• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1187-1188
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• 2006

This paper a new method which applies a genetic algorithm for determining which sectionalizing switch to operate in order to solve the distribution system loss minimization re-configuration problem. In addition, the proposed method introduces a ultra efficient MPP tracking in a solar power generation system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.298-305
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• 2010

In this paper, a new algorithm of optimal Volt/Var Control is proposed using Volt/Var control for the Distribution Automation System (DAS) with Distributed Generation (DG) based on the modeling of the distributed load and the distributed current. In the proposed, algorithm based on the modeling of the distributed load and the distributed current are estimated from constants of four terminals using the measurement of the current and power factor from a Feeder Remote Terminal Unit (FRTU) and DG data from RTU for DG. For the optimal Volt/Var Control, the gradient method is applied to find optimal solution for tap, capacity and power control of OLTC (On-Load Tap Changers), SVR (Step Voltage Regulator), PC (Power Condenser) and DG (Distributed Generation). In the case studies, the estimation and control of the voltages have been testified in a radial distribution system with DG using matlab program.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1070-1072
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• 2001

In recent years, customers and power supplies are interested in power quality. Demands of customers are change from standard quality of distribution power system to various high quality of distribution power system. so, it is necessary to apply power quality compensator, in our project, we develop the power quality compensator of 150kVA which compensates power factor and voltage sag, interruption. it is very frequently occurred power qualify problems[1,2]. As a series and shunt compensator, power quality compensator consists of two inverters with common do link capacitor bank. It compensates the current quality in the shunt part and the voltage qualify in the series part. In this paper we present the design and control algorithm of power quality compensator. As a control algorithm is implemented by digital controller, we consider sample-and-hold of signals. In this simulation, we use EMTDC/PSCAD V3.0 software which can simulate instantaneous voltage and current.

• Journal of Power Electronics
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• v.19 no.3
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• pp.815-826
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• 2019

This paper discusses a simple control approach for a Unified Power Conditioner (UPC) system to achieve power quality compensation at the point of common coupling in distribution systems. The proposed Instantaneous Power Estimation Algorithm (IPEA) for shunt and series active power filters uses a simple mathematical concept that reduces the complexity in the design of the controller. The performance of a UPC is verified with a system subjected to voltage distortions, sags/swells and unbalanced loads using MATLAB/SIMULINK. The simulation study shows that a UPC with the proposed control algorithm can effectively compensate for voltage and current harmonics, unbalance and reactive power. The control algorithm is experimentally implemented using dSPACE DS1104 and its effectiveness has been verified.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.95-96
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• 2006

As the power industry moves towards open competition, there has been a call for methodology to evaluate distribution power system reliability by using customer interruption costs. Accordingly, it is increased for methodology to evaluate distribution power system reliability in power supply zones under competitive electricity market. This paper presents algorithm to evaluate system average interruption duration index. expected energy not supplied and system outage cost taking Into consideration failure rate of distribution facility and industrial customer interruption cost. Also, to apply this algorithm to evaluate system outage cost presented in this paper, distribution system of a dual supply system consisting of mostly high voltage customers in industrial complex in Korea is used as a sample case study. Finally, evaluation results of system interruption cost, system average interruption duration index and expected energy not supplied in sample industrial complex area are shown in detail.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.2
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• pp.76-82
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• 2001

This paper presents a approach for a service restoration and optimal reconfiguration of distribution network using Genetic algorithm(GA) and Tabu search(TS) method. Restoration and reconfiguration problems in distribution network are difficult to solve in short times, because distribution network supplies power for customers combined with many tie-line switches and sectionalizing switches. Furthermore, the solutions of these problems have to satisfy radial operation conditions and reliability indices. To overcome these time consuming and sub-optimal problem characteristics, this paper applied Genetic-Tabu algorithm. The Genetic-Tabu algorithm is a Tabu search combined with Genetic algorithm to complement the weak points of each algorithm. The case studies with 7 bus distribution network showed that not the loss reduction but also the reliability cost should be considered to achieve the economic service restoration and reconfiguration in the distribution network. The results of suggested Genetic-Tabu algorithm and simple Genetic algorithm are compared in the case study also.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.5
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• pp.854-859
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• 2010

Distribution Automation System(DAS) is designed to improve operational efficiency by acquisition and control of remote data using its components such as central computation units, communication network and feeder remote terminal units. A conventional human machine interface of the DAS adopts a schematic diagram which is made by drawing power equipments on the geographic information system map. The single line diagram is more useful than the schematic diagram for the main tasks of distribution system operation such as protective relay coordination, service restoration and loss minimization. Since the configuration of the distribution line is changed according to the relocation of the open tie switches, the auto-drawing algorithm based on the connection between the sections and the switches is an essential technique. This paper proposes a new auto-drawing algorithm for a single line diagram of distribution systems based on tertiary tree and collision avoidance method. The feasibility of the proposed algorithm has been testified for various cases using practical distribution system with 12 feeders.

• 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.

• KIEE International Transactions on Power Engineering
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• v.5A no.4
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• pp.371-377
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• 2005

Congestion problems of transmission lines are very important research issues in power system operations. Load curtailment is one of the ways to solve congestion problems by a major contingency. A systematic and effective mechanism for load shedding has been developed by investigating congestion distribution factors and the direct load control program. In this paper, a load shedding algorithm using linear programming for congestion problems by a major contingency is presented. In order to show the effectiveness of the proposed algorithm, it has been tested on the 6-bus sample system and the power system of Korea, and their results are presented.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.190-192
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• 1999

This paper presents an algorithm for optimal reactive power dispatch problem based on genetic algorithm. Optimal reactive power dispatch is particularized to the minimization of transmission line losses by suitable selection of generator reactive power outputs and transformer tap settings. To attain for the objective, in this paper, loss re-distribution algorithm(LRDA) is applied to ORPD. The proposed method has been evaluated on the IEEE 30 bus system. Results of the application of the method are compared with a simple genetic algorithm.