Yon-Do Chun

Fractional Slot Concentrated Winding PMSM With Consequent Pole Rotor for a Low-Speed Direct Drive: Reduction of Rare Earth Permanent Magnet

This paper deals with a 44pole-48slot fractional slot concentrated winding permanent magnet synchronous machine (FSCW PMSM) for a low-speed direct drive. Two different rotor topologies, a surface permanent magnet (SPM) rotor and a consequent pole (CP) rotor, are optimized and compared both analytically and experimentally. The experimental results confirmed that an FSCW PMSM with a CP rotor can achieve almost equivalent performance at the rated state when compared to an FSCW PMSM with an SPM rotor with 33% less permanent magnet material.

Design and Analysis of Axial Flux Permanent Magnet Synchronous Machine

In this article, a special kind of axial flux permanent magnet machine has proved to be suitable for high torque and low speed applications. An innovative design of the machine has been proposed in order to make the machine suitable for traction applications by means of field-weakening. The aim of this paper is to analyze, in general terms, the basic equations that describe the operating conditions of such machines. Optimal sizes for design can be obtained by calculating the power density and the air-gap flux density, etc.

Cogging torque reduction in a novel axial flux PM motor

This article shows the reduction of cogging torque in a novel axial flux permanent magnet (AFPM) motor through the various design schemes. 3D finite element method is used for the exact magnetic field analysis. The effects of slot shapes and skewing of slot on the cogging torque and average torque have been investigated in detail. The validity of the analysis results is also clarified by comparison between calculated results and measured ones

Application of flux reversal principle for axial flux permanent magnet machines

Applications of flux reversal machine can be found both for linear and radial flux machines. For axial flux machines, only one application is reported considering a two phase machine. In general, flux reversal effect can produce higher back electromotive forces than other topologies for the less amount of permanent magnets and thus can increase the performance of the machine. Combining the axial structure with the flux reversal effect feature allows higher power density machines suitable for high speed or low speed direct drive applications. Proposed model has a 12-slot stator and a 16-pole variable reluctance rotor. Nd–Fe–B magnets are fixed on the surface of the pole of the stator. The objective of this article is to present an effective method for the design and performance prediction for the axial flux reversal configuration. Basic dimension equations are presented and a two-dimensional equivalent model based on finite element analysis is used for the reduction of the simulation time.

An Analytical Approach for a High Speed and High Efficiency Induction Motor Considering Magnetic and Mechanical Problems

This paper deals with the analysis techniques of a high speed and high efficiency 10 kW, 30,000 rpm rated induction motor. The induction motor has been analyzed by time-varying magnetic finite element method and the test results show that there is a possibility that the motor could be used in a high speed spindle system application. All analysis techniques are introduced to develop a high speed and high efficiency induction motor made by copper die casting. The analysis techniques are composed of magnetic analysis considering losses and input current (PWM and sinusoidal), structural analysis of rotor and stator, 3-D rotordynamic analysis and 3-D CFD. All performances of the prototype are successfully verified.

Sensorless control using improved stator flux estimator for high-speed induction motors

In this paper, a sensorless control scheme using improved stator flux estimator for high speed induction motors has been proposed to compensate a Programmable Low Pass Filter. This paper has analyzed the affect between the estimated speed error and the phase error of the stator flux in high speed range. The estimated speed error compensation scheme has also proposed. The validity of the proposed schemes has been proven by the simulation and experiment results.

Characteristic Analysis on Overhang Effect in Axial Flux PM Synchronous Motors with Slotted Winding

This paper deals with an overhang effect of permanent magnet (PM) in the new type axial flux permanent magnet synchronous motor (AFPMSM) with a double-sided air-gap. 3-D electromagnetic finite element method (FEM) is used to calculate the air-gap magnetic flux density, back electromagnetic force (EMF) and the cogging torque according to the variation of the overhang angle. From the results, we can confirm the overhang effect quantitatively which improves the performance of the AFPM motor

The study to substitute aluminum for copper as a winding material in induction machine

It is to make motors more efficient because of the higher conductivity of copper. In addition, reduced tosses in such motors may lead to better design flexibility and motors are more compact. However, copper price and weight is higher than aluminum so, copper wire motor has disadvantage compared with aluminum wire in manufacturing cost. This paper presents aluminum wire motor design to reduce motor manufacture cost and compares the cost with copper wire motor.

Analysis of overhang effect in a novel axial flux PM motor

This paper deals with an overhang effect of permanent magnet (PM) in the new type axial flux permanent magnet (AFPM) motor with a double-sided airgap. 3-D electromagnetic finite element method (FEM) is used to calculate the airgap magnetic flux density, back electromagnetic force (EMF) and the cogging torque according to the variation of the overhang angle. The validity of the analysis results is also clarified by comparison between calculated results and measured ones. From the results, we can confirm the overhang effect quantitatively which improves the performance of the AFPM motor