• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.838-846
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• 2015

This paper deals with the modified modeling of PV system based on the PSCAD/EMTDC and optimal control method of customer voltages in real distribution system interconnected with the photovoltaic (PV) systems. In order to analyze voltage variation characteristics, the specific modeling of PV system which contains the theory of d-q transformation, current-control algorithm and sinusoidal PWM method is being required. However, the conventional modeling of PV system can only perform the modeling of small-scale active power of less than 60 [kW]. Therefore, this paper presents a modified modeling that can perform the large-scale active power of more than 1 [MW]. And also, this paper proposes the optimal operation method of step voltage regulator (SVR) in order to solve the voltage variation problem when the PV systems are interconnected with the distribution feeders. From the simulation results, it is confirmed that this paper is effective tool for voltage analysis in distribution system with PV systems.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.373-378
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• 2003

It is important that overheat protection of super heated tube in boiler operation and maintenance. The overheat of super heat tube can make damage and rupture of tube material, which causes accidental shutdown of boiler. The super heated tube overheat is almost due to the lack of uniformity of gas temperature distribution. There are two ways to protect overheat of super heated tube. The one is to control hot gas operation pattern which is temperature or flow distribution. the other is to control super heated steam flow distribution. The former is difficult than the later, because of control device design. In this paper steam flow control method which uses orifices is proposed to protect overheat of super heat tube.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.1
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• pp.6-12
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• 2020

In recent years, the demand for the distribution of energy resource has been increasing. However, the output power is limited by the stability of the distribution network. This study proposes an active distribution network that can reconfigure the distribution line using an active phase controller. The conventional distribution network has a fixed structure, whereas the proposed active distribution network has a variable structure. Therefore, the active distribution network can increase the output power of the distribution energy resource and reduce the overload of distribution line facilities. The active phase controller has two operation modes to minimize the circulating current during dynamic reconfiguration. In this study, the voltage and current control algorithms are proposed for the active phase controller. The proposed method for the active phase controller is simulated via PSIM simulation.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.231-233
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• 2001

Nowadays, small scale DGS(Distributed Generation System), as a wind power generation or photovoltaic generation, becomes to be introduced into the power distribution system. But in that case, it is difficult to properly maintain the terminal voltage of low voltage customers. So, it is necessary to determine the permissible operation limit of the introduced DGS for proper voltage in distribution system. In this paper computes permissible operation limit of DGS when the DGS is connected to power distribution system using fixed tap(without LDC operation). For this simulation, KEPCO distribution system is used.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.3
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• pp.87-94
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• 2013

The main purpose of the distribution automation system (DAS) is to achieve efficient operation of primary distribution systems by monitoring and control of the feeder remote terminal unit(FRTU) deployed on the distribution feeders. DAS simulators are introduced to verify the functions of the application software installed in the central control unit(CCU) of the DAS. Because each DAS is developed on the basis of its own specific data model, the power system data cannot be easily transferred from the DAS to the simulator or vice versa. This paper presents a common information model(CIM)-based DAS simulator to achieve interoperability between the simulator and the DASs developed by different vendors. The CIM-based data model conversion between Smart DMS (SDMS) and Total DAS (TDAS) has been performed to establish feasibility of the proposed scheme.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.5
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• pp.221-229
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• 2003

This paper suggests a control algorithm of 3-phase 3-wire series active power filter. This suggested algorithm can compensate source harmonics and reactive power in 3-phase 3-wire power distribution systems. These harmonics are generated by nonlinear loads such as diode rectifiers and thyristor converters. This control algorithm extracts a compensation voltage reference from performance function without phase transformation. Therefore, this control algorithm is simpler than any other conventional control algorithms. 3-phase 3-wire series active power filters which have a harmonic voltage source and a harmonic current source are manufactured and experiments are carried out to verify the effectiveness of suggested control algorithm.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.251-255
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• 2003

This paper proposes a novel UPQC(unified power quality conditioner) based on H-bridge modules, isolated through single-phase multi-winding transformers. The dynamic performance of proposed system was analyzed by simulation with EMTDC/PSCAD, assuming that the UPQC is connected with the 22.9kV distribution line. The proposed system can be directly connected to the transmission line without series injection transformers. It has flexibility in expanding the operation voltage by increasing the number of H-bridge modules and can compensate reactive power, harmonics, voltage sag and swell, voltage unbalance. The control strategy for the proposing UPQC was derived using the instantaneous power method. The proposing UPQC has the ultimate capability of improving power quality at the point of installation on power distribution systems and can be utilized for the future distribution system.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.73-75
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• 2000

The new distribution automation system was developed in KEPCO just recently. This system has many functions for remote control and data acquisition but it has not all functions for the full automated distribution system. This paper presents the contents of many kinds of additional application programs on the stage of developing and coming to the final completion for the large scaled distribution automation system.

• Proceedings of the KIEE Conference
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• summer
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• pp.381-383
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• 2004

This paper presents for service restoration Abstract -in electric power distribution systems. The aim of the service restoration is an emergency control in distribution system to restore out-of service areas as soon as possible when a fault occurs in distribution system. For this reason, this paper presents a new service restoration strategy for multi-outage areas. Proposed algorithm consists of two methods. One is individual restoration scheme, the other one is integrated restoration scheme. The former determines restoration order of outage areas based on restoration index. If the former method can not generate a feasible restoration plan, the latter would try to find new configuration without overloaded section through tie exchange method.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.5
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• pp.369-375
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• 2020

Distribution energy resources have been increasing in recent years. However, output power is limited for distribution network stability. This study proposes an active distribution network that can reconfigure distribution lines by using an active phase controller. A conventional distribution network has a fixed structure, whereas an active distribution network has a variable structure. Therefore, the latter can increase the output power of distribution energy resources and decrease the overload of distribution line facilities. An active phase controller has two operation modes for minimizing circulating current during dynamic reconfiguration. In this study, voltage and current control algorithms are proposed for active phase controllers. The simulation of the proposed methods for active phase controllers is performed using PSIM software.