• Journal of Electrical Engineering and Technology
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• v.1 no.4
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• pp.520-527
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• 2006

The electrical discharge and operational characteristics of needle and wire-cylinder corona charger based on current measurements for positive and negative coronas were evaluated and compared. A semi-empirical method was used to determine the ion concentrations in the charging zone and at the outlet of both chargers. Results from experimental investigation revealed that magnitudes of the charging current from the wire-cylinder charger were approximately 3.5 and 2 times smaller than those from the needle charger for the positive and negative coronas, respectively. The ion number concentrations at the outlet for positive corona of both chargers were higher than fur negative corona at the same voltage. Flow and electric fields in the charging zone of both chargers were also analyzed via numerical computation. Strong electric field strength zone was identified and led to high charging and particle deposition. Effect of particle deposition on the evolution of discharge current was presented. It was shown that ions loss inside the wire-cylinder charger was higher than the needle charger The particle deposited on the corona electrodes and on the grounded cylinder caused a great reduction in charging efficiency of both chargers.

• Design & Manufacturing
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• v.16 no.2
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• pp.13-19
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• 2022

Recently, electric vehicles are gaining popularity among many domestic and foreign users due to their eco-friendly advantages of reducing fine dust and environmental greenhouse gases. As the demand and supply of electric vehicles increase, the demand for electric vehicle charging infrastructure is also growing together. Many users are experiencing inconvenience due to poor charging infrastructure, which makes them hesitant to buy electric vehicles. Research on the user experience of chargers in apartment complexes, a common residential type in Korea, is being conducted somewhat, but research on the design of electric vehicle charging devices in public places is insufficient. The purpose of this research is to identify user requirements and complaints based on the product design of the electric vehicle charger in public places and propose a new electric vehicle product design concept that meets the requirements. The research method understood the charging base and status of electric vehicles in public places through literature research and examined and analyzed the characteristics and problems of product design cases that improved the charging problem of electric vehicles recently released in the market. It is intended to identify and analyze the problems of the charging device product design through user interviews, a qualitative research method, and based on this, it is intended to propose a user-centered product design concept that improves major complaints.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.590-595
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• 2016

The US is pursuing a plan to raise the subsidies for electric vehicles by more than 30%. The number of electric vehicles in Europe is expected to be one million by 2020 and 2030 and there are plans to expand in the center of Germany to supply six million electric vehicles on the dissemination and development policies. The development of the electric vehicle is not simply a technical trend but there is the potential to improve the access to this technology and the possibility of changing the entire social system and long-term energy security. Domestic competition is also increasing the supply of electric vehicles, as new blue ocean markets are emerging. The current domestic On-board Charger (Home Charger) plans to be suspended from the 2015 government-sponsored installation, This paper on the IEC 61851-1 and IEC 61851-22 specifications analyzes the development of a midnight electricity charger as a low-cost algorithm, the decrease in price and the improved convenience of the On-board Charger for Bluetooth module with the ATmega128 existing charger system, and the UI configuration via the LCD Panel to a Smartphone app are proposed.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.143-153
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• 2014

This paper presents a novel application of LCC resonant converter for 60kW EV fast charger and describes development of the high efficiency 60kW EV fast charger. The proposed converter has the advantage of improving the system efficiency especially at the rated load condition because it can reduce the conduction loss by improving the resonance current shape as well as the switching loss by increasing lossless snubber capacitance. Additionally, the simple gate driver circuit suitable for proposed topology is designed. Distinctive features of the proposed converter were analyzed depending on the operation modes and detail design procedure of the 10kW EV fast charger converter module using proposed converter topology were described. The proposed converter and the gate driver were identified through PSpice simulation. The 60kW EV fast charger which generates output voltage ranges from 50V to 500V and maximum 150A of output currents using six parallel operated 10kW converter modules were designed and implemented. Using 60kW fast charger, the charging experiments for three types of high-capacity batteries were performed which have a different charging voltage and current. From the simulation and experimental results, it is verified that the proposed converter topology can be effectively used as main converter topology for EV fast charger.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.5
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• pp.373-380
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• 2016

In this paper, a 50-kW high-efficiency modular fast charger for both electric vehicle (EV) and neighborhood electric vehicle (NEV) is proposed. The proposed fast charger consists of five 10-kW modules to achieve fault tolerance, ease of thermal management, and reduce component stress. Three-level topologies for both AC-DC and DC-DC converters are employed to use 600V MOSFET, resulting in ease of component selection and increase in switching frequency. The proposed three-level DC-DC converter with coupled inductor and its hybrid switching method can reduce the circulating current under wide output voltage range. A 50-kW prototype of the proposed fast charger was developed and tested to verify the validity of the proposed concept. Experimental results show that the proposed fast charger achieves a rated efficiency of 95.2% and a THD of less than 3%.

• JOURNAL OF ELECTRICAL WORLD
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• s.406
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• pp.64-65
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• 2010

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.6
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• pp.511-521
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• 2014

This study proposes an electric vehicle (EV) smart panel board and its control method on the basis of charging scheduling. The proposed system consists of batteries, a three-phase battery charger, three single-phase inverters, transfer switches for electric power distribution, and a controller. The three-phase battery charger usually charges the batteries at midnight when electric rates are cheap and in light load. When the electric power consumption of the EV standard chargers connected to one phase of the power line is relatively large or when a blackout occurs, the electric power stored in the battery is supplied by discharging through the inverters to the EV standard chargers. As a result, the value of peak load and the charging electric power quantity supplied from a utility grid are reduced, and the current unbalance is improved. The usefulness of the proposed system is confirmed through simulations, experiments, and case studies.

• Proceedings of the KIPE Conference
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• 2018.11a
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• pp.42-44
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• 2018

An integrated charger is used for bi-directional power conversion between an electric vehicle and a power grid. The proposed integrated charger works in a way that motor windings are utilized as filter inductances for charging/discharging of batteries in addition to the original purpose of motor drives. After a mathematical model of the integrated charger based on an dual winding induction machine (DWIM) is discussed, a current control method is designed for grid connection. The effectiveness of the proposed method is examined with simulation results.

• Journal of Electrical Engineering and Technology
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• v.8 no.5
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• pp.1122-1130
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• 2013

This paper proposes a new design for quick battery charger systems for electric vehicles that consists of a three-phase inverter and a full-bridge converter which use the phase-shift method. The 3-phase inverter controls the input and DC-link voltage by use of a current controller and a voltage controller. The full-bridge converter transfers the DC-link voltage to a fixed output voltage. Designs for the output-side converter and controller for improved performance are proposed in this paper. Design schemes for the filter and controller of an input-side inverter are also presented. Furthermore, the paper proposes a compensation method for the offset current that is caused by switch failure and circuit problems. Simulations and experiments have been performed on a 50kW-battery charger system that is suitable for vehicles. The presented results verify the validity of the proposed method and the superiority of the system over conventional methods.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.6
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• pp.566-572
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• 2015

This study introduces an LCC resonant converter operating on a continuous conduction mode. The LCC resonant converter has the advantage of improving system efficiency, especially under the rated load condition, because it can reduce conduction loss by improving the resonance current shape and switching loss by increasing the lossless snubber capacitance. The proposed LCC resonant converter is applied to various applications, including a 60 kW EV fast charger, a 24 kJ/s high-voltage capacitor charger, and a 20 kV, 20 kW high-precision DC power supply. Experimental results prove that the proposed LCC resonant converter topology can be effectively used as a converter topology for these applications.