by Thermo 3. June 2011 13:37
Space Charge Discharge
 
Most people think of me as “Oh, so cute” and “Way too smart.”  What few know about me is yet another dimension of my persona.  I am an artist!  It shouldn’t come as a big surprise; others before me like Leonardo Da Vinci have demonstrated that brilliance spans the presumed gap between right and left brain hemispheres. My inspiration comes from the confluence of mathematics, aesthetics, high energy physics, and cable degradation mechanisms.  You read that right. Putting those four things together is something only this frog could conceive. You see, as cables fail, gloriously beautiful (aesthetics) fractal structures (mathematics) are created called electrical trees.  I know better than anyone how to stop electrical trees from inception and propagation, but I also know how to make them. We used a particle accelerator (high energy physics) to inject massive space charges into our specimen.  The space charges are violently grounded, and presto … electrical trees form spontaneously.  Don’t try this at home kids.

Add a simple, but handsome mount and some cool blue lighting and we have a Thermonuclear work of art. You don’t have to be a cable engineer to appreciate the beauty of my electric sculpture, but only a cable engineer will appreciate its value as a tool of understanding. I have made only a few.  Each is unique, thanks to the fractal mathematics that explain the discharge of space-charge. Ten years from now these sculptures of frozen electricity will undoubtedly be resold at a Sotheby’s auction.

With one of these beauties on your desk, everybody will want you to explain the nature of the sculpture.  For the first time, people will visualize the cable degradation process and they will be more sympathetic to the plight of those aging miles of cable. Budgets for reliability will increase, and I will have catalyzed a long overdue Renaissance of reliability.

How would you like to have your limited edition, Thermonuclear Space Charge Discharge sculpture?  Talk to your friends at Novinium.
Artfully yours,

P.S. The card below with my coveted signature is attached to each unique sculpture.

Tags:

All About Me

by Thermo 19. May 2011 14:14

 On-line Diagnostic Testing

Dear Ms. Conducting-

Thank you for your comment of May 13, 2011 to Middle East Query – Diagnostic Testing Timing.  Click here to see the original post and comment.  In short, Ms. Conducting wanted to dive deeper into the data. Below I have reproduced slide number 281 from the CDFI (Cable Diagnostic Focused Initiative) Regional meeting presented by NEETRAC (The National Electric Energy Testing Research & Application Center at Georgia Tech’s College of Engineering) and hosted by American Electric Power (AEP).  The meeting was held on October 13-14, 2009 in Columbus, Ohio, U.S.A. The entirety of the presentation slides are available by clicking here. The figure below (from slide 278) shows the failure results tracked for over three years on 114 feeder cable miles tested using online PD on cables that included EPR, XLPE, and PILC cables. After the testing was completed, the cables and attached accessories were allowed to fail – that is, no rehabilitation actions were taken.  There were about 85 accessory failures; there were about 90 cable failures.

Definitions

False Positive – Testing indicates the existence of an incipient fault in a cable or accessory, but the presumed incipient fault does not progress to a fault during the observation period.

False Negative – Testing fails to indicate the existence of an incipient fault in a cable or accessory, and the unidentified incipient fault progresses to a fault during the observation period.

 

 The online PD testing indicated the need for action (i.e. imminent failure) on 45 accessories.  Of the identified 45, 14, or 31%, actually failed.  The false positives were 69%. The results on the cable were marginally better. Of the 52 cables, which were diagnosed as “bad,” 23 actually failed or about 44%.  The false positives were 56%.  For both accessories and cables the number of faults that occurred on plant, that had been deemed “good” by the testing firm, far outnumbered those identified as “bad.”  There were about 71 and 67 false negative failures for accessories and cable respectively.

Not only did the observations show that the testing was unable to provide reasonable discrimination between bad and good, the raw number of failures that occurred in the presumably “good” sub-population was about 3 to 5 times higher. Because the researchers did not provide population statistics beyond the total mileage of cable installed, it is not possible to determine with precision the relative false negative performance. However, I can make some frogstimates. If the average three-phase feeder run length were 1760 feet (typical for North America) and there were 2.2 components per cable segment (also typical), there would have been approximately 343 cable segments (or about 114 three-phase cables, termination to termination) and about 750 accessories.  The relative failure rate over the three-year period would have been 11% (i.e. 85/750) for accessories and 26% (i.e. 90/343) for cables. My frogstimate of the false negatives are 9.5% (i.e. (85-14)/750) and 19.5% (i.e. (90-23)/343) for accessories and cables respectively.

Amazingly, these profoundly dismal results are spun by testing proponents as proof that a testing program is a fruitful endeavor. It’s no wonder to me why humans get sucked into tulip and real-estate bubbles and Ponzi schemes – no frog has ever been so duped.  There have been a few would-be-princesses that have been duped by a frog, but never the other way around.  Alas, wishing that a frog is a prince does not make him so. Wishing that a diagnostic provides useful information does not make it so.

There are two immutable reasons and their “anti-synergy” that explain why the current generation of diagnostics cannot work. These two reasons are:

1.   The economics of aged circuit rehabilitation, and

2.   The second law of thermodynamics.

Further, without some technological breakthrough that reduces the cost of applying diagnostics by an order of magnitude, it is unlikely these immutable and anti-synergetic forces will ever be reconciled. To inoculate yourself from these ill-conceived schemes, read and understand the DEIS (Dielectric and Electrical Insulation Society) feature article, “Diagnostic Testing of Stochastic Cables” published in the March/April 2009 pages of IEEE’s Electrical Insulation Magazine.  Click here to learn.

Data and Frogs don’t lie (unless you’re a fly),

T. B. Frog

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Potpourri

by Thermo 18. March 2011 13:54

Really Long Term Life

In my December 29, 2010 post at …

Crazy-Competitor-Claims

Wonderer in the Wilderness inquired …

1. How can Novinium get the same cable life extension without a soak period?  It would seem to me that Novinium puts less fluid into the cable than one would get with a soak period.

In my first post addressing this question I provided an abbreviated answer. We learned from the abbreviated answer that that when Novinium founders conceived of the first generation of treatment fluid over two decades ago, there was a failure to check the relative diffusion rates of the phenylmethyldimethoxysilane (PMDMS) monomer and the condensation catalyst we had chosen to provide long life.  This turned out to be a grave mistake, which we have corrected.  In a subsequent post on January 3, 2011 at …

Catalytic Considerations – Component I

… I provided a more comprehensive answer, but I promised five new posts that would explain the functional improvement of the five kinds of ingredients in Ultrinium™ 732 and Ultrinium™ 733 fluids.  In this last of those five sub-posts, I explain how a component with a really ugly name provides extraordinarily long life.  Chemists call the material found in Ultrinium™ fluids cyanobutylmethyldimethoxysilane (Pronounced: Sigh-an-Oh•butte-ill•meth-ill•die-meth-ox-ee•sigh-lane); we will call it CBMDMS for short.

In the graph nearby I explain the first dimension of why CBMDMS works so well for so long.  The graph plots the “permeation product” of the three most commercially important rejuvenation silanes.  Permeation is the product of the diffusion coefficient and the solubility of the material in cross-linked polyethylene (XLPE).  The rate of fluid exudation from a cable is directly proportional to this permeation product.  Remember that if a fluid exudes out of the cable, it is not providing any life extension benefit.  The lower the permeation value, the longer the fluid will stay in the cable.  The permeation of the primary ingredient in Novinium’s Perficio™ 011 fluid and other older technology fluids is illustrated by the light-blue-colored (upper-most) line over the range of 15 to 90°C.  This fluid is called phenylmethyldimethoxysilane (Pronounced: Fen-ill•meth-ill•die-meth-ox-ee•sigh-lane) by chemists; we will call it PMDMS.  In a recent post, Chain Entanglement, I explained how extending the length of the side chains entangled the silicone in the polyethylene polymer chains and slowed the diffusion.  The orange line shows the advantage enjoyed by tolylethylmethyldimethoxysilane (Pronounced: Tall-ill•eth-ill•die-meth-ox-ee•sigh-lane by chemists) or TEMDMS, which is a result of this chain entanglement.  The permeation rate and proportional exudation rate of TEMDMS, is always lower than that of PMDMS.  At low temperature they are about the same, but at 75°C, the TEMDMS permeates about 5-times slower.  But the focus of this post is the amazing CBMDMS, which enjoys a 25-fold to 45-fold permeation advantage over the PMDMS.  That’s a really big deal!  At 75°C CBMDMS will outlast PMDMS by a factor of 45!

TEMDMS and CBMDMS are available only from Novinium, as their use is protected by U.S. Patent 7,643,977, other pending applications, and their foreign equivalents.

 

3D rendering of CBMDMS or cyanobutylmethyl-dimethoxysilane (and proper pronunciation)

 

The second really cool thing about CBMDMS, besides its incredibly long persistence in the cable, is how it works.  If you look carefully at the CBMDMS molecule just below its permeation line in the graph or in the video, you may notice the feature from which it gets its name.  A carbon-nitrogen triple bond and an unbonded pair of electrons make a cyano-group.  This cyano-group (alternatively called a nitrile-group) is very polar, that is, it has a positive end and a negative end.  Consequently, CBMDMS has a very high dielectric constant.  Its dielectric constant is between 50 and 100, which puts it on par with the dielectric constant of pure water.  Ultrapure water is used in high voltage electrical laboratories’ water terminations to grade electrical stress.

 

The cyano-group, found only in Novinium rejuvenation products, grades stress in the same way, but at the nano-scale.    Before I explain how this works we need to define a thermonuclear-sized word:  dielectrophoresis, pronounced die-EE-lek-trow-for-EE-sis or DEP for short.  DEP is a phenomenon in which a force is exerted on a dielectric molecule when it is subjected to a non-uniform electric field – the greater the dielectric constant of the material, the greater the force.  The illustration nearby explains how the diverging electrical field near an imperfection imparts a force upon CBMDMS molecules and draws them into the local-region of highest electrical stress.  The presence of the high dielectric constant material smoothes the electrical stress and interferes in several ways with dielectric failure mechanisms:

1.    The local AC stress is reduced, and water trees grow more slowly.

2.    The high electrical fields around space charges are reduced, which reduces the likelihood of UV photon creation and the inception of free electrons.

3.    Any free electrons will not be accelerated to the same energy as they would have been in a greater field.

4.    The reduced local field increases both the partial discharge inception and extinction voltages.

Greater persistence in the insulation and stress grading provide longer post-injection life even in demanding applications.  Performance at high temperature and performance in cables with constrained geometry that limit the amount of fluid that can be supplied, are greatly enhanced by the presence of CBMDMS.

Longer life through better chemistry,

Thermonuclear B.F.

by Thermo 14. March 2011 14:56

AO, AO … it’s home from work we go

 

In my December 29, 2010 post at …

Crazy-Competitor-Claims

Wonderer in the Wilderness inquired …

1. How can Novinium get the same cable life extension without a soak period?  It would seem to me that Novinium puts less fluid into the cable than one would get with a soak period.

In my first post addressing this question I provided an abbreviated answer. We learned from the abbreviated answer that that when Novinium founders conceived of the first generation of treatment fluid over two decades ago we failed to check the relative diffusion rates of the phenylmethyldimethoxysilane (PMDMS) monomer and the condensation catalyst we had chosen to provide long life.  This turned out to be a grave mistake, which we have corrected.  In a subsequent post on January 3, 2011 at …

Catalytic Considerations – Component I

… I provided a more comprehensive answer, but I promised five new posts that would explain the functional improvement of the five kinds of ingredients in Ultrinium™ 732 and Ultrinium™ 733 fluids.

In this third of five sub-posts we will explore the role of the anti-oxidants (AO).  Every human knows the benefits of including anti-oxidants in their diets.  I am not as susceptible to oxidative damage, because I keep my temperature lower – that way I do not have to consume foul tasting raspberries and blueberries.  Besides their sickening sweet taste, the antioxidants found in berries are single-shot deals.  A single anti-oxidant molecule consumes a single oxidizer.  What we need for cables is a molecule that quenches the nasty oxidizer and then regenerates itself – indefinitely.  It would be nice for people too, but don’t hold your breath.  For cables the folks at BASF® and Novinium have a solution.

The primary AO in Novinium’s Ultrinium™ fluid formulations is BASF’s Irgastab® Cable KV10.  Furthermore all of the components of the Ultrinium UV package have anti-oxidant properties.  These materials were described in To UV or not to UV.  In the vernacular, these UV components are “two-fers” or “two-for-one” ingredients, because they fulfill at least two1 independent and important life-extension functions.

Antioxidants are included in virtually all modern cable compound formulations.  Originally deployed by polymer compound manufacturers to prevent oxidation during cable extrusion, it has been shown by

Matey and Labbe, in “Exploring the Water Treeing Inhibition Effect of Antioxidants for XLPE Insulation”, presented at Jicable ’07, the 7th International Conference on Insulated Power Cables (see pp 754-757), that antioxidants also slow the growth of water trees.  It was further demonstrated be Sekii et al, in “Effects of Antioxidants on Electrical Tree Generation in XLPE”, presented at the 2001 IEEE 7th International Conference on Solid Dielectrics (see pp 460-464), that the presence of antioxidants increases the electrical tree inception voltage.  KV10, the sulfur containing phenolic antioxidant utilized in Novinium Ultrinium™ formulations, has been demonstrated to slow the growth of water trees by a factor of four.  The class of sulfur containing phenolic antioxidants has been shown to increase electrical tree initiation voltage by up to 75% at a concentration of just 0.2%w.  KV10 enjoys a very high solubility in polyethylene and EPR, and because of its high molecular weight of 424.7, a very low diffusion rate.  The combination of high solubility and low diffusivity yields a very low sweat-out or exudation flux as was shown by Matey and Labbe.  AO can be found only in Ultrinium™ 732 fluids and Ultrinium™ 733 fluids, because it enjoys protection of U.S. patent 7,658,808, other pending patent applications, and their foreign equivalents.

Cold blooded and not oxidized,

Thermonuclear

1Ferrocene and Tinuvin® 123 are “three-fers.”  Ferrocene is an anti-oxidant (AO), an ultra-violet absorber (UVA), and a voltage stabilizer.  Tinuvin® 123 is an anti-oxidant (AO), a hindered amine light stabilizer (HALS), and a methanolic corrosion inhibitor.

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Crazy Competitor Claims | Rejuvenation Science

by Thermo 25. January 2011 17:20

To UV or not to UV

In my December 29, 2010 post at …

Crazy-Competitor-Claims

Wonderer in the Wilderness inquired …

1. How can Novinium get the same cable life extension without a soak period?  It would seem to me that Novinium puts less fluid into the cable than one would get with a soak period.

In my first post addressing this question I provided an abbreviated answer. We learned from the abbreviated answer that that when Novinium founders conceived of the first generation of treatment fluid over two decades ago we failed to check the relative diffusion rates of the phenylmethyldimethoxysilane (PMDMS) monomer and the condensation catalyst we had chosen to provide long life.  This turned out to be a grave mistake, which we have corrected.  In a subsequent post on January 3, 2011 at …

Catalytic Considerations – Component I

… I provided a more comprehensive answer, but I promised five new posts that would explain the functional improvement of the five kinds of ingredients in Ultrinium™ 732 and Ultrinium™ 733 fluids.

In this second of five sub-posts, we will explore the role of the ultra-violet absorbers (UVAs) and hindered amine (pronounced a-mean) light stabilizers or HALS.  The primary UVA is BASF®’s Tinuvin® 1130.  Additionally ferrocene (pronounced fair-O-seen), which was discussed in my last post, Voltage Stabilizer, is not only a voltage stabilizer, but also absorbs ultraviolet photons in the appropriate wave length.  In the vernacular, ferrocene is a “two-fer” or a “two-for-one” ingredient, because it fulfills two independent and important life-extension functions.

As you know, frog skin is very sensitive, and so I slather on the UVA (sunscreen) every time I am out in the sun – doing so helps keep me beautiful.  Cables buried one meter underground do not need protection from the sun’s relentless ultraviolet onslaught.  They do need UV protection, however, from UV that is created when space charges recombine near the ends of water trees.  Consider for example the work of Bamji, Bulinski, Chen and Densley in the Proceeding of the 3rd International Conference on Properties and Applications of Dielectric Materials, held in Tokyo in July 1991:

“… at points of electric stress enhancement in the polymer, the light emitted during the initiation phase of electrical treeing is … due to the recombination of electrons and holes injected into the material.  The spectra of the emitted light is in the visible and ultraviolet ranges.  The ultraviolet light can photodegrade the polymer and lead to electrical treeing.”

It is easy for us all to understand how UVA materials work.  They are opaque to UV light.  The potentially damaging UV photon strikes a resonance stabilized structure in the UVA molecule, is safely absorbed, and is converted to harmless heat.  That’s how sunscreens for our skin work too.  On my skin, if I want to stop 100% of the UV photons I need to apply unattractive zinc-oxide in a thick pasty layer – yuck!  In insulation if I want to stop 100% of the UV photons, I need to apply clay – we call those insulations EPR, EPDM, et al.  So UVA materials cannot intercept 100% of the damaging UV photons.

Unlike the common experience we all have with UVA materials, HALS are not within our normal experience.  HALS are free radical scavengers and they are beneficial, because the mechanism of photodegradation involves the creation of a free radical by errant UV photons – a photon strikes an electron and imparts so much energy to the electron that the molecule, to which it was bound, can no longer hold on to it.  A free radical (an unpaired electron in the molecule) and a free electron are created.  Electrons don’t like to be unpaired, and so, they search out other electrons and try to borrow them from their parent molecules.  As they do this, they tear apart innocent molecules and generally there is still an unpaired electron after the damage from the first encounter.  The free radical survives (or spawns a daughter) and creates cascading systemic damage.  HALS quench free radicals, and here is the cool part, they auto-regenerate to a HALS after they kill the free radical.  How cool is that?  I wish they would make HALS for amphibians, because I could take a HALS pill and snack on crickets all day without worrying about the consequences of free radicals ravaging my DNA.

It gets even better.  The word “synergy” is overused in business circles and promised synergies are often quixotic.  The poster tadpole for synergy is the interaction between UVA and HALS components.  Alone, each has a positive effect on cable life, but together they work better than the sum of their parts – one plus one equals three!  Ultrinium™ 732 and 733 fluids and Perficio™ 011 fluid utilize BASF®’s state-of-the-art Tinuvin® 123 HALS.  As we learned in the previous post, DMDB Doubts, Tinuvin 123 also stabilizes aluminum strand patina, which all but eliminates the potential for strand corrosion suffered by older injection technology.  Tinuvin 123 provides another formulation two-fer.

For over two decades, UVA and HALS have been included in TRXLPE (tree retardant cross-linked polyethylene) formulations.  See for example U.S. Patent 4,870,121, "Electrical Tree Suppression in High-voltage Polymeric Insulation,” September 26, 1989.  With the introduction of Ultrinium™ 732 and 733 fluids, Novinium delivers improved UV stabilization using the best available technology.  Novinium’s UV package is protected by U.S. Patent 7,658,808 and other pending patents and their foreign equivalents.  Only Novinium rehabilitation technology provides UV stabilization in the proper UV range.  To learn how first generation technology fails to address the UV photons created by space charge recombination, see Section 8 of the CIGRÉ Canada paper of October 18, 2010, “Cable Rejuvenation Mechanisms: An Update.”

To UV or not to UV, that is the question.  Answer:  Come out of the sunlight into the shade; live longer and with greater reliability,

Thermonuclear

by Thermo 14. January 2011 16:58

Voltage Stabilizer

 In my December 29, 2010 post at …

Crazy-Competitor-Claims

Wonderer in the Wilderness inquired …

1. How can Novinium get the same cable life extension without a soak period?  It would seem to me that Novinium puts less fluid into the cable than one would get with a soak period.

In my first post addressing this question, I provided an abbreviated answer. We learned from the abbreviated answer that that when Novinium founders conceived the first generation of treatment fluid over two decades ago, we failed to check the relative diffusion rates of the phenylmethyldimethoxysilane (PMDMS) monomer and the condensation catalyst we had chosen to provide long life.  This turned out to be a grave mistake, which Novinium has corrected.  In a subsequent post on January 3, 2011 at …

Catalytic Considerations – Component I

… I provided a more comprehensive answer, but I promised five new sub-posts that would explain the functional improvement of the five kinds of ingredients in Ultrinium™ 732 and Ultrinium™ 733 fluids.

In this first of five sub-posts we will explore the role of voltage stabilizers and partial discharge suppressers, geranylacetone (pronounced ger-an-ILL-ass-e-tone) and ferrocene (pronounced fair-O-seen), which are included in all Ultrinium™ fluids.

Ketone-type (pronounced KEY-tone) voltage stabilizers like geranylacetone have been studied in depth by several researchers.  Most prominent among those researchers is Johann Wartusch.  His work culminated in German patent DE 3017442 of August 3, 1983 and is described in his paper “Increased Voltage Endurance of Polyolefin Insulating Materials by Means of Voltage Stabilization” (IEEE 1980).  Wartusch demonstrated that the presence of geranylacetone increased tree inception voltage over three-fold, and due to its affinity for the polymer, it persists in the insulation for many years.

EPRI studied the tree inhibition properties of ferrocene in TD-145 EPRI Project RP 7830-1, “A new class of additives to inhibit tree growth in solid extruded cable insulation” of March 25, 1976, and concluded:  “Ferrocene completely suppresses treeing and increases the breakdown strength of polyethylene by [at least] 100%.”  Kato and his colleagues obtained similar results and the culmination of their effort was U.S. Patent 3,956,420, Polyolefin (pronounced poly-OLE-e-fin) Composition for Electrical Insulation, May 11, 1976.

In short, geranylacetone and ferrocene are proven tree retardants that can each provide 100% improvements in the dielectric breakdown strength of polymers in which they are dispersed.  Both materials persist in treated insulation for decades and both are found only in Novinium® rejuvenation fluids.  The use of ferrocene in rejuvenation fluids is protected by Novinium's U.S. patent 7,658,808 and its foreign equivalents.  Other patents are pending.

Occasionally in polymeric insulation, free electrons are created by one of two known mechanisms.

1.    Recombinant space charges near the tips of water trees may generate enough energy to knock electrons out of their orbitals.

2.    Cosmic ray bombardment is the second source of ionization energy that can create free electrons.  For a 1 mm3 cavity such ionization is likely to occur every five minutes. (See Boggs, “Partial Discharge in the Context of Distribution Cable Testing”, ICC minutes.)

Whatever the source of the free electron, in the absence of a voltage stabilizer, the electron will almost certainly be accelerated by the electrical field and may inflict damage to the surrounding polymer.  Voltage stabilizers scavenge these free electrons and let them resonate within their structure.  The resonation allows the excess energy of the electron to be bled off in small, non-damaging quanta. (i.e. infrared photons, which do not have enough energy to damage the polymer.)  When a suitable and stable receptor for the electron (most likely a cation [pronounced KAT-eye-on] generated when the electron was knocked out of its orbital) is found, the voltage stabilizer gives up the excess electron and returns to its original state, ready to deal with the next errant electron.

Stable and able,

Thermonuclear

Tags: , ,

Crazy Competitor Claims | Rejuvenation Science

by Thermo 3. January 2011 21:20

Catalytic Considerations – Component I

In my December 29, 2010 post at …

Crazy-Competitor-Claims

Wonderer in the Wilderness inquired …

1. How can Novinium get the same cable life extension without a soak period?  It would seem to me that Novinium puts less fluid into the cable than one would get with a soak period.

In the previous post, I provided an abbreviated answer; in this post I will provide a more comprehensive answer.  We learned from the abbreviated answer that when Novinium founders conceived of the first generation of treatment fluid over two decades ago, we failed to check the relative diffusion rates of the phenylmethyldimethoxysilane (PMDMS) monomer and the condensation catalyst we chose to provide long life.  In the figure nearby, I show diffusion data that demonstrate that the monomer diffuses about six times faster than the catalyst.  I also show two-dimensional scale representations of these two molecules.   From what we learned in Size Does Matter, one can see that the larger and less flexible titanium(IV) isopropoxide (TIP) molecule would diffuse slower than the PMDMS and it does.

This diffusion mismatch was a tragic mistake, because the monomer does not condense to a longer molecule in the absence of a catalyst.  As a consequence, a substantial portion of the PMDMS diffuses out of the cable shortly after injection without adding to the long-term reliability of the cable.  In fact, about 39% diffuses out prematurely.  This premature exudation is caused by catalytic inefficiency.  We cleverly fixed that problem with U.S. Patent 7,700,871, and I will explain the elegance of that solution in a subsequent post in this series …

Catalytic Considerations – Component II

It isn’t just how much fluid is delivered to the cable strands.  Even more important than the fluid quantity injected are:

1.    The amount of fluid that persists in the cable insulation over its post-injection life, and

2.    The capabilities of the molecules that are delivered to …

a.    interfere with the growth of water trees,

b.    interrupt the conversion of water trees to electrical trees, and

c.    disrupt the inception of partial discharges.

However, it is true that when using Unsustained Pressure Rejuvenation (UPR), more fluid can be delivered into the cable strands with longer soak periods.  Novinium is not dead-set against soak periods.  We employ soaking for special cases.  For example, we sometimes employ a soak period on submarine cables with constrained geometries.  A soak period, however, to compensate for a catalyst error is unforgiveable.  Soak periods compromise safety and operational efficiency and should only be utilized where technical or economic considerations preclude the use of sustained pressure rejuvenation or for unusual cases such as the aforementioned constrained geometry submarine cable.  The figure nearby provides a summary of laboratory measurements of the amount of PMDMS fluid that is supplied during a typical 60-day soak period for 1/0 AWG and No. 2 AWG cables.  Each experiment was performed in triplicate.  The amount of PMDMS provided during the soak period is about the same as the amount of fluid lost from catalytic inefficiency.  Perficio™ 011 fluid uses a patented catalyst system that enjoys a 2% catalytic inefficiency compared to the 39% inefficiency suffered by the TIP catalyst.  Therefore, Perficio fluid delivers about the same amount of active ingredient in the cable insulation without a soak as the older technology delivers with a 60-day soak period.

An even better option is to use Ultrinium™ 732 fluid, which not only uses the same state-of-the-art catalyst used by Perficio, but also includes five other ingredient types (both water reactive and not water reactive), which all increase cable life well beyond that possible with the venerable PMDMS fluid utilized in the Perficio formulation.  In future posts, I will examine each of these ingredients in more detail to shed light on how they function to extend cable life.  The table nearby will be updated to provides the links to the post for each of the five ingredient types.

 

Short Name

Long name

Comment

Link

GA

geranylacetone

voltage stabilizer and PD suppression in Ultrinium™ 732 fluid

Voltage Stabilizers

Ferrocene

ferrocene

voltage stabilizer and PD suppression and UVA in all Novinium® fluids

TEMDMS

tolylethylmethyldimethoxy silane

silane in Ultrinium™ 732 fluid

Chain

Entanglement

CBMDMS

cyanobutylmethyldimethoxy silane

silane in Ultrinium™ 732 fluid

Really Long-term Life

KV10

Irgastab® Cable KV10

anti-oxidant in Ultrinium™ 732 fluid

AO, AO

T1130m

Tinuvin® 1130 monomer

UVA in Ultrinium™ 732 fluid

To UV or not to UV

 

T1130d

Tinuvin® 1130 dimer

UVA in Ultrinium™ 732 fluid

T123

Tinuvin® 123

HALS and methanolic corrosion suppression in Ultrinium™ 732 and Perficio™ 011 fluids

In the mean time check out Cable Rejuvenation Mechanisms: An Update from the 2010 CIGRÉ Canada Conference on Power Systems.

Smarter each day,

Thermonuclear

by Thermo 12. December 2010 14:12

Electrical Treeing and the Principle of Parsimony

Dear Thermo,

A representative of a certain off-line partial discharge testing firm is saying that injection can cause electrical trees and faults.  His premise is that the water tree is superimposed over the electrical tree and thus grades the electrical stress around the electrical tree.  By curing the water tree, the electrical tree is unleashed to grow to a fault. Basically the water tree acts like a barrier.  This is the first I have heard of this, and on the surface the notion seems outlandish.  What would the Frog say?

Alarmed in Atlanta

 


Dear Alarmed-

I heard that one too at an ICC meeting several years ago.  I’m surprised anyone is still croaking that tune.  The principle of parsimony that underpins all of science is that the simplest explanation, requiring the fewest assumptions is most likely to be right.  The reason you find the notion outlandish is because of this principle.

Let’s review the facts and two possible explanations.  The annotated images nearby (taken from the Spring 2004 ICC meeting minutes, Cable PD Facts – Field Experience, M. S. Mashikian) illustrate a beautiful water tree and two equally as attractive electrical trees astride the water tree, near its base.  The author is suggesting with the blue arrows that the electrical tree avoids the water tree in its growth pattern.  This suggestion is bizarre for two reasons.  First the electrical trees are clearly associated with the water tree.  The alternative explanation, that they sprung up there randomly would require the “willing suspension of disbelief” to quote a former New York Senator and now Secretary of State.  (It’s true that she was wrong, but she was politically motivated.  I, on the other hand, seek only truth and understanding.  Amphibians would make poor politicians, because we simply call them as we see them.)  Secondly, upon closer inspection both electrical trees have a substantial branch that heads right into the water tree – just the opposite of what is being suggested.  There is no doubt that the water tree alters the electrical field in its neighborhood.  For every location where the field is concentrated there has to be a neighboring location where it is less concentrated.  Electrical trees grow where the field is most concentrated.

It is common knowledge that water trees normally precede electrical trees.  It is possible to induce electrical tree growth before the presence of water trees, but that takes a great deal of voltage.  This, of course, is precisely what the off-line PD guys do – use a great deal of voltage.  Except for the folks at this single testing firm, experts agree that water trees are a leading cause of electrical trees.  In order to claim that water trees somehow moderate the fields around electrical trees we would have to ignore all of the evidence to contrary. 

What does happen when silicone fluids react with and displace the water that is associated with electrical trees?  A thorough answer is available from the CIGRÉ Canada, Conference on Power Systems, Vancouver, October 17-19, 2010, paper “Cable Rejuvenation Mechanisms: An Update” at …

www.novinium.com/pdf/papers/Cable_Rejuvenation_Mechanisms.pdf

In short, the poor dielectric properties of the water in the water tree are replaced with the superb dielectric properties of silicones and tree retardant organics.

Why would anyone suggest such a bizarre explanation?  Could it be that the superior economics of rejuvenation compared to diagnostic testing are limiting the growth of the firm that is making the claim?  Check out “Diagnostic Testing of Stochastic Circuits” from the March/April Edition of IEEE Electrical Insulation Magazine for a complete analysis.  That paper is available at …

www.novinium.com/pdf/papers/Diagnostic_Testing_of_Stochastic_Cables.pdf

So, Alarmed in Atlanta, use the principle of parsimony and the available evidence to determine if electrical trees are moderated by the presence of water trees or if they are caused by water trees and exasperated by the application of voltage two and a half times greater than operating voltage.  

Parsimoniously yours,

Thermo

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