are being developed. However, the magnetic properties of permanent magnets have nonlinearity. Therefore, this paper proposes a method to calculate the operating point of a permanent magnet by considering not only the nonlinear magnetic properties of the electrical steel sheet but also the nonlinear properties of the permanent magnet and analyze the characteristics of the electric motor based on this proposed method. Through this, the characteristics of the permanent magnet synchronous motor are analyzed according to the rotor type and the design direction for each type is suggested.

This paper deals with the fuel economy of the light electric vehicle (LEV) according to the size of the traction motor. Firstly, the cross-sectional area design was conducted considering the electromagnetic and mechanical properties of materials for the traction motor. Based on this design result, the characteristics of the traction motor was estimated according to the stack length by using finite element analysis (FEA) and equivalent circuit. Next, to investigate the effect on fuel economy, the vehicle simulation was constructed. The ADVISOR, freeware of the MATLAB-based program, was utilized. Especially, to reflect the successive charge-discharge situation, 2nd order RC equivalent circuit was adopted. Finally, the relationship between the traction motor size and fuel economy was analyzed for the urban driving cycle and highway driving cycle.

The LSPM (line-start permanent magnet synchronous motor) is an alternative to increase the efficiency and power factor of induction motors. Magnetization of permanent magnet in LSPM is the most important issue for manufacturing process. The manufacturing process can be improved as the magnetization of the permanent magnet is conducted after the rotor assembly. Circuit of LSPM magnetization after the assembly is introduced and finite element analysis is conducted. Finally, magnetizing yoke is manufactured and the magnetization is conducted. Flux density in the permanent magnet of LSPM rotor is checked. The result is presented for the verification of the magnetizing analysis.

In the rotor of the interior permanent magnet synchronous motor (IPMSM), leakage flux that cannot link the coil of the stator among the magnetic flux generated by the permanent magnet (PM). Among the rotor leakage flux generated in the IPMSM, the 2D component passing through the rib can be considered through the 2D finite element analysis (FEA). However, in the rotor leakage flux of an IPMSM, there is a component of a 3D path that cannot be considered by a 2D FEA. This 3D rotor leakage magnetic flux is generated between the rotor core regions separated by PMs, and its path is 3D through air, which is a non-magnetic substance located at the upper and lower ends of the rotor core in the axial direction. In this study, a 3D FEA model with an axial air dummy is proposed to analyze the cause of 3D leakage magnetic flux in a IPMSM and to accurately consider it. Also, how the calculation result of the 3D leakage magnetic flux according to the height of the axial air dummy is affected was analyzed. Finally, the effect of 3D rotor leakage magnetic flux on no-load back electromotive force and cogging torque was confirmed through comparison of 2D FEA and 3D FEA of IPMSM with specific specifications.