• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권12호
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• pp.709-714
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• 1999

This paper is focused on the adhesion control method to improve traction efficiency using the estimated adhesion for railway propulsion system. Recently, the wheel slippery is frequently occurred due to light weight of train and power increasement of traction parts. This phenomenon occurs a traction loss and a poor ride comport. Therefore, the adhesion control which is able to prevent the slippery and to control the traction on a maximum adhesion is absolutely needed. This paper introduces typical methods for adhesion control and proposes two novel adhesion methods using the estimated adhesion.

• Journal of Biosystems Engineering
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• 제9권2호
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• pp.19-26
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• 1984

This study intended to develop the prediction models of the traction and field performance of two-wheel tractors by using the principles which were applied for predicting those of the four-wheel tractors. The traction model developed in this study consists of the net traction coefficient, rolling resistance coefficient and traction efficiency, Which are expressed as functions of both wheel numeric and slip. A computer program on the field performance of two-wheel tractors is also developed to predict the drawbar horsepower, traction force, traction efficiency, rotational speed of engine and engine horsepower if the characteristics of the engine performance and operational condition of the two-wheel tractor are known. Based on the developed models, the conditions of basic variables to maximize the field performance were analyzed so as to assess the existing two-wheel tractor.

• 한국정밀공학회지
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• 제14권3호
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• pp.35-40
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• 1997

The traction drive has advantages of having high efficiency and transmitting the power without blacklash. However, when high ratio of speed reduction is desired, excessively large size is required. In this study, a new type of traction drive is invented, designed and manufactured so that stable speed reduction mech- anisms are available by adopting a cross roller type drive. It has a simple structure, but produces high speed reduction ratio. Power loss is observed, and also, driving torque and torque transfer efficiency are calculated. Pre-loads are needed in order that the traction drive transfers power without slipping, and the spacer is enlarged due to the pre-loading. After all, the key point of pre-load mechanism is that the spacer's diameter becomes larger as pre-loads are applied.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.688-694
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• 2009

As a drive system for next generation train, we have been making research and development of a direct drive traction motor system without the conventional reduction gear. This traction motor is expected to have many advantages such as low noise, reduced maintenance, and energy saving. Due to the demand for high-output motors in the limited space between the wheels, open-ventilating traction motors with gear box have been widely used for many years. However, a conventional open-ventilating traction motor is necessary periodical disassembly to remove the accumulated dust from open-air ventilation. Reducing this burden, as well as increasing energy efficiency and reducing noise, would benefit the next generation of traction motors. To address these needs, KRRI have been developing a fully enclosed type direct drive motor(DDM) with high-efficiency permanent magnet for the next generation train.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.101-105
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• 2004

The traction drive have a high power transmission efficiency and small size, a light weight, a low noise. So it is expected that alternative drive part of engine. Because it is necessary stillness that essential condition of drive part used moving tool in a room, it has many-sided in field of application. This traction drive is better suitable than other speed reducer as drive part of electric wheelchair. Also it is sufficiently necessary capacity of existing advanced product as apply traction drive to electric wheelchair.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.393-396
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• 2001

According to the development of power electronic element(GTO, IGBT) and material for electrical machines(permanent magnet, super conductor), the technology for electrical machines is nowaday rapidly developing. Here with, a novel electrical machine, based on the new conception of transverse flux configuration leads to a considerable Increase in power density and enables simultaneously high efficiency. The transverse flux machine with PM excitation will be applied to gearless direct drives for railway traction system and magnetic levitation system. The designed and measured performance of transverse machine for railway traction system and magnetic levitation system revealed a great potential of system improvements to reduce linear motor mass and increase efficiency.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
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• pp.141-143
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• 2008

Due to the demand for high-output motors in the limited space between the wheels in an electric train, self-ventilating traction motors have been used for many years. periodical disassembly maintenance is necessary to remove the small quantities of dust that enter the motor from the open-air ventilation. Reducing this burden, as well as increasing efficiency and reducing noise, would benefit the next generation of moters To address these needs, KRRI is developing a fully enclosed type traction motor, a fully enclosed type traction motor with outer fans, a high-efficiency permanent-magnet synchronous motor and a direct-drive motor(DDM) as traction motors for the next generation of trains.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1212-1218
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• 2003

A novel loading mechanism of wedge roller type has been developed. This type traction drive has long system life and high efficiency by changing the pre-load on a contact point. And this loading mechanism does not need precision machining. So it has, as opposed to the conventional loading mechanism, an advantage in saving manufacturing cost. In this paper, by analyzing pre-load generating mechanism, spring pre-load and the roller size are defined and the stress on the contact point by pre-load is calculated. On the basis of this analysis, the model of wedge roller type traction drive for the test is made and was carried out its performance test. It can transmit input torque up to 1.5 N m, with high efficiency over 91% up to 98%, with slip rate under 2.5%.

• 한국철도학회논문집
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• 제9권6호
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• pp.682-688
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• 2006

In this paper, a method which can deduce the traction farce or the braking force from the acceleration or the deceleration of the train, has been suggested. In the case of Korean high speed train (HSR-350x), the traction force and the braking forces have been obtained by using this method. It is proven that the proposed method is a very good tool in estimating the traction force or the braking force when the train starts or stops. Also, these forces on be used to calculate friction coefficients of mechanical brakes and the transmission efficiency of the traction system.

• 전기전자학회논문지
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• 제26권4호
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• pp.671-680
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• 2022

본 논문에서는 현재 출시되어 있는 전기차의 구동모터 사양을 대부분 포괄하는 200kW급 구동용 모터드라이버를 개발하였다. 고효율ㆍ고전력밀도를 달성하기 위해 기존 전력반도체(Insulated-gate bipolar transistor, IGBT)대신에 차세대 전력반도체(Silicon carbide, SiC)를 적용하였으며 SiC를 최적사용하기 위해 하드웨어에 대한 분석을 통해, 예상되는 효율 및 방열특성을 구하여 최적 설계를 하였다. 전기차 구동모터에 대부분 활용되는 매입형 영구자석 동기모터(Interior permanent-magnet synchronous machine, IPMSM)를 위한 벡터 제어 알고리즘을 DSP를 활용하여 구현하였다. 본 논문에서는 SiC기반 전기차 구동용 모터드라이버 시작품을 설계ㆍ제작하였으며 실험을 통해 성능을 검증하였다.