• 한국약용작물학회:학술대회논문집
• /
• 2008.05a
• /
• pp.306-307
• /
• 2008

• 한국약용작물학회:학술대회논문집
• /
• 2008.05a
• /
• pp.69-70
• /
• 2008

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.48 no.3
• /
• pp.177-183
• /
• 1999

This paper presents how to evaluate the transformer damage caused by reclosing scheme at the distribution substation. We describe a quantitative relationship between the reclosing scheme and the number of fault current flowing through transformer wsing the probability of a reclosing success/failure. The transformer damage from reclosing scheme is presented using a weight function and a damage function. A weight function is associated with the number of reclosing attempts and the reclosing deadtime to consider cumulative stress caused by reclosing scheme. A damage function is associated with a transformer impact ratio and a transformer functional life. In the case study, the transformer damage is simulated for the probability of a reclosing success. And the evaluation of transformer damage using KEPCO's operation data is performed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.15 no.1
• /
• pp.112-117
• /
• 2001

This paper presents an intelligent reclosing scheme to reduce a damage of power equipments in power distribution systems. As the number of reclosing shot increases, an power supply reliability is improved, but an impact of electric facilities by fault currents is accumulated. The proposed scheme determines the number of reclosing shots and its intervals according to ilie magnitude of fault current. Therefore, this scherre reduces a harm of electric facilities and muntains the power supply reliability. Case studies is performd to verify the effectiveness of the proposed scheme using field operation data.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.51 no.1
• /
• pp.1-6
• /
• 2002

This paper proposes an advanced reclosing scheme to improve power quality in power distribution systems. When a fault occurs in distribution system, the proposed schema determines the number of reclosing shots and its intervals according to the magnitude of fault current. Thus, an advanced reclosing scheme takes account of the power quality problem in customer\`s and the damage in electric facilities. To verify the effectiveness of the proposed scheme, a numerical simulation that calculates various indices to consider the reliability and the other effects on electric facility, in carried out with actual field data.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11a
• /
• pp.382-385
• /
• 2001

In the previous study, a new LTCC material in the PbWO$_4$-TiO$_2$-B$_2$O$_3$-CuO system was introduced. The developed material can be sintered at 850$^{\circ}C$ and its dielectric properties are $\varepsilon$$\sub$r/=20-25, Qxf$\sub$o/=30000∼500000Hz, and $\tau$$\sub$f/=0.2∼30ppm/$^{\circ}C$, respectively Therefore this material can be used as a LTCC substrate material for fabrication of multilayered high frequency communication module set. In present study, using this material, tape casting condition was established. With this condition, a multilayered resonator was fabricated and its electrical properties were examined. In present study, an antenna-duplexer module was also fabricated. Frequency characteristics of as-fabricated antenna-duplexer module was compared with simulation results.

• Proceedings of the KIEE Conference
• /
• 1996.07b
• /
• pp.740-742
• /
• 1996

This paper analyzes the Impact of customer system at the transients due to auto-reclosing on 22.9kV distribution lines. The various factors affecting this phenomena are analyzed In detail through parametric studies. These factors Include the fault current, fault location, reclosing angle, capacitor bank size, and customer load characteristics. The impacts of these transients on customer system are described and available to identify the optimal auto-reclosing scheme.

• Proceedings of the KIEE Conference
• /
• 1996.07b
• /
• pp.856-858
• /
• 1996

This paper describes a simulation model to analyze the interconnection operation of battery energy storage system(BESS) and utility system. The computer model used to these analysis composed by using PSCAD/EMTDC. The impacts experienced at load side are studied when occur faults in utility system, and also harmonics analysis are implemented. Results of these study are available to design the harmonic filter.

• Proceedings of the KIEE Conference
• /
• 1993.07a
• /
• pp.112-114
• /
• 1993

This paper presents a partitioning technique for equivalent models to large scale power system. The proposed partitioning technique is utilized by using a heuristic approach based on distributed array processor and the coherent groupings of generator buses. In this paper the reduced Ward-PV method considering the characteristics of buses is used to equivalent models of external system. The technique is demonstrated on New England system with 39 buses, 46 lines and 10 generators.

• Proceedings of the KIEE Conference
• /
• 1993.07a
• /
• pp.70-72
• /
• 1993

This paper presents an expert system that sheds loads considering priority in the localized SCADA power systems during an emergency states. The proposed algorithm uses neural networks to detect local load shedding location and heuristic rules to determine load shedding amounts. The proposed expert system is demonatrated at one of the model system which incorporates two localized SCADA power system. It is operated under workstation.