• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.49-59
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• 2009

Vibrations of the tower structures of 750kW and 6kW wind turbines(WT) are investigated by measurement and analysis. Acceleration responses of the WT towers under various operation condition are monitored in real time by the remote monitoring system using LabVIEW. Using the monitoring system, resonance condition of the tower structures is diagnosed with the wind speed data within the operating speed range. To predict the tower resonance frequency, 750 kW tower is modeled as an equivalent beam with a lumped mass and Rayleigh energy method is applied. For 6 kW WT, Rayleigh-Ritz analysis is carried out on the tower-cable coupled system. Calculated tower bending frequency is in good agreement with the measured value. Using the analysis model, parametric study is available in order to prevent the severe resonance.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.10
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• pp.486-493
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• 2000

This paper presents an application to a multimachine power system of power system stabilizer using revised pole shift adaptive algorithm. Controller parameters are determined by using adaptive control theory in order to maintain optimal operation of generator under the various operating conditions. To determine the optimal parameters of controller and overcome the problem of pole placement algorithm, this paper presents pole shift algorithm revised pole shift factor. Also, the difference between the speed deviation with weighted factor and voltage deviation is used as the input signal of adaptive controller, which provides good damping characteristics. The results tested on a multimachine power system verify that the proposed controller has better dynamic and transient performance than conventional controller.

• 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.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.77-80
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• 2003

As rapid growth of energy demand in line with modern society's industrialization led to environmental pollution by fossil fuels, there are more and more interest and international research on energization of water, which is clean energy and comprising $70\%$ of earth. In offshore countries, the water is commercially used already and water has very attractive characteristics in terms of economy and efficiency compared to the existing gas welder. Brown Gas welder does not produce $CO_2$ from combustion of Hydrogen-Oxygen-Gas, which was gained by electrolysis of water, In this paper, the result from operating characteristic improvement of Gas Generator and Current-Controlled converter is to be considered into design in electrode, source/ controller, standized into level of whole system design base.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.2
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• pp.113-118
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• 1999

In this, sensitivity based approach to estimate BITC(bilateral interchange transfer capacity) considering the real power flow control function of FACTS devices is presented. The real power flow setting of the FACTS devices is adjusted so that it transfers the power flow from the first violation point of transmission capacity to other transmission lines in the power system, thus allowing more power to be transferred from the specified generator bus to the specified load bus. The transfer between the two bus locations is increased from this new operating condition until a violation of transmission capacity limits occurs or until the setting of the FACTS devices can no longer be adjusted. The proposed algorithm is illustrated using examples of small and real life power system.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.1
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• pp.14-17
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• 2015

This paper presents a analysis method for power system stability using a Modified Genetic-based Power System Stabilizer(MGPSS). The proposed MGPSS parameters are optimized using Modified Genetic Algorithm(MGA) in order to maintain optimal operation of generator under the various operating conditions. To improve the convergence characteristics, real variable string is adopted. The results tested on a single machine infinite bus system verify that the proposed controller has better power system stability than conventional controller.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2578-2580
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• 2000

A siumlator had been developed and used for reliability verification on medium size 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 valve and steam regulation valve. This simulator is able to generate steam pressure, turbine speed, electrical power, and power system frequency.

• Journal of Advanced Marine Engineering and Technology
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• v.18 no.4
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• pp.33-42
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• 1994

The radiative heat transfer analysis in the fluidized particles layer has important application in many technological areas such as combustion chambers at high pressure and temperature, plasma generators for nuclear fusion, MHD generator using pulverized coal and the liquid droplet radiator used to reject wasted heat from a power plant operating in space. To accurately model the radiation properties of the fluidized particles layer, it is necessary to know the radiation interchange factors of particles in each layer. But the solutions are usually not possible for the equations of radiative heat transfer because it has an inherent difficulty in treating the governing intergo- differential equations, which are derived from the remote effects of radiative heat transfer. In this study, the analysis uses the Monte Carlo simulation method with optical depth model to calculate the radiation interchange factors of particles in each layer with wall and with each other.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.8
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• pp.629-635
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• 2008

Recently, microturbines have received attention as a small-scale distributed power generator. Since the exhaust gas carries all of the heat release, the microturbine CHP (combined heat and power) system is relatively compact and easy to maintain. Generating hot water or steam is usual method of heat recovery from the microturbine. In this work, a heat recovery unit producing hot water was installed at the exhaust side of a 30 kW class microturbine and its performance characteristics following microturbine power variation was investigated. Heat recovery performance has been compared for different operating conditions such as constant hot water temperature and constant water flow rate. In particular, the influence of water flow rate and hot water temperature on the recovered heat was analyzed.

• 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.