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In this article, a clear and concise analytical method for predicting the performance of a Liquid-cooling eddy current brake (LC-ECB) is proposed. The LC-ECB has a coolant channel in the rotor to allow direct cooling of the inner surface of the stator. The static air-gap magnetic field distribution is obtained by the dynamic magnetic equivalent circuit (MEC) method, and the magnetic flux leakage and global magnetic saturation effects are fully considered. The magnetic field intensity distribution function of the eddy current reaction magnetic field is derived for the first time based on Ampere circuital theorem. Considering the local magnetic saturation and skin effect, a novel double-iteration algorithm based on the conservation principle of magnetic pressure drop is applied to obtain the transient air-gap flux density distribution, and then the brake torque expression is obtained. The finite element method (FEM) and experimental results show that the proposed method is feasible and effective. The new model is easy to program and can be easily used in the initial design and optimization of LC-ECB. [ABSTRACT FROM AUTHOR]

In this paper, power-sizing equations of rotor-permanent-magnet flux-switching (RPM-FS) machines are proposed and implemented, where the main decisive factors of the electromagnetic torque, namely electric loading and magnetic loading, are deduced, respectively. Although the topologies of RPM-FS machines are evolved from traditional stator-PM flux-switching machines, there are still seriously flux leakages between poles, and it is hard to derive the peak value of the air-gap flux density directly. Hence, a local simplified magnetic equivalent circuit is utilized to calculate the magnetic loading, which is crucial for the power-sizing equation. The influences of the pole-to-pole flux-leakages and harmonics in back-EMF are considered to improve the calculated accuracy of the power-sizing equation. Consequently, the electromagnetic torque can be predicted with acceptable accuracy. The feasibility of the power-sizing equation is verified by the finite element analysis and experimental results. [ABSTRACT FROM AUTHOR]

Due to their advantages of high efficiency, high power density, and strong fault-tolerance ability, fractional-slot concentrated-winding permanent-magnet (FSCW-PM) machines are of particular interest in the applications such as wind power generation and electric vehicles. However, FSCW-PM machines suffer from rich winding magnetomotive force (MMF) space harmonics by the armature reaction field, which may increase eddy current loss. In this paper, a new low harmonic FSCWPM machine is designed, which can reduce some space harmonics of low order in the air-gap flux density. A new magnetic equivalent circuit (MEC) model is developed to analyze the designed PM machine, which offers less computation time and more calculation accuracy. Finally, a prototype machine is built and the measured results verify the theoretical analysis and the developed MEC model. [ABSTRACT FROM AUTHOR]

The cogging torque calculation of interior permanent magnet synchronous motors (IPMSMs) has only been conducted by the finite element method (FEM) due to their complexities. However, FEM analysis requires considerable computational time during the design process. To deal with this problem, a new analytical method is proposed to calculate the cogging torque in IPMSMs. The radial and circumferential air-gap flux density for calculating the cogging torque utilizes the magnetic equivalent circuit model, conformal mapping method, and approximate equations of the magnet end. The validity of the proposed method was confirmed by comparing the results of the proposed method with those of FEM. [ABSTRACT FROM AUTHOR]