• Journal of Power Electronics
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• 제16권1호
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• pp.268-276
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• 2016

A hybrid sinusoidal-pulse current (HSPC) charging method for the Li-ion batteries in electric vehicle applications is proposed in this paper. The HSPC charging method is based on the Li-ion battery ac-impedance spectrum analysis, while taking into account the high power requirement and system integration. The proposed HSPC method overcomes the power limitation in the sinusoidal ripple current (SRC) charging method. The charger shares the power devices in the motor inverter for hardware cost saving. Phase shifting in multiple pulse currents is employed to generate a high frequency multilevel charging current. Simulation and experimental results show that the proposed HSPC method improves the charger efficiency related to the hardware and the battery energy transfer efficiency.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.1-2
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• 2015

In this paper, a 2-phase feeder system for wireless vehicle charging is investigated, which generates moving magnetic field with nearly constant magnitude using 2-phase currents. A moving field is very useful to magnetizing pickups mounted on underneath of electric vehicles.

• 한국정보통신학회논문지
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• 제16권3호
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• pp.541-548
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• 2012

본 논문에서는 전기자동차의 보급 확대에 따른 충전 인프라 구축을 위해서 차량의 충전 시 충전상태를 모니터링 할 수 있는 충전 모니터링 시스템의 설계 방법을 제안하였다. 급속충전 기술은 현재 battery의 성능 및 안전성 등 다양한 요인에 따라 동작성능이 좌우되므로 모니터링 시스템에 의한 충전상태 파악은 충전 알고리즘의 개선, 전기자동차 BMS와 연동, 사용자와의 충전 프로세스 제어 등 다양한 작업환경과 연계되어 있다. 급속충전시스템의 동작상태를 CAN 프로토콜을 이용하여 배터리의 충전 상태 등을 실시간으로 감시가 가능한 시스템을 설계 제작하여 전기자동차용 battery를 최단시간에 최적화된 상태로 충전 가능하도록 CAN 통신기반 급속충전 모니터링 시스템을 설계하는 방법을 제안하고 시스템을 구현하여 성능을 확인하였다.

• 한국정밀공학회지
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• 제33권12호
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• pp.1015-1020
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• 2016

An advantage of electric vehicles is that they are environmentally sustainable because they do not emit exhaust gases, such as $CO_2$ or Nox. A disadvantage is the low power performance of the motor and battery source, necessitating a reduction in the weight of the vehicle to increase efficiency. Another disadvantage is that the rechargeable battery enables an electric vehicle to only run for a limited number of miles before requiring electric charging. To solve these problems, the hybrid vehicle has been developed by combining environmental sustainability with the high performance of a conventional internal combustion engine. In this study, an electric UTV (Utility Terrain Vehicle) was transformed into a hybrid vehicle system by outfitting the vehicle with a drive auxiliary power system including a 125 cc internal combustion engine. This modification enabled us to extend the range of the hybrid UTV from 50km to 100km per one electric charging.

• 산업경영시스템학회지
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• 제44권2호
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• pp.1-14
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• 2021

It is highly challenging to measure the efficiency of electric vehicle charging stations (EVCSs) because factors affecting operational characteristics of EVCSs are time-varying in practice. For the efficiency measurement, environmental factors around the EVCSs can be considered because such factors affect charging behaviors of electric vehicle drivers, resulting in variations of accessibility and attractiveness for the EVCSs. Considering dynamics of the factors, this paper examines the technical efficiency of 622 electric vehicle charging stations in Seoul using data envelopment analysis (DEA). The DEA is formulated as a multi-period output-oriented constant return to scale model. Five inputs including floating population, number of nearby EVCSs, average distance of nearby EVCSs, traffic volume and traffic congestion are considered and the charging frequency of EVCSs is used as the output. The result of efficiency measurement shows that not many EVCSs has most of charging demand at certain periods of time, while the others are facing with anemic charging demand. Tobit regression analyses show that the traffic congestion negatively affects the efficiency of EVCSs, while the traffic volume and the number of nearby EVCSs are positive factors improving the efficiency around EVCSs. We draw some notable characteristics of efficient EVCSs by comparing means of the inputs related to the groups classified by K-means clustering algorithm. This analysis presents that efficient EVCSs can be generally characterized with the high number of nearby EVCSs and low level of the traffic congestion.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.68-70
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• 2021

제주지역에 설치된 풍력발전기는 이미 제주지역의 공급량을 초과하여, 버려지고 있는 실정이다. 이에 정부는 기술개발 사업을 통해 2MWh급 ESS(energy storage system)를 설치하여 버려지는 전력을 충전하고, 전기자동차 충전스테이션에 활용하는 연구를 진행하고 있다. 본 논문에서는 2MWh급의 ESS를 안정적으로 설치하기 위해, Matlab Simulink를 이용하여 전기자동차 충전 모델과 ESS방전 모델을 모델링하고 시뮬레이션 하였다. 시뮬레이션을 통해, 2MWh급 ESS가 다양한 시나리오에서 안정적으로 동작하는 것을 검증하였다.

• 전기학회논문지
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• 제60권3호
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• pp.566-571
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• 2011

As Plug-in Hybrid Vehicle and Electric Vehicle (PHEV/EV) take a greater share in the personal automobile market, their high penetration levels may bring potential challenges to electric utility especially at the distribution level. Thus, there is a need for the flexible charging management strategy to compromise the benefits of both PHEV/EV owners and power grid side. There are many different management methods that depend on the objective function and the constraints caused by the system. In this paper, the schema and dispatching schedule of centralized PHEV/EV charging spot network are analyzed. Also, we proposed and compared three power allocation strategies for centralized charging spot. The first strategy aims to maximize state of vehicles at plug-out time, the rest methods are equalized allocation and prioritized allocation based on vehicles SoC. The simulation results show that each run of the optimized algorithms can produce the satisfactory solutions to response properly the requirement from PHEV/EV customers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 B
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• pp.570-572
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• 1999

An equivalent circuit model of vehicle charging-discharging system for simulation is developed. The vehicle electric power system consists of alternator and battery. The alternator must have adequate capacity for providing electric energy to all loads, and the battery supports the alternator by offering insufficient energy when the alternator output energy is not enough. The alternator model is simplified for the use of characteristic curve, which was provided by its manufacturer, and the battery model is separated in charging mode and discharging mode because of its complex characteristics. Developed circuit model is validated by comparing the simulation data and real experimental data.

• 한국산업융합학회 논문집
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• 제26권6_1호
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• pp.985-991
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• 2023

This study proposes a solution to the voltage drop in electric vehicle chargers, due to the parasitic resistance and inductance of power cables when the chargers are separated by large distances. A method using multi-level electric vehicle chargers that can output power in stages, without installing an additional energy supply source such as a reactive power compensator or an energy storage system, is proposed. The voltage drop over the power cables, to optimize the charging scheduling, is derived. The obtained voltage drop equation is used to formulate the constraints of the optimization process. To validate the effectiveness of the obtained results, an optimal charging scheduling is performed for each period in a case study based on the assumed charging demands of three connected chargers. From the calculations, the proposed method was found to generate an annual profit of $20,800 for a $12,500 increase in installation costs.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 전력전자학술대회
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• pp.64-65
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• 2017

This paper review the core technical trends of TESAL EV(Electric Vehicle) Motors. The object of this study analyzes electric vehicle's body appearance, motor cooling system, battery arrangement, battery management system (BMS), and super charging station etc.