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This paper proposes an optimal rotor design method of an interior permanent magnet synchronous motor (IPMSM) by using a permanent magnet (PM) shape. An IPMSM is a structure in which PMs are buried in an inner rotor. The torque, torque ripple, and safety factor of IPMSM can vary depending on the position of the inserted PMs. To determine the optimal design variables according to the placement of the inserted PMs, parameter analysis was performed. Therefore, a response surface methodology, which is one of the statistical analysis design methods, was used. Among many other response surface methodologies, Box–Behnken design is the most commonly used. For the purpose of this research, Box–Behnken design was used to find the design parameter that can achieve minimum experimental variables of objective function. This paper determines the insert position of the PM to obtain high-torque, low-torque ripple by using a finite-element-method, and this paper obtains an optimal design by using a mechanical stiffness method in which a safety factor is considered. [ABSTRACT FROM PUBLISHER]

In this paper, an interior permanent magnet (PM) synchronous motor (IPMSM) with concentrated windings was designed for railway traction applications. This IPMSM was analyzed using a 2-D FEM. The results showed that the designed IPMSM has a significant PM eddy-current loss. For more accurate calculation, a 3-D FEM analysis was carried out. Further, the PM eddy-current loss was reduced without critical torque reduction by changing the position of the magnets at the rotor. Finally, frequency analysis of air-gap magnetic flux density waveforms was carried out to investigate the effect of magnet placement on the eddy-current loss. [ABSTRACT FROM AUTHOR]

The design of a motor with a large armature reaction, such as the electric vehicle traction motor, can be implemented using a trial-and-error method based on the finite element method (FEM). The base model-design method that uses conventional magnetic equivalent circuits is quite inaccurate. To avoid such inaccuracy, this study proposes a method that accurately calculates the inductance values at a practical operating point considering the control issue. To achieve this objective, the flux linkage due to the current phase angles in each section is modeled using magnetic equivalent circuits. The result is used to calculate the inductance, assuming relative permeance waves. Finally, the validity of this study is verified by FEM simulation and testing. [ABSTRACT FROM PUBLISHER]

Thi\s paper proposes a novel plot called an NE-Map that has two axes representing the no-load electromotive force (EMF) and the number of windings per slot. The NE-Map is applied to the design of an interior permanent magnet synchronous motor. Here, the design of the rotor is implemented using a magnetic equivalent circuit. In addition, the phase currents and current phase angles are estimated by considering the maximum torque per ampere and the flux weakening control method, and a stator is designed using this estimation. As these processes are presented in terms of the values of the EMF and the number of windings per slot, this representation allows for the verification of the relationship among the motor parameters and the determination of the final model by reflecting the design constraints. This process is applied to the design of a traction motor in hybrid EVs, and its validity is verified by comparison with finite element analysis and test data. [ABSTRACT FROM PUBLISHER]

Permanent magnet (PM) synchronous motors (PMSMs) have been used to drive a number of vehicles. They have high torque density, high efficiency, and a wide speed range. However, the high cost of PMs is disadvantageous. This paper presents a technique for increasing the torque density by modifying the shape of the PMs and minimizing the magnet volume. The PM characteristics such as flux density, demagnetizing force, PM energy product, and the air-gap flux density are represented by a lumped magnetic equivalent circuit when the thickness and width of the PM are increased for the same volume but with different shapes. The torque, torque ripple, core loss, magnet loss, and efficiency of three interior (IPMSM) models designed by the proposed method are compared by finite element analysis. In addition, the demagnetization of the PM due to high temperature, maximum torque load angle, and an adverse field is analyzed. Finally, the analysis result is compared with that of the experiment to verify the proposed model. [ABSTRACT FROM AUTHOR]

In this study, the losses due to the time-harmonic current in a permanent magnet synchronous motor (PMSM) are calculated through a co-analysis of the time harmonics using a space vector pulse width modulation (SVPWM) inverter. PMSM is typically used as a control motor. The current in the PMSM contains harmonics because the inverter voltage is not sinusoidal, and as a result, losses occur. These losses have a negative effect on the synchronous motor performance, which is vulnerable to heat. Therefore, for efficiency and performance evaluation of the PMSM, it is necessary to consider a co-analysis of the time harmonics. In this study, we present a co-analysis method for a PMSM designed for buses and compare the analysis results with those of the current source analysis in order to verify the significance of the co-analysis. In particular, it is observed that the difference in the eddy current losses in the PM individually determined with the current source analysis and co-analysis is approximately 500%. For validating this study, the experimental equipment is established, and it can be confirmed that the experimental results are close to the co-analysis results. [ABSTRACT FROM AUTHOR]