tailieunhanh - Báo cáo hóa học: " Research Article Classification of Underlying Causes of Power Quality Disturbances: Deterministic versus Statistical Methods"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Classification of Underlying Causes of Power Quality Disturbances: Deterministic versus Statistical Methods | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2007 Article ID 79747 17 pages doi 2007 79747 Research Article Classification of Underlying Causes of Power Quality Disturbances Deterministic versus Statistical Methods Math H. J. Bollen 1 2 Irene Y. H. Gu 3 Peter G. V. Axelberg 3 and Emmanouil Styvaktakis4 1STRIAB 771 80Ludvika Sweden 2 EMC-on-Site Luleă University of Technology 931 87 Skellefted Sweden 3 Department of Signals and Systems Chalmers University of Technology 412 96 Gothenburg Sweden 4 The Hellenic Transmission System Operator 17122 Athens Greece Received 30 April 2006 Revised 8 November 2006 Accepted 15 November 2006 Recommended by Moises Vidal Ribeiro This paper presents the two main types of classification methods for power quality disturbances based on underlying causes deterministic classification giving an expert system as an example and statistical classification with support vector machines a novel method as an example. An expert system is suitable when one has limited amount of data and sufficient power system expert knowledge however its application requires a set of threshold values. Statistical methods are suitable when large amount of data is available for training. Two important issues to guarantee the effectiveness of a classifier data segmentation and feature extraction are discussed. Segmentation of a sequence of data recording is preprocessing to partition the data into segments each representing a duration containing either an event or a transition between two events. Extraction of features is applied to each segment individually. Some useful features and their effectiveness are then discussed. Some experimental results are included for demonstrating the effectiveness of both systems. Finally conclusions are given together with the discussion of some future research directions. Copyright 2007 Hindawi Publishing Corporation. All rights reserved. 1. INTRODUCTION With the increasing amount .