정부에서는 수송부분에서 발생하는 온실가스 감축을 위해 친환경자동차 구매보조금 지급, 개별소비세 감면, 취득세 감면 등의 정책 을 시행함으로 친환경자동차 등록대수는 매년 증가하고 있는 추세이다. 충전 수요에 따른 전기차 충전소 구축을 진행하고 있으나 충 전소 구축이 충전수요 대비 부족하여 충전관련 민원과 이용자들의 불편이 발생하고 있는 실정이다. 하지만 충전소 설치 시 소모되는 재화, 부지 등의 비용을 지속적으로 투입하기에는 한계가 있어 최대효과를 발생시키는 지역에 충전소를 설치하는 방법과 기존 충전소 를 효과적으로 이용하는 방안에 대한 중요성이 대두되고 있다. 따라서 본 연구에서는 급속충전소가 설치 되지 않았다는 가정하에 전 기차 급속충전소 최적입지를 도출하여 실제 충전소 입지와 최적입지를 비교하여 입지적정성을 분석하고, 최적입지에 입지한 충전소와 입지하지 않은 충전소의 충전량을 비교하여 도출된 최적입지의 충전효율성을 검증하고자 한다. 급속충전소 최적입지 선정에는 교통량 을 이용하였으며, 교통량을 “QGIS 생활 SOC 입지분석 툴킷”에 변수로 설정하여 급속충전소 접근성에 따른 최적입지를 1~10등급으로 나누어 도출하였다. 각 등급에 위치한 실제 충전소의 입지적정성을 평가하고 충전소별 충전량을 수집하여 비교하였다. 충전소 입지 등 급과 교통량간의 상관성을 확인하였다.

In this work, a series of BaTiO3-based ceramic materials, Ba(Al0.5Nb0.5)xTi1-xO3 (x = 0, 0.04, 0.06, 0.08), were synthesized using a standard solid-state reaction technique. X-ray diffraction profiles indicated that the Al+Nb co-doping into BaTiO3 does not change the crystal structure significantly with a doping concentration up to 8 %. The doping ions exist in Al3+ and Nb5+ chemical states, as revealed by X-ray photoelectron spectroscopy. The frequencydependent complex dielectric properties and electric modulus were studied in the temperature range of 100~380 K. A colossal dielectric permittivity (>1.5 × 104) and low dielectric loss (<0.01) were demonstrated at the optimal dopant concentration x = 0.04. The observed dielectric behavior of Ba(Al0.5Nb0.5)xTi1-xO3 ceramics can be attributed to the Universal Dielectric Response. The complex electric modulus spectra indicated the grains exhibited a significant decrease in capacitance and permittivity with increasing co-doping concentration. Our results provide insight into the roles of donor and acceptor co-doping on the properties of BaTiO3-based ceramics, which is important for dielectric and energy storage applications.

In this study, polyimide (PI)-based activated carbon fibers (ACFs) were prepared for application as electrode materials in electric double-layer capacitors by varying the steam activation time for the PI fiber prepared under identical cross-linking conditions. The surface morphology and microcrystal structural characteristics of the prepared PI-ACFs were observed by field-emission scanning electron microscopy and X-ray diffractometry, respectively. The textural properties (specific surface area, pore volume, and pore size distribution) of the ACFs were calculated using the Brunauer–Emmett–Teller, Barrett–Joyner–Halenda, and non-local density functional theory equations based on N2/ 77 K adsorption isotherm curve measurements. From the results, the specific surface area and total pore volume of PI-ACFs were determined to be 760–1550 m2/ g and 0.36–1.03 cm3/ g, respectively. It was confirmed that the specific surface area and total pore volume tended to continuously increase with the activation time. As for the electrochemical properties of PI-ACFs, the specific capacitance increased from 9.96 to 78.64 F/g owing to the developed specific surface area as the activation time increased.

This paper aims to study the modeling and controller of an electrically driven tractor optimized for energy efficiency under off-road conditions and when subjected to loads such as plowing. The dynamic model design is aimed at a 30kW electric tractor. The vehicle model consists of a 30kW motor, transmission, wheels, and a controller, designed using the commercial software Matlab/Simulink. In order to optimize energy efficiency under load conditions, this paper designs and implements a PID controller focusing on the vehicle's speed and wheel slip. The newly proposed electric tractor modeling and PID controller aim to demonstrate improved energy efficiency through simulation.

In this study, we developed a new electric low-height beds mechanism with a stable driven rack and pinion by analyzing the current state of existing beds development and supplementing shortcomings of the beds. Structural safety is evaluated through Finite-Element-Analysis using a simulation method applying existing elevate system types and a new type. Furthermore, we designed and manufactured a trial bed with increased variable height considering medical instrument standards to use both for home and hospital. The elevation mechanism suggested in this study could be valuable to electric beds development.

전기공사 분리발주 제도는 전기설비의 시공품질 향상과 전기공사업의 경쟁력 강화를 위하여 지난 1976년 도입된 이후 현재까지 운영되고 있다. 국민들의 실 생활과 산업 발전에 필수적인 전기를 효율적이고 안정적으로 사용하기 위해서 는 고품질의 전기설비를 구축하는 것이 요구된다. 제도 도입 이후 전기공사 분 리발주를 통해 당초의 취지에 맞게 시공 품질 향상과 중소기업의 경쟁력 강화 라는 성과를 내며 운영되고 있다. 하지만, 전기공사 분리발주 제도가 완전히 정착되었다고 평가할 수는 없는 상황이다. 국가, 지자체, 공공기관 등 공공발주 자는 전기공사업을 준수하여 분리발주를 지키고 있으나, 민간 영역에서는 아 직 분리발주 제도가 익숙하지 않고, 입찰과 발주 관련 전문성도 부족하여 분리 발주를 지키기 어려운 상황에 있다. 또한, 공공 영역에서도 기술제안 입찰과 민간투자사업 등이 분리발주 예외공사로 운영되고 있어 당초 분리발주 제도의 도입 취지에도 역행하고 있는 실정이다. 전세계적인 탄소중립 추진과 화석에 너지 저감 정책으로 친환경 에너지로 평가받고 있는 전기에너지의 수요는 폭 발적으로 증가할 것으로 예상되기 때문에 고품질의 전기설비를 생산할 수 있 도록 법과 제도의 정비가 반드시 요구된다. 이에 전기공사 분리발주 제도를 공 고히 하기 위해서는 분리발주 이행기반 구축, 인센티브 제공과 더불어 이를 위 반할 경우 처벌강화 등의 제도적 보완을 만들어 가야 할 것이다.

Earthquakes of magnitude 3.0 or greater occur in Korea about 10 times on average yearly, and the number of earthquakes occurring in Korea is increasing. As many earthquakes have recently occurred, interest in the safety of nuclear power plants has increased. Nuclear power plants are equipped with many cabinet-type control facilities to regulate safety facilities, and function maintenance is required during an earthquake. The seismic performance of the cabinet is divided into structural and functional performances. Structural performance can be secured during the design procedure. Functional performance depends on the vibration performance of the component. Therefore, it is necessary to confirm the seismic performance of the components. Generally, seismic performance is confirmed through seismic simulation tests. When checking seismic performance through seismic simulation tests, it is difficult to determine the effect of frequency and maximum acceleration on an element. In this paper, shaking table tests were performed using various frequencies and various maximum accelerations. The seismic performance characteristics of the functions of electrical equipment components were confirmed through tests.

PURPOSES : This study is conducted to evaluate the development of materials for extinguishing ESS(Energy Storage System) fires in electric vehicles using industrial byproducts. METHODS : Grout containing an appropriate amount of fly ash, silica fume, blast furnace slag powder, and ferronikel slag, which are industrial byproducts, was prepared. The fluidity, stress, and mechanical properties were evaluated in accordance with standard test methods. RESULTS : The fluidity of the materials used for the evolution of ESS fires differed depending on the material of the industrial byproducts. In the case of blast furnace slag, its fluidity is low owing to viscosity even when it content is high, and the use of ferronikelsrag is shown to be suitable for the evolution of ESS fires in fluidity and curing tests. CONCLUSIONS : Fire-extinguishing materials using industrial byproducts require a long curing time but exhibit the fluidity required for ESS fire extinguishment. In particular, the curing and fluidity of Peronikel slag and fly ash are suitable for ESS fire extinguishing.

This study attempted to experimentally confirm the change in damping force for a prototype self-leveling damper with a pump rod and a leveling port applied with a new spiral flow path for small and medium-sized electric SUVs. The faster the excitation speed of the piston rod, the higher the damping force during compression and rebound and it can be seen that the graph shape appears in a similar pattern. Based on this, it can be used as basic data for additional characteristic tests such as temperature, sliding resistance, and operating sound test, etc.

In compliance with environmental regulations at sea and the introduction of unmanned autonomous ships, electric propulsion ships are garnering significant attention. Induction machines used as propulsion electric motor (PEM) have maintenance advantages, but speed control is very complicated and difficult. One of the most commonly used techniques for speed control is DTC (direct torque control). DTC is simple in the reference frame transformation and the stator flux calculation. Meanwhile, two-level and three-level voltage source inverters (VSI) are predominantly used. The three-level VSI has more flexibility in voltage space vector selection compared to the two-level VSI. In this paper, speed is controlled using the DTC method based on the specifications of the PEM. The speed controller employs a PI controller with anti-windup functionality. In addition, the characteristics of the two-level VSI and three-level VSI are compared under identical conditions. It was confirmed through simulation that proper control of speed and torque has been achieved. In particular, the torque ripple was small and control was possible with a low DC voltage at low speed in the three-level VSI. The study confirmed that the application of DTC, using a three-level VSI, contributes to enhancing the system's response performance.

The curb weight of electric trucks is more than 10% higher than that of conventional internal combustion engine trucks due to the motor and battery. For this reason, cargo box developed for small electric trucks is required weight reduction, and cargo door that can reduce weight and maintain strength are being developed. In this paper, we designed the lightweight cargo door, confirmed the stability of the door through structural analysis, and developed a cargo box door that was more than 25% lighter by applying composite materials such as Sheet Molding Compound(SMC) and Fiber Reinforced Plastic(FRP).

The electrification of transportation is expected to greatly contribute to achieving the global climate change target. This study analyzed technological competitiveness in the fuel cell electric vehicle (FCEV) field based on patent family and citation index. Technology analysis was conducted by dividing FECV into six sub-technology areas based on IPC with fuel cell system, fuel cell technology, vehicle system, hydrogen storage and fueling, catalyst technology and etc. The largest number of patents are being filed in the fuel cell system technology field, and the fields with high growth rates over the past 10 years (2012-2022) were vehicle systems (12.4%) and hydrogen storage fuel field(11.5%). As of 2021, among global automakers, Toyota ranks the first in patent applications for FECV followed by Hyundai Motors in Korea, followed by Honda and Audi, with an average annual growth rate of 19.8%, the highest among competitors.

ZnO/Cu/ZnO (ZCZ) thin films were deposited at room temperature on a glass substrate using direct current (DC) and radio frequency (RF, 13.56 MHz) magnetron sputtering and then the effect of post-deposition electron irradiation on the structural, optical, electrical and transparent heater properties of the films were considered. ZCZ films that were electron beam irradiated at 500 eV showed an increase in the grain sizes of their ZnO(102) and (201) planes to 15.17 nm and 11.51 nm, respectively, from grain sizes of 13.50 nm and 10.60 nm observed in the as deposited films. In addition, the film’s optical and electrical properties also depended on the electron irradiation energies. The highest opto-electrical performance was observed in films electron irradiated at 500 eV. In a heat radiation test, when a bias voltage of 18 V was applied to the film that had been electron irradiated at 500 eV, its steady state temperature was about 90.5 °C. In a repetition test, it reached the steady state temperature within 60 s at all bias voltages.

전기자동차의 빠른 확산은 지구온난화와 자연재해 대응을 위해 국제적으로 중요한 과제이다. 대중화를 위해 “캐즘(Chasm) 극복”은 필수적이나, 선행연구들은 전기차 초기시장 분석이 대부분이며 캐즘 단계의 연구는 다소 제한적이다. 본 연구는 전기차 초기 단계를 벗어나는 국내시장에서 소비자의 전기차 구매 주요 저해 요인과, 이에 영향을 주는 소비자의 인구통계학적 특성 및 자동차 관련 경험을 설문과 통계 기법을 통해 심층 분석하였다. 연구 결과, 한국 전기차 시장은 캐즘 전 단계로 판단되며, 전기차의 “기술에 대한 낮은 신뢰성”, “경제성에 대한 의문”, “충전-운전 불편성”이 전기차의 주요 수용 저해 요인으로 확인되었다. 지역에 따른 고속/완속 충전 인프라의 적절한 구축, 교육과 홍보를 통한 전기차의 인식개선, 전기차 수용에 우호적인 얼리어답터(Early adopter)의 전기차 수용 촉진은 캐즘을 극복하는 과정에서 중요한 역할을 할 것으로 판단된다.