• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.730-734
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• 2007

National projects on renewable energy and new energy are driven more actively than ever in many countries for the exhaustion of fossil fuel energy from the turn of the century. Such activities began to spread out in railway industry with centering around west European countries. Electric energy is generated on the hybrid vehicle itself, which contributes to reduction of the cost for construction of the infrastructure required for the supply of electric power. Hybrid tram is mainly composed of propulsion system to control electric energy, automatic guidance system to control steering and operation, and central vehicle unit to control and monitor major electronic devices. Generation and supply of electric power are made by the combination of engine generator and battery, or fuel cell and super capacitor.

• 한국통신학회논문지
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• 제35권9B호
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• pp.1381-1389
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• 2010

동적인 전력 공급을 통해 에너지 효율을 높여줄 것으로 기대되는 스마트 그리드 기술은 최근 전기자동차 기술의 발달과 함께 차량의 배터리를 가정용 축전지로 활용하는 Vehicle-to-Grid(V2G) 기술에 대한 관심으로 이어지고 있다. 한편, 무선으로 전력을 공급해주는 비접촉 충전 방식은 직접 사용자가 전기 플러그를 콘센트에 꽂지 않고도 자기장 유도 기반으로 전력을 공급해줌으로써 사용자의 안전과 편의성을 보장해 줄 수 있다. 더욱이 이러한 무선 충전과 동시에 자기장을 활용한 통신 시스템이 구축되면 스마트 그리드의 동적 전력 공급의 영역을 이동하는 전기자동차까지 확장함으로써 보다 실용적인 V2G 기술을 제공할 수 있다. 본 논문에서는 이를 위한 자기장 통신 시스템을 제안한다. 자기장 통신 시스템은 데이터 통신 기능과 위치 인식 기능을 제공하며 비접촉식 충전인프라를 그대로 활용할 수 있는 장점이 있기 때문에 V2G 활용에 있어서 핵심적인 기술이라고 할 수 있다. 제안하는 시스템의 데이터 통신을 전력 공급 관련 정보를 패킷화하여 송수신하고, 위치 인식을 통해 차량과 충전인프라의 위치에 따른 충전 효율 및 통신 성능을 향상시킨다. 또한 테스트 베드를 개발하여 다양한 환경에서 성능 검증을 수행하였다.

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.665-673
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• 2017

This paper proposes a field weakening control method for operating an induction motor with a variable DC input voltage condition. In the variable DC voltage condition such as a battery, the field weakening method are required for the maximum output power. The conventional field weakening control methods can be used for operating the induction motor over the rated speed in a constant DC-link voltage condition. However, the conventional methods for operating the motor with the variable DC voltage is not suitable for the maximum output power. To overcome this problem, this paper proposes the optimized field weakening control method to extend the operating range of the induction motor with a rated power in a limited thermal and a wide DC input voltage conditions. The optimized d-axis and q-axis current equations are derived according to the field weakening region I and II to extend the operating region. The experimental results are presented to verify the effectiveness of the proposed method.

• 한국자동차공학회논문집
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• 제20권1호
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• pp.8-13
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• 2012

In this paper, Hybrid Electric Vehicle is directly designed and manufactured for base study of HEV's system and Green Car. Foundation design consists of power train design and the frame design. The power train concept includes motor, engine, generator and battery. And the concept of the frame is the single-seat of this self-made HEV. A frame installed in hybrid system contains suspension, steering wheel, seat, accelerating pedal, brake pedal, clutch handle and various chassis parts with bearings. Electromagnetic clutch is equipped to transmit engine power to drive axle. The control algorism make using LabVIEW to control of an engine and a motor depending on drive condition. A parallel type hybrid system is manufactured to control operation of a motor and an engine depending on vehicle speed.

• Journal of Power Electronics
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• 제11권4호
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• pp.430-438
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• 2011

This article proposes a robust nonlinear control based on Lyapunov's redesign, whose purpose is to deal with parametric uncertainty in the resistance of the motor windings. The robust controller design is based on the passivity properties of the motor, as well as energy shaping and damping injection. The application of this control technique is focused on electric vehicles mainly formed by a battery bank, a power inverter, an AC brushless motor and the mechanical transmission. The sine PWM technique is used to trigger the switching devices of inverter. The results were obtained from simulation, where is shown that robust control makes a proper tracking of electromagnetic torque.

• 산업기술연구
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• 제40권1호
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• pp.13-18
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• 2020

Lithium-ion batteries have a small volume, light weight and high energy density, maximizing the utilization of mobile devices. It is widely used for various purposes such as electric bicycles and scooters (e-Mobility), mass energy storage (ESS), and electric and hybrid vehicles. To date, lithium-ion batteries have grown to focus on increasing energy density and reducing production costs in line with the required capacity. However, the research and development level of lithium-ion batteries seems to have reached the limit in terms of energy density. In addition, the charging time is an important factor for using lithium-ion batteries. Therefore, it was urgent to develop a high-speed charger to shorten the charging time. In this thesis, a discharger was fabricated to evaluate the capacity and characteristics of Li-ion battery pack which can be used for e-mobility. To achieve this, a smart discharger is designed with a combination of active load, current sensor, and temperature sensor. To carry out this thesis, an active load switching using sensor control circuit, signal processing circuit, and FET was designed and manufactured as hardware with the characteristics of active discharger. And as software for controlling the hardware of the active discharger, a Raspberry Pi control device and a touch screen program were designed. The developed discharger is designed to change the 600W capacity battery in the form of active load.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 F
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• pp.2613-2615
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• 1999

In the paper, a new single phase uninterruptible power supply(UPS) scheme is proposed. A conventional UPS can supply power to the load continuously. However, it may generate input current harmonics and the input power factor is very poor. This paper proposes a phase control converter for single phase UPS. It mainly consists of a minimized structure of power converter which is capable of providing a specified constant output voltage, phase controlled battery charger. The proposed scheme is validated with a computer simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.2054-2056
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• 1998

A conventional UPS can supply the clean power to the load. However, it may generate input current harmonics and the input power factor can be very poor. Therefore, the UPS itself may be a power interruption. This paper provides multifunctional converter of using single phase UPS. The proposed UPS can supply the clean power to the load without polluting the mains power system. The multi-functional converter provides battery charging, var compensation and harmonic suppression simultaneously. It was simulated to verify this work.

• Smart Structures and Systems
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• 제4권4호
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• pp.493-515
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• 2008

Semi-active control systems have attracted a great deal of attention in recent years because these systems can operate on battery power alone, proving advantageous during seismic events when the main power source of the structure may likely fail. The behavior of semi-active devices is often highly non-linear and requires suitable and efficient control algorithm. This paper presents the comparative study and performance of variable semi-active friction dampers by using recently proposed predictive control law with direct output feedback. In this control law, the variable slip force of semi-active variable friction damper is kept slightly lower than the critical friction force, which allows the damper to remain in the slip state during an earthquake, resulting in improved energy dissipation capability. This control algorithm is able to produce a continuous and smooth slip forces for a variable friction damper. The numerical examples include a structure controlled with multiple variable semi-active friction dampers and with multiple passive friction dampers. A parameter, gain multiplier defined as the ratio of damper force to critical damper control force, is investigated under four different real earthquake ground motions, which plays an important role in the present control algorithm of the damper. The numerically evaluated optimum parametric value is considered for the analysis of the structure with dampers. The numerical results of the variable friction dampers show better performance over the passive dampers in reducing the seismic response of structures.

• 전기학회논문지
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• 제65권5호
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• pp.843-850
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• 2016

In this paper, we propose a digital controller design process for the interleaved type of a boost PFC (Power Factor Correction) converter which can disperse the heat of the switching devices due to the interleaved topology. We establish a mathematical model of a boost PFC converter and propose a controller design method based on the root locus. The performance of the designed controller is verified by simulations. The measurement of the input voltage, inductor currents, and the converter output link voltage are needed for the control of the converter system which consists of a power unit and a control unit where a high-performance 32-bit microcontroller is used. The adjustment of A/D conversion timing is also needed to avoid high frequency noise generated when the switches on/off. It is illustrated by the real experiments that the designed control system with the properly adjusted ADC timing satisfies the given performance specifications of the interleaved boost PFC converter in the on-board slow battery charger.