• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.418-419
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• 2005

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.11
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• pp.73-82
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• 2011

The solid insulation system of stator windings in high voltage rotational machines is usually aging in accordance with long time operation. The partial discharge test have been known to check whether insulation deterioration exist or not, and the PD test can effectively diagnose a solid insulation condition regardless of during operation(on-line) or not(off-line). The on-line PD measurement have proven to be a successful technique in monitoring stator insulation condition nowadays. This paper describes the characteristics of comparing the on-line PD measurement data using PDMS-HG(Partial Discharge Monitoring System for Hydro-electric Generator) installed in field with the off-line diagnosis measurement data(insulation resistance, winding resistance, PI, ${\Delta}tan{\delta}$ and PD) on hydro generator(13[kV]) stator windings. These results make good use of managing rotational machines through evaluating the solid insulation condition of stator windings.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.452-455
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• 2005

We have studied the prearranged plan and the economy of a candidate site for the development of small hydro power. And also we have confirmed its economy by suggesting the technology of the unmanned operation and the selection of the water turbine generator which has a great efficiency. working rate and suitability to the topographical characteristics of various development sites, for example, irrigation reservoirs, water works pipes, sewage systems and cool ing water of a steam power stat ion. Besides we give more examples of the select ion of Francis, propeller turbine and induction generator which can achieve a maximum of power production at a minimum construction cost. With a water turbine which runs at the low head we are able to suggest many programs to boost a development of small hydro power more economically.

• Journal of Power System Engineering
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• v.19 no.5
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• pp.67-72
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• 2015

The reliable operation of onsite emergency diesel generator(EDG) should be ensured by a conditioning monitoring system designed to maintain, monitor and forecast the reliability level of diesel generator. The purpose of this paper is to develop condition diagnosis algorithm(logic) and analysis program of engine for the accurate diagnosis in actual condition of emergency diesel generator engine. As a result of this study, we confirmed that developed engine condition diagnosis algorithm and analysis program could be efficiently applied for actual EDG engine in nuclear power plant.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1769-1773
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• 1996

The remaining life of generator stator winding has been the controversial issue amomg many experts in this area. The report from Japan claims that they can predict the remaining life of generator winding, while the North American has the negative opinion about it. This study aimed at verifying the validity of both Japanese criteria and North American argument on evaluation of generator winding insulation. Non destructive and destructive tests were performed on two hydro-generators. The test results showed that the trend analysis of stator winding insulation was the better option.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.4
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• pp.102-107
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• 2015

In this paper, the generator control system by using PSCAD/EMTDC was modeled and several faults simulation were performed. The generator control system is composed of generator, turbine, exciter and governor. The parameters of generator control system model were obtained from field power plant. And then, the various transient phenomena through obtained several signal of developed modeling were analyzed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.9
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• pp.67-72
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• 2014

Inflow or outflow from the water treatment plant and the sewage water has potential energy. If this potential energy can be converted into electrical energy by water turbine generator, it can help to save energy because of the high capacity utilization. So recently, micro hydro power plant is reviewed in the water treatment facility. If generation capacity is low, induction generator is primarily used. If output capacity is low, generated power is supplied to the inside load. Induction generator can cause voltage drop by the inrush current at a start-up and requires reactive power for magnetization. In this study, we analyzed the flow of power and voltage variation against inrush current that occurs when the induction generator starts under the terms that loads of linear and non-linear of the water purification plant are used. Analysis results are that the voltage drop is within an allowable range and the power factor is slightly reduced by the need of reactive power.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.3
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• pp.428-438
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• 2016

This paper shows the design of the 100 kW IPMSG for small hydraulic power generator. The high-efficient generator, method of the dual layer interior permanent magnet was studied to improve the method of the single layer interior permanent magnet, which is mostly used. Analysis of magnet arrangement and cogging torque was done by FEM. According to structure analysis of dual layer interior permanent magnet, the amount of usage of the permanent magnet was reduced and cogging torque was decreased as well. With these successful results, the high-efficient generator design was accomplished. Based on the results of the structure analysis, the test product was designed and manufactured. And the design values and performance outputs were compared and verified with success. Also, the economic feasibility was conducted based on the electric power generated from the test product installed at the site. By the B/C analysis, in case that only SMP was analyzed, B/C ratio was 1.24 at the discount ratio of 5.5%, which considered to be economically feasible. The study is expected to be used for the application of developing large scale high-efficient interior permanent magnet synchronous generator.

• Nuclear Engineering and Technology
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• v.46 no.6
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• pp.869-874
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• 2014

It was discovered in a Korean PWR that an extensive number of very short and shallow cracks in the SG tubes were undetectable by eddy current in-service-inspection because of the masking effect of sludge deposits. Axial stress corrosion cracks at the outside diameter of the steam generator tubes near the line contacts with the tube support plates are the major concern among the six identical Korean nuclear power plants having CE-type steam generators with Alloy 600 high temperature mill annealed tubes, HU3&4 and HB3~6. The tubes in HB3&4 have a less susceptible microstructure so that the onset of ODSCC was substantially delayed compared to HU3&4 whose tubes are most susceptible to ODSCC among the six units. The numbers of cracks detected by the eddy current inspection jumped drastically after the steam generators of HB4 were chemically cleaned. The purpose of the chemical cleaning was to mitigate stress corrosion cracking by removing the heavy sludge deposit, since a corrosive environment is formed in the occluded region under the sludge deposit. SGCC also enhances the detection capability of the eddy current inspection at the same time. Measurement of the size of each crack using the motorized rotating pancake coil probe indicated that the cracks in HB4 were shorter and substantially shallower than the cracks in HU3&4. It is believed that the cracks were shorter and shallower because the microstructure of the tubes in HB4 is less susceptible to ODSCC. It was readily understood from the size distribution of the cracks and the quantitative information available on the probability of detection that most cracks in HB4 had been undetected until the steam generators were chemically cleaned.

• Journal of Power Electronics
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• v.9 no.2
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• pp.267-274
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• 2009

This paper deals with a voltage and frequency (VF) controller for an isolated power generation system based on an asynchronous generator (AG) driven by a pico hydro turbine. The proposed controller is a combination of a static compensator (STATCOM) and an electronic load controller (ELC) for decoupled control of the reactive and active powers of the AG system to control the voltage and frequency respectively. The proposed generating system along with its VF controller is modeled in MATLAB using SIMULINK and PSB (Power System Block Sets) toolboxes. The performance of the controller is verified for the proposed system and feeding various types of consumer load such as linear/non-linear, balanced/unbalanced and dynamic loads.