• Title, Summary, Keyword: auxiliary brake

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Analysis of Multiple Factor of the Eddy Current Brake for Railway Application (철도차량용 와전류 브레이크의 다중 인자 분석)

  • Lee, Chang-Mu;Park, Hyun-Jun;Cho, Sooyoung;Lee, Ju;Lee, Hyung-Woo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.9
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    • pp.1385-1390
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    • 2015
  • This paper is analysis of multiple factor that should be considered in the design of an eddy current brake used as auxiliary brake system. The eddy current brake is a brake that generates a braking torque in a rotational direction opposite to the direction of the rotor by using a time-varying magnetic flux. The eddy current brake has the advantage of being able to take high current densities because this is used for a short period of time. Also, the eddy current brake is influenced by multiple factor such as number of slots, teeth width, coating thickness, air-gap length and so on. Therefore the eddy current brake was designed for use in railway application in consideration of the operation region and critical parameters.

Electromagnetic Retarder's Power Recovery Device and Voltage Control (전자기형 리타더의 전력회수장치 및 전압제어)

  • Jung, Sung-Chul;Yoon, In-Sik;Ko, Jong-Sun
    • The Transactions of the Korean Institute of Power Electronics
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    • v.21 no.5
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    • pp.396-403
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    • 2016
  • Usually, large-sized buses and trucks have a very high load. In addition, frequent braking during downhill or long-distance driving, causes the conventional method using the brake friction to have a problem in safety because of brake fade and brake burst phenomenon. Auxiliary brakes dividing the braking load is essential. Hence, environment-friendly auxiliary brakes, such as contactless brake rather than the engine auxiliary brake system are needed. A study aimed at improving the energy efficiency by recharging electric energy with changing mechanical to electrical energy that occurs when braking is actively in progress. In this paper, the voltage control method is utilized to recover the electric energy generated in the electromagnetic retarder instead of the eddy current. To regenerate the braking energy into the electrical energy, the resonant L-C circuit is configured in the retarder. The voltage generated in the retarder is simply modeled as a transformer. However, retarder voltage control in this paper is simulated by modeling the induction generator because this induction generator modeling is more practical than transformer modeling. The changes in the voltage of the resonance circuit, which depends on the switch pulse duration of the control device, were analyzed. A PI controller algorithm to control this voltage is proposed. The feasibility of modeling retarder and voltage controller are shown by using MATLAB Simulink in this paper.

Improvement of Diesel Engine Performance for Alternative Fuel Oil (대체연료를 사용할 경우의 디젤기관의 성능향상에 관한 연구)

  • 고장권
    • Journal of the Korean Society of Marine Engineering
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    • v.16 no.5
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    • pp.97-110
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    • 1992
  • Rape-seed oil has high viscosity and high rubber content like other vegetable oils. When crude rape-seed oil obtained by a general oil extraction process is used in a diesel engine, automization condition during injection is not good and a large amount of combustion product is doposited in a combustion chamber. The improvement of a diesel engine is required to use rape-seed oil as a diesel engine fuel. In this study, the physical and chemical properties and combustion characteristics of rape-seed oil were investigated. The auxiliary aid was developed to improve automization condition and the effect of the auxiliary injection aid on the performance of a diesel engine was determined. The results are as follows. 1) Oil content of rape-seed is 45%. The exraction rate is 33%. The resuls show higher values compared to those of other vegetable oils. 2) The viscosity of rape-seed oil is 50.8 cSt and nearly 14 times of diesel oil viscosity. 3) The heating value and flash point of rape-seed oil are 9720kcal/Kg and 318$^{\circ}C$, respectively. 4) In case rape-seed oil is used as fuel, brake horse power, specific fuel consumption and brake thermal efficiency are compared to those of diesel oil. The results of rape-seed oil show 3.6%, 12.7% and 3.1% higher values. 5) Particle size of injection fuel with the auxiliary injection aid on the performance of a diesel engine was determined. The results are as follows. 1) Oil content of rape-seed is 45%. The extraction rate is 33%. The results show higher values compared to those of other vegetable oils. 2) The viscosity of rape-seed oil is 50.8 cSt and nearly 14 times of diesel oil viscosity. 3) The heating value and flash point of rape-seed oil are 9720kcal/Kg and 318.deg.C, respectively. 4) In case rape-seed oil is used as fuel, brake horse power, specific fuel consumption and brake thermal efficiency are compared to theose of diesel oil. The results of rape-seed oil show 3.6%, 12.7% and 3.1% higher values. 5) Particle size of injection fuel with the auxiliary injection aids is 100.mu.m smaller than that od injection fuel without the aid. 6) Brake horse power and brake thermal efficiency with the auxiliary injection aid increase 5.07% and 6.07%, respectively. However, specific fuel consumption decreases 3.85% with the auxiliary injection aid.

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Design and Analysis of the Eddy Current Brake with the Winding Change

  • Cho, Sooyoung;Liu, Huai-Cong;Lee, Ju;Lee, Chang-Moo;Go, Sung-Chul;Ham, Sang-Hwan;Woo, Jong-Hyuk;Lee, Hyung-Woo
    • Journal of Magnetics
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    • v.22 no.1
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    • pp.23-28
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    • 2017
  • This paper is a study of the eddy current brake designed to replace the air brake of railway application. The eddy current brake has the advantage of being able to take a high current density compared to the other application because this brake is used for applying brakes to the rolling stock for a shorter amount of time. Also, this braking system has the merit of being able to take a high current density at low speed rather than at high speed, because the heat generated by the low speed operation is less than that of the high speed operation. This paper also presents a method of improving the output torque of the eddy current brake at low speed operation through a change of the winding as well as the basic design.

The Development for Localizing KTX Brake Devices and Performance Test (KTX 제동장치의 국산화 개발과 성능시험)

  • So, Jin-Sub;Lee, Seung-Gu;Hwang, Sang-Kyu;Keum, Jong-Ho;Kwak, Soo-Tae;Kim, Jong-Ryeol
    • Proceedings of the KSR Conference
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    • pp.630-636
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    • 2011
  • Air brake system of KTX effectively distributes air to brake panel in each bogie. System consists of carrying bogie brake panel, motor bogie brake panel, driver's valve panel, pneumatic auxiliary panel and other accessories. For the prove endurance, confirm test number. Distributor and control moderable magnet valve are 500,000 times and respectively, carrying bogie MR/BP cut-out cock are 12,000 times. Tests satisfy all of condition until now. Developments conduct a performance test to brake tester of domestic manufacturer and operating authority.

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The Study on Miniaturization and Weight Reduction of Auxiliary Power Unit in Magnetic Levitation Train

  • Lee, Na Ri;Shin, Hee Keun;Choi, Sung Ho;Kim, Ju Bum;Lim, Jae Won;Park, Doh Young;Mok, Hyung Soo
    • International Journal of Railway
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    • v.8 no.1
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    • pp.10-14
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    • 2015
  • Due to the characteristics of the vehicle structure, the magnetic levitation train has a confined bottom space thus a study on miniaturization and weight reduction of auxiliary power unit is essential. This auxiliary power unit is an essential device used for illumination, air conditioning, heating and air brake equipment excluding the motor. The previous auxiliary power unit for magnetic levitation train has used the hard switching having a high switching frequency with heavy loss in order to reduce the size of filter reactor and transformer but the reduction in volume was not significant. In this paper, by reducing the loss, reducing the size of the cooling unit and by increasing the switching frequency using the soft switching of resonant converter, it has miniaturized and reduced the weight of filter reactor and transformer which occupy significant space in the auxiliary power unit. This study has verified the performance of 50KVA grade prototype through simulated interpretation and analysis, and compared the size and weight of auxiliary power unit of the previous magnetic levitation train.

Extraction Method of Parameter of Self Excited Eddy Current Brake Using L-C Resonance and characteristic research (L-C 공진형 자여자 와전류 브레이크의 파라미터 추출 방법 및 특성연구)

  • Jeong, Taechul;Cho, Sooyoung;Ahn, Hanwoong;Jeong, Geochul;Park, Eung-Seok;Cho, Hyuntae;Lee, Ju
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.11
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    • pp.82-88
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    • 2015
  • In recent years, numerous studies have attempted to find and explore the auxiliary brake and the oil pressure type and electrical type are mainly used. However, the model proposed here is to self-excited eddy current brake. The advantage of this is it does not require an external power supply and can be produced to reduce the size than others. This self-eddy current brake consists of RLC circuit so resistance, inductance and capacitance value can be considered a fixed value. But, inductance and resistance value changes depending on the shape, temperature and magnetic alteration. Therefore, in this paper, the focal point is characteristic analysis according to the parameter variations. Also, using this result, this paper explains how to estimate the capacitance.

DC-DC Converter Design For Electric Regenerative auxiliary Brake System (전기식 회생 보조 브레이크 시스템을 위한 DC-DC 컨버터 설계)

  • Kwak, Tae Kyun;Ko, Jong Sun;Yoo, Chang Hee;Lee, Jun Young
    • Proceedings of the KIPE Conference
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    • pp.297-298
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    • 2014
  • 현재 제동장치(Brake system)는 운동에너지를 열에너지로 바꾸어 공기 중으로 발산시킴으로서 제동 작용을 하는 마찰형 Brake가 대부분이다. 이러한 제동장치 속에는 리터더라는 제동력을 유발하는 장치가 있는데 이중 빠른 응답특성을 띄는 전기식 리타더의 단점인 전기에너지 소비 측면을 극복하기 위하여 제동에너지를 전기에너지로 회생하여 에너지를 절감 할 수 있는 기술이 선진국에서는 이미 진행이 되고 있다. 본 논문에서는 리타더에서 발생되는 3상 전압을 정류하여 받은 DC전압을 입력으로 받아 24V로 강압시키고 배터리를 충전하는 DC-DC 컨버터를 제작하고 이에 따른 보완점 및 타당성을 실험을 통하여 검증하였다.

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Numerical Analysis on Pressure Characteristics of the Pipe system of Train

  • Nam Seong-Won;Zhang Bo
    • Proceedings of the KSR Conference
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    • pp.503-509
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    • 2004
  • With modem computational fluid dynamics method (CFD), air-charging models of the air brake pipe system and auxiliary reservoir are built. Compared with one-dimension model, no empirical formula is introduced to solve branch pipe fields for two-dimension model. A modified operator-splitting method is presented to solve the coupled equations of pressure and velocity, and numerical simulation shows that it is very stable. Compare the numerical results with empirical data of heavy haul trains in home and abroad so as to prove the correctness of the theory and algorithm presented. This paper gives theoretic reference to the experiments of braking effects of heavy haul trains, and forms a basis for development of complete freight train air brake system simulation.

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A Study on a Robot for Moving a Double-parked Car (이중 주차된 차량을 이동하기 위한 로봇에 관한 연구)

  • Kim, Min-Chan;Sung, Young Whee
    • Journal of the Korean Society of Industry Convergence
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    • v.23 no.2_2
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    • pp.233-244
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    • 2020
  • A double-parked car is the one that is parked in a crowded parking lot with its transmission gear in neutral position and its auxiliary brake released. A double-parked car can be moved by pushing it but doing so is very difficult and dangerous. In a previous study, we proposed an omni-directional mobile robot for moving a double parked car. In that study we adopted Mecanum wheels. Even though the proposed robot showed successful results, it has some drawbacks such as dependency on a load condition, complexity in control, inefficiency in power use, etc. To overcome those drawbacks, we propose a differential drive robot with ordinary two tire wheels. The proposed robot consists of two parts, one is a wheel part and the other is a body part. By selectively connecting or disconnecting those two parts with the aid of an electric brake, the proposed robot is able to have omni-directional mobility.