• Proceedings of the KIEE Conference
• /
• 1987.07a
• /
• pp.685-687
• /
• 1987

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2011.06a
• /
• pp.193-193
• /
• 2011

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.1469-1470
• /
• 2015

Recently induction generator has been applied to many small hydro power plants. Induction generator needs a reactive power for magnetization. The reactive power of induction generator is being supplied from the supply side mostly. The use of induction generators in the power distribution grid can affect the power factor. The power factor of induction generator is fixed already during production. The power factor in the distribution system is due to the increase or decrease of the load rather than due to the induction generator. In this study, we analyzed how the power factor is changed according to the load increase or decrease in the distribution lines.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.22 no.2
• /
• pp.51-56
• /
• 2008

High quality power supplying of high voltage distribution lines electric railway system is the important function, high voltage distribution system is complicated witch is compose with distribution line, circuit break, protection facilities and so on. Among this components, role of substation is most important for elevation of reliability in electric power system. Therefore, the enhanced reliability considering the preventive inspection, repair work replacement is necessary. This paper proposes protection method in railway high voltage distribution lines. we model distribution system using PSCAD/EMTDC(Power System Computer Aided Design/Electro Magnetic Transients DC Analysis Program) and extract various fault data. In conclusion this methods can protection of ground fault.

• Proceedings of the KIEE Conference
• /
• 1993.07a
• /
• pp.476-478
• /
• 1993

Instead of installing new communication wiring to each house in the apartment house building. the power distribution network. which is already installed in the building. can be use as communication medium. In a safty management, by adoption of power line communication system, at remote we can monitor safty related sensors such as fire, gas leakage, burglar intrusion and emergency call which are located at each house. From this viewpoint, we developed security monitoring system for apartment house building using power lines. Security monitoring system consists of Power Line Communication-Sub Controller (PLC-SC). Power Line Communication-Main Controller (PLC-MC) and Management System (MS). Between a PLC-MC and a PLC-SC, the transmission rate is 1200 bps in power lines and modulation technique is frequency shirt keying (FSK). In between a PLC-MC and a MS, the transmission rate is 1200 bps in communication line (RS-485). As a result of this research. transmission loss is 0.1dB per meter of intrabuilding distribution network. Transmission can be reach in 250 meters. So it is enough to communicate for security monitoring system in apartment house building.

• Journal of Electrical Engineering and Technology
• /
• v.7 no.1
• /
• pp.23-33
• /
• 2012

The current paper deals with a new live-line insulator inspection tool system that will be used by the Korea Electric Power Corporation for its 154 kV power transmission lines in 2011. Unlike the existing contact type tools, the developed inspection tool automates parts of the insulator inspection process using a sensor and an actuator. The tool sustains its weight independently, not by a lineman. In addition, the inspection tool measures the insulation resistance of an insulator together with its distribution voltage, thus providing more information for analysis and diagnosis. Such characteristics improve the system's operation efficiency, measurement reliability, and usability. We confirmed its effectiveness through live-line field tests with actual power transmission lines.

• KIEE International Transactions on Power Engineering
• /
• v.5A no.4
• /
• pp.357-365
• /
• 2005

This research investigates the influences of distributed generations (DG), which are interconnected to the bus by the dedicated lines, on the overcurrent relays (OCR) of the neighboring distribution feeders and also proposes a novel method to reduce the negative effects on the feeder protection. Due to the grid connected DG, the entire short-circuit capacity of the distribution networks increases, which may raise the current of the distribution feeder during normal operations as well as fault conditions. In particular, during the switching period for loop operation, the current level of the distribution feeder can be larger than the pickup value for the fault of the feeder's OCR, thereby causing the OCR to perform a mal-operation. This paper proposes the adaptive setting algorithm for the OCR of the distribution feeders having the neighboring dedicated feeders for the DG to prevent the mal-operations of the OCR under normal conditions. The proposed method changes the pickup value of the OCR by adapting the power output of the DG monitored at the relaying point in the distribution network. We tested the proposed method with the actual distribution network model of the Hoenggye substation at the Korea Electric Power Co., which is composed of five feeders supplying the power to network loads and two dedicated feeders for the wind turbine generators. The simulation results demonstrate that the proposed adaptive protection method could enhance the conventional OCR of the distribution feeders with the neighboring dedicated lines for the DG.

• Proceedings of the KIEE Conference
• /
• 2003.07a
• /
• pp.500-502
• /
• 2003

This paper reviews calculating of induced voltage onto a communication line from 22.9kV-Y Distribution Lines. The coexistence of both power line and communication line in parallel generates the induction of significant longitudinal voltage in the weak current line. In order to evaluate a precise induced voltage, this paper indicated some problems about coefficient and numerical formula. It also presents some induced voltage production technology standard application.

• Proceedings of the KIEE Conference
• /
• 1997.07c
• /
• pp.800-802
• /
• 1997

After flashover occurs on the overhead distribution line by lighting strokes(direct or induced), the power frequency arc current continues. If lightning flashover occurs on the overhead lines using covered conductors, the power frequency art current with fixed path overheats the conductor, and arc fusion fault can be occurred. There are two categories protecting or reducing methods of arc fusion faults caused by lightning stokes. - Reducing lightning flashover rate : G/W, LA, etc. - Protection by AFPD(Arc Fusion Protection Device) : power follow current interruption. This paper presents lightning surge phenomena on overhead distribution lines and protecting performance of arc fusion Protection devices to the lightning strokes nearby overhead line.

• KIEE International Transactions on Power Engineering
• /
• v.5A no.1
• /
• pp.9-15
• /
• 2005

In the operation of distribution systems, DGs (Distributed Generations) are installed as an alternative to extension and the establishment of substations, transmission and distribution lines according to the increasing power demand. In the operation planning of DGs, determining optimal capacity and allocation achieves economical profitability and improves the reliability of power distribution systems. This paper proposes a determining method for the optimal number, size and allocation of DGs in order to minimize the operation costs of distribution systems. Capacity and allocation of DGs for economical operation planning duration are determined to minimize total cost composed with power buying cost, operation cost of DGs, loss cost and outage cost using the GA (Genetic Algorithm).