• 한국자동차공학회논문집
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• 제22권3호
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• pp.179-185
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• 2014

Average temperature and temperature uniformity in a battery cell are the important criteria of the thermal management of the battery pack for hybrid electric vehicles and electric vehicles (HEVs and EVs) because high power with large size cell is used for the battery pack. Thus, liquid cooling system is generally applied for the HEV/EV battery pack. The liquid cooling system is made of multiple cooling plates with coolant flow paths. The cooling plates are inserted between the battery cells to reject the heat from batteries to coolant. In this study, the cooling plate with U-shaped coolant flow paths is considered to evaluate the effects of coolant flow condition on the cooling performance of the system. The counter flow and parallel flow set up is compared and the effect of flow rate is evaluated using CFD tool (FLUENT). The number of counter-flows and flow rate are changed and the effect on the cooling performance including average temperature, differential temperature, and standard deviation of temperature are investigated. The results show that the parallel flow has better cooling performance compared with counter flow and it is also found that the coolant flow rate should be chosen with the consideration of trade-off between the cooling performance and pressure drop.

• 한국자동차공학회논문집
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• 제22권7호
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• pp.117-126
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• 2014

Recently, due to various environmental problems such as global warming, increasing of international oil prices and exhaustion of resource, a paradigm of world automobile market is rapidly changing from vehicles using internal combustion engine to eco-friendly vehicles using electric power such as EV (Electric Vehicle), HEV (Hybrid Electric Vehicle), PHEV (Plug-in Hybrid electric Vehicle) and FCEV (Fuel Cell Electric Vehicle). There are many driving cycles for performance evaluation of conventional vehicles. However there is a lack of researches on driving cycle for EV. This study is composed of part 1 and part 2. In this paper part 1, in order to develop urban driving cycle for performance evaluation of electric vehicles, Gwacheon-city patrol route of police patrol car was selected. Actual driving test was performed using EV. The driving data such as velocity, time, GPS information etc. were recorded. GUDC-EV (Gwacheon-city Urban Driving Cycle for Electric Vehicles) including road gradient was developed through the results of analyzing recorded data. Reliability of the driving cycle development method was substantiated through comparison of electricity performance. In the second part of this study, the developed driving cycle was compared to simulation result of the existing urban driving cycle. Verification of the developed driving cycle for EV performance evaluation was described.

• 전기학회논문지
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• 제65권5호
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• pp.777-784
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• 2016

In this paper, the performance design and analysis for an Interior Permanent-Magnet Synchronous Motor (IPMSM) that will be used as a traction motor in the e-4WD system of hybrid SUV(Sports Utility Vehicle) and RV(Recreational Vehicle), are investigated using finite element method. In order to improve the accuracy of design, the tolerances of parts and assemblies as well as the material properties of permanent magnet, stator, rotor and winding etc. are considered under the conditions similar to real driving state of motor. Both no load performance test and maximum load performance test, in which real driving state and cooling condition have been considered, are also implemented via proto sample build to verify the validity of motor's performance design.

• Journal of Power Electronics
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• 제3권4호
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• pp.230-238
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• 2003

Electric vehicles (EV) demands for greater acceleration, performance and vehicle range in pure electric vehicles plus mandated requirements to further reduce emissions in hybrid electric vehicles (HEV) increase the appeal for combined on-board energy storage systems and generators. And the power electronics plays an important role in providing an interface between fuel cells (FC) and loads. This paper deals with a multiple input DC-DC power converter devoted to combine the power flowing of multi-source on energy systems. The multi-source is composed of (i) FC system as a prime power demands, (ii) super capacitor banks as energy storage devices for high and intense power demands, (iii) superconducting magnetic energy storage system (SMES), (iv) multiple input DC-DC power converter and (v) a three phase inverter-fed permanent magnet synchronous motor as a drive. In this system, It is used super capacitor banks and superconducting magnetic energy replaces from the battery system. The modeling and transient performance simulation is effective for reducing transient influence caused by sudden charge of effective load. The main purpose of power electronic converters is to convert the DC power output from the fuel cell and other to a suitable AC voltage, which can be connected to electric loads directly (PMSM). The fuel cell and other output is connected to the DC-DC converter, which regulates the DC link voltage.

• 에너지공학
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• 제24권3호
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• pp.27-33
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• 2015

Recently, global warming has been accelerated due to air pollution and air pollutants are coming from the exhaust of the ICE vehicles, which are gradually increasing in number globally. That is why all the countries in the world are striving to reduce pollutant emissions of automobiles by strengthening regulations on air pollution. To comply with the regulations, the auto industry came up with hybrid vehicles, which have features of both ICE vehicles and electric vehicles. Hybrid vehicles show improvements in emissions, fuel efficiency, as well as functions as electric vehicles. This study aims to show possible troubles that occur at times of damages in high-voltage systems, and to suggest responsive measures.

• 전기화학회지
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• 제15권1호
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• pp.1-11
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• 2012

최근 리튬이차전지는 높은 에너지 밀도와 고용량화되어 급속도로 발전하고 있다. 그 중에서도 친환경 수송 장치의 전기자동차가 주목 받고 있는데 이를 위해서는 리튬이차전지의 많은 성능개선이 요구된다. 현재 리튬이차전지는 '하이브리드 전기자동차 (Hybrid Electric Vehicle, HEV)'에 실제 적용되고 있으며 이를 위해서 높은 용량, 긴 수명, 그리고 안전성 확보가 반드시 필요하다. 하지만현재 리튬이차전지에서 리튬이온의 이동을 위해 사용하는 유기전해액의 과열 및 과충전 상태에서 폭발의 위험성을 가지고 있기에 높은 안전성을 가진 고체전해질로의 대체가 시급하다. 따라서 본 연구에서는 리튬이차전지의 안정성 및 성능 개선을 위한 고체전해질의 연구 동향과 출원된 특허 및 논문에 대하여 논의하고자 한다.

• 한국자동차공학회논문집
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• 제22권3호
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• pp.60-67
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• 2014

The battery cells in lithium-ion battery pack assembled with high-capacity and high-power pouch cells, are commonly cooled with thin aluminum cooling plates in contact with the cells. For HEV/EV lithium-ion battery systems assembled with high-capacity, high-power pouch cells, the cells are commonly cooled with thin aluminum cooling plates in contact with the cells. Thin aluminum cooling plates are cooled by cold plate with coolant flow paths. In this study, the effect of the battery cooling system design including aluminum cooling plate thickness and various position of cold plate on the cooling performance are investigated by using finite element methods (FEM). Optimal cooling plate and cold plate design are proposed for improving the uniformity in temperature distributions as well as lowering average temperature for the cells with large capacities based on the simulation results.

• Journal of Power Electronics
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• 제11권4호
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• pp.479-489
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• 2011

The bidirectional dc-dc converter, being the interface between Energy Storage Element (ESE) and DC bus, is an essential component of the power management system for vehicle applications including electric vehicle (EV), hybrid electric vehicle (HEV), and fuel cell vehicle (FCV). In this paper, a novel multiphase bidirectional dc-dc converter interfacing with battery to supply and absorb the electric energy in the FCV system was studied with the help of real time digital simulator (RTDS). The mathematical models of fuel cell, battery and dc-dc converter were derived. A power management strategy was developed and first simulated in RTDS. A Power Hardware-In-the-Loop (PHIL) simulation using RTDS is then presented. The main challenge of this PHIL is the requirement for a highly dynamic bidirectional Simulation-Stimulation (Sim-Stim) interface. This paper describes three different interface algorithms. The closed-loop stability of the resulting PHIL system is analyzed in terms of time delay and sampling rate. A prototype bidirectional Sim-Stim interface is designed to implement the PHIL simulation.

• Journal of Power Electronics
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• 제11권4호
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• pp.393-400
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• 2011

The main objective of this paper is to control the speed of Nonlinear Hybrid Electric Vehicle (HEV) by controlling the throttle position. Various control techniques such as well known Proportional-Integral-Derivative (PID) controller in conjunction with state feedback controller (SFC) such as Pole Placement Technique (PPT), Observer Based Controller (OBC) and Linear Quadratic Regulator (LQR) Controller are designed. Some Intelligent control techniques e.g. fuzzy logic PD, Fuzzy logic PI along with Adaptive Controller such as Self Organizing Controller (SOC) is also designed. The design objective in this research paper is to provide smooth throttle movement, zero steady-state speed error, and to maintain a Selected Vehicle (SV) speed. A comparative study is carried out in order to identify the superiority of optimal control technique so as to get improved fuel economy, reduced pollution, improved driving safety and reduced manufacturing costs.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.261-265
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• 2005

본 논문에서는 하이브리드 자동차용 보조전원 공급이 목적인 DC-DC Converter에 대하여 기술하였다. DC-DC Converter는 차량 내의 헤드램프, 오디오, 각종 ECU등 전기/전자 부하에 전력을 공급하며 또한 12V 보조 배터리를 충전하는데 사용된다. 고주파 동작 조건하에서 유기되는 전자파 노이즈와 스위칭 손실을 저감하기 위하여 컨버터 토폴로지로 위상천이 영전압 풀브리지 방식을 적용하였으며 제어기의 용이한 보상 및 안정된 시스템 응답 특성을 위하여 슬로프 보상이 포함된 전류 모드 제어방식을 사용하였다 정전압/정전류 충전 제어 방식은 전기부하에 안정적인 전원공급과 보조 배터리의 안정적인충전을 보장한다. 초기의 회로 파라메타 설정 및 하드웨어 디버깅을 위하여 시뮬레이션 툴로 PSIM 6.0을 사용하였으며. DC-DC Converter에서 스위칭 소자의 발열문제는 Thermo Tracer 장비를 사용하여 개선하였다.