• 한국소음진동공학회논문집
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• 제12권1호
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• pp.73-81
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• 2002

This paper introduces a four-Pole Lorentz force type self-bearing motor in which a new winding configuration is proposed to enable the sing1e winding to function both as a synchronous PM motor and as a magnetic bearing. The Lorentz force type has some good points such as the linearity of control force, freedom from flux saturation, and high efficiency, unlike conventional self-bearing motors using a reluctance force. And also, compared with the previously proposed eight-pole type, this four-pole self-bearing motor is more profitable for high rotational speed. In this paper, mathematical expressions of torque and radial force in the proposed self-bearing motor are derived to show that they can be separately controlled regardless of rotational speed and time. For verification of the theory, a prototype is made, where a ring-shape outer rotor is actively controlled in two radial directions while the other motions are passively stable supposing the radial stability. Through some experiments. it is shown that the proposed scheme can provide high capability and feasibility for a small high-speed self-bearing motor.

• 한국전기전자재료학회논문지
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• 제33권3호
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• pp.186-193
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• 2020

We investigate a fog-detection CCT control system using low deck lighting as a solution to the forward visibility of pole-type street lamps employed on existing roads. The lighting standards were met with a light source that has less compared with those of pole-type street lamps. The results show that the transmission rate was increased by changing the color temperature by automatically recognizing fog in bad weather and minimizing the phenomenon of lighting. In addition, it was allowed to create a safer and more comfortable driving environment for drivers owing to flicker or light pollution of existing pole-type street lamps. As a result, if lighting is used at a lower level than pole-type street lamps, the accident rate caused by securing the driver's forward visibility can be reduced sharply and existing problems can be resolved.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권5호
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• pp.222-230
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• 2005

This paper deals with the reduction of cogging torque of a outer-rotor type BLDC motor mainly used for washing machines. The motor comprises permanent magnet outer-rotor and stator with coils and core. This structure inherently produces vibration and cogging torque because of uneven reluctance according to rotation of the rotor. Up to now, adopted a type of 24 magnet pole and 36 slot-stator. This generates high main torque but accompanies comparatively large cogging torque. This paper proposes a 32-pole 36-slot type motor which reduces cogging torque remarkably. The influence of cogging torque is varied according to pole-slot combinations. The characteristic of the motor was obtained by a two-dimensional finite element method coupled with a drive circuit. The performance of the proposed model is superior to that of the existing model because of the reduction of torque ripple and the improvement of back ernf wave form.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 춘계학술대회 논문집 에너지변화시스템부문
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• pp.46-49
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• 2009

An optimal design procedure is proposed to effectively reduce the torque ripple by optimizing the rotor pole shape of the spoke type IPMSM with concentrated winding. The procedure is composed of two steps. In step I, the steepest descent method (SDM) is used with only two design variables to rapidly approach the optimal shape. From the near optimal rotor shape as a result of the step I, the design variables are reselected and the drawing spline curves are utilized to explain more complex shape with the Kriging model in step II. By using an optimal design procedure, we show that the optimized rotor pole shape of the spoke type IPMSM effectively reduces the torque ripple while still maintaining the average torque.

• 자동차안전학회지
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• 제4권2호
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• pp.27-31
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• 2012

In Korea, side impact type accidents are one of the main cause of fatality. MLTM and KATRI established sie impact regulation as well as NCAP type assessments to protect occupants. Recently, WP29 formed a informal group to study a possible harmonization of pole side impact test methods with WorldSID as a GTR. In this paper, two different dummies, ES-2 and WorldSID were evaluated with three different types of pole side impact test methods.

• 동력기계공학회지
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• 제4권4호
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• pp.84-91
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• 2000

This paper describes a state feedback controller design method of the integral type magnetic levitation servo system which satisfies the design objectives. The design objective is a $H_{\infty}$ performance, asymptotic disturbance rejection and a robust pole assignment in linear matrix inequality(LMI) region. To the end, we investigated the validity of the designed controller which considering a robust pole assignment region, through results of simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.170-172
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• 2006

This paper proposes a design method by varying rotor pole shape to reduce cogging torque, torque ripple and harmonics of back emf in Spoke type brushless DC(BLDC) motor. In the process of design and analysis, Response surface method(RSM) and finite-element method(FEM) are employed to get the rotor geometry and verify the results of new pole shape.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 춘계학술대회 논문집
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• pp.54-61
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• 1997

Furthermore the rothor pole, with a solid type, manufactured by cold forging process at present should dmploy 3 press lines which consist of total 7 processes. Since A.S.B. treatment is prerequisite for the press line, the 3 times of A.S.B. treatment requires a long lead time, with little contribution to the reduction in cost. The author has investigated, through this researach, the possibility of a new forging method for a rotor pole production with (1) 2 pass instead of 3 press lines (2) only one A.S.B. treatment instead of 3 ones (3) solid type instead of sectional type, and (4) improvment of material property during process using a modified forging process and a specially designed die.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.868-870
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• 2001

Salient pole rotor type single phase SRM(switched reluctance motor) can be use axial direction magnetic flux and radial direction magnetic flux at the same time. Then, it has higher energy density per unit volume and can be lessened the shaft length of motor or exciting magnetic force. Additionally, it's durability is good because it is simple structure and driving device. Prototype of Salient pole rotor type single phase SRM was fabricated by using parameters of three phase SRM and 3D FEM analysis. Also, driving device was fabricated for prototype. Speed and torque characteristic was confirmed through the experiments, and flux linkage, which is important parameter of SRM for generating torque, was measured. The induction emf was calculated by using ideal inductance graph and current graph. Calculated emf and measured emf was compared for confirming loss of prototype in this paper.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권1호
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• pp.1-5
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• 2004

This paper deals with the design and analysis of a 2-phase Switched Reluctance Motor (SRM) used for the cooling fan motor of a refrigerator. To reduce the dead zone and improve the efficiency, the snail-earn type rotor pole and the asymmetric stator pole are investigated. For the optimal shape design, the performances of each model are obtained from numerical calculation results by 2D time-stepping finite element method (FEM) coupled with circuit equations. The accuracy of analysis is verified by comparing the analysis results with experimental data. According to the investigation results, improved shapes of stator and rotor poles are proposed.