• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.198-200
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• 2017

보조동력장치(Auxiliary Power Unit: APU)는 항공기에 장착되어 주엔진의 지상 및 공중 시동을 위한 에너지를 공급하고 항공기의 비상 및 보조 전원을 공급하는 역할을 하는 소형 가스터빈엔진이다. 항공기용 APU는 구조가 간단하고 소형이지만 유인 항공기에 장착되기 때문에 높은 신뢰성이 요구되므로 인증 절차를 통하여 그 신뢰성을 입증하여야 한다. 한국항공우주연구원은 2007년부터 2012년까지 한화 테크윈과 함께 축적된 국내 연구개발 역량 및 경험을 바탕으로 헬리콥터용 APU의 설계/해석, 제작 및 조립, 개발시험 및 인증시험을 평가를 성공적으로 완료하였다. 본 논문에서는 헬리콥터용 보조동력장치의 개발 및 인증 과정에 대하여 정리하였다.

• 한국산학기술학회논문지
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• 제22권2호
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• pp.774-780
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• 2021

회전익 항공기의 보조동력장치(APU, Auxiliary Power Unit)는 지상 운용/비행 중 주 동력 기관의 시동, 환경제어시스템용 고압 공기 공급, 비상발전기 등의 역할을 수행한다. 보조동력장치(이하 'APU')는 소형 가스터빈엔진형태로 구성되어 있으며, 해당 구성품의 시동 원리는 전기 시동 모터를 사용하는 방식으로, 축을 회전시켜 시동에 필요한 동력을 발생시킨다. 본 연구에서는 회전익 항공기에 장착된 APU의 시동 모터 운용성 확보를 위해 APU와 APU 시동 모터 간 축간 분리 장치(Over-Running Clutch) 적용을 통한 품질개선을 수행하였다. APU 시동 모터는 초기 APU 시동이 주 역할이지만, 운용 시 실제 작동 시간 이후에도 APU 기어축의 회전력에 의해 무 부하 회전을 하게 되어 구성품/부품 간 과도한 마찰력이 지속적으로 발생하였다. 이러한 현상은 시동 모터 내부 브러시 마모를 유발하게 되고, 결과적으로 항공기 운용을 위한 APU 작동 시간 증가 시 브러시 운용 수명 감소와 APU의 운용성에 영향을 미치게 된다. 따라서 본 연구에서는 APU 시동 모터의 운용성/내구성 향상을 위하여 시동 모터 브러시 마모와 APU 작동시간의 연동성을 분리하는 축간 분리 장치(Over-Running Clutch)적용하여 시험으로 효과를 검증하였고, 설계변경에 따른 기술적 타당성을 분석하였다.

• 한국유체기계학회 논문집
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• 제15권5호
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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.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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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.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.615-619
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• 2009

There are many increasing demands for efficient high power density of auxiliary power unit(APU) for high speed traction application. Many techniques have been proposed to measure the voltage flicker on the traditional pulse width modulation(PWM) inverter. This paper proposes a novel functionality of the static inverter on the APU to mitigate the voltage flicker and regulate the output voltage. A new control algorithm for the inverter based on the Hilbert transform(HT) is presented. The HT is employed as an effective technique for tracking the voltage flicker levels in APU systems. Simulation results are provided to verify the tracking capabilities of the HT and to evaluate the performance of the proposed DG interface for multi-function operation.

• 품질경영학회지
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• 제47권4호
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• pp.895-910
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• 2019

Purpose: The purpose of this study is to lighten the APU (Auxiliary Power Unit) structure of the KAAV (Korea Assault Amphibious Vehicle) through structural analysis. Methods: Commercially-available program (MIDAS.NFX) was used for finite element analysis. Frequency response analysis was performed through linear static and mode analyses to verify the structural stability according to the change of the structural materials. Results: Numerical simulation (linear static, mode and frequency response analyses) results showed that the safety factor of the APU was over 1.5 even under the worst case conditions. The APU made by aluminum structures was expected to be available in the military field, since every requirements in the KDS (Korean Defense Specifications) was fulfilled during the various tests and evaluations. Conclusion: The structural analysis was verified that the structural stability of the APU structure of the KAAV after change of the structural material.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1999년도 유체기계 연구개발 발표회 논문집
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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.

• International Journal of Automotive Technology
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• 제7권1호
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• pp.91-99
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• 2006

The diesel Auxiliary Power Unit (APU) for vehicle applications is a complex nonlinear system. For the purpose of this paper presents a dynamic average model of the whole system in an entirely physical way, which accounts for the non-ideal behavior of the diode rectifier, the nonlinear phenomena of generator-rectifier set in an elegant way, and also the dynamics of the dc load and diesel engine. Simulation results show the accuracy of the model. Based on the average model, a simple PI control scheme is proposed for the multivariable system, which includes the steps of model linearization, separate PI controller design with robust tuning rules, stability verification of the overall system by considering it as an uncertain one. Finally it is tested on a detailed switching model and good performances are shown for both set-point following and disturbance rejection.

• International Journal of Railway
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• 제8권1호
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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.

• 한국군사과학기술학회지
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• 제19권2호
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• pp.211-217
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• 2016

The fuel cell based auxiliary power unit (APU) is promising for power source of armed vehicles due to its silence and high efficiency. Especially, the on board hydrogen generation and fed to fuel cell system was core technology of this power system. In this study, we analyzed the performance of the Auto thermal reactor (ATR) that produce the hydrogen from the fuel, integrated High temperature polymer electrolyte fuel cell (HT-PEFC) by Aspen plus software. The fuel was designed as a n-dodecane for analysis of military fuel (JP-8).