• 인터넷정보학회논문지
• /
• 제24권1호
• /
• pp.87-97
• /
• 2023

충전기 인프라 시설은 일정한 전력 공급량을 기반으로 설계 및 설치되어 있다. 초기 설계된 충전 시설은 급속히 성장하는 전기 차량의 충전을 한정된 공급 전력량 기반으로 지원한다. 또한, 현재 상용차량은 완전 충전만 가능하며, 급속 균등 충전 방식으로 지원된다. 하지만 상용차량은 정해진 스케줄에 따라 운영되기에 탄력적인 충전이 필수적이다. 본 논문에서는 전기 차량의 급속한 성장 및 증가에 따라 동일 전력량을 기반으로 상용 버스의 고정 스케줄 기반 충전 스케쥴링 및 전력 분배 기법을 활용하여 20%이상 효율 향상된 전력 운영방안을 제시한다.

• International journal of advanced smart convergence
• /
• 제11권1호
• /
• pp.94-100
• /
• 2022

It is common for commercial vehicles to make the top part according to the use after making the bear chassis, and to connect various devices with the bear chassis. Various brackets used in bear chassis for the development of all automobiles, including commercial vehicles, play a role of connecting the components required for driving and operating the car to the car body. In commercial vehicles, components necessary for operation are installed in the bear chassis; that is, the bear chassis of commercial vehicles is a space where the devices required for driving and operating the vehicle are installed. The devices required for the configuration of the vehicle are drive, brake, exhaust and steering, etc. These devices are basically connected to the body, the front axis, or the rear axis. The part interlinking the apparatuses required for the vehicle drive to the car body or axis is bracket. In this study, we analyzed the boundary conditions to evaluate the stability of the three brackets that connect the components of the car to the front axis of the new type of 30-seater bus in the development process. In order to analyze the boundary conditions, the boundary conditions according to the driving condition of the vehicle were classified. For stress analysis to evaluate the stability of brackets according to the driving state of the vehicle, it is reasonable to give the bracket a boundary condition of harsh conditions.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1996년도 하계학술대회 논문집 A
• /
• pp.426-430
• /
• 1996

A new generator excitation system using a boost-buck chopper as a kind of static exciters is proposed to overcome the lack of field forcing capability of the bus fed exciter under the Input line fault condition. It increases or maintains the generator field current by boosting the field voltage in the case of the input AC line voltage drop during and immediately after a fault. The validity of the proposed excitation system is verified with the computer simulation. The generator stability according to the each difference exciter is tested using a commercial software package-CYME. The simulation results of the stability analysis on the generator with the proposed exciter is better than that of the bus fed exciter. This boost-buck chopper exciter can be simply implemented and controlled by the modem power electronics technology.

• 한국자동차공학회논문집
• /
• 제13권2호
• /
• pp.10-15
• /
• 2005

This study was initiated to evaluate the cooling performance of CAC (charged air cooler) and radiator in the engine room of a mini bus. So we had firstly to predict the mass flow rate coming from radiator grille and front bum per opening using computational fluid dynamics (CFD) simulation based on 3D configuration. And simulations were carried out for different cooling module layout and bum per opening hole size on sam e vehicle operating condition. Simulation results show that CAC cooling performance at reverse protecting plate-applying model was much efficient than that of the bum per opening hole size-increasing model in IMTD point of view. Part of the CFD simulation results was com pared to with experimental data. It was confirm ed that the CFD approach using STAR-CD based on pursuing no-com promise solution could provide design engineers with useful design information in the early design stage of vehicle development.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 A
• /
• pp.396-398
• /
• 2003

This paper presents the scheme for load model based dispersed generation system (DGs) installation and operation in unbalanced distribution systems. Groups of each individual load model consist of residential, industrial, commercial, official and agricultural load. The main idea of solving fuzzy nonlinear goal programming is to transform the original objective function and constraints into the equivalent multiple objective functions with fuzzy sets to evaluate their imprecise nature for the criterion of power loss minimization, the number or total capacity of DGs and the bus voltage deviation, and then solve the problem using genetic algorithms. The method proposed was applied to IEEE 13 bus test systems to demonstrate its effectiveness.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 A
• /
• pp.569-571
• /
• 2003

As a definition of NERC, Available Transfer Capability(ATC) is a measure of the transfer capability remaining in the physical transmission network for the future commercial activity. To calculate ATC, accurate and defensible TTC, CBM and TRM should be calculated in advance. In this paper, we propose a method to quantify TRM using probabilistic load flow based on the method of moment. Generation output, bus voltages, loads, and line outages are considered as complex random variables (CRV) to take into account for uncertainties related to the transmission network conditions. Probability Density Function (PDF) of line flow at the most limiting line is used to quantify TRM with the desired probabilistic margin. Suggested method is compared with the results from conventional CPF method and verified using 24 bus MRTS, and the suggested method based on PLF shows efficiency and flexibility for the quantification of TRM compared with the conventional method.

• 전력전자학회논문지
• /
• 제1권1호
• /
• pp.47-55
• /
• 1996

A new generator excitation system using a boost-buck chopper as a kind of static exciters is proposed to overcome the lack of field forcing capability of the bus fed exciter under the input line fault condition. It increases or maintains the generator field current by boosting the field voltage in the case of the input AC line voltage drop during and immediately after a fault. The validity of the proposed excitation system is verified with the computer simulation. The generator stability according to the each difference exciter is tested using a commercial software package-CYME. The simulation results of the stability analysis on the generator with the proposed exciter is better than that of the bus fed exciter. This boost-buck chopper exciter can be simply implemented and controlled by the modern power electronics technology.

• 산업경영시스템학회지
• /
• 제42권4호
• /
• pp.23-30
• /
• 2019

Automobiles are largely divided into passenger cars with less than five passengers and commercial vehicles such as construction machines, trucks, mixers, special lorries, and large buses. Automobile maintenance companies are also divided into passenger cars and commercial vehicles. Because commercial vehicles are the livelihood vehicles of individual carriers engaged in cargo transportation, passenger transportation, and construction, fast and accurate maintenance is important. Access to the expressway is also important because the car is large and uses highways. In addition, the time required for troubleshooting is long, so sufficient space must be secured for parking the vehicle, and ease of entry and exit of the vehicle in the maintenance shop should be fully considered. For this reason, commercial vehicle maintenance companies have higher initial investment costs than car maintenance companies, and it is difficult to supply and maintain maintenance personnel. Therefore, it is necessary to carefully examine and analyze various related factors for successful commercial vehicle maintenance company selection. However, most existing commercial vehicle maintenance companies often choose their location based on the empirical judgment of the founder, the customs and the case, without a clear analysis. In this study, we show how to derive the location selection factors to be considered when establishing professional maintenance company for commercial vehicles and to select the optimal location by using AHP (Analytic Hierarchy Process) method.

• 한국항공운항학회지
• /
• 제15권1호
• /
• pp.61-67
• /
• 2007

The importance and cost of avionics system in the integration of an aircraft is continuously increasing. And we can expect enlarged software portion in the system integration for the more intelligent, reliable, and automated avionics system. Both military and commercial avionics community have moved toward commercial-off-the-shelf(COTS) equipment and open systems architecture not only to increase affordability but also to reduce acquisition cost, shorten development time and risk. The same concept is applied in developing avionics test system used for the avionics system integration test. In this paper, we present important topics in the development of avionics system including real-time operating system, interconnect data bus, software development methodology, software development process, and system integration test.

• 대한기계학회논문집A
• /
• 제33권3호
• /
• pp.231-236
• /
• 2009

Recently, The Hydroforming technology has recognized general technique in manufacture industry. Especially automotive industry, It has applied to increase strength, and decrease weight, cost and part number. The rigid axle suspension type is widely used for truck and bus in commercial vehicles due to simplicity. To develop the hydroforming rigid axle, it is necessary to estimate of the characteristics of front suspension from the design process. In this study, the characteristics estimation of the hydroforming rigid axle is preformed using Finite Element Analysis and apply to shape optimization.