Outlier detection and data filling based on KNN and LOF for power transformer operation data classification

The missing and abnormal data in power transformer operation and monitoring greatly affect the accuracy of fault diagnosis and thus threaten the stable operation of power systems. To conduct outlier detection and improve data quality for safety warning, this paper proposes a transformer operation da...

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Main Authors: Dexu Zou, Yongjian Xiang, Tao Zhou, Qingjun Peng, Weiju Dai, Zhihu Hong, Yong Shi, Shan Wang, Jianhua Yin, Hao Quan
Format: Article
Language:English
Published: Elsevier 2023-09-01
Series:Energy Reports
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2352484723004250
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author Dexu Zou
Yongjian Xiang
Tao Zhou
Qingjun Peng
Weiju Dai
Zhihu Hong
Yong Shi
Shan Wang
Jianhua Yin
Hao Quan
author_facet Dexu Zou
Yongjian Xiang
Tao Zhou
Qingjun Peng
Weiju Dai
Zhihu Hong
Yong Shi
Shan Wang
Jianhua Yin
Hao Quan
author_sort Dexu Zou
collection DOAJ
description The missing and abnormal data in power transformer operation and monitoring greatly affect the accuracy of fault diagnosis and thus threaten the stable operation of power systems. To conduct outlier detection and improve data quality for safety warning, this paper proposes a transformer operation data preprocessing method based on KNN (K-nearest neighbor) and LOF (local outlier factor) for power transformer operation data classification. Firstly, this paper analyzes the characteristics of transformer operation data. Secondly, the local reachable density of the input data is calculated by LOF algorithm. The local outlier factor score of the data is derived according to the local reachable density, and the abnormal data is output according to the abnormal score. Then, KNN algorithm is utilized to classify the relevant data around the abnormal value and missing value of the transformer. The data are filled or corrected according to the classification results. Thirdly, the elbow method is used to determine the optimal K value and cluster operation data by K-Means algorithm. Finally, the proposed method is applied and verified with real transformer operation data in case study. The results show the method can effectively detect and correct the abnormal and missing data, conduct transformer data cleaning and preprocessing and provide accurate and effective data samples for transformer fault diagnosis.
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spelling doaj.art-d40c84194be44cd9a9897abc3261b7252023-09-06T04:51:36ZengElsevierEnergy Reports2352-48472023-09-019698711Outlier detection and data filling based on KNN and LOF for power transformer operation data classificationDexu Zou0Yongjian Xiang1Tao Zhou2Qingjun Peng3Weiju Dai4Zhihu Hong5Yong Shi6Shan Wang7Jianhua Yin8Hao Quan9Electric Power Research Institute, China Southern Power Grid Yunnan Power Grid Co., Ltd., Kunming 650217, ChinaSchool of Automation, Nanjing University of Science and Technology, Nanjing 210094, ChinaSchool of Automation, Nanjing University of Science and Technology, Nanjing 210094, China; Corresponding author.Electric Power Research Institute, China Southern Power Grid Yunnan Power Grid Co., Ltd., Kunming 650217, ChinaElectric Power Research Institute, China Southern Power Grid Yunnan Power Grid Co., Ltd., Kunming 650217, ChinaElectric Power Research Institute, China Southern Power Grid Yunnan Power Grid Co., Ltd., Kunming 650217, ChinaChina Southern Power Grid Yunnan Power Grid Co., Ltd., Kunming 650217, ChinaElectric Power Research Institute, China Southern Power Grid Yunnan Power Grid Co., Ltd., Kunming 650217, ChinaSchool of Artificial Intelligence, Nanjing University of Information Science and Technology, Nanjing 210044, ChinaSchool of Automation, Nanjing University of Science and Technology, Nanjing 210094, ChinaThe missing and abnormal data in power transformer operation and monitoring greatly affect the accuracy of fault diagnosis and thus threaten the stable operation of power systems. To conduct outlier detection and improve data quality for safety warning, this paper proposes a transformer operation data preprocessing method based on KNN (K-nearest neighbor) and LOF (local outlier factor) for power transformer operation data classification. Firstly, this paper analyzes the characteristics of transformer operation data. Secondly, the local reachable density of the input data is calculated by LOF algorithm. The local outlier factor score of the data is derived according to the local reachable density, and the abnormal data is output according to the abnormal score. Then, KNN algorithm is utilized to classify the relevant data around the abnormal value and missing value of the transformer. The data are filled or corrected according to the classification results. Thirdly, the elbow method is used to determine the optimal K value and cluster operation data by K-Means algorithm. Finally, the proposed method is applied and verified with real transformer operation data in case study. The results show the method can effectively detect and correct the abnormal and missing data, conduct transformer data cleaning and preprocessing and provide accurate and effective data samples for transformer fault diagnosis.http://www.sciencedirect.com/science/article/pii/S2352484723004250Power transformerOutlier detectionData sufficiencyLOFKNN
spellingShingle Dexu Zou
Yongjian Xiang
Tao Zhou
Qingjun Peng
Weiju Dai
Zhihu Hong
Yong Shi
Shan Wang
Jianhua Yin
Hao Quan
Outlier detection and data filling based on KNN and LOF for power transformer operation data classification
Energy Reports
Power transformer
Outlier detection
Data sufficiency
LOF
KNN
title Outlier detection and data filling based on KNN and LOF for power transformer operation data classification
title_full Outlier detection and data filling based on KNN and LOF for power transformer operation data classification
title_fullStr Outlier detection and data filling based on KNN and LOF for power transformer operation data classification
title_full_unstemmed Outlier detection and data filling based on KNN and LOF for power transformer operation data classification
title_short Outlier detection and data filling based on KNN and LOF for power transformer operation data classification
title_sort outlier detection and data filling based on knn and lof for power transformer operation data classification
topic Power transformer
Outlier detection
Data sufficiency
LOF
KNN
url http://www.sciencedirect.com/science/article/pii/S2352484723004250
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