An Islanding Protection for Distributed Generators

碩士 === 聖約翰科技大學 === 電機工程系碩士班 === 95 === A series of islanding detection methods for use with grid-connected distributed generator (DG) are proposed in this thesis. The proposed passive islanding detection method is based on two indices: the rate of change of frequency (ROCOF) and rate of change of vo...

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Main Authors: Wu,Jun Nan, 吳俊男
Other Authors: 張文宇
Format: Others
Language:zh-TW
Published: 2007
Online Access:http://ndltd.ncl.edu.tw/handle/79251668569248089695
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spelling ndltd-TW-095SJSM04420022015-10-13T16:45:45Z http://ndltd.ncl.edu.tw/handle/79251668569248089695 An Islanding Protection for Distributed Generators 分散式發電機之孤島保護 Wu,Jun Nan 吳俊男 碩士 聖約翰科技大學 電機工程系碩士班 95 A series of islanding detection methods for use with grid-connected distributed generator (DG) are proposed in this thesis. The proposed passive islanding detection method is based on two indices: the rate of change of frequency (ROCOF) and rate of change of voltage (ROCOV). The detection system monitors the terminal voltage at the grid-interconnected point, and operates when the value of ROCOF or ROCOV exceeds a setting and duration exceeds a time delay setting. When DG is grid-interconnected, the ROCOF and ROCOV are lower than the threshold values. In contrast, as an islanding occurs, the ROCOF or ROCOV would become much higher than the threshold values. Two proposed active islanding detection methods are based on voltage fluctuation injections. One method obtains voltage fluctuation through the high impedance load switching on the grid periodically. Another method obtains voltage fluctuation through the field voltage regulating of the DG periodically. The correlation factor between the periodic perturbed signal and the fluctuant voltage is then used as an islanding detection index. When DG is connected to the grid, the correlation factor is lower than a threshold value. In contrast, as an islanding occurs, the correlation factor would become much higher than the threshold value. Experiments are discussed which demonstrate the principles of the technique. Test results are presented which show that the new proposed methods are reliable, economical and easy for implementation. 張文宇 2007 學位論文 ; thesis 0 zh-TW
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description 碩士 === 聖約翰科技大學 === 電機工程系碩士班 === 95 === A series of islanding detection methods for use with grid-connected distributed generator (DG) are proposed in this thesis. The proposed passive islanding detection method is based on two indices: the rate of change of frequency (ROCOF) and rate of change of voltage (ROCOV). The detection system monitors the terminal voltage at the grid-interconnected point, and operates when the value of ROCOF or ROCOV exceeds a setting and duration exceeds a time delay setting. When DG is grid-interconnected, the ROCOF and ROCOV are lower than the threshold values. In contrast, as an islanding occurs, the ROCOF or ROCOV would become much higher than the threshold values. Two proposed active islanding detection methods are based on voltage fluctuation injections. One method obtains voltage fluctuation through the high impedance load switching on the grid periodically. Another method obtains voltage fluctuation through the field voltage regulating of the DG periodically. The correlation factor between the periodic perturbed signal and the fluctuant voltage is then used as an islanding detection index. When DG is connected to the grid, the correlation factor is lower than a threshold value. In contrast, as an islanding occurs, the correlation factor would become much higher than the threshold value. Experiments are discussed which demonstrate the principles of the technique. Test results are presented which show that the new proposed methods are reliable, economical and easy for implementation.
author2 張文宇
author_facet 張文宇
Wu,Jun Nan
吳俊男
author Wu,Jun Nan
吳俊男
spellingShingle Wu,Jun Nan
吳俊男
An Islanding Protection for Distributed Generators
author_sort Wu,Jun Nan
title An Islanding Protection for Distributed Generators
title_short An Islanding Protection for Distributed Generators
title_full An Islanding Protection for Distributed Generators
title_fullStr An Islanding Protection for Distributed Generators
title_full_unstemmed An Islanding Protection for Distributed Generators
title_sort islanding protection for distributed generators
publishDate 2007
url http://ndltd.ncl.edu.tw/handle/79251668569248089695
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