Detecting broken strands in transmission line — Part 1: Design of a smart eddy current transducer carried by inspection robot

SUMMARY Transmission line is the primary facility for power delivery and is mainly composed of twisted aluminum wires. During the long-term outer door field service, overhead transmission lines will encounter strikes of lightning, corrosion of chemical contaminants, ice shedding, wind vibration of conductors, lines galloping, damage due to external forces and so on which will generally bring a series of latent faults such as aluminum strands fracture. It will induce some fatal accidents such as broken transmission lines which have a very strong impact on the safe operation of power grids if the latent faults can not be recognized and restored as early as possible. The method of detecting broken strands in transmission line by inspection robot with detectors is a method with good prospect. In this paper, a kind of eddy current transducer (ECT) for detecting broken strands in transmission line is developed. The developed ECT can be integrated to the transmission line inspection robot. Simulation and field experiment results show that the magnitude field induced by transmission current has no influence on the detection of broken strands in transmission line. Hence, the developed ECT carried by robot can identify broken strands with high reliability and sensitivity. At the same time, the proposed structural style and design method of the ECT can be applied to different types of transmission line. Copyright © 2012 John Wiley & Sons, Ltd.

[1]  Alain Cardou,et al.  Use of Eddy Current Technology to Assist in the Evaluation of the Fatigue Damage of Electrical Conductors , 2008 .

[2]  Antanas Kudzys.  Safety of power transmission line structures under wind and ice storms , 2006 .

[3]  J. Sawada,et al.  A Mobile Robot for Inspection of Power Transmission Lines , 1991, IEEE Power Engineering Review.

[4]  Rahmat A. Shoureshi,et al.  Electro-Magnetic-Acoustic Transducers for Automatic Monitoring and Health Assessment of Transmission Lines , 2004 .

[5]  Xinjun Wu,et al.  Ferromagnetic material pulsed eddy current testing signal modeling by equivalent multiple-coil-coupling approach , 2011 .

[6]  C.R.F. Azevedo,et al.  Failure analysis of aluminum cable steel reinforced (ACSR) conductor of the transmission line crossing the Paraná River , 2002 .

[7]  Hwa-Young Kim,et al.  Modeling of eddy current sensor using geometric and electromagnetic data , 2007 .

[8]  Wai Ho Li,et al.  Image processing to automate condition assessment of overhead line components , 2010, 2010 1st International Conference on Applied Robotics for the Power Industry.

[9]  Tatsumi Maeda,et al.  Study of inspection of wire breakage in aluminum transmission line using SQUID , 2009 .

[10]  T. Kawashima,et al.  Electromagnetic induction method for detecting and locating flaws on overhead transmission lines , 1990 .

[11]  Y. Goda,et al.  Melting and breaking characteristics of OPGW strands by lightning , 2004 .

[12]  Nicolas Pouliot,et al.  Transmission line maintenance robots capable of crossing obstacles: State-of-the-art review and challenges ahead , 2009 .

[13]  Ryszard Tadeusiewicz,et al.  Recognition of defects in high voltage transmission lines using the acoustic signal of corona effect , 2000, Neural Networks for Signal Processing X. Proceedings of the 2000 IEEE Signal Processing Society Workshop (Cat. No.00TH8501).

[14]  Jangmyung Lee,et al.  Inspection of Insulators on High-Voltage Power Transmission Lines , 2009, IEEE Transactions on Power Delivery.

[15]  G. W. Cameron,et al.  Incomplete Faraday cage effect of helicopters used in platform live-line maintenance , 1998 .

[16]  Z. Mottl,et al.  The quantitative relations between true and standard depth of penetration for air-cored probe coils in eddy current testing , 1990 .

[17]  Lothar Gaul,et al.  Wave-based defect detection and interwire friction modeling for overhead transmission lines , 2009 .

[18]  Tatsumi Maeda,et al.  Detection of wire element breakage in power transmission line using HTS-SQUID , 2009 .

[19]  Masanori Isozaki,et al.  Study of corrosion resistance improvement by metallic coating for overhead transmission line conductor , 2008 .

[20]  C. Dodd,et al.  ANALYTICAL SOLUTIONS TO EDDY--CURRENT PROBE COIL PROBLEMS. , 1968 .

[21]  V. O. de Haan,et al.  Analytical expressions for transient induction voltage in a receiving coil due to a coaxial transmitting coil over a conducting plate , 2004 .