• Journal of IKEEE
• /
• v.11 no.4
• /
• pp.315-321
• /
• 2007

The fast charging photoflash capacitor charger with wide range current limiter is presented. By using proposed control logic block and wide range current limiter, the photoflash capacitor charger can reduce charging time and control life of battery for user convenience. The proposed photoflash capacitor charger has 3s charging time at 3.3V battery voltage, 1.2A current limit condition. It is well-suited for portable device application like digital camera, digital video camera, and mobile phone with camera.

• Proceedings of the KIPE Conference
• /
• 2012.07a
• /
• pp.279-280
• /
• 2012

In this paper, as a part of studying the fast battery charger, designed the charging system by applying dual converter. This dual converter was applied to the charging system for reducing time by dividing high current which prevents the damage of parts from heating of components. In this paper continued the task by switching the topology of the dual converter for fast charging battery into SISO, PISO, and PIPO. The study to derive the optimized system topology by analyzing the efficiency of charging system.

• Journal of the Korean Electrochemical Society
• /
• v.25 no.3
• /
• pp.119-124
• /
• 2022

Because high power with large size cell is used for the battery pack of hybrid electric vehicles and electric vehicles (HEV and EV), average temperature in a battery cell is the important criteria of the thermal management of the battery pack. Furthermore, fast charging technology is required to reduce battery charging time. Since battery pack performance and lifespan are deteriorated due to the heat of cells and electronic components caused by fast charging, an effective cooling system is required to reduce performance deterioration. In this study, a cooling system and module design applied to a pouch-type for fast charging battery cell are investigated, and the cooling performance that can maximize the efficiency of the battery was analyzed. The result shows that the vapor chamber cooling system has better cooling performance, the temperature drop in the module was 5.82 ℃ compared with aluminum cooling plates.

• Journal of Korean Society of Transportation
• /
• v.35 no.3
• /
• pp.210-219
• /
• 2017

Electric vehicles, which are attracting attention as eco-friendly vehicles, have been increasing in number since 2011 in Korea. The purpose of this study is to analyze the efficient operation of existing charging stations and factors to consider when installing additional charging stations based on the case of Jeju Island where the electric vehicle penetration rate is high and the charging infrastructure is relatively well established. The characteristics of using electric car charging stations by region, type of facility, and time of day are analyzed. As a result of analyzing the frequency of using the charger installed in Jeju Island, the utilization of both the fast charger and the slow charger is found to be concentrated in a specific area. The usage rate of charger installed in a business facility and a public parking lot is high in both fast charger and slow charger. However, according to the usage rate by time of day, the fast charger has a high utilization rate throughout the afternoon, while the use of a slow charger is concentrated in the morning. In order to enable users to utilize the electric vehicle charging station efficiently, it is necessary to provide a publicity guide for the charging station having a low utilization rate, a notice for using the charger, and a notification of completion of charging. Considering the charging demand, the area where the charger is not yet installed should be considered as the area to install the charger, and in addition, the additional installation should be considered in the area and the facility where the amount of charge is large. Service improvement is expected to be possible by utilizing actual electric vehicle charging behavior analysis result.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.50 no.2
• /
• pp.72-78
• /
• 2001

A compact size high voltage pulse generator with nanosecond rise time has been designed and investigated experimentally. The inductance of a pulse generator can be reduced by fixing the Marx generator and pulse forming network components into a single cylindrical unit. As a result, nanosecond rise time about $8{\sim}10[ns]$ and pulse width of several hundred [ns] can be obtained from a modified Marx pulse generator. And parametric studies showed that the rise time of the output pulse was depended little on the change of the load resistance and the charging capacitance while, the pulse width of the output pulse was depended greatly upon the change of the load resistance and the charging capacitance. The theoretical showed the possibility to design the laboratory-size pulse generator very fast rising time and a proper pulse width by minimizing stray inductance and varying resistance and capacitance.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.2
• /
• pp.244-251
• /
• 2013

This paper presents a study the change of the load profile on the power system by the charging impact of electric vehicles (EVs) in 2020. The impact of charging EVs on the load demand is determined not only by the number of EVs in usage pattern, but also by the number of EVs being charged at once. The charging load is determined on an hourly basis using the number of the EVs based on different scenarios considering battery size, model, the use of vehicles, charging at home or work, and the method of charging, which is either fast or slow. Focusing on the impact of future load profile in Korea with EVs reaching up 10 and 20 percentage, increased power demand by EVs charging is analyzed. Also, this paper analyzes the impact of a time-of-use (TOU) tariff system on the charging of EVs in Korea. The results demonstrate how the penetration of EVs increases the load profile and decreases charging demand by TOU tariff system on the future power system.

• Proceedings of the IEEK Conference
• /
• 2000.07a
• /
• pp.187-190
• /
• 2000

In this paper, we proposed a PLL with the clock count type frequency detector, in which the very fast pull-in time can be realized by resetting the VCO at the rising of input signal after charging the capacitor of loop filter with the voltage corresponding to the frequency of the input signal.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.1396_1397
• /
• 2009

Recently, there has been considerable interest in electromagnetic pulse (EMP) source for no lethal directed energy weaponry applications. The compactness of the Marx generator, coupled with its ability to be powered by battery technology, makes it a viable handled impulse source. The marx generator has 2 stages. Each stage was constructed one charging capacitor, two electrodes and one charging resistor. A inductance structure is used in order to improve the switching performances fo the whole generator. The experiments of rise time in pure gas and mixtures of gases were described. The experimental results show that the rise time characteristics of the marx generator can be controlled through varying insulation gas.

• Proceedings of the KIEE Conference
• /
• 2000.07c
• /
• pp.2089-2091
• /
• 2000

Pulsed power systems consist of a capacitor bank, an isolated high-voltage charging power-supply, high-current bus-work for charging and discharging and a control system. In such pulsed power systems, the operating-lifetime of the capacitors is closely dependent on the voltage reversal. Hence, most capacitor-discharging systems includes crowbar circuits. The crowbar circuit prevents the capacitor recharging with reverse voltage. Usually it consists of crowbar resistors and high pulse-current diode-stacks connected in series. The requirements for the diode-stacks are fast-recovery time and high-voltage and large-current ratings, which results in the high cost of the pulsed-power system. This paper presents a protection scheme of a charging and discharging system of a 500kJ capacitor bank using a low-cost crowbar circuit and safety-fuses.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.28 no.5
• /
• pp.122-133
• /
• 2014

This paper deals with the rapid charger which is the mid-type between the slow and fast chargers in the aspect of charging time. In its functions, it can perform the Active Power Filter(APF) function without changing the topology besides the charging function. In addition, to perform the charging and APF function, this paper proposes the mode selection algorithm. The operation of the charger that has APF function and the mode selection algorithm are verified by the simulation and experiment.