Vienna 26-27 January, 2004 Health Monitoring of Overhead Power Transmission Line: User Needs Dmitri SNEGOVSKI (Mech. Eng., PhD student) Transmission and Distribution of Electrical Energy University of Liege - Montefiore Institute of Electricity Belgium
Summary 1. Monitoring Problematics 2. Sag & Temperature Monitoring 3. Sensible Elements 4. Damage Diagnostics 5. Wind-Induced Vibrations 6. Vibration Measurement 7. Conclusions Vienna, 26-27 January, 2004 2 ULG - Montefiore Institute of Electricity
1. What the User Needs NOT? New York - August 14, 2003 Black-Out in USA, initiated by increased conductor sag due to overheat Vienna, 26-27 January, 2004 3 ULG - Montefiore Institute of Electricity
Concerns Ageing Increasing Power Loads Deregulation in Power Transmission Vienna, 26-27 January, 2004 4 ULG - Montefiore Institute of Electricity
Impacts Wind Corrosion Contamination Vienna, 26-27 January, 2004 5 ULG - Montefiore Institute of Electricity
What kind of monitoring user needs? Real-time & Permanent Nondestructive & Hotline Mounted Predictive, Secure, Controllable etc. Vienna, 26-27 January, 2004 6 ULG - Montefiore Institute of Electricity
Why Real-time & Permanent? > Maintenance > Optimal Power Delivery Vienna, 26-27 January, 2004 7 ULG - Montefiore Institute of Electricity
Why Real-time & Permanent? > Maintenance > Optimal Power Delivery Wind-induced motion Ageing Prevent hazards Vienna, 26-27 January, 2004 8 ULG - Montefiore Institute of Electricity
Why Real-time & Permanent? > Maintenance > Optimal Power Delivery Sag and/or Temperature Monitoring Sag Vienna, 26-27 January, 2004 9 ULG - Montefiore Institute of Electricity
Why Real-time & Permanent? > Maintenance > Optimal Power Delivery Sag and/or Temperature Monitoring Sag Vienna, 26-27 January, 2004 10 ULG - Montefiore Institute of Electricity
Why Real-time & Permanent? > Maintenance > Optimal Power Delivery Sag and/or Temperature Monitoring Sag Vienna, 26-27 January, 2004 11 ULG - Montefiore Institute of Electricity
2. Sag monitoring methods PTI, Inc. Vienna, 26-27 January, 2004 12 ULG - Montefiore Institute of Electricity
Tension monitoring CAT monitor Load cells for tension monitoring SDG&E CAT monitor installed on a 230 kv anchor tower. Direct radio communications are established with the ground station (GS). GS dumps the data to the post via telephone line. Vienna, 26-27 January, 2004 13 ULG - Montefiore Institute of Electricity
Sag monitoring Sagometer (EDM International, Inc.) Meteo (optional) Camera Target Datalogger & Communications Vienna, 26-27 January, 2004 14 ULG - Montefiore Institute of Electricity
3.OHL Sensible elements 1. Conductors 2. Fittings (spacers, insulator chains, ) 3. Towers Vienna, 26-27 January, 2004 15 ULG - Montefiore Institute of Electricity
Conductor damages Fretting fatigue of second layer of strand (left) or surface failure (right) Vienna, 26-27 January, 2004 16 ULG - Montefiore Institute of Electricity
Conductor damages Strand breaking due to corrosion Vienna, 26-27 January, 2004 17 ULG - Montefiore Institute of Electricity
Conductor damages Vienna, 26-27 January, 2004 18 ULG - Montefiore Institute of Electricity
Conductor damages Aeolian vibration-induced damages of conductor - contact with suspension saddle Vienna, 26-27 January, 2004 19 ULG - Montefiore Institute of Electricity
Conductor damages Aeolian vibration-induced damages of conductor - contact with Aircraft Warning Marker Vienna, 26-27 January, 2004 20 ULG - Montefiore Institute of Electricity
Tower Damages Galloping Aeolian vibration Vienna, 26-27 January, 2004 21 ULG - Montefiore Institute of Electricity
Other: Spacers, spacer dampers Vibration dampers Insulators Aircraft warning markers etc. Stockbridge damper Twin bundle spacer damper Insulator chain Vienna, 26-27 January, 2004 22 ULG - Montefiore Institute of Electricity
4. Damage Diagnostic Methods Corona Discharge-based (CM) Electro-magnetic Acoustic (EMAT) Space potential probes (EPRI project) Vienna, 26-27 January, 2004 23 ULG - Montefiore Institute of Electricity
Damage Diagnostic EMAT (Electro Magnetic Acoustic Transducer) Colorado School of Mines, U.S.A. Vienna, 26-27 January, 2004 24 ULG - Montefiore Institute of Electricity
EMAT (Electro Magnetic Acoustic Transducer) + Can be used on live (hot) conductors + Allows detecting minor defects - Time-limited Vienna, 26-27 January, 2004 25 ULG - Montefiore Institute of Electricity
5. Diagnose the Wind - Induced Vibrations Unavoidable Turbulence-induced Necessary to minimize: Galloping Wake-induced vibrations Aeolian vibrations Vienna, 26-27 January, 2004 26 ULG - Montefiore Institute of Electricity
Aeolian Vibration Oscillation Amplitude ~ 1 D Vienna, 26-27 January, 2004 27 ULG - Montefiore Institute of Electricity
Wake-Induced Vibration Wind F Z x & z & F X V r V x& γ z & F L F D Vienna, 26-27 January, 2004 28 ULG - Montefiore Institute of Electricity
Turbulence-Induced Buffeting 40 35 30 25 20 15 10 5 0 Y, m -8 4 6 8 10 12 14 16 18-10 -12 Z, m ASTER -14 AERO-Z -16 10.00 14.00 18.00 22.00 02.00 06.00 Time (Hrs) Vienna, 26-27 January, 2004 29 ULG - Montefiore Institute of Electricity
Galloping Wind Ice C L y + C < D 0 Vienna, 26-27 January, 2004 30 ULG - Montefiore Institute of Electricity
6. Vibration Measurement Existing measuring devices SEFAG vibration recorder (Conductor diameter: about 0.03 m) Vienna, 26-27 January, 2004 31 ULG - Montefiore Institute of Electricity
Vibration Measurement Heavy weight (more than 5 kg) - > conductor fatigue High cost (~10000 ) Limited Autonomy Impossible to detect reliably the large amplitude at mid-span Higher frequencies cannot be recorded. Vienna, 26-27 January, 2004 32 ULG - Montefiore Institute of Electricity
7. Conclusions? Health Monitoring of Overhead Transmission Lines is of increasing importance Tension & sag monitoring is more elaborated but still a competitive field OHL conductor vibration monitoring devices have limitations (cost, monitoring period) Diagnostic of damages and hazards in OHL needs both «Artificial Intelligence» and hardware tools. Vienna, 26-27 January, 2004 33 ULG - Montefiore Institute of Electricity
The most challenging studies Vienna, 26-27 January, 2004 34 ULG - Montefiore Institute of Electricity
are the worst garnished! Vienna, 26-27 January, 2004 35 ULG - Montefiore Institute of Electricity
Jean-Louis Lilien Lilien@montefiore.ulg.ac.be Dmitri Snegovski snegovsk@montefiore.ulg.ac.be tel.(04) 366-26-30 Vienna, 26-27 January, 2004 36 ULG - Montefiore Institute of Electricity