• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.427-431
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• 2009

In this study, the dynamic characteristic of a contact wire and pantograph suppling electrical power to high-speed trains are investigated from an electrical response point of view. To analysis power line disturbance by induced contact loss phenomenon for high speed operation, a hardware Simulator which considered contact loss between contact wire and the pantograph as well as contact wire deviation is developed. It is confirmed that a contact wire and pantograph model are necessary for studying the dynamic behavior of the pantograph system. One of the most important needs accompanied by increasing the speed of high-speed train is reduced that an arc phenomenon by loss of contact brings out EMI. In case of a high-speed train using electrical power, as comparison with diesel rolling stock, PLD(Power Line Disturbance) such as harmonic, transient voltage and current, EMI(Electromagnetic Interference), dummy signal injection etc usually occurs. Throughout experiment, it is verified that an arc phenomenon is brought out for simulator operation and consequently conducted noise is flowed in electric circuit by power line disturbance.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
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• pp.93-93
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• 1999

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.1-7
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• 2008

This paper presents electromagnetic interference(EMI) suppression method applied on the direct current(DC) motor driver for power tail gate control. EMI noise is generated by the fast switching of power devices connected to electric loads. It has become a matter of concern because of the vast increase in the number and sophistication of electronic system in automotive environment. The proposed EMI reduction method is based on the principle of reducing the transient speed of power devices by changing the parameters of the driver circuit related to the power MOSFET. In this paper, power losses were calculated by loss equations and thermal simulation was used to evaluate the effect on printed circuit board. Based on these results, the DC motor driver was fabricated and tested. The proposed method can help to design a DC motor driver which allows it to obtain an acceptable compromise between power losses and EMI.

• Journal of IKEEE
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• v.15 no.1
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• pp.96-103
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• 2011

This paper deals with the characteristic analysis of the integrated power system applied for the electric propulsion ships. This includes the electric power system modeling which is accomplished with the electric power network mainly composed of generators, switchboards, variable frequency devices, electric motors, and etc. In addition, performance comparison between the permanent magnet synchronous motor (PMSM) and the induction motor (IM) for 3.7MW ship propulsion has been done. In order to investigated the main performance of propulsion motor, a coupled model taking into account torque density, copper loss, iron loss, efficiency, power factor, and torque ripple using finite element analysis (FEA) has been employed.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.4
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• pp.389-392
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• 2020

In order to accurately predict the losses in the power cable, analysis of the eddy current losses in the metal sheath is required. The copper loss is easily calculated by the resistance and current of the conductor, but it is difficult to measure and predict the eddy current generated from the metal sheath. For this purpose, the previous study analyzed the eddy current loss in single phase cable, but there is a limit to apply it because three phase cables are used in real environment. Therefore, in this paper, the eddy current loss occurring in the metal sheath of three phase cable according to the cause was analyzed theoretically. In addition, the eddy current loss occurring in the triangular and horizontal array were predicted through electromagnetic numerical analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.3
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• pp.231-240
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• 2005

Recently, the needs and concerns for the power loss are increasing according to the energy conservation at the level of the national policies and power utilities's business strategies. Especially, the issue of the power loss is the main factor for the determining the electric pricing rates in the circumstances of the deregulation of electrical industry. However, because of the lacking of management for power loss load factors (LLF) it is difficult to make a calculation for the power loss and to make a decision for the electric rates. And loss factor (k-factor) in korea, which is a most important factor for calculation of the distribution power loss, has been used as a fixed value of 0.32 since the fiscal year 1973, There(ore, this study presents the statistical calculation methods of the loss factors classified by load types and seasons by using the practical data of 65 primary feeders which are selected by proper procedures. Based on the above the algorithms and methods, the optimal method of the distribution loss management classified by facilities such as primary feeders, distribution transformers and secondary feeders is presented. The simulation results show the effectiveness and usefulness of the proposed methods.

• Proceedings of the KIEE Conference
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• 2006.07e
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• pp.31-32
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• 2006

Pohang accelerator Laboratory is from 1994 analyzed electric power amount used for about 10 years. It is one of equipment that consume electric power of greate electric power to single test equipment. Accelerator Laboratory institute investigates the consumption rate of energy that is spent to each building could divide by linear accelerator and save ring and analyzed about the equipment utilization rate and average electric power. Countermeasure that this treatise can forecast power loss of electric power by equipment through analysis of electric power amount used and heighten the utilization rate of equipment wishes to do comparative analysis.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.381-384
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• 2008

This paper presents an operational technique to maximize profit of a cogeneration power plant. To minimize errors in a loss and gain analysis of a cogeneration power plant, the energy sale profit in the cost-based-pool electric power trade market, the heat sale profit, and the supplementary fund profit for electric power industry are taken into consideration. The objective is to optimize the heat-electric power ratio to maximize profit of a cogeneration power plant. Furthermore, the constrained bidding technique to optimize heat-electric power ratiocan be obtained. Profits from of a cogeneration power plant are composed of three categories, such as the energy sale profit in the cost-based-pool electric power trade market, the heat sale profit, and the supplementary fund profit for electric power industry. Profits of a cogeneration power plant are varied enormously by the operation modes. The profits are mainly determined by the amount of constrained heat generation in each trading time. And the three profit categories arecoupled tightly via the heat-electric power ratio. The result of this case study can be used as a reference to a cogeneration power plant under the power trading system considered in this case.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.2
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• pp.93-96
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• 2022

The boiler tubes of thermal power plants are exposed to harsh environment of high temperature and high pressure, and the deterioration state of materials rapidly increases. In particular, parent material and welds of the materials used are subjected to a temperature change and various constraints, resulting in deformation and its growth, resulting in frequent leakage accidents caused by tube failure. The power plant checks the integrity of boiler tubes through non-destructive testing as it may act as huge costs loss and limitation of power supply during power station shutdown period due to boiler tube leakage. However, the current non-destructive testing is extremely limited in the field to detect micro cracks. In this study, the ability of metal magnetic memory technique to detect flaws of size that are difficult to inspect by the visual or general non-destructive methods was verified in the early stage of their occurrence.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.5
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• pp.39-44
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• 2005

This paper is about the new distribution system of the electric customer inside. The power loss in the distribution system of the customer is disregarded and rarely managed so for. But, economically, this loss is not small quantity to ignore. So, in this paper, we suggest that the new distribution system of the electric customer inside by simply changing the locations of power transformer and other power facilities which is located inside of the customer. And we also show that the power loss is decreased with this systematic changing by approximated calculation.