Use of Composite Materials for High Temperature, Low Sag ...
Transcript of Use of Composite Materials for High Temperature, Low Sag ...
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Use of Composite Coresfor High Temperature-Low Sag (HTLS)
Conductors (T-33)
PSERC Tele-SeminarSeptember 4, 2007
Ravi Gorur & Barzin Mobasher: Principal Investigators at Arizona State UniversityR. Olsen: Principal Investigator at Washington State UniversityM. Dyer & J. Hunt: Industry Advisors, Salt River ProjectJ. Gutierrez: Industry Advisor, Arizona Public Service
Disclaimer• The information contained in this presentation was prepared by ASU
as an account of work sponsored certain utilities and PSERC. Neither PSERC, any cosponsor, ASU:(a) makes any warranty or representation whatsoever, express or implied, (i) with respect to the use of any information, apparatus, method, process, or similar item disclosed in this presentation,including merchantability and fitness for a particular purpose, or (ii) that such use does not infringe on or interfere with privately owned rights, including any party’s intellectual property, or (iii) that this presentation is suitable to any particular user’s circumstance: or
• (b) Assumes responsibility for any damages or other liability whatsoever (including any consequential damages) resulting from your selection or use of this presentation or any information, apparatus, method, process, or similar item disclosed in this package
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Motivation
• Increase power delivery on existing ROW without violating sag criterion
• Different methods presently in use– ACSS (aluminum conductor steel supported)– AAAC (aluminum alloy conductor)– ACIR (aluminum conductor invar reinforced)– Gap type conductor
• Composite cores for conductors is fairly recent
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What we intend to achieve
• Develop laboratory techniques for fingerprinting and screening core materials
• Understand failure modes and mechanisms of composite core materials
• Develop thermal models for evaluating core temperature
Practical Benefits• Better technical specifications• Data to assist in dynamic rating
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Research Questions• Two “very different” types of HTLS conductors using
composite cores presently available. How do they compare?
• Supposed to operate at 180-240 oC (> 2 times presently used values). How does this affect performance (mainly mechanical)?
• Conductors are expected to last many decades, how can be predict useful life? What about failure mechanisms?
• Performance is strongly related to formulation and processing (manufacturer’s domain). What measures can users employ to validate manufacturers’ claims
• Mixed experience with composite (polymeric) materials for insulators, can we avoid doing the same mistakes?
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Microscopic DetailsMetal matrix composite Carbon composite
Submicron size Al2O3 fibers in aluminum metal matrix
glass fibers + carbon fibers in epoxy resin matrix
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Preliminary observations• Visible physical changes in different
batches of carbon composite provided
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1: 2004, 2: 2005, 3: 2006 ; 4: sample 3 tested at 180 oC for 500h
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650 1150 1650 2150 2650 3150 3650
Wave numbers
%Tr
ansm
ittan
ceInfra-Red Spectroscopy Finger Prints of composite housing materials used in insulators
Numerous formulations available presently, big differences in electrical and mechanical stability
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Thermal stability of Carbon Composite core
• Fiberglass section • Carbon fiber section Initial Weight: 32 mg
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10 200 400 600 800 1000 1200
Temperarure (C)
Mas
s Lo
ss (m
g)
140 C, start of degradation
Degradation starts at 140oC
Initial Weight: 28.75 mg
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Temperature (C)
Mas
s Lo
ss (m
g)
150 C, Start of degradation
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Thermal Stability of metal matrix core
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Temperature (C)
Mas
s Lo
ss (m
g)
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Ongoing Research
• Explore different methods of fingerprintingSpectroscopic: Infrared, Energy Dispersive X-ray,
Optical microscopyAssess fiber volume and distributionElectrical: partial discharge, tan δ (fiberglass)Mechanical: Failure under tension, bending and
fatigue loadsAre their differences before and after laboratory
aging?
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Ongoing Research
Accelerated aging tests:elevated temperatures (150, 200, 250 oC) for
500 hoursCombined mechanical (bending) and Chemical
exposure (water, nitric acid) testsCharacterize samples
Spectroscopic analysisMechanical (tensile) tests
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Ongoing research
• Core is expected to be hotter than the conductor• Can the core temperature exceed the glass
transition temperature (transition from elastic to plastic phase)?
• IEEE 738 used for ACSR, new materials and construction methods have yield heat transfer properties. How does this affect ampacity
• We will use Finite elements packages available at ASU
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Finite element modeling for conductor temperature distribution
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X
Y
Z
MAR 26 200615:05:30
ELEMENTS1
MN MXX
Y
Z
325.14
334.473343.806
353.139362.472
371.805381.138
390.471399.804
409.137
MAR 26 200615:06:26
NODAL SOLUTION
STEP=1SUB =7TIME=115TEMP (AVG)RSYS=0SMN =325.14SMX =409.137
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Collaboration with Advisors
• Brief monthly progress reports (email)• In-person meeting with local advisors
(APS, SRP)• Conference call (quarterly) with BCTC• Discussions during IAB meetings
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