• Title/Summary/Keyword: Auxiliary power unit

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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.

Studies on the improvement of driving gears quality at Inlet Guide Vane of aircraft auxiliary power unit (항공기 보조동력장치 입구안내익 구동기어의 품질개선에 관한 연구)

  • Park, Sungjae;Park, Sunwook;Suh, Jaekyoung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.6
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    • pp.512-519
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    • 2016
  • Auxiliary Power Unit of FA-50 which provides energy other than propulsion is an important element to maintain airworthiness on aircraft. Also Inlet Guide Vane of Auxiliary Power Unit is a device that supplies appropriate airflow into the Auxiliary Power Unit after adjusting influent airflow into the load compressor. This report, based on the problems occurred the driving gears of Inlet Guide Vane, deals with cause of occurrence, troubleshooting, design improvement and result of test flight verification for FA-50 aircraft Auxiliary Power Unit lifespan.

Development and Qualification of an Auxiliary Power Unit for Helicopter (헬리콥터용 보조동력장치 개발 및 인증)

  • Lim, ByeungJun
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.198-200
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    • 2017
  • An Auxiliary Power Unit (APU) is a small gas turbine engine that is mounted on an aircraft and serves to supply energy for ground and air starting of the main engine. APU also supplies emergency and auxiliary power for the aircraft. APU for aircraft is simple and compact in structure, but because it is mounted on manned aircraft, high reliability is required, so it must be proved its reliability through qualification procedure. The Korea Aerospace Research Institute and Hanwha Techwin successfully completed the design / analysis, fabrication, assembly, development test and certification test of APU for helicopter based on accumulated domestic R & D capability and experience from 2007 to 2012. In this paper, the development and certification process of auxiliary power unit for helicopter is summarized.

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A Study on the Life Cycle Cost Evaluation of the Conventional Auxiliary Power Unit for 8200 Series Electric Locomotive (8200호대 전기기관차용 기존품 보조전원장치의 수명주기비용 평가에 관한 연구)

  • Lee, Kye-Seung;Kim, Wan-il;Kim, Jae-Moon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.2
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    • pp.331-336
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    • 2018
  • In this paper, the life cycle cost of the auxiliary power unit in the conventional 8200 series electric locomotive is evaluated and an effective life cycle cost reduction method is sought. For this, a life cycle cost evaluation model was proposed using IEC 60300-3-3 standard. As a result of analysis, material cost which accounted for a large percentage of preventive maintenance cost, accounted for 64% of total cost, and breakdown maintenance cost was as high as 27%. Except for the cost of preventive maintenance, the breakdown maintenance cost ratio was the highest. In order to reduce the LCC of the auxiliary power unit(APU) of the 8200 series in the future, it is necessary to reduce the material cost in case of development and to secure the high reliability according to the parts manufacturing so as to minimize the maintenance cost.

The Development of APU(Auxiliary Power Supply Unit) for DC 3000V (DC 3000V용 보조전원장치 개발)

  • Kim, Jin-Yong;Kimg, Youn-Chung;Han, Jung-Soo
    • Proceedings of the KSR Conference
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    • 2011.05a
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    • pp.1654-1660
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    • 2011
  • The korea Electric Railway feeder voltage is DC 1500V and AC 250000V. The auxiliary power supply of the vehicle auxiliary power units for domestic electrical feed has been developed with domestic technology hyeonchae mounted station, and domestic uses, such as voltage, have been exported to other countries. However, do not use at domestic that can be used for DC 3000V voltage auxiliary power unit does not develop, vehicle exports global. This has already been replaced by imported products from other nations is a real situation. Thus, our auxiliary power unit for the DC 3000V was developed, it will be exported to Ukraine. In this paper, We introduced circuit and structure of developed auxiliary power supply unit, and verified the performance with output characteristic of the auxiliary power unit.

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Experimental Research on the Altitude Performance of an Auxiliary Power Unit for Helicopters (헬리콥터용 보조동력장치 고공성능에 관한 실험적 연구)

  • Kim, Chun-Taek;Cha, Bong-Jun
    • The KSFM Journal of Fluid Machinery
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    • v.15 no.5
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    • pp.20-26
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    • 2012
  • An APU(Auxiliary Power Unit) for helicopters has been developed in Korea and tested at the AETF(altitude engine test facility) in KARI(Korea Aerospace Research Institute) for the purpose of the military qualification. A cell correlation test was performed before the official test, and the results are within the tolerance. The APU has the capability of supplying electric power as well as compressed air to the helicopters. It was tested at bleed extraction conditions, electric power extraction conditions, and maximum continuous concurrent power conditions within the entire helicopter flight envelop. Some special test equipments were implemented for the measurement of air flowrate, electric power and so on. The tests were successfully performed and their results satisfy the requirements of the helicopters.

Development of 100 Kw Power Class Airborne Auxiliary Power Unit (100 Kw급 항공용 보조동력장치(APU) 개발)

  • Yang, Soo-Seok;Lee, Dae-Sung;Kim, Seung-Woo
    • 유체기계공업학회:학술대회논문집
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    • 1999.12a
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    • pp.291-300
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    • 1999
  • Currently under development is an airborne auxiliary power unit with 100 Kw equivalent power, which is composed of a centrifugal compressor, a reverse annular combustor, and a radial turbine. Air-foil bearings are used in this power unit to eliminate the oil supplying system, which can reduce the system complexity and weight. The high speed generator is adopted as an electric power generation and engine starting system, which can also eliminate the reduction gear system. Not only electric power but also pneumatic power is provided by bleeding the compressed air This power unit is aimed for the multi-purpose use such as a primary power unit In the army weapon system, an auxiliary power and environmental control unit in a next-generation tank, and a smoke generating unit.

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Auxiliary Power Unit Control Algorithm for Input Voltage Disturbance Suppression (입력 급변 대응을 위한 철도 차량용 보조전원장치 외란 억제 알고리즘 구현)

  • Kim, Ji-Chan;Baek, Seoung-Gil;Cha, Hanju
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.12
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    • pp.1810-1817
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    • 2015
  • The railway vehicle has an auxiliary power unit for supplying power to the associated electronic control devices and passenger service unit. Typically, input voltage from the catenary for rolling stock is highly fluctuating according to the substation capacity, vehicle propulsion and regeneration. Especially, the frost and freezing on contact wire in winter can cause a blackout inside vehicle, and also brings about electronic components damaging and the system down. To prevent this problem, a large filter and capacitor is used. But this is not a perfect solution, because it is increasing weight of the unit. In this paper, a new algorithm is proposed to suppress the disturbance without adding devices. Simulation and experimental results show that the proposed algorithm has performance to suppress the disturbance at the sudden input voltage variations.

A Study on Prediction of Fatigue Life and Shock Fracture for the Engine Base of Auxiliary Power Unit for Tracked Vehicle (보조동력장치 엔진 Base의 피로수명 예측 및 충격파손에 관한 연구)

  • Lee, Sang-Bum;Chung, Kyung-Taek;Shin, Jae-Ho;Jang, Hwan-Young;Suh, Jeong-Se
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.4
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    • pp.86-92
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    • 2008
  • This paper is to investigate the behavior of linear static structure stress, the fatigue and experimental shock fracture far engine base in the Auxiliary Power Unit to resolve its restricted electrical power problem. The shock fracture test was experimentally made under MIL standard criteria. The numerical results by finite element method had a good agreement with those from the shock test. The design data of predicting the fracture at the initial crack and the damage behavior of structure with shock and vibration load in the battle field can be obtained from shock test. In the functional shock test, the crack at the side parts of the engine base was found at peak acceleration of 40g.