• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2597-2599
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• 2004

The high quality power is consisted with uniform frequence, no interruption and uniform voltage. In these components, the voltage of the distribution systems affects making economic distribution facility and improving power quality. This paper describes on the voltage apportion rates of the distribution systems in KEPCO.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
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• pp.82-84
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• 2000

This paper deals with a evaluation algorithm of interruption cost in distribution systems in the case where Dispersed Storage and Generation (DSG) systems are interconnected with the distribution systems. If DSG systems are operated as the function of the load levelling in distribution systems at the normal conditions and as the uninterruptible power supply in fault areas at the emergency conditions, the reliability improvement of the distribution systems can be expected. In other words, the benefit can be represented by the cost avoiding interruption according to the operation of DSG systems when a fault is occurred. Therefore, this paper presents the evaluation algorithm for interruption cost in order to evaluate the benefit for the uninterruptible power supply of DSG systems in a quantitative manner.

• Transactions on Electrical and Electronic Materials
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• 제18권5호
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• pp.303-309
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• 2017

The flexible AC transmission system (FACTS) provides a new advanced technology solution to improve the flexibility, controllability, and stability of a power system. The unified power flow controller (UPFC) is outstanding for regulating power flow in the FACTS; it can control the real power, reactive power, and node voltage of distribution networks. This paper investigates the performance of the UPFC for power flow control with a series of step changes in rapid succession in a power system steady state and the response of the UPFC to distribution network faults and islanding mode. Simulation was carried out using the MATLAB's simulink sim power systems toolbox. The results, which were carried out on a 5-bus test system and a 4-bus multi-machine electric power system, show clearly the effectiveness and viability of UPFC in rapid response and independent control of the real and reactive power flows and oscillation damping [6].

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제3B권2호
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• pp.103-110
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• 2003

With significant development of power electronics technology, the proliferation of nonlinear loads such as static power converters has deteriorated power quality in power transmission and distribution systems. Notably, voltage harmonics resulting from current harmonics produced by the nonlinear loads have become a serious problem in many countries. Many photovoltaic power generation systems installed in building systems have harmonics that are the worst object for distribution systems as a utility interactive system, and it tends to spread out continuously. Proposed and implemented in this paper is a multi-function inverter control strategy that allows a shunt active filter function to the power inverter of the photovoltaic power generation system established on a building system. The effectiveness of the proposed system is demonstrated through the simulation of a hypothetical power system using PSCAD/EMTDC.

• Journal of Electrical Engineering and Technology
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• 제12권6호
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• pp.2208-2218
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• 2017

To resolve overload in a distribution system, a distribution system operator (DSO) often performs a load transfer using normally open tie points and switches in the distribution line. During this process, the distribution system is momentarily operated in closed-loop operation. A closed-loop current in the distribution system can cause a power failure due to excess breaking current in the circuit breakers and reclosers. Therefore, it is necessary to calculate the closed-loop current exactly. However, if there are a large number of distributed generation (DG) systems in the distribution system, such as energy storage systems (ESS), they might obstruct the closed-loop operation based on bidirectional power flow. For quick and precise operation of a closed-loop system, the ESS has to regulate the power generation while satisfying closed-loop operation in the worst cases. We propose a strategy for balanced power regulation of an ESS. Simulations were carried out using PSCAD/EMTDC, and the results were compared with calculation results.

• Wind and Structures
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• 제23권4호
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• pp.351-366
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• 2016

Nowadays, wind energy is the most rapidly developing technology and energy source and it is reusable. Due to its cleanliness and reusability, there have been rapid developments made on transferring the wind energy systems to electric energy systems. Converting the wind energy to electrical energy can be done only with the wind turbines. So installing a wind turbine depends on the wind speed at that location. The expected wind power can be estimated using a perfect probability distribution. In this paper Weibull and Weibull distribution with multiple parameters has been used in deriving the mathematical expression for estimating the wind power. Statistically the parameters of Weibull and Weibull distribution are estimated using the maximum likelihood techniques. We derive a probability distribution for the power output of a wind turbine with given rated wind speeds for the regions where the wind speed histograms present a bimodal pdf and compute the first order moment of this distribution.

• 대한전기학회논문지:전력기술부문A
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• 제55권4호
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• pp.139-143
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• 2006

Recently, standard of living improved and Information-Communication industry developed rapidly. Thereby, interest about electric power quality is rising worldwide. So, research and Development to enhance electric power quality in various viewpoint until most suitable supply system from each kind device to improve electric power quality. And specially, interest about voltage quality is rising by diffusion increase of information communication appliance and minuteness control appliance etc. Also Power consumption is increasing, but expansion of large size generator by environmental and site security problem is difficult. So, introduction of distribution generation is investigated actively by electric-power industry reorganization. Voltage management of power system had been controlled by ULTC (Under Load Tap Changer) in substation and pole transformer on the high voltage distribution line. But, voltage control device on substation and distribution line is applied each other separatively. Therefore, efficiency of line voltage control equipment is dropping. Also, research about introduction upper limit of distribution generation is consisting continuously. This paper presents cooperation use way between voltage control device and introduction upper limit of distribution generation for most suitable voltage control in distribution power system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.277-280
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• 2002

With significant development of power electronics technology, the proliferation of nonlinear loads such as static power converters has deteriorated power quality in power transmission and distribution systems. Notably, voltage harmonics resulting from current harmonics produced by the nonlinear loads have become a serious problem in many countries. There are already a lot of PV power generation systems installed in building systems whose harmonics are the worst object for distribution systems as a utility interactive system and also it tends to spread out continuously. In this paper, the authors propose a multy-function inverter control strategy which puts a shunt active filter function to the power inverter of the PV power generation system established on a building system. The effectiveness of the proposed system is demonstrated through the simulation of hypothetical power system using PSCAD/EMTDC.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1321-1324
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• 2004

Unbalanced systems, such as distribution systems, have difficulties in fault locations due to single-phase laterals and loads. In this paper, a novel fault location algorithm is suggested for a line to line faults using inverse theorem of matrix on electric power lines. The fault location for balanced systems has been studied using the current distribution factor, by a conventional symmetrical transformation, but that for unbalanced systems has not been investigated due to their high complexity The proposed algorithms overcome the limit of the conventional algorithm using the conventional symmetrical transformation, which requires the balanced system and are applicable to any electric power system but are particularly useful for unbalanced distribution systems. The simulation results oriented by the real distribution system are presented to show its effectiveness and accuracy.

• International Journal of Computer Science & Network Security
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• 제24권1호
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• pp.31-44
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• 2024

People have been using more energy in the last years. Several research studies were conducted to develop sustainable energy sources that can produce clean energy to fulfill our energy requirements. Using renewable energy sources helps to decrease the harm to the environment caused by conventional power plants. Choosing the right location and capacity for DG-RESs can greatly impact the performance of Radial Distribution Systems. It is beneficial to have a good and stable electrical power supply with low energy waste and high effectiveness because it improves the performance and reliability of the system. This research investigates the ideal location and size for solar and wind power systems, which are popular methods for producing clean electricity. A new artificial intelligent algorithm called Nutcracker Optimization Algorithm (NOA) is used to find the best solution in two common electrical systems named IEEE 33 and 69 bus systems to examine the improvement in the efficiency & reliability of power system network by reducing power losses, making voltage deviation smaller, and improving voltage stability. Finally, the NOA method is compared with another method called PSO and developed Hybrid Algorithm (NOA+PSO) to validate the proposed algorithm effectiveness and enhancement of both efficiency and reliability aspects.