• Title, Summary, Keyword: external bus

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Analysis of the stresses induced by magnetic field and cooling in the CICC type superconducting bus-line (CICC 형태의 초전도 버스 선에서 냉각 및 자기장에 의한 응력 해석)

  • Lee, Ho-Jin;Nam, Hyeon-Il;Kim, Gi-Baek;Hong, Gye-Won
    • Progress in Superconductivity and Cryogenics
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    • v.2 no.2
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    • pp.20-25
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    • 2000
  • A CICC type superconducting bus-line electrically connecting a superconducting magnet to a power supply is cooled down to low temperature under the external magnetic field during operation. The thermal contraction during the cooling may be constrained by the supports which are installed to protect the bus-line from Lorenz magnetic forces. This constrained contraction causes thermal stresses in the bus-line to release thermal contraction. The minimum stress conditions in the bus-line may be optimized by controlling the supporting arrangement considering the thermal contraction and the external field. The analytical method to find optimal supports arrangement was suggested by using the beam theory, and numerical calculation using commercial code was performed to verify the suggested analytical optimization method.

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Design and Implementation of Inter-IC Bus Interface for Efficient Bus Control in the Embedded System (임베디드 시스템에서 효율적인 주변장치 관리를 위한 Inter-IC Bus Interface 설계 및 구현)

  • Seo, Kyung-Ho;Seong, Kwang-Su;Choi, Eun-Ju
    • Proceedings of the IEEK Conference
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    • pp.535-536
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    • 2006
  • In the embedded system, external device interface that operates serial protocol with lower speed than the general computers is used commonly. This paper describes I2C bus protocol that is a bi-directional serial bus with a two-pin interface. The I2C bus requires a minimum amount of hardware to relay status and reliability information concerning the processor subsystem to an external device.

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A Current Differential Relaying Algorithm for Bus Protection Using a Compensating Algorithm of Secondary Currents of CTs (변류기 전류보상 알고리즘을 이용한 모선보호용 전류 차동계전 알고리즘)

  • Gang, Yong-Cheol;Yun, Jae-Seong;Kim, Dong-Yong
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.49 no.9
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    • pp.446-450
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    • 2000
  • A conventional variable percentage current differential relaying algorithm for bus protection may misoperate for external faults with severe CT saturation and internal faults with high impedance. This paper proposes a percentage differential current relaying algorithm for bus protection combined with a compensating algorithm of secondary currents of CTs. Even though CTs are saturated and their secondary currents are severely distorted, the proposed relaying algorithm does not only misoperate for external faults with CT saturation but also detects the internal faults with high fault impedance. Thus, the method improves the sensitivity of the relays and does not require any counterplan for CT saturation.

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A Percentage Current Differential Relaying Algorithm for Bus Protection Blocked by a CT Saturation Detection Algorithm (변류기 포화 곤단 알고리즘으로 억제된 모선보호용 비율 전류차동 계전방식)

  • 강용철;윤재성
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.52 no.1
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    • pp.44-49
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    • 2003
  • This paper describes a percentage current differential relaying algorithm for bus protection blocked by a CT saturation detection algorithm. The detection algorithm blocks the output of a current differential relay only if a differential current is caused by CT saturation in the case of an external fault. Moreover, if a current differential relay operates faster than the detection algorithm, the blocking signal is not ignited. On the other hand. if the detection algorithm operates faster than a current differential relay, the output of the relay is blocked. The results of the simulation show that the proposed algorithm can discriminate internal faults from external faults ever when a CT is saturated in both cases. This paper concludes by implementing the algorithm into the TMS320C6701 digital signal processor. The results of hardware implementation are also satisfactory The algorithm can not only increase the sensitivity of the current differential relay but Improve the stability of the relay for an external faults.

State Estimation for Interconnected Electric Power Systems (상호연계된 전력계통에 대한 상태추정기법의 개발)

  • Kim, Hong-Rae
    • Proceedings of the KIEE Conference
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    • pp.1180-1183
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    • 1997
  • This paper addresses the issues of the external system modeling and power system state estimation with the external model. A set of significant measurements is identified in the external system based on their sensitivities on the tie-lines. These measurement data are transferred to internal system and updated in real-time. The state estimator is run for different loading conditions by using the actual values for the internal system and selected significant external system measurements while keeping the rest of the external system measurements at their base case values. Simulation results are presented using the IEEE 118 bus system as an example.

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VLSI design of a bus interface unit for a 32bit RISC CPU (32비트 멀티미디어 RISC CPU를 위한 버스 인터페이스 유닛의 설계)

  • 조영록;안상준;이용석
    • Proceedings of the IEEK Conference
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    • pp.831-834
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    • 1998
  • This paper describes a bus interface unit which is used in a 32bit high-performance multimedia RISC CPU including DSP unit. The main idea adopted in designing is that the bus interface unit enables the processor to provide on-chip functions for controlling memory and peripheral devices, including RAS-cAS multiplexing, DRAM refresh and parity generation and checking. The number of bus cycles used for a memory or I/O access is also defined by the processor, thus, no external bus controllers are required. All memories and peripheral devices can be connected directly, pin to pin, without any glue logic. That is the key point of the design.

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Development of the Temperature Prediction Program for the Bus Bar of a Gas-insulated Switchgear (가스차단기 모선부의 온도상승 예측 프로그램 개발)

  • Ham, Jin-Ki;Kim, Young-Ki;Lee, Hee-Won;Kim, Jin-Soo;Song, Seok-Hyun
    • Proceedings of the KSME Conference
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    • pp.169-174
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    • 2003
  • The thermal design of the bus bar of a Gas-Insulated Switchgear(GIS) becomes important since the current-carrying capacity of the GIS is limited by maximum operating temperature. In order to predict temperature rise of the bus bar, a program has been developed. Various heat sources possibly generated in the bus bar are calculated in the program. To estimate temperature rises at the bus bar caused by the heat balance between the heat generation and heat transfer, the finite volume method as well as the $4^{th}$ order Runge-Kutta method has been employed. In the experiments, temperature rises at conductor, contact part and external tank are measured for full-scale gas-insulated bus bars. The comparisons of the predicted values of the heat balance calculation to those of the experiments are made. From the comparisons, it is concluded that the developed program can predict the temperature rise of the bus bar quite well.

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Implementation of Multipurpose PCI Express Adapter Cards with On-Board Optical Module

  • Koo, Kyungmo;Yu, Junglok;Kim, Sangwan;Choi, Min;Cha, Kwangho
    • Journal of Information Processing Systems
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    • v.14 no.1
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    • pp.270-279
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    • 2018
  • PCI Express (PCIe) bus, which was only used as an internal I/O bus of a computer system, has expanded its function to outside of a system, with progress of PCIe switching processor. In particular, advanced features of PCIe switching processor enable PCIe bus to serve as an interconnection network as well as connecting external devices. As PCIe switching processors more advanced, it is required to consider the different adapter card architecture. This study developed multipurpose adapter cards by applying an on-board optical module, a latest optical communications element, in order to improve transfer distance and utilization. The performance evaluation confirmed that the new adapter cards with long cable can provide the same bandwidth as that of the existing adapter cards with short copper cable.

Development of a Flash Memory Drive for ATA bus (ATA 버스 방식을 위한 Flash Memory Drive 개발)

  • Kang, Kyung-Sik;Jang, Moon-Kee;Hwang, Yeon-Bum;Jung, Nam-Mo;Park, Jin-Soo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.547-550
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    • 2005
  • This treatise studies and developed flash memory drive of ATA bus that use flash memory which is employment amount memory semiconductor to improve problem of hard-disk that is existing ATA bus. While general hard-disk is sensitive external impact or shock, but flash memory drive do save chapter as well as is strong in external impact using semiconductor memory element that disk is not low electric power, light weight possible . Practical use is expected do save chapter for embedded system or black box for vehicles, soldiers hereafter therefore.

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A Percentage Current Differential Relay for Bus Protection Using a Compensation Algorithm Unaffected by a Remanent Flux (잔류자속에 무관한 보상 알고리즘을 적용한 모선보호용 전류차동 계전방식)

  • Kang, Yong-Cheol;Yun, Jae-Sung;Lim, Ui-Jai
    • Proceedings of the KIEE Conference
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    • pp.308-310
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    • 2003
  • This paper proposes a percentage current differential relaying algorithm for bus protection with a compensation algorithm of a CT. The compensating algorithm estimates the core flux at the start of the first saturation based on the value of the third-difference of the secondary current. It calculates the core flux and compensates distorted currents in accordance with the magnetization curve. The test results indicate that the algorithm can discriminate internal faults from external faults when the CT saturates. It can improve not only stability of the relay in the case of an external fault but sensitivity of the relay in the case of an internal fault.

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