• Title/Summary/Keyword: Auxiliary power unit

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A Control Algorithm for Highly Efficient Operation of Auxiliary Power Unit in a Series Hybrid Electric Bus (직렬형 하이브리드 버스에서 보조동력장치의 고효율 작동을 위한 제어 알고리즘)

  • 함윤영;송승호;민병문;노태수;이재왕;이현동;김철수
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.5
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    • pp.170-175
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    • 2003
  • A control algorithm is developed for highly efficient operation of auxiliary power unit (APU) that consists of a diesel engine and a directly coupled induction generator in series hybrid electric Bus (SHEB). In a series hybrid configuration the APU supplies the electric power needed for maintaining the state of charge (SOC) of the battery unit in various conditions of vehicle operation. As the rotational speed of generator does not depend on the vehicle speed, an optimized operation of engine-generator unit based on the efficiency map of each component can be achieved. The output torque of diesel engine can be controlled by the amount of fuel injection, and the power converted from mechanical to electrical energy can be adjusted by generate control unit (GCU) using the decoupling vector control of torque and flux. As for the given reference of the generating power, the multiply of speed and torque, many combinations of operating speed and torque are possible. The algorithm decides the new operating point based on the engine efficiency map and generator characteristic curve. During the transition of operating points, the speed controller saturation is avoided using variable limit and filtering of generator torque reference. A test rig and SHEB consist of a 1.5L diesel engine and a 30kw induction generator are constructed by Hyundai Motor Company.

A Study on the Failure code of the MVB Protocol when the Electric locomotive(8200 series) New Auxiliary Power Supply is applied (전기기관차(8200호대) 신규 보조전원장치 적용 시 MVB 통신프로토콜 중 고장코드에 관한 연구)

  • Bae, Young-Kyu;Shin, Hwa-Song;Jeong, Hwi-Seob;Son, Ki-Hwan
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.2
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    • pp.377-382
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    • 2018
  • In order to partially localize the electric locomotive(8200 series) currently being operated, analysis of the inter-device MVB protocol in the electric locomotive should be performed first. Especially, it is necessary to analyze the operation when a newly developed auxiliary power supply is applied. In this paper, when a new auxiliary power supply applied to a conventional electric locomotive through a newly developed communication control unit using the analyzed protocol, a protocol for a failure codes was analyzed.

Fault Tolerant Operation of CHB Multilevel Inverters Based on the SVM Technique Using an Auxiliary Unit

  • Kumar, B. Hemanth;Lokhande, Makarand M.;Karasani, Raghavendra Reddy;Borghate, Vijay B.
    • Journal of Power Electronics
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    • v.18 no.1
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    • pp.56-69
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    • 2018
  • In this paper, an improved Space Vector Modulation (SVM) based fault tolerant operation on a nine-level Cascaded H-Bridge (CHB) inverter with an additional backup circuit is proposed. Any type of fault in a power converter may result in a power interruption and productivity loss. Three different faults on H-bridge modules in all three phases based on the SVM approach are investigated with diagrams. Any fault in an inverter phase creates an unbalanced output voltage, which can lead to instability in the system. An additional auxiliary unit is connected in series to the three phase cascaded H-bridge circuit. With the help of this and the redundant switching states in SVM, the CHB inverter produces a balanced output with low harmonic distortion. This ensures high DC bus utilization under numerous fault conditions in three phases, which improves the system reliability. Simulation results are presented on three phase nine-level inverter with the automatic fault detection algorithm in the MATLAB/SIMULINK software tool, and experimental results are presented with DSP on five-level inverter to validate the practicality of the proposed SVM fault tolerance strategy on a CHB inverter with an auxiliary circuit.

A Study on Optimization of Noise Reduction of Auxiliary Power Unit for Military Tracked Vehicle (군용 궤도장비 보조동력장치의 소음저감 최적화 연구)

  • Lee, Ju-Seung;Kim, Byeong-Ho;Kim, Byung-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.8
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    • pp.336-342
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    • 2018
  • Noise reduction is an important issue in auxiliary power unit(APU) of tracking equipments for using military. In this study, we designed and tested reduction methods of structure borne noise and airborne source noise at the auxiliary power unit. From the bench test results, it is found that the effect of noise reduction is about 22 dB(A) if the silencer is redesigned, which is the rescue structure. However, the influence of noise reduction by air is insufficient. In addition, it is confirmed that the effect of noise reduction is excellent when structure borne noise reduction is applied to the vehicle. We expected that the test results of this study are used as basic data to reduce the noise of other tracking equipment developed later.

A Study on the Reliability Evaluation of Start-up Power Supply in Fossil Power Plant by Minimal Cut-Set Method (최소 컷셋법에 의한 화력발전소 기동전원의 신뢰도 예측에 관한 연구)

  • Choe, Gyu-Sik
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.4
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    • pp.358-364
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    • 1999
  • The auxiliary transformers or start-up/stand-by transformer(s) are installed against the start-up and shut-down of generator and emergency status in fossil power plant. The on-site power supply configuration using these transformers must be determined, considering configuration requirements, site characteristics, reliability and availability severely because it is remarkably important for safety and ecfonomy of plant. The auxiliary or start-up/stand-by power supply configuration has been determined considering only safety requirements and construction cost until now in Korea. This paper presents general theorems for the reliability estimation and proposes 2-unit based 4 alternatives for the start-up power supply stystem of 500㎿ standardized fossil power plant. The reliability and unavailability of equipment, system and configuration are determined using minimal cut-set methodology. The optimized plan of 4 alternatives is determined based on this ultimate reliability and unavailability.

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Analysis for Performance of the HT-PEFC based Auxiliary Power Unit by Aspen Plus Software (Aspen Plus 프로그램에 의한 장갑차량용 고온고분자전해질 연료전지 기반 보조전원장치 성능 시뮬레이션 분석)

  • Yu, Minkyu;Park, Ji-il;Kwon, Hyuksang
    • Journal of the Korea Institute of Military Science and Technology
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    • v.19 no.2
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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).

The Study of Auxiliary Power Unit for locomotive (철도차량용 보조전원장치에 관한 연구)

  • Jeong, Han-Dong;Lee, Won-Cheol;Lee, Sang-Seok;Kim, Tae-Hwan;Won, Chung-Yuen
    • Proceedings of the KSR Conference
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    • 2009.05b
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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.

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Research on Technical Trends of IGBT Gate Driver Unit for Railway Car (철도차량용 IGBT Gate Driver Unit 기술 동향 분석 연구)

  • Cho, In-Ho;Lee, Jae-Bum;Jung, Shin-Myung;Lee, Byoung-Hee
    • Journal of the Korean Society for Railway
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    • v.20 no.3
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    • pp.339-348
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    • 2017
  • Power supply for railway cars can be divided into propulsion system power supply and auxiliary power units (APU). The propulsion system power supply is for propulsion of railway cars, and regenerative braking; the APU provides power for the air compressor, lighting, car control and other auxiliary parts. According to high voltage and high current specifications, generally, an insulated-gate bipolar transistor (IGBT) is adopted for the switching component. For appropriate switching operation, a gate driver unit (GDU) is essentially required. In this paper, the technical trends of GDU for railway cars are analyzed and a design consideration for IGBT GDU is described.

Investigation of Transient Performance of An Auxiliary Power Unit Microturbine Engine (보조동력용 마이크로터빈 엔진에 대한 과도성능 해석)

  • Son, Ho-Jae;Kim, Soo-Yong
    • Journal of the Korean Society of Propulsion Engineers
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    • v.11 no.3
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    • pp.20-28
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    • 2007
  • The easiest way to see the phenomena of compressor surge is to show the static and dynamic operation characteristic on the map. Its operation zone will be restricted by the surge limit and, static and transient process must have some margin for it. Effect of rotor moment of inertia, air/gas volumes and heat transfer are factors to cause the transition from the static line. In case a large volume such as heat exchanger exists in the system it will exert a substantial influence to dynamic characteristics. In the present paper, influence of air volume bled from the compressor exit on transient process is investigated with an example of an auxiliary power unit micro-turbine engine. Turbine mass, pressure ratio, rotation speed, power and moment are calculated based on mass and work conservation. Result from the present study can give guidance to design the control system. A computer program is developed to calculate the dynamic process using the MathCAD commercial software.