• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.10 s.181
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• pp.2529-2534
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• 2000

Torsional vibration analysis in a large two -stroke low speed diesel engine and generator system for stationary power plants is performed to verify that the vibration characteristics of shafting system meet design requirements. Our own developed S/W is employed for the analysis, whose results are evaluated comparing with measurements. Vibration analysis results of the system are presented according to the change of loading(unload, 100%load, 110% load) and operating(mis-firing, uneven firing) conditions of the stationary power plants.

• Journal of the Korea Society for Simulation
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• v.13 no.3
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• pp.43-54
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• 2004

Studies of Internet algorithms or policies require experiments on the real large-scale networks. But practical problems with large real networks make them difficult. Instead many researchers use simulations on the Internet topology models. So, It is Important that study about topology model that reflect characteristic of the internet exactly. We propose new topology model which reflect of hierarchical network and addition, removal of nodes and accompanied change of topologies. In the modeling scheme for network generation, we applied DEVS formalism and analyzed the topologies generated by our algorithms.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1990-1992
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• 2000

Isolated phase bus is, as a special bus which allows large current from a generator to main transformer, composed of main conductor, enclosure and auxiliary equipments such as insulating bellows, bus elbows, support insulator, etc. To develop this kind of high power devices, it is required to secure the technique of selection of conducting and insulating materials, basic arrangement skills, and analysis on eddy current which causes temperature increase in enclosures. By the way, these techniques are based on the analysis of electromagnetic phenomena for high voltage and large current. In this study, an electromagnetic field analysis program is developed and applied to the isolated phase bus. which could be the basic numerical method for the analysis design and modifying isolated phase bus.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2138-2140
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• 2001

A siumlator had been developed and will be used for reliability verification on large steam turbine control programs prior to its actual operation in field. A mathematical model on thermal dynamics pertaining to prime mover steam turbine and electrical generator was realized and included in this simulator. Also, many operating data acquired from fields was utilized in order to decide mechanical and thermal dynamic characteristics such as friction loss, windage loss and inertia. A user can decide closing or opening velocity of steam stop valves and steam regulation valves. This simulator is able to generate steam pressure, turbine speed, electrical power, and power system frequency.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.1
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• pp.86-93
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• 1999

It is necessary to calculate the system's factor for reasonable operation and security enhancerrent of large scale distribution system This paper presents an effective three phase load flow calculation for distribution system unbalance evaluation. It takes into account an untranspoed transmission line, the core loss as a functioo of voltage on the serondary side of the transformer, and a generator unbalance mxle1 which is also suitable for a salient pole machine. The load flow algorithm is used Newton-RaiDson method of load flow equations in bus phase voltage.oltage.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.198-200
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• 1987

This paper presents the choice of appropriate sets of input variables for large-scale linear multivariable systems. It is shown that the selection of a good set of input variables for control may become important when both strong and weak input variables are available. The transmission of information from the inputs to the outputs is investigated and appropriate scaling procedures to derive a scaled input matrix are proposed. Singular value decomposition methods facilitate the quantification of the systems excitation stemming from the various input variables, and thus the selection of an appropriately strong and orthogonal set of input variables. The need for and the implementation and benefits of reducing the number of input variables are illustrated by a large-scale steam generator model of a real process.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.12
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• pp.1718-1723
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• 2015

The diameter of the rotor of 2MW wind turbine is being developed by a number of companies with more than 80m, reliability and economic efficiency of the wind power generator has been improved. The need for large-scale wind turbine with excellent economy has been attracting attention because the new orders and the location of the wind turbine market has reached a limit. Technology development for enlargement of wind turbine is possible not only the improvement of energy efficiency but also reduce the construction costs per unit capacity. However, mechanical gearboxes used in wind generators have problems of wear, damage, need for lubrication oil and maintenance. Therefore, we want to configure the gearbox of a large-scale wind turbine using a magnetic gear in order to solve these problems of mechanical gearbox.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.633-635
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• 2007

To cope with increasing power demand in metropolitan area, the power system in Korea has equipped with unit generator of large capacity, high density and uneven distribution, and transmission line of long distance, large capacity and high voltage. As the power system growing up enormous, it has become difficult to maintain the standard voltage in case of radical fluctuation of load or severe change of voltage by power system fault for its weakness of responsive characteristics although the power condenser has been installed to solve the unstability by lack of reactive power. Consequently, we review harmonic wave production and control characteristics to solve unstability problem of voltage in northern metropolitan, to reduce transmission restriction cost and to minimize load shedding by relocation of SVC (Static Var Compensator), which is highly effective for improvement of responsive characteristics for radical voltage fluctuation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.478-479
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• 2007

Many electrical fires are occurred by leakage currents and sparks generated by a short circuit. Earth leakage circuit breakers (ELCBs) should be tripped at the moment of the faults mentioned above. In this paper, we described the tripping characteristics of ELCBs against parallel arcing faults. A diesel engine generator with the capacity of 375 kVA source was adopted to provide enough large current when a parallel arcing occurred. The experimental results showed that most ELCBs we experimented were not tripped against short-duration pulse currents produced by parallel arcing because the ELCBs are designed to be tripped by a large current with long duration similar to power frequency.

• Progress in Superconductivity and Cryogenics
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• v.10 no.1
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• pp.57-61
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• 2008

A 1MW class HTS(High-Temperature Superconducting) synchronous motor has been developed. This motor was aimed to be utilized for industrial application such as large motors operating in large plants. The HTS field windings of the developed motor is cooled by way of Neon thermosiphon mechanism and the stator coil is cooled by water through hollow copper conductor. This paper describes performance test results of our motor, which was conducted at steady state in generator mode and motor mode.