• 제목/요약/키워드: Saturation current

검색결과 658건 처리시간 0.028초

직통직권 발전기에 의한 직통분권 전동기의 특성해석 (Analysis of D-C Shunt Motor Characteristics, driving D-C Series Generator)

  • 이승원;한송엽
    • 전기의세계
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    • 제16권1호
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    • pp.7-13
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    • 1967
  • There are many kinds of motors operating by rated voltage which is constant. In this paper, the characteristics of separately excited direct current motor is analyzed when its terminal voltage is varied as its load current. As for this source, direct current generator of a series field is used, and it is driven at constant speed by a primemover. The induced voltage of the generator is propotional to its load current but it saturates as its load current is large. The charateristics of motor is studied by analog computer because of the nonlinearity of generator. The results are as follows: (1) The load current and the rotor speed of motor increase as the load of motor increases. But the speed of rotor decreases for the influence of the saturation of the iron of generator field when its load current is large. (2) Decreasing the inertia of motor and increasing the inductance of the armature circuit improve the stability of motor and the region of stable state. (3) By changing the field current of the motor, the speed and the direction of rotor can be controlled in wide range.

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두 개의 자속경로를 갖는 직렬연결형 초전도한류기의 이중 피크전류제한 특성 (Double Peak Current Limiting Properties of Series Connection-Type SFCL with Two Magnetic Paths)

  • 고석철;한태희;임성훈
    • 조명전기설비학회논문지
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    • 제28권7호
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    • pp.62-68
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    • 2014
  • We proposed a series connection-type superconducting fault current limiter(SFCL) using E-I core that can prevent the internal magnetic flux generation of cores during normal operation, and prevent the saturation of cores due to a sudden magnetic flux generation at the initial stage of fault occurrence while limiting the peak current. Through a short-circuit simulation experiment, we analyzed the operating status of the two superconducting elements and limiting characteristics according to the size of the fault current peak before and after the failure. Further, the double peak current limiting characteristics according to the winding directions as well as the current and the voltage of each coil were compared and analyzed.

입력 포화를 가지는 불확실한 전기 구동 로봇 시스템에 대해 PSO를 이용한 RBFNN 기반 분산 적응 추종 제어 (RBFNN Based Decentralized Adaptive Tracking Control Using PSO for an Uncertain Electrically Driven Robot System with Input Saturation)

  • 신진호;한대현
    • 융합신호처리학회논문지
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    • 제19권2호
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    • pp.77-88
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    • 2018
  • 본 논문은 입력 포화를 가지는 불확실한 전기 구동 로봇 시스템에 대해 입자 군집 최적화(PSO)를 이용한 방사형 기저 함수 신경망(RBFNN) 기반 분산 적응 추종 제어 기법을 제안한다. 실제적으로 로봇 시스템에서는 구동기의 포화로 인해 입력 전압과 전류 신호 크기가 제한된다. 제안된 제어기는 이러한 입력 포화를 극복하며, 어떠한 로봇 링크 및 구동기의 모델 파라미터들을 요구하지 않는다. 제시된 PSO 기법에서 쓰인 적합도 함수는 추종 오차만이 아니라 전압과 전류의 크기를 포함하는 다중 목적 함수로 표현된다. PSO 기법을 이용하여 제어 이득과 방사형 기저 함수의 개수가 자동으로 조정되어 제어 시스템의 성능이 개선된다. 리아푸노프 안정도 해석에 의해 전체 제어 시스템의 안정도가 보장된다. 제안된 제어 기법의 타당성과 강인성이 시뮬레이션 결과를 통해 검증된다.

Development of a predictive functional control approach for steel building structure under earthquake excitations

  • Mohsen Azizpour;Reza Raoufi;Ehsan Kazeminezhad
    • Earthquakes and Structures
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    • 제25권3호
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    • pp.187-198
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    • 2023
  • Model Predictive Control (MPC) is an advanced control approach that uses the current states of the system model to predict its future behavior. In this article, according to the seismic dynamics of structural systems, the Predictive Functional Control (PFC) method is used to solve the control problem. Although conventional PFC is an efficient control method, its performance may be impaired due to problems such as uncertainty in the structure of state sensors and process equations, as well as actuator saturation. Therefore, it requires the utilization of appropriate estimation algorithms in order to accurately evaluate responses and implement actuator saturation. Accordingly, an extended PFC is presented based on the H-ifinity (H∞) filter (HPFC) while considering simultaneously the saturation actuator. Accordingly, an extended PFC is presented based on the H-ifinity (H∞) filter (HPFC) while considering the saturation actuator. Thus, the structural responses are formulated by two estimation models using the H∞ filter. First, the H∞ filter estimates responses using a performance bound (𝜃). Second, the H∞ filter is converted into a Kalman filter in a special case by considering the 𝜃 equal to zero. Therefore, the scheme based on the Kalman filter (KPFC) is considered a comparative model. The proposed method is evaluated through numerical studies on a building equipped with an Active Tuned Mass Damper (ATMD) under near and far-field earthquakes. Finally, HPFC is compared with classical (CPFC) and comparative (KPFC) schemes. The results show that HPFC has an acceptable efficiency in boosting the accuracy of CPFC and KPFC approaches under earthquakes, as well as maintaining a descending trend in structural responses.

충청북도 학교도서관 장서 및 보존 현황 분석 연구 (A Study on the Analysis of Book Saturation and Preservation Status in School Libraries in Chungcheongbuk-do)

  • 노영희;강봉숙;곽승진;장인호
    • 한국문헌정보학회지
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    • 제58권1호
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    • pp.83-97
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    • 2024
  • 본 연구에서는 충청북도교육청을 중심으로 한 공동보존관의 설립 타당성을 검토하고자 학교도서관 담당자를 대상으로 설문조사를 실시하였다. 연구결과, 첫째, 조사대상 학교도서관들은 이미 포화도가 극에 달해 개별 도서관은 장서 포화도의 관리와 적정 장서 수의 관리를 요구받는 상황이었다. 둘째, 장서보존을 위한 시설을 갖추고 있는 도서관이 거의 없었다. 셋째, 78%의 학교도서관에서 장서포화도가 이미 75% 이상을 넘고 있고, 이로 인해, 매년 폐기 장서가 폭발적으로 증가하고 있는 것으로 조사되었다. 따라서, 신속한 공동보존 자료관의 체계적인 운영이 필요한 것으로 보인다. 또한 단위 도서관에 보존을 위한 시설을 갖추기 어려운 상황으로 희귀서, 특화자료 등 보존가치가 있는 자료는 공동보존자료관으로 이관이 필요하며, 자료보존 관련 정책 및 규정도 필요할 것이다.

대전력 시험설비용 변류기 특성에 관한 연구 (A Study of Current Transformer for High Power Testing Facility)

  • 정흥수;나대열;김선구;노창일;김원만;이동준
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 B
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    • pp.735-737
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    • 2002
  • A current transformer for measuring current in high power testing laboratory is exactly proportional to the current including D.C component due to electrical transient. But, current transformer isn't designed to consider D.C component, therefore when data acquisition system measure that current. the error is increased because of saturation of core. This paper describe the concept of transient factor and how to design the current transformer.

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디지털 제어 시스템의 연산시간 지연을 고려한 예측전류제어기에 관한 연구 (A Study on the Predictive Current Controller with the Compensation of Computation Time Delay in a Digital Control Systems)

  • 우명호;정승기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 F
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    • pp.2028-2032
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    • 1997
  • When a high performance current control is desired, a computation time delay of a digital control system may deteriorate the control performance of a current controller. Such a non-negligible effect can be considerable in transient state. This paper deals with the modified predictive current control that compensates the time delay effects of a conventional predictive current control. The method is closely related to a local average current control and a symmetrical PWM pattern generation. Also some theoretical approaches are presented to describe the voltage saturation boundary of the power converter. For validation, the proposed method is applied to an active power filter system. The experimental results show considerable improvement in current tracking capability.

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광전자식 과전류 보호계전기의 구현 및 성능 평가 (Implementation and Performance Evaluation of Opto-Electronic OverCurrent Relay)

  • 박병석;안성준;장문종;우희곤
    • 제어로봇시스템학회논문지
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    • 제6권3호
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    • pp.284-290
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    • 2000
  • The measurement of electric current using optical techniques provides a number of important practical advantages including effective isolation from high line potentials and freedom from the saturation effects observed in conventional current transformers. In this work the optical current sensor which uses thin YIG(Yittrium Ion Garnet) film as a Faraday element has been developed. We have characterized this optical current sensor and implemented it to the OOCR(Opto-electronic OverCurrent Realy) Performance of the OOCR shows the possibility of replacing the present overcurrent relays with OOCR.

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변압기 보호용 전류비율차동 계전기의 동작영역 설정방법 (Setting Method of a Percentage Current Differential Relay for Transformer Protection)

  • 김수환;강상희
    • 전기학회논문지
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    • 제60권1호
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    • pp.8-13
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    • 2011
  • A percentage current differential relay is widely used for transformer protection. Because many percentage current differential relays recently use modified methods instead of conventional methods for deciding the operating characteristics of the large current region, in this paper, the operating region of a percentage current differential relay is analyzed in input-output current domain instead of operating-restraint current domain. An effective method to set the operating region when a CT is saturated is proposed with a series of investigations comparing a conventional method with the proposed modified method. The performance of the proposed method is evaluated for internal and external faults of a power transformer having the voltage rating of 345/154kV. EMTP-RV is used for the relaying data collection.

전력시스템 보호를 위한 공극을 이용한 유도형 고온초전도체 한류기의 디자인과 동작특성 (Novel Design and Operational Characteristics of Inductive High-Tc Superconducting Fault Current Limiter to Protection the Power System)

  • 장미혜;이찬주;주민석;고태국
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 A
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    • pp.281-283
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    • 1999
  • A novel prototype of an inductive superconducting fault current limiter with an iron core and an air sap was fabricated and tested. If its impedance is not high enough to limit the fault current, then destructive damage occurs in the power system. We attained a magnetic saturation under the higher current by introducing an air gap in the three-legged magnetic core. The fault current was successfully limited to two times as much as the nominal current without high fault current within 1/4 cycles at a 60 Hz source having an effective voltage of 70V.

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