• International Journal of CAD/CAM
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• v.8 no.1
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• pp.63-67
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• 2009

This paper puts forward a method based on the boundary deformation for planar grid generation. Many methods start with the special properties of grid and switch to the solution of a direct optimization or a non-linear minimum cost flow. Though with high theoretical significance, it's hard to realize due to the extremely complicated computing process. This paper brings out the automatic generation of planar grid by studying the boundary deformational properties of planar grid, which leads to uniform grid and enjoys the simplicity of computation and realization.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.861-863
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• 1998

F.I(Fault Indicator) is equipped in automatic switchs for Distibution Automation System(DAS), and plays important role of providing the information for picking out a fault section. The restrictive sentence that F.I doesn't react for the inrush current is in the F.I specification. Nevertheless F.I has sometimes mal-functioned on the DAS in Kang-Dong branch office of KEPCO for latest 2 years. This Paper Proved the causes of the mal-function, and proposed the new F.I specification and operation methods against the mal-function causes.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.1
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• pp.28-37
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• 2001

This paper presents an efficient algorithm for the loss minimization of distribution system by automatic sectionalizing switch operation in large scale distribution systems. Simulated annealing is particularly well suited for large combinational optimization problem, but the use of this algorithm is also responsible for an excessive computation time requirement. Tabu search attempts to determine a better solution in the manner of a greatest-descent algorithm, but it can not give any guarantee for the convergence property. The hybrid algorithm of two methods with two tabu lists and the proposed perturbation mechanism is applied to improve the computation time and convergence property Numerical examples demonstrate the validity and effectiveness of the proposed methodology using a KEPCO's distribution system.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.4
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• pp.371-378
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• 1999

This paper presents an efficient algorithm for loss reduction of distribution system by automatic sectionalizing switch operation in large scale distribution systems of radial type. Simulated Annealing algorithm among optimization techniques can avoid escape from local minima by accepting improvements in cost, but the use of this algorithm is also responsible for an excessive computation time requirement. To overcome this major limitation of Simulated Annealing algorithm, we may use advanced Simulated Annealing algorithm. All constaints are divided into two constraint group by using perturbation mechanism and penalty factor, so all trail solutions are feasible. The polynomial-time cooling schedule is used which is based on the statistics calculation during the search. This approaches results in saving CPU time. Numerical examples demonstrate the validity and effectiveness of the proposed methodology.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.4
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• pp.188-196
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• 2001

This paper presents and efficient algorithm for the loss minimization by automatic sectionalizing switch operation in distribution systems. Ant colony algorithm is multi-agent system in which the behaviour of each single agent, called artificial ant, is inspired by the behaviour of real ants. Ant colony algorithm is suitable for combinatiorial optimization problem as network reconfiguration because it use the long term memory, called pheromone, and heuristic information with the property of the problem. The proposed methodology with some adoptions have been applied to improve the computation time and convergence property. Numerical examples demonstrate the validity and effectiveness of the proposed methodology using a KEPCO's distribution system.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1164-1166
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• 1996

This system is an unified Digital Generator Controller. It has an Electronical Generator Sequencer which control the sequence of a generator, an AVR(Automatic Voltage Regulator) which perform the regulation of generator terminal voltage optimally to user's needs, and an Auto Synchronizer, it can switch the power source on from generally used an the generator to load automatically. It also possesses a Battery Charger which charge a storage battery to appropriate voltage level. Here we describe it's configuration, specifications, the way of control, figure, functions and waveforms.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.335-337
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• 1998

This paper presents a efficient algorithm for loss reduction of distribution system by automatic sectionalizing switch operation in distribution systems of radial type. Simulated Annealing can avoid escape from local minima by accepting improvements in cost, but the use of this algorithm is also responsible for an excessive computation time requirement. To overcome this major limitation of Simulated Annealing Algorithm, we may use advanced Simulated Annealing Algorithm. Numerical examples demonstrate the validity and effectiveness of the proposed methodology.

• International journal of advanced smart convergence
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• v.8 no.1
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• pp.82-86
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• 2019

We aim to use public data different from the remote BEMS energy diagnostics technology and already established and then switch the conventional operation environment to a big-data-based integrated management environment to operate and build a building energy management environment of maximized efficiency. In Step 1, various network management environments of the system integrated with a big data platform and the BEMS management system are used to collect logs created in various types of data by means of the big data platform. In Step 2, the collected data are stored in the HDFS (Hadoop Distributed File System) to manage the data in real time about internal and external changes on the basis of integration analysis, for example, relations and interrelation for automatic efficient management.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.1
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• pp.66-73
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• 2021

This study presents a novel four-channel light-emitting diode (LED) current balancing topology using a current-fed hybrid quasi-Z-source converter. With the proposed structure, currents flowing through four LED strings are automatically balanced owing to the charge (amp-sec) balance condition on capacitors. Thus, automatic current balancing of the proposed driver is simple and precise. In addition, the proposed LED driver uses only one active switch and three diodes. The operating principle and characteristics of the proposed four-channel LED driver are analyzed in detail. To verify the operation of the proposed LED driver, a prototype is built and tested with different numbers of LEDs.

• Journal of the Korea Society of Computer and Information
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• v.17 no.12
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• pp.31-39
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• 2012

In this paper, we propose a microprocessor-based automatic voltage regulator(AVR) to reduce consumers' electric energy consumption and to help controlling peak demanding power. Hybrid Switching Automatic Voltage Regulator (HS-AVR) consist of a toroidal core, several tap control switches, display and command control parts. The coil forms an autotransformer which has a serial main winding and four parallel auxiliary windings. It controls the output voltage by changing the combination of the coils and the switches. Relays are adopted as the link switches of the coils to minimize the loss. To make connecting and disconnecting time accurate, relays of the circuit have parallel TRIACs. A software phase locked loop(PLL) has been used to synchronize the timings of the switches to the voltage waveform. The software PLL informs the input voltage zero-crossing and positive/negative peak timing. The traditional voltage transformers and AVRs have a disadvantage of having a large mandatory capacity to accommodate maximum inrush current to avoid the switch contact damage. But we propose a suitable AVR for every purpose in smart grid with reduced size and increased efficiency.