The Weidmann Conference The Aging of America s Transformers

Transcription

1 The Weidmann Conference 2006 The Aging of America s Transformers by Jon L. Giesecke, Director, (610) jlgassociatesllc@yahoo.com

2 How Old is Old? The aging of the electrical infrastructure in the United States is a serious problem!! Until recently this problem has slipped thru the cracks. A new level of awareness is needed as these aging transformers are failing.

3 Average Age As of today, our transformer population has an average age of 40 years The published life expectancy of many of our transformers is years TIME S UP..NOW WHAT?

4 WE MUST BE PRO-ACTIVE WHAT S NEEDED? The best asset management program using condition monitoring. HOW?

5 WE MUST BE PRO-ACTIVE I have dedicated the past decade in search of the optimal tests for condition assessment of Oil Filled Power Transformers and their Sub-Systems.

6 WE MUST BE PRO-ACTIVE During that time, I helped develop a program using the newest technologies and the very best equipment, methods and techniques for condition assessments.

7 WE MUST BE PRO-ACTIVE Infrared, Vibration Analysis, DGA, Oil Quality and Functional Testing of the cooling systems and load tap changers was the backbone of the process. What was needed was an easy and reliable test method for Partial Discharge.

8 WE MUST BE PRO-ACTIVE USING THE NEWEST TECHNOLOGY A Partial Discharge (PD) testing method using acoustic sensors and a high frequency current transducer is now available This increases the protection factor for these utility industry assets: Transformers, LTC s, Lightning Arrestors, Pumps, OCB s, GIS, etc.

9 WE MUST BE PRO-ACTIVE This presentation will describe the process for PD detection / location and answer many key questions that may arise.

10 However, before we start.. One Question..What do Oil Circuit Breakers, Load Tap Changers and Voltage Regulators have in common? Anybody??????

11 Ahaa! Answer.. They all have contacts which arc under insulating oil!

12 Abnormal Arcing (bad ju-ju) Something that shouldn't arc under oil ANYBODY????

13 Abnormal Arcing (bad ju-ju) OIL FILLED POWER TRANSFORMERS

14 LET S TAKE A WALK DOWN MEMORY LANE The Date The Viet Nam War Peace & Love DGA My Discharge from the Navy Hippies & Flower Power Bell Bottoms

15 Let s take a walk down memory lane. Did he just say DGA???

16 Back in the OLD DAYS I was a maintenance electrician high volt group. The high volt group was responsible for OCB, LTC and Regulator maintenance. Everything was based on time and operations / fault trippings

17 Back in the OLD DAYS The most high tech device we all used was the Cincinnati Analyzer for breaker timing. Like many of you, I licked many charts until they came out with self stick. (new technologies)

18 Back in the OLD DAYS Then a brand new technology came into existence.dga on Transformer Oil. By the way it was slow to catch on. And yes, we were still using the old Cincinnati Analyzer And doing overhauls based on time and operations

19 Back in the OLD DAYS I was threatened with bodily harm when I suggested doing DGA on an LTC I imagine I would have been institutionalized if I had suggested doing DGA on OCB s

20 BACK TO THE FUTURE BUT, as most of you know and are probably doing; both LTC and OCB problems are easily detected by DGA What about voltage regulators? Aren t they in the same family? Arcing Contacts under oil, exhibit much of the same characteristics.

21 Back to the Future And of course there came into major use in our industry, Infrared Thermography Everyone is doing IR OCB and LTC infrared is very telling and useful for diagnosing problems A full set of functional tests on LTC S saved many costly failures

22 Back to the Future Then along came Ultrasonic Analysis Computerized motion analysis and capture of 1 st trip. Wave Shape analysis, Etc., Etc.

23 A combination of ultrasonics and electrical capture of an arc is being done. And with it, the ability to analyze Source Locate Trend And make the big dollar decision on when to say when.

24 Today, we are able to capture and analyze a burst of acoustic energy BUT, HOW MANY DO???

25 And Expand a selected Portion for a closer look

26 And Expand even more to measure the Frequency Content.

27 Technology today is able to capture the acoustic signal from the operation of an LTC. BUT, HOW MANY DO???

28 Then expand and analyze the acoustic signal!

29 Technology today is able to capture the Arcing from the operation of an LTC.

30 Then Expand and Analyze the Arc B C

31 Expand again to show the arcing contact and the follow-thru. (B Phase) B

32 Then Expand C Phase for analysis. (C Phase) C

33 AND BY THE WAY. Did you realize??? This was a VACUUM TYPE LTC!

34 I NOW HAVE THE ABILITY TO INSPECT VACUUM CONTACTS IN AN LTC DURING AN OPERATION.ALSO MECHANICAL LTC S OCB s VOLTAGE REGULATORS

35 ALSO THE ABILITY TO INSPECT OIL FILLED TRANSFORMERS AND SUPPORT EQUIPMENT DURING NORMAL OPERATION CORE, WINDING, BUSHING LEADS PUMPS LA S LTC S DETECTING PD AND ARCING IS FAST AND EASY

36 The Rest of the Story When you look at the next few slides Remember the top screen is acoustic energy.. The bottom screen is electrical energy..

37 THE COMPLETE LTC PICTURE FROM PREVIOUS SLIDES

38 PARTIAL DISCHARGE IN MPT/GSU

39 Cursors measure difference, PD is confirmed in this GSU

40 Expand 1 Burst for a closer look.

41 Expanding more shows #3 is closest (notice the spike shape)

42 The fault Location Screen (front view) Pink Ball shows location of PD.

43 The fault Location (top down view)

44 BAD LIGHTNING ARRESTOR (bottom screen only)

45 ONE SPIKE FROM THE LA

46 ONE SPIKE FROM PD (flip back and forth)

47 Combining Data, a Holistic Approach Partial Discharge Detection Infrared Thermography Vibration Analysis (main tank and pumps) Functional Testing of Cooling System & LTC DGA & Oil Quality Review Furan Analysis Review of Transformer Loading History All done on energized, loaded transformers

48 Combining Data, a Holistic Approach We only talked about one of the technologies from the list. Many times two or more methods point to the problem. Don t short change yourself. This knowledge is available, learn to do a complete condition assessment.

49 THANK YOU QUESTIONS PLEASE