• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.301-302
• /
• 2007

Energy harvesting from the vibration through the piezoelectric effect has been studied for powering the wireless sensor node. For the driving wireless sensor node, the generated energy is required to store the capacitor or battery. For the rapid charging, higher voltage than battery's capacity voltage and a large current are necessitated. However, the piezoelectric energy harvester is generally featured as a high voltage and low current generator. As it is known that the generated current in the piezoelectric energy harvester is related to an area of electrode of piezoelectric ceramics, we fabricated the multilayer ceramics to increase effective area for the faster charging. The energy harvesting properties and charging characteristics of multilyaer ceramics were investigated and discussed.

• Korean Journal of Materials Research
• /
• v.31 no.2
• /
• pp.84-91
• /
• 2021

To cope with automobile exhaust gas regulations, ISG and charging control systems are applied to HEV vehicles for the purpose of improving fuel economy. These systems require quick charge-discharge performance of high current. Therefore, a Module of the AGM battery with high energy density and EDLC(Electric Double Layer Capacitor) with high power density are constructed to study the charging and discharging behavior. In CCA, which evaluates the starting performance at -18 ℃ & 30 ℃ with high current, EDLC contributed for about 8 sec at the beginning. At 0 ℃ CA (Charge Acceptance), the initial Charging current of the AGM/EDLC Module, is twice that of the AGM lead acid battery. To play the role of EDLC during high-current rapid charging and discharging, the condition of the AGM lead-acid battery is optimally maintained. As a result of a Standard of Battery Association of Japan (SBA) S0101 test, the service life of the Module of the AGM Lead Acid Battery/EDLC is found to improve by 2 times compared to that of the AGM Lead Acid Battery.

• Journal of Advanced Navigation Technology
• /
• v.18 no.4
• /
• pp.393-400
• /
• 2014

With developed countries, nationally the supply and development of electric vehicle(EV) has been going at a rapid pace. Now, the charger specifications, charging methods and standardization of communication protocols is going in each country and a lot of company are involved in the business about those. To popularize it as existing car, it is required to build the network and infrastructure which is proper for domestic environment. It should also need to be able to develop standardized protocols can be beyond the construction of the protocol of the upper stage server and charger, and is used in a residential environment actually applied to related industries. Therefore, in this paper, we propose a home network model of EV that raised the need for a study of the charging system for EV, using M2M technology and multi-charging system tailored to the residential environment of our country.

• Journal of Internet Computing and Services
• /
• v.20 no.2
• /
• pp.51-59
• /
• 2019

In this paper, we analyzed the relationship between charging operation system and electricity charges connected with charging infrastructure among data of many demonstration projects focused on electric vehicles recently. At this point in time, due to the rapid increase in demand for the electric charging infrastructure that will take place in the future, we can prepare for an upcoming era in the sense of forecasting the demand value. At the same time, demonstrating and modeling optimized system modeling centering on sites is a prerequisite. The modeling based on the existing small - scale simulation and the design of the operating system are based on the data linkage analysis. In this paper, we implemented a new optimized system modeling and introduced it as a standard format to analyze time - dependent time - divisional data for each vehicle and user in each point and node. In order to verify the efficiency of the optimization based on the data linkage analysis for the actual implemented electric car charging infrastructure and operation system.

• Journal of Advanced Marine Engineering and Technology
• /
• v.32 no.7
• /
• pp.1019-1029
• /
• 2008

In this study, visual investigation of sprays and flames has been performed and soot formation in Diesel and GTL fuels has been compared in a specially designed Rapid Charging Combustion Vessel (RCCV) under various ambient gas $O_2$ concentrations and two injection pressures. It has been concluded that soot in the mixing-controlled combustion of Diesel and GTL fuels has similar tendency to be formed in the leading portion of the jet boundaries. Auto-ignition delay for GTL fuel is shorter than that for diesel fuel. The temporal and special variation of soot concentration in the diesel flame jets at various $O_2$ concentrations was correlated with the heat release rate. Soot concentration appears in the regions when diffusion combustion starts, and its concentration reaches maximum at the peak of heat release curve and then decreases due to oxidation. Visualization by shadowgraph method showed that soot decreases with lower $O_2$ concentration, and higher injection pressure.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.1025_1026
• /
• 2009

This paper introduces the test a rapid pulsed power charging system for pulsed power application. The charger is designed based on three-phase series resonant inverter followed by air cooled step-up transformers. It has many advantages of lower weight, small size and high efficiency compared with large bulky traditional pulse power charging system. To apply 150kJ pulsed power system, detail test was carried out at various condition and its results shows 90% efficiency at full load condition. And additional experiments such as short, open, and self discharging during charging status are performed to verify reliable operation at abnormal condition and it was confirmed that developed capacitor charger showed very reliable operation all over the tests.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.66 no.11
• /
• pp.1575-1583
• /
• 2017

With the development of DC distribution, DC circuit breaker is required to ensure the stability of the DC grid. Unlike a mechanical circuit breaker that blocks after several tens of milliseconds, a DC SSCB(Solid-State Circuit Breaker) can break the fault well within 1 [ms], so it can prevent the damage of accident. However, the previous DC SSCB requires a lot of switching elements for charging commutation capacitors, and the control is complicated. Therefore, this paper proposes a new DC SSCB suitable for DC grid. The proposed DC SSCB is simple to control for charging commutation capacitors, and it can perform the rapid breaking and operating duty of reclosing and rebreaking. The proposed DC SSCB was designed to 380 [V] and 5 [kW] class which is suitable for residential DC distribution, and the operating characteristics of the proposed DC SSCB were verified by simulations and experiments. It is anticipated that the proposed DC SSCB may be utilized to design and realize DC grid system.

• Korean Journal of Microbiology
• /
• v.24 no.2
• /
• pp.79-85
• /
• 1986

We have determined the sequence of $tRNA^{Arg}$ of A. nidulans partially by enzymatic rapid RNA sequencing technique. The sequence was 5'GGCCGGCUGGCCCAAXUGGCAAGGXUCUGAXUACGAAXCAGGAGAUUGCACXXXXXGAGCXXUXXGUCGGUCACCA3' The cloverleaf structure was made from above data. As a result, the anticodon sequence was identified as ACG. This result was confirmed with charging test. The complete sequence was proposed by supplementing the DNA sequence to and by assigning the position of minor bases to this RNA sequence.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.1499-1505
• /
• 2003

Rapid development of electronic technology requires small size, high density packaging and high power of electronic devices. So, in this paper, characteristics on oscillating heat pipe according to operating conditions(environment temperature, charging ratio of working fluid, inclination) based on experimental study was investigated. From the experimental results, $25^{\circ}C$environment temperature), R-141b(working fluid)40%(charging ratio) was best performace at others of inclination angle and The top heating mode of OCHP performed 80% efficiency of the bottom heating mode.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.988-989
• /
• 2008

This paper describes a rapid pulsed power charging system for pulsed power application. It is capable of charging 35kJ/s energy up to 0.47uF 25kV within 3ms and maximum pulse repetition rate of 300 pps can be achieved. The charger is designed based on three-phase series resonant inverter followed by air cooled set-up transformers thus it has many advantages of lower weight, small size and high efficiency compared with large bulky traditional pulse charger system. Detail design procedure of resonant inverter and high voltage transformers is explained. Experimental results carried out at different condition and its results shows 90% efficiency at full load condition.