• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.4
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• pp.377-385
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• 2000

This paper presents the test and operation results of the domestic demonstration of the reactive power compensation device called STATCOM (STATic COMpensator). The object of the paper is to describe the reliability of the unit based on the extensive operation databases. The custom power is similar in nature to the concept of FACTS(Flexibel AC Transmission System). By controlling reactive power, the technology offers utilities the opportunity for increased efficiency and their capabilities will permit transmission planners make the best use of their existing transmission resources. STATCOM is a custom power device in a way and can be used in a similar way for the dynamic compensation of power transmission systems, providing reactive power compensation, voltage regulation and mitigation of voltage flicker. It is shown that the STATCOM has clear advantages in areas such as; providing reactive power compensation and improving power factor.

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.172-175
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• 1992

This paper proposes the methods to construct the tree-structured database and analyze the distribution system network. In order to cope with an extensive amount of data and the frequent breaker switching operations in distribution systems, the database for system configuration is constructed using binary trees. Once the tree-structured database has been built, the system tracing of distribution network can be rapidly performed. This remarkably enhances the efficiency of data search and easily adapts to system changes due to switching operations. The computation method of fast power flow using tree search strategies is presented. The methods in the paper may be available in the field of distribution system operation.

• Journal of the Ergonomics Society of Korea
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• v.27 no.1
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• pp.53-60
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• 2008

The purpose of this study is to provide basic data, such as exerting muscle power of the lower-extremity, EMG test and pressure distribution for designing ergonomic workstation in sitting posture. The exerting muscle power of the lower-extremity was measured by PRIMUS in 4 postures of 90$^{\circ}$, 120$^{\circ}$, 150$^{\circ}$ and 180$^{\circ}$. And performed ANOVA test on Max. and Mean 100%MVC. In EMG test for surveying muscle mobiligation, 5 muscles(Rectus Femoris, Vastus Lateralis, Gastrocnemius, Soleus, Tibialis Anterior) were employed. Additional experiment in pressure distribution in sitting posture by Pliance(16$\time$16 poles), Max. pressure was measured and performed ANOVA test on the results. Concludingly, sitting posture with 120$^{\circ}$ lower-extremity is the best design criterion for ergonomic workstation in sitting posture.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1056-1057
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• 2015

A common DC bus is a useful connection for several DC output sources such as photovoltaic (PV), fuel cells, and batteries. Operation of the common DC power system with more than two DC output sources, especially in a stand-alone mode, requires a control scheme for the stable operation of the system. In this paper, a control scheme has been developed for applying DC power sources to the distribution system. The purpose of the control scheme is to make the best use of the DC power sources. The DC power system consists of PV, two energy storage systems and a DC-AC inverter with the control scheme. A distribution system was modeled in PSCAD/EMTDC. As the results, the control scheme is applied to the DC-AC inverter and the DC-DC converter for transfer operations between the grid-connected and the stand-alone mode to keep the DC bus and the AC voltage constant. The results from the simulation demonstrate the stable operation of a grid connected DC power system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.11
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• pp.5218-5233
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• 2018

The coexisting wireless body area networks (WBAN) is a very challenging issue because of strong inter-networks interference, which seriously affects energy consumption and spectrum utilization ratio. In this paper, we study a power control strategy with nearest neighbor nodes distribution for coexisting WBAN based on stochastic geometry. Using homogeneous Poisson point processes (PPP) model, the relationship between the transmission power and the networks distribution is analytically derived to reduce interference to other devices. The goal of this paper is to increase the transmission success probability and throughput through power control strategy. In addition, we evaluate the area spectral efficiency simultaneously active WBAN in the same channel. Finally, extensive simulations are conducted to evaluate the power control algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1629-1633
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• 2004

In this paper, we first implement the simulation environment to investigate the efficient control method of a Fuel Cell Electric Vehicle (FCEV) system with battery. The subsystems of a FCEV including the fuel cell system, the electric motor (including the power electronics) and the tansmission (reduction gear), and the auxiliary power source (battery) are mathematically fomulated and coded using the Matlab/Simulink software. Some examples are given to show the capabilities of the modeled system and d a basic control strategy is examined for the economic energy distribution between the fuel cell and the auxiliary power source. It is illustrated by simulations that the actual vehicle velocity follows the given desired velocity pattern while both SOC control and power distribution control are being performed.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1234-1235
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• 2011

A DC Power Distribution Systems(DC PDS) are widely used in telecommunication system, electric vehicle, aircraft, military system, etc. In the DC PDS, DC bus voltage instability may be occurred by the operation of multiple loads such as pulsed power load, motor drive system, and constant power loads. To damp the transients of the DC bus voltage, the Voltage Bus Conditioner(VBC) with the PI compensator is used. In this paper, the validity of the proposed VBC system is verified by PSIM simulation package.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.324-327
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• 2002

For the characterization of arbitrary shaped printed circuit board, lossy transmission line grid model based on SPICE netlist and analytical plane model based on the segmentation method are proposed in this paper. Two methods are compared with an arbitrary shaped power/ground plane. Furthermore, design considerations for the complete power distribution network structure are discussed to ensure the maximum value of the PDN impedance is low enough across the desired frequency range and to guide decoupling capacitor selection.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.598-602
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• 2002

This paper presents the 3-phase hybrid series active power filter with dynamic voltage restorer(DVR) which serve as an energy buffer and current harmonics blocking resistor connected to sensitive loads, such as, to compensate voltage dips and current harmonics in power distribution system. The DVR is to inject a dynamically controlled voltage generated by a forced commutated converter in series to the bus voltage by means of a booster transformer. The momentary amplitudes of the three injected phase voltages are controlled such as to eliminate any detrimental effects of a bus fault to the load voltage. The proposed system is able to simultaneously compensate current harmonics, voltage fluctuating and voltage unbalance in power distribution systems. The reference phase angle detected by synchronized with the positive sequence component of the unbalanced source by using symmetrical component transformation. The effectiveness of proposed system is verified by the computer simulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.1965-1970
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• 2016

This paper studies generator rescheduling technique for congestion management in power system with wind farms. The proposed technique is formulated to minimize the rescheduling cost of conventional and wind generators to alleviate congestion subject to operational line overloading. The generator rescheduling method has been used with incorporation of wind farms in the power system. The locations of wind farms are selected based upon power transfer distribution factor (PTDF). Because all generators in the system do not need to participate in congestion management, the rescheduling has been done by generator selection based on the proposed generator sensitivity factor (GSF). The selected generators have been rescheduled using linear programming(LP) optimization techniques to alleviate transmission congestion. The effectiveness of the proposed methodology has been analyzed on IEEE 14-bus systems.