Power Transformer Manufacturer s Experience with Transportation Mishandling

Transcription

1 Weidmann Diagnostic Solutions 7 th Annual Conference Power Transformer Manufacturer s Experience with Transportation Mishandling Enrique Betancourt Carlos Hernández New Orleans, LA, Sep

2 Life Cycle Management SPECIFICATION ENQUIRIES CONTRACT REVIEW DESIGN REVIEW MANUFACTURING SHIPPING & INSTALLATION OPERATION AND MAINTENANCE RECYCLING Manage the total cost of a piece of equipment, considering its entire service life. Ideal balance: Low purchase cost Low cost of operating losses High reliability Easy installation Low maintenance effort Easy troubleshooting Environmental friendly Biodegradable Low CO2 Low Noise 2 Prolec GE

3 Importance of Transportation Process Selection of transportation method has big influence on power transformers: Initial cost (materials, packaging and carrier) Delivery cycle Maintenance cost Reliability Insurance cost 3 Prolec GE

4 Transformer Transportation Map 4 Prolec GE

5 Transportation Method Truck or Lowboy: Lowest mechanical loads Limited scope, depending on road availability Higher cost Slow, but easy follow up Special trucks required for certain routes Limited on load weight and size Frequently exposed to vandalism Railroad: High dynamic loads, impact and continuous vibration Widespread, heavy duty tracks Cost in the medium range (except when dedicated train) Open air transport: easy follow up 5 Prolec GE

6 Transportation Method Sea Carrier: Low impact, though continuous, quasi-static and rotational loads Load must be designed for and properly fitted within container Indirect monitoring of impacts Highly dependent on schedule control Must be complemented with other method Air Carrier: Moderately heavy accelerations Limited on size and weight Very expensive, but fast Normally approached as emergency measure 6 Prolec GE

7 Railroad Transportation Loads 40 ton shipment example Every manufacturer has its own technology framework: Longitudinal Load Stress Strength Field Exp. G s RELIABLE PRODUCT 2 0 A B C D E Technology Transversal Vertical G s A B C D E G s A B C D E Technology Technology 7 Prolec GE

8 Experience with Longitudinal Loads Example of a Specific Design Solution* Damage Longitudinal Impact (G) 3 G 10 No damage Damage probable Normaly safe Service Records Design dependent Std. Design Shipping weight (t) * See Unit s particular Instruction Book 8 Prolec GE

9 Mechanical design Design according to spec requirements or manufacturer standards 9 Prolec GE

10 Shipment preparation... Profile Measuring System Procedure: Measure dimensions of loaded railcar Compare transformer shipping outline to carrier s clearance file Create transformer s dimensions file Forward dimension s file to carrier s approval department 10 Prolec GE

11 Load Dimensions Measuring System Objectives: Minimize the risk of damage Reduce transit time Reduce dimensions verification cycle at shipping bay Spec for the L-kopia System: Fast (9,600 to 43,200 points/sec per laser unit) Accurate (down to +/- 4 mm or 1/8 inch) High resolution (one point every degrees) Measuring range from 0 70 meter (0 230 ) Scans 360 degrees 100% eye safe (Laser Class 1) Operates under most environmental conditions Lightweight, compact operational full daylight or darkness 11 Prolec GE

12 Shipping Profile 12 Prolec GE

13 Compare measured dimensions vs. route clearance 13 Prolec GE

14 Preparation for shipment Perform FRA test Disassemble transformer Pressurize with Dry Air (3 to 5 PSI) Install impact recorders (digital and analog) Ship Transformer to destination 14 Prolec GE

15 Delivery process 15 Prolec GE

16 Transformer receipt, assembly, operation & maintenance 16 Prolec GE

17 Transformer reception Verify registers of impacr recorder Perform Dew Point test Inspection for physical damage Measure core insulation Perform FRA 17 Prolec GE

18 Impact recorder reading 18 Prolec GE

19 Impact limits 19 Prolec GE

20 Railroad Transportation issues 8 8 Events 6 5 Humps Bridge Vandalism Trees 85% Cost from shipping issues 103 Days impact on delivery cycle 15% 0% 0% Humps Bridge Vandalism Trees Humps Bridge Vandalism Trees 20 Prolec GE

21 Examples 21 Prolec GE

22 Test unit MVA GSU, 230 kv Small bushings added for monitoring of transportation Unit arrived with no issues Perfect match between traces before and after shipping Demonstrated feasibility and reproducibility, for GSU s and no bumps 22 Prolec GE

23 E1. Railroad impact MVA Auto, 230 kv Multi-unit package Unit E suffered 8g bump, resulting slight change in tertiary FRA traces Fig 1 Y1-Y ,000 1,000, F 02 F F 06 F 05 P 05 F Prolec GE

24 E1. Railroad impact MVA Auto, 230 kv Multi-unit package Unit E suffered 8g bump, resulting slight change in tertiary FRA traces Fig 2 Y2-Y ,000 1,000, F 02 F F 06 F 05 P 05 F Prolec GE

25 E1. Railroad impact MVA Auto, 230 kv Multi-unit package Unit E suffered 8g bump, resulting slight change in tertiary FRA traces Fig 3 Y3-Y ,000 1,000, F 02 F F 06 F 05 P 05 F Prolec GE

26 E1. Railroad impact MVA Auto, 230 kv Unit shipped back to factory, inspected, reassembled and tested Factory inspection disclosed slight shift on core support and one phase winding package; no other displacement or damage This case showed that FRA could detect minor changes, but yet hard to interpret FRA seems sensitive and meaningful... But practical interpretation rules must be developed. 26 Prolec GE

27 E2. Railroad impact MVA Auto, 345 kv Multi-unit package Unit suffered 7g bump, resulting in tie down damage Fig 1 Fig 2 27 Prolec GE

28 E2. Railroad impact MVA Auto, 345 kv Unit shipped back for inspection and repair On transportation back unit suffered 17.5g bump Factory inspection disclosed slight gap in top and bottom step blocks close to phase C; no other displacement or damage Reassembled and tested This case showed that the windings are not sensitive to heavy vertical humps, but C&C clamps to tank might fail under high vertical acceleration Correction of displaced components re-establishes the integrity of the unit 28 Prolec GE

29 E3. Truck impact - 45 MVA SUB, 115 kv On transportation suffered 6g bump Insulation resistance tests presented no deviations Internal inspection without any deviations No paper, blocks or insulation damaged or out of position No leads out of position or loose No core lamination sheets bent or out of position No loose hardware and no broken nylon bolts No foreign material on the bottom of the tank No spacers block out of position or loose No correction required... field tests and inspection could not be avoided 29 Prolec GE

30 E4. Railroad impact - 72 MVA SUB, 345 kv On transportation suffered 17.5g bump Insulation resistance tests presented no deviations Internal inspection without any deviations No paper, blocks or insulation damaged or out of position No leads out of position or loose No core lamination sheets bent or out of position No loose hardware and no broken nylon bolts No foreign material on the bottom of the tank No spacers block out of position or loose No correction required... field tests and inspection could not be avoided 30 Prolec GE

31 Examples Summary Example 1 Example 2 Example 3 Example 4 Activities Field tests Inspection Transportation Factory work Field tests Field inspection Transportation Factory work Field tests Field inspection Field tests Field inspection Potential ($K USD) $700 $1,100 $25 to $40 $30 to $50 Who is paying? 31 Prolec GE

32 Conclusions Power transformer transportation is a process that requires highest attention, as it bears impact on reliability, cost and delivery cycle. FRA is a powerful tool, that must be paired with good engineering judgement and supplemented with basic tests. Transformer specifications should reflect users experience with their own geographic conditions, as a resource to spare costly issues and project delays. Research work is desirable to develop more tools for detection and analysis of effects from transportation loads (Dynamic Response models?). In our experience, the mechanical design of power transformers should consider pessimistic impact loads for railroad transportation, mainly dependent on transformers shipping weight, as effective control still seems a challenge for many carriers. 32 Prolec GE

33 Further Readings T.Lundquist, E.Schweiger, M.Silvestre, W.Hoffman, Transportation Issues of Power Transformers, IEEE TC Meeting, San Diego, CA, 2004 Minutes from DOBLE Engineering Conferences (SFRA methodology and experiences) Minutes from WGs Transportation Issues Guide and Frequency Response Analysis Guide, from IEEE Transformers Committee 33 Prolec GE

34 34 Prolec GE