• Proceedings of the KSR Conference
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• 2007.05a
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• pp.858-863
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• 2007

With increase of load power the case it will not be able to supply the power which is necessary to the vehicle, it establishes dosage increase of main transformer of substation or power compensation equipment, and must supply the power which is necessary. But like this method the expense and the hour when it is considerable are necessary. As an alternative plan, if neighborhood substation can supply power through parallel feeding then it can supply power applying the equipment of existing. So we investigate the possibility of parallel feeding method between neighboring substations through measuring results of voltage phase difference and analysing feeding circuit,

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.744-748
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• 2002

This paper describes a power supply of a CW magnetron for driving a electrodeless plasma lamp. The proposed power supply consists of a power factor controller, a series resonant ZVS half bridge inverter, a high voltage leakage transformer, and two IGBT drives. From the simulation results, it was confirmed that the proposed circuits can control the input power of the magnetron up to 33.3[%] linearly by adjust driving frequency of the inverter.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.459-462
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• 2005

Recently, the PDP is the most remarkable media for a next generation display device. But the PDP is a high power consumption device. It is to required a high efficiency power supply. We reported the experimental result the high efficiency PDP power supply for 550w class. The proposed converter is quasi-resonant flyback topology, it achieves soft-switching in the single-switch flyback converter. As a result, we realize to very high efficiency power supply for PDP of 95% at 400v dc input and 550Watt output.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.106-108
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• 2005

High accuracy and stability digital controlled power supply for magnet is developed at PLS. This power supply has three sections. The first section is digital controller including DSP&FPGA and precision ADC, the second section consists of IGBT driver and four quad IGBT switch, and the third section is LC output filter section. AC input voltage of power supply is 3-phase 21V, output current is 0 ${\sim}$ 150 A dc. Switching frequency of four quad IGBT switch is 25 kHz. The output current of power supply has very high accuracy of 100 A step resolution at full range and the stability of +/- 1.5 ppm for short term and +/- 5 ppm for long term. This paper describes characteristics of filter and output current performance improvement after LC output filter at four quad digital power supplies.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.216-218
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• 2017

The imbalance at the 3-phase side at the railway power supply substation has been a well-known issue. Due to the difference in status of loads at each phase at any given moment, it is difficult to maintain the balance in the 2-phase side of the transformer. Consequently, the 3-phase side also presents a certain level of imbalance as well. A co-phase power supply was proposed as a solution. The real application of such system is gradually expanding, proving the effectiveness of the system. In this paper, the application of the single phase D-Q rotating frame theory was applied to the control of the co-phase power supply system. In addition, the power stack of the system was composed of MMC valves, which offers superior operational characteristics. The effectiveness of the system was verified with a real-time simulation, and the results are presented.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.6
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• pp.738-744
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• 2018

This paper proposes a low cost hot swap operation circuit of a parallel operation power supply for servers. Hot swap function for server power system is essential in 24 hour operation system such as internet data center, server, factory and etc. Server power supplies used in internet data centers have two or more parallel operations with the hot swap operation. However, the cost of the power supply is high because the controller IC for hot swap operation is very expensive. Therefore, this paper proposes a parallel-operated power supply with a low-cost hot swap controller for servers. The proposed system can operate hot swap function by using discrete devices and reduce the cost by more than 50%. A 1.2kW prototype system is implemented to verify the proposed low cost hot swap controller.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.93-94
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• 2014

Recently, According to increase of power demand, it was increased a demand that switching power supply have characteristic of low-loss and high-efficiency. So increase of using device, the failure rate increases and service life problem arises. Even though normal circuit protection is applied in designing stage, it is often hard to identify the cause of malfunction in certain cases such as fatigued power supply due to over-running, malfunctions of main elements or over heating. This report will cover experimental results with the prototype we made, that monitors the efficiency of switching power supply and that protects a circuit when it drops below the standard value.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.164-165
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• 2012

This paper proposes an AC Chopper based DC power supply for specific DC voltage ranges. AC chopper is attached to the input side of PFC to generate specific ranges of DC voltage which are not available with PFC itself alone. The input power factor of the proposed DC power supply is proportional to that of PFC. Performance of the proposed power supply was verified by carrying out simulations.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.680-682
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• 2022

The closed-loop supply chain's central enterprises aim to maximize the revenue and reduce the reclaiming channel level to the greatest extent by using blockchain and modern management methods. The traditional recycling network has more links, and there is less communication between enterprises in each link. There is a particular "bullwhip effect" in the channel link, making it difficult for power battery manufacturers to respond to the dynamic market quickly. It is often challenging to obtain scaled waste power batteries, which aggravates how power battery raw materials are expensive and difficult to recycle. Therefore, the closed-loop supply chain design of power batteries adopting blockchain shall minimize channel links and reduce transaction levels to reduce costs.

• Environmental and Resource Economics Review
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• v.15 no.2
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• pp.269-296
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• 2006

With the concern of the potential problems which can be observed in terms of the power supply of renewable energies, we need to analyze the impact of additional power generation capacities of renewable energy sources on peak load. Each renewable energy sources are dependent upon wind speed, solar radiation, head differences caused by lunar calendar. Considering that these exogenous renewable energy sources follow their own stochastic distributions, we analyze the probability distribution of the impact of each renewable energy power supply on peak load. As a conclusion, we note that traditional tools used for the analysis of power supply such as capacity factors are no longer appropriate for the analysis of renewable energy sources in that perspective.