• Title/Summary/Keyword: Power Subsystem

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Auxiliary Power Interface Design for Power Control and Distribution Unit (전력조절분배기의 보조전원 설계)

  • Park, Sung-Woo;Jang, Jin-Beak;Park, Hee-Sung;Yoon, Hee-Kwang
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2009.10a
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    • pp.239-242
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    • 2009
  • Power Control and Distribution Unit (PCDU) plays roles of power generation control for solar array panel, power storage control for battery system, power conversion for unregulated and regulated primary bus and power distribution to bus and payload system. The selection and design of the proper auxiliary power interface for PCDU depending on various mission is one of the most important step for electrical power subsystem design. In this paper, the general design approach of auxiliary power interface for PCDU which can be used for small-sized LEO satellites application is given. And, the auxiliary power design concept for always alived modules such as solar array regulator and house keeping module is also suggested.

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Safety Analysis and Safety Measures of 22900/1200V Oil Immersed Transformer at Power Supply System (전철 급전시스템의 22900/1200V 유입변압기 안전성 분석)

  • Lee, Jong-Su;Lee, Jongwoo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.9
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    • pp.1335-1342
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    • 2013
  • Subway is electrified railway system nowadays, in which liquid dielectric transformers have been widely used, though mold type transformers are replacing it. The transformers supplies large electric power and have innate hazards causing accidents under operation. A number of researcher have carried out on failures of it and have oriented to identify transformer's failure causes and how to maintain it healthy state. The transformer failures can cause serious accidents which can provoke economic loss and leads persons to kill. In this paper, we carried out a safety activity to reveal hazards and to estimate risk of subway liquid dielectric transformers using FMEA, HAZOP and What-if methods. In case of installing safety devices in oil immersed transformer, we tried to evaluate an effect on a subsystem's failure rate. We proposed how to design subsystem failure rate and safety device failure rates.

INTEGRATED DIAGNOSTIC TECHNIQUE FOR NUCLEAR POWER PLANTS

  • Gofuku, Akio
    • Nuclear Engineering and Technology
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    • v.46 no.6
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    • pp.725-736
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    • 2014
  • It is very important to detect and identify small anomalies and component failures for the safe operation of complex and large-scale artifacts such as nuclear power plants. Each diagnostic technique has its own advantages and limitations. These facts inspire us not only to enhance the capability of diagnostic techniques but also to integrate the results of diagnostic subsystems in order to obtain more accurate diagnostic results. The article describes the outline of four diagnostic techniques developed for the condition monitoring of the fast breeder reactor "Monju". The techniques are (1) estimation technique of important state variables based on a physical model of the component, (2) a state identification technique by non-linear discrimination function applying SVM (Support Vector Machine), (3) a diagnostic technique applying WT (Wavelet Transformation) to detect changes in the characteristics of measurement signals, and (4) a state identification technique effectively using past cases. In addition, a hybrid diagnostic system in which a final diagnostic result is given by integrating the results from subsystems is introduced, where two sets of values called confidence values and trust values are used. A technique to determine the trust value is investigated under the condition that the confidence value is determined by each subsystem.

통신위성 원격측정명령계 RF 링크버짓 개념설계 연구

  • Kim, Joong-Pyo;Koo, Cheol-Hea
    • Aerospace Engineering and Technology
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    • v.1 no.2
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    • pp.45-50
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    • 2002
  • A conceptual design on the link budget of TC&R RF subsystem which transfers command and telemetry data as RF signal between the ground system and the 2005SAT spacecraft is presented in this paper. In order to perform the analysis of the link budget, we divided the analysis process into two processes, i.e., uplink and downlink process. For the uplink the power flux density at the spacecraft and the margin of the command receiver are calculated. In the case of the downlink the downlink EIRP and the margin of C/ No and Eb / No at the ground station are calculated. Through the uplink performance analysis, the power at the command receiver has well efficient margin, and the margin of C/ No and Eb / No is also fully proper for the downlink case.

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Standard Model Development for EPS Simulator of a Satellite (인공위성 전력계 시뮬레이터의 표준화 모델 개발)

  • Jung, Ok-Chul;Lee, Sang-Uk;Kim, Jae-Hoon
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.360-362
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    • 2005
  • In this paper, standard model for electrical power subsystem of a satellite simulator is presented and analyzed. The main purpose of standard model simulator is to promote platform independency, interoperability and reusability of simulation models. And, EPS simulator prototype model is proposed using the SMP2 standard.

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Analysis of Passive Intermodulation Distortion of Ku-Band Payload System for Communication & Broadcasting Satellite (통신방송위성 Ku 대역 탑재체 수동 상호혼변조왜곡 분석)

  • 이용민;김현국;정태진;이성팔;박계영
    • Proceedings of the IEEK Conference
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    • 2002.06a
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    • pp.355-358
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    • 2002
  • This paper describe the passive intermodulation products(PIMs) which are formed in high power Ku-band transponder and antenna subsystem on the Communication St Broadcasting Satellite(CBS)program when two transmit carriers beat together to generate harmonics that fall into the receive band. How the PIMs are initially generated and the effect of PIMs for Ku-Band payload system are analyzed by calculating the PIMs frequencies and the power level of PIMs.

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Development of SCADA Simulator for Power System Operator (기존 SCADA 시스템의 훈련용 시뮬레이터 개발)

  • Choe, Seong-Su;Woo, Hee-Gon;Suh, Joong-Seok
    • Proceedings of the KIEE Conference
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    • 1993.07a
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    • pp.522-524
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    • 1993
  • This paper discusses the training simulator designed to improve the skills of operators who handle the SCADA System of KEPCO (Korea Electric Power Co. ). The system is composed of the simulation subsystem and database, and implemented on the 380-based P. C. It is 1 inked to existing SCADA system (HARRIS and TADCOM) to work realistically for the situation of accidents and corresponding actions.

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On the study of decentralized model reference adaptive controller design (분산형 기준모델 적응 제어기 구성에 관한 연구)

  • 장석주;김국헌;양흥석
    • 제어로봇시스템학회:학술대회논문집
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    • 1987.10b
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    • pp.193-197
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    • 1987
  • Decentralized model reference adaptive controller is used to control interconnected system. Influences caused by interactions between each subsystem are regarded as unmodeled dynamics or disturbances, thus decentralized adaptive controller is designed using MRAC algorithms which guarantees robustness. To expand the stability regions of over all system and to improve control performances, higher level controller is introduced to adjust the control factors such as filter band, size of deadzone or maximum norm of parameter. Local controllers for each subsystem are realized in real time and higher level controller has an ability of detecting the instability phenomena and adjusts the local controller by analysis of power spectrum or square sum of tracking errors.

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Reliability Analysis Procedures for Repairable Systems and Related Case Studies (수리 가능 시스템의 신뢰성 분석 절차 및 사례 연구)

  • Lee, Sung-Hwan;Yum, Bong-Jin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.9 no.2 s.25
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    • pp.51-59
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    • 2006
  • The purpose of this paper is to present reliability analysis procedures for repairable systems and apply the procedures for assessing the reliabilities of two subsystems of a specific group of military equipment based on field failure data. The mean cumulative function, M(t), the average repair rate, ARR(t), and analytic test methods are used to determine whether a failure process follows a renewal or non-renewal process. For subsystem A, the failure process turns out to follow a homogeneous Poisson process, and subsequently, its mean time between failures, availability, and the necessary number of spares are estimated. For subsystem B, the corresponding M(t) plot shows an increasing trend, indicating that its failure process follows a non-renewal process. Therefore, its M(t) is modeled as a power function of t, and a preventive maintenance policy is proposed based on the annual mean repair cost.