• 에너지공학
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• 제20권4호
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• pp.286-291
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• 2011

하이브리드 자동차는 전기방식 회생제동을 이용하여 연비가 우수하다. 본 논문에서는 새로운 공압식 회생제동 장치를 소개하였다. 공압식 회생제동장치는 압축과 팽창기능을 동시에 가지는 스크롤 기구를 이용한다. 차량 감속시에는 스크롤 기기는 압축기로 작동되면서 대기중의 공기를 압축하여 압축탱크에 저장한 후 차량 가속시에는 스크롤기구가 팽창기로 작동되면서 탱크에 저장된 압축공기가 차량 운동에너지로 활용된다. 회생제동장치를 사용함으로써 개선되는 연비를 분석하기 위해, CVS-75 모드 주행조건에서 시뮬레이션을 수행하였다.

• 한국자동차공학회논문집
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• 제18권4호
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• pp.84-91
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• 2010

Owing to revolutionary developments in automobile technologies, a variety of advanced vehicles - hybrid vehicle, hydrogen fuel-cell vehicle, electric vehicle, etc. - emerges recently. The safety is getting more important for developing automobiles. The electro-magnetic compatibility has to be assured, since those advanced vehicles are equipped with various new electronic systems. Electro-magnetic compatibility tests, in general, consist of an EMI(electro-magnetic interference) test and an EMS (electro-magnetic susceptibility) test. We investigated the susceptibility test method suggested in KMVSS (Korean Motor Vehicle Safety Standard) as the EMS test method. A series of experiments results that the above test method should be partially revised to comply with a Korean governmental standard method. In this paper, the some directions of modifications are presented to enhance the quality of the above EMS test method.

• Agribusiness and Information Management
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• 제6권2호
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• pp.40-48
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• 2014

As basic research to develop HEV and EV agricultural field machinery, the present study analyzes the technical trend of electric agricultural field machinery through product analysis, paper analysis, and patent analysis concerning HEV and EV in the automobile, construction machinery, and agricultural machinery sectors. For product analysis, the homepages of companies in these sectors were consulted to analyze the number of products of each company. For paper analysis, key words related to HEV and EV were selected, a search formula was drawn up, and articles search sites were consulted. And for patent analysis too, key words were selected and then a search formula was drawn up to examine published patent applications or registered patent applications, and trends were analyzed by structure, country, and year. The number of HEV and EV products were 17 in the automobile area, 8 in construction machinery, and 4 in agricultural machinery. Notably, in the agricultural machinery area, all HEV and EV products were from advanced companies overseas. In terms of papers, papers published in the past 5 years were searched and 33,195 papers were from the automobile area, 3,806 were from construction machinery, and 2,687, the fewest papers, were from the agricultural machinery area. A search of patents in the electric drive technology area in Korea, USA, and Japan, and Europe showed 1,927 valid patents, with 1,120 in Japan, 497 in USA, 193 in Korea, and 117 in Europe. Analysis of the trend of research on electric agricultural field machinery by product, paper, and patent shows the development of HEV and EV technology in Korea is insufficient compared to USA, Japan, and Europe, which means rapid technological development is needed.

• 한국분무공학회지
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• 제28권3호
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• pp.150-155
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• 2023

Cold-start emissions are given great importance under the Euro-7 emission standard due to their significant impact on overall vehicle emissions. When an engine is started from a cold state, the combustion process is not yet optimized, leading to higher emissions. Hybrid vehicles, in particular, may face additional challenges, as their engine may remain inactive for extended periods, causing their catalysts to cool down and potentially become less effective in reducing emissions. In the present study, the performance of an electric heater was investigated as a means to enhance the catalyst heating during the start-up time. A simulation tool was utilized to develop a model for the gasoline exhaust aftertreatment system. The result indicates that the heater was able to increase the three-way catalyst temperature to 500℃ in 4 s using 20 kW power. In addition, the implementation of a secondary air supply resulted in reduced temperature overshoot and improved conversion efficiencies.

• 한국항공운항학회지
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• 제31권1호
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• pp.11-17
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• 2023

In this study, the correlation analysis between total system error and environmental factor variables was performed to confirm the effect on the performance of the integrated navigation system by various environmental factors. To collect flight data of hybrid vertical take-off and landing UAVs, scenarios including various turning sections and straight sections such as left turn, right turn, turning rate, and path change angle were selected, and environmental data of wind direction, wind speed, temperature, air pressure, and humidity were collected in real time through weather station. As a result of the correlation analysis between the collected flight data and environmental data, it was concluded that the performance of the integrated navigation system by environmental factors within the collected data was not significant affected and was robust.

• 한국자동차공학회논문집
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• 제20권1호
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• pp.53-60
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• 2012

As enforced by the regulation on the improving fuel efficiency and increased the demand on green technology, many interests are focused on electric vehicles and hybrid vehicles. Thus the technology development in electrification of vehicle operation system, including steering and braking field, is actively progressive. Especially electric power steering substitutes for hydraulic power steering rapidly in the market, which is more complex and bigger in packaging volume compared with electric power steering system. The core component in electric power steering system is a motor, which is required to be silent and powerful to guarantee required system performance. Brushless synchronous motors are widely used and many variations of the motors are introduced in the market, while the performance of each type is not well defined or studied for electric power steering system. In this paper, recent developments in brushless synchronous motor are reviewed and compared applying finite element analysis in electromagnetic field. As results, each characteristic of different types of brushless synchronous motors is compared and summarized for optimized selection in electric power steering system.

• 한국전자통신학회논문지
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• 제9권1호
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• pp.83-90
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• 2014

본 논문에서는 BLDC 모터로 구동되는 오일 펌프 제어 시스템을 설계하고 구현하는 문제를 다룬다. 제안된 오일 펌프는 하이브리드 차량에 장착되어 엔진 클러치와 변속기에 충분한 양의 작동유를 공급하는 역할을 한다. BLCD 모터로 구동되는 제어기를 단순화하여 전원 전압을 PWM 방식으로 직접 제어하는 일반적인 방법을 사용함으로써 응답성 및 정확성을 향상시키는 것을 주목적으로 한다. 제안된 제어 기법은 오일 펌프 장치의 효율성과 신뢰성을 높인다. BLCD 모터의 회전과 오일 펌프 가동 실험을 실시하여 제안된 기법의 성능을 검증한다.

• Journal of Electrical Engineering and Technology
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• 제13권5호
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• pp.1965-1977
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• 2018

This paper proposed a regenerative braking system (RBS) strategy for battery electric vehicles (BEVs) with a hybrid energy storage system (HESS) driven by a brushless DC (BLDC) motor. In the regenerative braking mode of BEV, the BLDC motor works as a generator. Consequently, the DC-link voltage is boosted and regenerative braking energy is transferred to a battery and/or ultracapacitor (UC) using a suitable switching pattern of the three-phase inverter. The energy stored in the HESS through reverse current flow can be exploited to improve acceleration and maintain the batteries from frequent deep discharging during high power mode. In addition, the artificial neural network (ANN)-based RBS control mechanism was utilized to optimize the switching scheme of the vehicular breaking force distribution. Furthermore, constant torque braking can be regulated using a PI controller. Different simulation and experiments were implemented and carried out to verify the performance of the proposed RBS strategy. The UC/battery RBS also contributed to improved vehicle acceleration and extended range BEVs.

• Journal of Power Electronics
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• 제13권3호
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• pp.429-436
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• 2013

Online simulations are utilized to reduce time and cost in the development and performance optimization of plug-in hybrid electric vehicle (PHEV) and electric vehicles (EV) systems. One of the most important factors in an online simulation is the accuracy of the model. In particular, a model of a battery should accurately reflect the properties of an actual battery. However, precise dynamic modeling of high-capacity battery systems, which significantly affects the performance of a PHEV, is difficult because of its nonlinear electrochemical characteristics. In this study, a dynamic model of a high-capacity battery cell for a PHEV is developed through the extraction of the equivalent impedance parameters using electrochemical impedance spectroscopy (EIS). Based on the extracted parameters, a battery cell model is implemented using MATLAB/Simulink, and charging/discharging profiles are executed for comparative verification. Based on the obtained results, the model is optimized for a high-capacity battery cell for a PHEV. The simulation results show good agreement with the experimental results, thereby validating the developed model and verifying its accuracy.

• 한국항공운항학회지
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• 제30권2호
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• pp.1-6
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• 2022

Recently, the development of UAM, which was named by NASA as an alternative to solve the traffic and environmental problems caused by the rapidly progressing urbanization. When designing UAM, the location of lift fans greatly affects the core technology of the eVTOL type, distributed electric propulsion technology and aerodynamic performance of the vehicle. In this paper, a hybrid UAM model was designed using OpenVSP, an open source aircraft configuration modeling program, and aerodynamic analysis was performed according to the lift fans position change by the vortex lattice method. As a result, it is confirmed that the flight parameters and trailing wakes are stable by fixing the lift fan with the state rotated 0° to the flow direction of the aircraft during cruise flight. Also, OpenVSP is a suitable tool to be used in aircraft configuration modeling and design.