• Title/Summary/Keyword: Adaptive protection

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An Adaptive Overcurrent Relay for a Wind Power Generator Having Variable Outputs (풍력발전기의 출력변화에 따른 적응형 과전류계전기)

  • Choi, Dong-Min;Kwon, Young-Jin;Lee, Dong-Kyu;Kang, Sang-Hee
    • Proceedings of the KIEE Conference
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    • 2005.11b
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    • pp.99-101
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    • 2005
  • This paper presents an adaptive overcurrent relay applied to interconnecting wind generators in distribution networks. When a fault occurs in the case of the decreasing the wind power generator output, the conventional overcurrent relay can't detect the fault. The suggested adaptive overcurrent relay can detect. An adaptive overcurrent relay improves reliability and security of the power system protection with distributed generator APSCAD/EMTDC simulation results have shown effectiveness of the proposed method.

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New Adaptive Linear Combination Structure for Tracking/Estimating Phasor and Frequency of Power System

  • Wattanasakpubal, Choowong;Bunyagul, Teratum
    • Journal of Electrical Engineering and Technology
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    • v.5 no.1
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    • pp.28-35
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    • 2010
  • This paper presents new Adaptive Linear Combination Structure (ADALINE) for tracking/estimating voltage-current phasor and frequency of power system. To estimate the phasors and frequency from sampled data, the algorithm assumes that orthogonal coefficients and speed of angular frequency of power system are unknown parameters. With adequate sampled data, the estimation problem can be considered as a linear weighted least squares (LMS) problem. In addition to determining the phasors (orthogonal coefficients), the procedure estimates the power system frequency. The main algorithm is verified through a computer simulation and data from field. The proposed algorithm is tested with transient and dynamic behaviors during power swing, a step change of frequency upon islanding of small generators and disconnection of load. The algorithm shows a very high accuracy, robustness, fast response time and adaptive performance over a wide range of frequency, from 10 to 2000 Hz.

Development of ACL Modul For Agent Communication in Auto-Adaptive OCR Agent (자율적응형 과전류계전기 에이전트의 통신을 위한 ACL모듈 개발)

  • Oh, T.W.;Lee, S.J.;Choi, M.S.;Kim, K.H.;Lim, S.I.;Min, B.W.;Lee, H.W.
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.193-195
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    • 2002
  • In this paper, a communication module is proposed to be applied to communication between over current relay (OCR) agents in multi agent protection system. A multi agent system can achieve a global goal beyond the ability of each individual agent by working together, in which it is the prerequisite for each agent to be able to exchange or share information or processing status with other agent. The proposed communication module is purposed to enable not only each agent to bring about its own goal, but also the whole protective system to provide much improved coordinated protection. It is applied to a self adaptive protection system for a distribution network using multi agent concept to show its effectiveness.

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A Study on the Development of Adaptive Clothing for the Dementia Patients (치매환자용 기능성 의류개발)

  • Lee, Seung-Min;Lee, Kyung-Ok
    • Fashion & Textile Research Journal
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    • v.16 no.6
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    • pp.849-859
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    • 2014
  • This study developed adaptive clothing to increase psychological comfort and protection for dementia patients. Our research method and data collection were as follows. The author selected and interviewed 10 caregivers and nurses to understand dementia patient behavior. The author collected eight pieces of clothing designed for dementia patients that are sold in Korean and overseas markets. We then analyzed garment details, open systems, close systems, and expected functions. Adaptive clothing for dementia patients were developed based upon our research. The results are as follows. First, dementia patients' behavior differed by dementia patient symptoms. Second, all items sold in Korean and overseas markets were jump suits designed to prevent behavior characteristic of dementia patients. Third, the author designed and manufactured five pieces of adaptive clothing for dementia patients that included two for mild dementia patients and three for moderate dementia patients. A panel of 50 caregivers gave high marks to developed clothing in regards to functionality, hygiene, patient human rights and aesthetics. The adaptive clothing of dementia patients from this research will increase the psychological and emotional satisfaction of dementia patients.

A Study on Distance Relay of Transmission UPFC Using Artificial Neural Network (신경회로망을 이용한 UPFC가 연계된 송전선로의 거리계전기에 관한 연구)

  • Lee, Jun-Kyong;Park, Jeong-Ho;Lee, Seung-Hyuk;Kim, Jin-O
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.6
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    • pp.37-44
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    • 2004
  • This paper represents a new approach for the protective relay of power transmission lines using a Artificial Neural Network(ANN). A different fault m transmission lines need to be detected classified and located accurately and cleared as fast as possible. However, The protection range of the distance relay is always designed on the basis of fixed settings, and unfortunately these approach do not have the ability to adapt dynamically to the system operating condition. ANN is suitable for the adaptive relaying and the detection of complex faults. The backpropagation algerian based multi-layer protection is utilized for the teaming process. It allows to make control to various protection functions. As expected, the simulation result demonstrate that this approach is useful and satisfactory.

Intelligent Electronic Device for Power Transformer Protection (전력용 변압기 보호를 위한 IED)

  • Park, Chul-Won;Shin, Myong-Chul
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.365-367
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    • 2005
  • This paper proposes a hardware of IED for power transformer protection that is well constructed using DSP chip and MPU chip. The performance of the adaptive relaying algorithm, by real-time testing in a prototype of it, has been verified. And test results indicate the proposed relaying of the IED was proven to be faster and more reliable.

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An Adaptive Setting Method for the Overcurrent Relay of Distribution Feeders Considering the Interconnected Distributed Generations

  • Jang Sung-Il;Kim Kwang-Ho;Park Yong-Up;Choi Jung-Hwan;Kang Yong-Cheol;Kang Sang-Hee;Lee Seung-Jae;Oshida Hideharu;Park Jong-Keun
    • KIEE International Transactions on Power Engineering
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    • v.5A no.4
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    • pp.357-365
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    • 2005
  • This research investigates the influences of distributed generations (DG), which are interconnected to the bus by the dedicated lines, on the overcurrent relays (OCR) of the neighboring distribution feeders and also proposes a novel method to reduce the negative effects on the feeder protection. Due to the grid connected DG, the entire short-circuit capacity of the distribution networks increases, which may raise the current of the distribution feeder during normal operations as well as fault conditions. In particular, during the switching period for loop operation, the current level of the distribution feeder can be larger than the pickup value for the fault of the feeder's OCR, thereby causing the OCR to perform a mal-operation. This paper proposes the adaptive setting algorithm for the OCR of the distribution feeders having the neighboring dedicated feeders for the DG to prevent the mal-operations of the OCR under normal conditions. The proposed method changes the pickup value of the OCR by adapting the power output of the DG monitored at the relaying point in the distribution network. We tested the proposed method with the actual distribution network model of the Hoenggye substation at the Korea Electric Power Co., which is composed of five feeders supplying the power to network loads and two dedicated feeders for the wind turbine generators. The simulation results demonstrate that the proposed adaptive protection method could enhance the conventional OCR of the distribution feeders with the neighboring dedicated lines for the DG.

Adaptive Bit-Reliability Mapping for LDPC-Coded High-Order Modulation Systems (LDPC 부호화 고차 변조 시스템을 위한 신뢰성 기반의 적응적 비트 매핑 기법)

  • Joo, Hyeong-Gun;Hong, Song-Nam;Shin, Dong-Joon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.12C
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    • pp.1135-1141
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    • 2007
  • In this paper, an adaptive bit-reliability mapping is proposed for the bit-level Chase combining in LDPC-coded high-order modulation systems. Contrary to the previously known bit-reliability mapping that assigns the information (or parity) bits to more (or less) reliable bit positions, the proposed mapping adaptively assigns codeword bits to the bit positions of various reliabilities by considering the characteristics of code and protection levels of bits in high-order modulation symbol. Compared with the symbol-level Chase combining and the constellation rearrangement bit mapping, the proposed mapping gives $0.7{\sim}1.3$ dB and $0.1{\sim}1.0$ dB performance gain at $FER=10^{-3}$ with no additional complexity, respectively. Adaptive bit-reliability mappings are derived for various environments and the validity of them is confirmed through simulation.

An Adaptive Watermark Detection Algorithm for Vector Geographic Data

  • Wang, Yingying;Yang, Chengsong;Ren, Na;Zhu, Changqing;Rui, Ting;Wang, Dong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.1
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    • pp.323-343
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    • 2020
  • With the rapid development of computer and communication techniques, copyright protection of vector geographic data has attracted considerable research attention because of the high cost of such data. A novel adaptive watermark detection algorithm is proposed for vector geographic data that can be used to qualitatively analyze the robustness of watermarks against data addition attacks. First, a watermark was embedded into the vertex coordinates based on coordinate mapping and quantization. Second, the adaptive watermark detection model, which is capable of calculating the detection threshold, false positive error (FPE) and false negative error (FNE), was established, and the characteristics of the adaptive watermark detection algorithm were analyzed. Finally, experiments were conducted on several real-world vector maps to show the usability and robustness of the proposed algorithm.

An Adaptive Reclosing Algorithm to Discriminate between Permanent Fault and Transient Fault using THD of Voltage Waveform (전압파형의 THD를 이용한 영구/일시고장 판별 적응형 재폐로 기법)

  • Lee, Chul-Moon;Kim, Chul-Hwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.8
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    • pp.1347-1352
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    • 2010
  • This paper presents a new adaptive single-phase auto reclosure (SPAR) algorithm to discriminate between a permanent fault and a transient fault and to minimize a protection dead time. The algorithm precisely detects the extinction of the secondary arc, based on THD's profiles on the faulted phase voltage waveform. The EMTP/ATPDraw program was used to simulate the single phase grounding fault for evaluating the proposed algorithm. And the simulation results show that the proposed algorithm is performing well.