• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.3 s.18
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• pp.174-183
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• 2004

In this paper, the performance improvement and modeling of small onboard generator were described. As the characteristics of the field coil which are a major parameters of generator were improved, the system bandwidth could be increased, therefore the generator could also be satisfied with fast characteristic loads. Established the brief control model of the generator, it could be possible to do the analysis of generator performance, and improve the operational stability of the generator system using the control model.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.31-35
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• 2003

In this paper, the improved performance of small aircraft onboard generator were described. As the characteristics of the field coil which are a major parameters of generator were improved, the system bandwidth could be increased, therefore the generator could also be satisfied with fast characteristic loads. Established the brief control model of the generator, it could be possible to do the analysis of generator performance, and improve the operational stability of the generator system using the control model.

• Journal of Power System Engineering
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• v.11 no.1
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• pp.16-19
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• 2007

The large generator rotor used in fossil power plant has the possibility of high 2X vibration due to asymmetric shaft stiffness. The generator rotor is machined into pole faces to reduce stiffness difference and then is tested through 2X vibration measurement when the balancing works are performed in the balancing shop. However, there are many cases of large difference values between 2X vibration in the balancing shop and 2X vibration in site. This paper presents a new method to estimate 2X vibration in site with more accuracy and applied for the retrofit of a fossil 400 MW class deteriorated generator. It shows that the new generator rotor is manufactured with a good 2X vibration characteristics and is operated in a low 2X vibration level although the generator rotor has high 2X vibration in the balancing shop.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.560-564
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• 2004

The optimal design and combustion analysis of the gas generator for Liquid Rocket Engine (LRE) were performed. A fuel-rich gas generator in open cycle turbopump system was designed for 10ton$_{f}$ in thrust with RP-1/Lox propellant. The optimal design was done for maximizing specific impulse of main combustion chamber with constraints of combustion temperature and power matching required by turbopump system. Design variables were selected as total mass flow rate to gas generator, O/F ratio in gas generator, turbine injection angle, partial admission ratio, and turbine rotational speed. Results of optimal design show the dimension of length, diameter, and contraction ratio of gas generator. Also, the combustion test was conducted to evaluate the performance of injector and combustion chamber. And the effect of the turbulence ring was investigated on the mixing enhancement in the chamber.r.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.4
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• pp.198-203
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• 2013

There are conditions that can be unbalanced three phase currents in a large generator by untransposed lines, unbalanced loads, unsymmetrical faults, and open phases. The unbalanced conditions can producing negative sequence components of current that induce two times frequence current in the surface of the rotor, the retaining rings, the slot wedges in the field windings. These rotor currents make the rotor rapidly overheat, so the rotor can cause substantial damage in a very short time. This paper presents the digital negative sequence relay algorithm for unbalanced protection in a generator. The proposed algorithm was tested by using collected current signals on PSCAD/EMTDC considering a hydro turbine based generator control system. It can be seen that the proposed relaying by negative sequence current is useful for detection of unbalanced state of large generator.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.216-219
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• 2021

In the Eco-Friendly Ship Act, the shaft generator is an equipment for eco-friendly ships. However, in order to apply the new technology in ships, high reliability is required, and the HILS (hardware in loop system) test is used as a verification method for this. Therefore, in this paper, a shaft generator is modeled and simulated for HILS test of a tugboat to which a shaft generator is applied. Through simulation, it was verified that the charging/discharging of the shaft generator operates according to the scenario.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.48-49
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• 2006

Recently, Importance of Generator's Active/Reactive Power Control Capability is highly emphasized for prevention of Large Blackout. Especially, Generator's frequency Response Capability is important to the Power System Frequency Stability. This paper deals with the Development & Implementation of Each Generator Frequency Response Capability Test via the Injection of Artificial Frequency to the Online Generator. Actual On-line Generator's frequency Response Test was successfully implemented to 13 Generator having various fuel source.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.6
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• pp.638-644
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• 2015

This paper describes the continuing effort to analysis and design on dynamic and electrical behavior of gamma-type free piston Stirling engine/generator with dual-opposed linear generator for domestic micro-CHP (Combined Heat and Power) system. The double acting Stirling engine/generator has one displacer and two power piston which are supported by flexure springs. Two power pistons oscillate with symmetric sinusoidal displacement and are connected with moving magnet type linear generators for power generation. To operate Stirling engine/generator, combustion heat of natural gas is supplied to hot-end and heat is rejected from cold-end by cooling water. The temperature difference across the displacer induces the oscillating motion, and it can be explained with mass-spring vibration system. The purpose of this paper is to describe the design process of linear generator for the double acting free-piston Stirling engine.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.2
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• pp.55-60
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• 2014

In general, A synchronous generator is higher than the voltage stability of the induction generator. However, induction generator has many advantages rather than a synchronous generator in terms of price and maintenance. So, coverage rate of the induction generator is gradually increasing in small hydroelectric power station rather than 1000kW recently. In order to increase the penetration of induction generator, pre-analysis of the operation of the generator is needed. In this study, we analyzed for the problems that occur when synchronous generator and induction generator of 1500kW is connected to the distribution system.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.1
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• pp.60-71
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• 2019

Electrical power supply is needed to operate the radar system in the field. In addition, it should not cause performance deterioration under the environmental factors due to characteristics of military equipment, and should not cause malfunction due to electromagnetic waves generated in radar, and then should not cause malfunction in radar equipment. Therefore, By applying a permanent magnet to the rotor of the generator, light weighting and high efficiency of generator were achieved. As a result, electrical performance test of the generator, the rated output power was 80.8 kW, the maximum output power was 88.1 kW, and the output power efficiency was 98.1 % under the full load condition. When the load capacity of the generator was changed from no load to full load, the maximum voltage variation was 3.6 % and the frequency variation was 0.3 %. As a result of the transient response test for measuring the output power of the generator according to the load characteristics change, the maximum voltage variation of 7.9 %, frequency variation of 0.5 % were confirmed, and the transient response time was 2.1 seconds. Environmental tests were conducted in accordance with MIL-STD-810G and MIL-STD-461F to evaluate the operability of the generator groups. Normal operation of radar system generator group was confirmed under high temperature and low temperature environment conditions. Electromagnetic tests were conducted to check if electromagnetic wave generated from both radar system and generator group in operation caused any performance deterioration to each other. As a result, it was confirmed that the performance deterioration due to electromagnetic wave inflow, radiation, and conduction did not occur. It is expected that it should be possible to provide high efficiency power supply and stable power supply by applying to various military system as well as radar system.