Going back in time to locate short circuits in power grids

Going back in time to locate short circuits in power grids

EPFL researchers have come up with a method to determine the exact location of short circuits in a power grid. This is an important step towards operating complex power grid topologies that enable the massive integration of renewable energy resources.

When a high-voltage power line is damaged by wind, ice or a tree, electricity utilities must quickly find the fault location and repair it to meet the power quality requirements or avoid cascade blackout. In the common practice, they locate the fault by first identifying the section without power through the use of sensors placed at regular intervals along the power line. A technician must then go to that section and visually inspect the line in order to find the fault location.

EPFL researchers at Distributed Electrical Systems and Electromagnetic Compatibility Laboratories have come up with a new method for precisely determining where the short circuit takes place. This technology is based on the theory of electromagnetic time reversal (EMTR), a process already being used in acoustics and electromagnetics.

With this method, researchers developed an embedded hardware platform hosting the fault location algorithm connected to the primary substation in the grid. When a short circuit occurs, the system analyzes the resulting waveforms observed at the measurement point. The fault location platform then time-reverses the waveforms and reinjects them into the grid model being simulated in the platform. The back-injected signals converge towards a given location which is the fault location.

Fast and less expensive

This technology offers two main advantages: compared to the conventional installed fault indicators, the developed fault location platform is faster and more efficient to locate the faults. "We can cover the entire from one observation point, which obviates the need to install numerous sensors over hundreds of kilometers of power lines," said Reza Razzaghi, a researcher at EPFL's Distributed Electrical Systems Laboratory. The proposed method has been implemented in a chip-scale real-time simulator, also developed by the same researchers at EPFL's Distributed Electrical Systems Laboratory, providing the fast and not expensive solution for the problem.

Another plus: the more complex the grid, the more effective this method. "With a large number of reflecting boundaries and inhomogeneous transmission lines along which the waves are traveling and reflected, the result are even more precise than for a simple topology," said the researcher. This method is thus ideal for large-scale grids with a complex topology, and for mixed networks that combine high-voltage lines and coaxial cables.

The developed platform also facilitate massive integration of renewable energy sources like offshore windfarms which require, in general, multi-terminal HVDC links. In particular, the protection and fault location problem represents a major challenge for the realization of these grids. The developed platform is able to identify the precise fault location in such complex topologies using a single measurement point and within a very short time.

The method developed at EPFL's Distributed Electrical Systems and Electromagnetic Compatibility Laboratories therefore meets a real need, and it has already caught the attention of several companies that specialize in power grid protection systems.


Explore further

An innovative response to the challenge of storing renewable energy

More information: R. Razzaghi et al. An Efficient Method Based on the Electromagnetic Time Reversal to Locate Faults in Power Networks, IEEE Transactions on Power Delivery (2013). DOI: 10.1109/TPWRD.2013.2251911
Citation: Going back in time to locate short circuits in power grids (2015, November 10) retrieved 22 July 2019 from https://phys.org/news/2015-11-short-circuits-power-grids.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
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Nov 10, 2015
Good development. We had folks who could read the waveshapes and predict within one tower where the problem was. Automatic is better.

Looking at the waveshapes gives one a sense of the quality of the loads and their activity, and there are several books now with waveshape analyses. The first was the Handbook of Power Signatures by McEachern. Look it up. Read page ten.


Nov 10, 2015
For Stumpy, the title on the page is "George's Comments", and it regards how to use site specificity to determine disturbance sources. Your buddies will not want to see it.

Nov 10, 2015
Oh boy, a one already by Auntie Ira. Now I suggest he tell you the secrets of reading power waveshapes, since he knows more than I do.

I had assumed I could reach anybody and teach them, but first they actually have to want to learn, and not just get their little egos hurt because of their ignorance.

Open up, Ira, admit your ignorance and learn something.

Nov 10, 2015
Okay, Ira, I will start to educate you. The combined impedances of the powerline reactance, plus the reactance of the loads changes the shape of the waveform over time and distance, and these changes can show us how far away from the recording instrument was from the event.

The transmission through transformers also change the characteristics of waveforms. Electronic loads drawing high third harmonic currents from a delta-wye transformer turn out to load the input circuit with fifths. Why is that?

Nov 10, 2015
Another "one" from Ira, but no discussion. Ira keeps thinking he is so smart we are all scared of him, but I found him to just be a vandal, a phony hiding behind a pseudonym, playing his silly personal games.

He is incapable of technical debate, and can only attack personally, . . the same character problem which keeps him on a tow boat in the mud.

Nov 10, 2015
Troubleshooting powerline disturbances is very interesting, and can be difficult. Again, the clues are the spectral content of the waveshape and how sharp the transitions happen to be. Higher frequencies come out early, as they are capacitively-coupled and inductively choked.

Understanding the differences between powerline impedances and building wiring impedances is also important, as well as the reference used for measurement.

Nov 10, 2015
"Number5" where are youuuu.

Nov 11, 2015
For Stumpy, the title on the page is "George's Comments", and it regards how to use ...Your buddies will not want to see it.
@gkam
1- you're getting irritating with this - STOP DRAGGING ME INTO IT - especially when YOU'RE WRONG!
2- i dont care who does/doesn't want to see it
3- Pg 10 means nothing without a validation or reference that can be seen by the general public... it is like saying:
"I wrote a book on why gravity doesn't exist but i can't show you the charts in it that validate all my claims, so go buy my book" (actually used here on PO)

validation requires some sort of link or reference that can be checked to reinforce the claims
if you want people to accept your "authority", then make a claim that can be validated!!!!

.

and quit whining about how Ira rates you... you brought that upon yourself!

you cry about him rating you but not posting anything...
but if he posts, you....

make up your mind, for Wakinyan's sake

Nov 11, 2015
Okay, Ira, I will start to educate you.


Skippy, you don't see how goofy you look? Why you don't go back and read your own postums and pretend they were written by somebody else.

,,,,,,, a bunch of blah blah blahs from glam-Skippy trying to sound smart,,,,,


You don't know what I know and don't know either (and what a lot of other people know and don't know either). That is why you keep ending up looking like a guy wearing a silly looking pointy cap. Yeah, the one with the silly looking moons and stars on him.

. . the same character problem which keeps him on a tow boat in the mud.


See what I mean? Why do you think that would bother me for you to say? I like my job. I am pretty good at it. It pays me more than enough to get by on. Why would I care if you approve or not Cher? You can be all puffed up about how you want peoples to see you if you want to be, but it makes you look goofy. Why would I care what you think of what I do?

Nov 11, 2015
Stumpy, Just prove me wrong or shut up.

I am sick of your petty suspicions, and your little nasty buddies.

I noticed how both of you dodged the technical aspects of my posts, out of ignorance. You folk simply cannot debate the issues without nastiness, can you?

Nov 11, 2015
I want to see how smart Ira and Stumpy and otto are regarding waveshape analysis. Can they beat a "liar", as otto put it? Or are they IGNORANT of technical issues? Remember this, and the fact experience beats wiki:

http://www.thegua...n-google

Nov 11, 2015
@ glam-Skippy. Cher, you should try to relax and not take your self so serious. It just ain't healthy Skippy.

Since you do not want to take my advice about going over your postums reading them like somebody else wrote them to see how goofy you look, maybe you will take another advice instead.

You will live longer, live better, and not be so much the object of peoples having the big fun with you if you would not act like the silly postums on the phyorg were the life and death struggle for the survival of all mankind. You are just too much sensitive and that can't be good for you health (or your image either too.)

Nov 11, 2015
I am sick of your petty suspicions, and your little nasty buddies.

I noticed how both of you dodged the technical aspects of my posts
Sorry liar youve been proven shamefully wrong on dozens of issues. One that nobody questions does NOT make all those dozens right, nor does it make you an engr, nor does it mean that your MS-EM isnt a lie.

Why would you think that it did?

Typical psychopathic ploy.

Go be sick somewhere else.

Nov 11, 2015
Just prove me wrong or shut up
@g
ok
the title on the page is "George's Comments", and it regards how to use site specificity to determine disturbance sources
there is no link or means to validate this claim, therefore this is by definition an "Untested claim" (at best) as noted here: http://www.auburn...ion.html

if not provable, it would then be a "false claim", regardless of your "reg" argument above

IOW- you are making what superficially appears to be a logical argument, however, it is based upon the access of a resource you can't provide & there is no means to validate your assertions that "page is "George's Comments""

you are also being intentionally abrasive and demonstrating sociopathic and psychotic behaviour, as Otto notes

you are also validating my previous assertions to your fragile ego issues:
https://www.psych...ttle-ego

Nov 12, 2015
I noticed how both of you dodged the technical aspects of my posts, out of ignorance. You folk simply cannot debate the issues without nastiness, can you?


You haven't provided any "technical aspects" save for the most vague hand-waving. There's almost nothing to comment on. You haven't presented any "issue" to talk about.

It's as if you were reading bullet-points from a powerpoint slide or a course introduction material out of context, and then pretending to be smart because nobody knows what the hell you're on about.

Electronic loads drawing high third harmonic currents from a delta-wye transformer turn out to load the input circuit with fifths. Why is that?


One reason is because in general, odd harmonics excite other odd harmonics in resonating non-linear systems, and a delta-wye transformer is internally "resonant" for third harmonics.

The "first" odd harmonic would be the mains frequency, so the next up is the fifth, then 7th, 9th, 11th... etc.


Nov 12, 2015
Basically, a delta-connected transformer primary has three windings end-to-end in a loop 1/3 cycle apart in phase, but for the third harmonic frequency this 1/3rd is the whole cycle, so each of the nodes connecting the winding sees zero volts while the third harmonic current goes around inside the transformer.

So the primary basically absorbs any 3rd harmonic currents from either side of the transformer by resonating with the frequency, as the 3rd harmonic current goes around inside the transformer and can't exit to the supply side, the voltage being zero at the exit nodes.

However, since the excitation of this resonant current means that the amplitude of the current grows to the point that the transformer windings' impedance start to limit it, causing the transformer to heat up, you get to the non-linear part which is familiar to people who play guitars: distortion.

Distortion of the waveform generates other harmonic frequencies higher up in the scale.

Nov 12, 2015
When a short circuit occurs, the system analyzes the resulting waveforms observed at the measurement point. The fault location platform then time-reverses the waveforms and reinjects them into the grid model being simulated in the platform. The back-injected signals converge towards a given location which is the fault location.


I see a potential problem with the system. It relies on the grid model being true to reality with all inputs and outputs and paths included and characterized.

Whereas, when a single fault occurs this introduces an uncertainty to the model which does not know what the effect of the flaw is to the system and cannot model it. If two short circuits happen at a short interval, e.g. during a storm, the first fault throws the simulation off and the second fault can no longer be reliably located.

That's why it works better with a more complex system: a single change makes less difference. However, with more complex systems, more things can change.

Nov 12, 2015
I see a potential problem with the system. It relies on the grid model being true to reality with all inputs and outputs and paths included and characterized.

It doesn't need to be perfect. If you look at the video you see that when the reverse peak occurs the rest of the search space is not zero (as it was in the forward case at that point)

The same algorithms are used in localization of epileptic loci from EEG measurements - which can be multiple. And there you also only have a limited number of sensor points over a not perfectly known material distribution. Still gives very good answers used for subsequent medical interventions.

You can always construct a case where two or more loci obsucre another one (the simplest would be three breaks along one line - with the middle break being undetectable. But in that unlikley case you always have the visual inspection fallback (or just run the algorithm again once the one of the found ones is repaired)

Nov 12, 2015
Okay, Ira, I will start to educate you. The combined impedances of the powerline reactance...


Also, gkam, that's just re-stating the article above in slightly different words. Anybody who actually read it knows that already.

It doesn't need to be perfect. If you look at the video you see that when the reverse peak occurs the rest of the search space is not zero (as it was in the forward case at that point)


Yes. In large systems this is true. They're probably running a monte-carlo simulation where the properties of the system being simulated are varied randomly and the simulation is run many times to generate the most probable outcomes.

Still, it can't be perfectly robust. If the real system changes more than you account for, or changes in a different way than you think it might, the prediction goes wrong.

In the epilepsy case, you have a sustained signal, whereas in a grid failure you have one non-repeating signature and then the power is out.

Nov 12, 2015
But in that unlikley case you always have the visual inspection fallback (or just run the algorithm again once the one of the found ones is repaired)


Interestingly enough, the regular way of doing fault isolation in the normal branching grid is a binary tree search. When the fault trips the circuit, the system tries to power up individual branches until it has isolated the problem into one, and then the visual inspection guys are sent in.

This is normally very efficient, taking only 2-3 minutes to place the fault on the map, and you could use regular signal reflectometry once you reach the affected stretch of cable, but with possible backfeeds from random sources such as wind turbines which might power the line from intermediate points, it becomes more difficult to pull off.

The advantage of having a sensor in a central location is lost once you realize that each fault trip switch is also a remote sensor, and has to be.

Nov 12, 2015
It used to be that the remote switches were operated on a LF signal injected into the power grid from central locations near the main lines. I have seen the old analog equipment with a wall full of knobs and dials to turn individual contacts on and off.

These days its being done via radio, and the power line signaling systems are all but phased out. Maybe they're still in use in some long cross-country links.

You can always construct a case where two or more loci obsucre another one (the simplest would be three breaks along one line - with the middle break being undetectable.


I was also thinking in terms of random power inputs and outputs from wind turbines and solar panels etc. mixing with the fault signal, and producing a non-repeating background so that you'd have to essentially replay the state of the entire power system as it happened in order to pull off the simulation.

Nov 12, 2015
e system tries to power up individual branches until it has isolated the problem into one,

That's the issue that the article solves. With the isolation technique you only go down to the ganularity of individual branches (which can be quite large). With the inverse wave calculations you get an exact spot. You only need one central point* from which to do diagnostics insead of starting your diagnostics at the lowest affected branch/breaker.

*well, they should have at least two. Because if the one central location is knocked out you're effectively back to doing it the old way.

Nov 12, 2015
With the isolation technique you only go down to the ganularity of individual branches (which can be quite large)


Well, you can isolate it down to the level of a single stretch of cable, because on the branch level you have remote switches at every junction point. There's a 3 minute delay largely in case there's a person hanging on the line.

Suppose A branches to B,C - in a fault to any, everyone turns off. Then A turns on, then B turns on, then C turns on. When the power trips off again, you know that the fault must be between A-BC or behind B or C.

The only problem then is that the length of transmission cable between A-BC and from B and C onwards to the ends might be many miles, but in these cases all you'd need is a signal reflectometer in each switch, that measures the distance to the fault down the line - and you get the exact information without simulation guesswork.

The switch is already in remote communication to you, so it's a simple addition.

Nov 12, 2015
(or just run the algorithm again once the one of the found ones is repaired)


Also, that is a problem because you have to be able to isolate the faults quickly. Actually fixing the issue may take days or weeks, depending on the extent of the damage.

The binary search method is robust in this respect because every node turns off, and then those nodes that still work are turned on, so other people get power while you fix the issues.

So the system might be fast and dependable on single faults, but generally this comes at little advantage because you get the approximate location of the fault anyways as the automatic switches turn on faster than the repair crew can be sent on their way. The important part is actually isolating the faulty bit from the rest of the grid, rather than getting to the fault site very quickly.

That's a job for the fire department, and for them there's other signs : a big pillar of smoke and people calling 911.


Nov 12, 2015
Well, you can isolate it down to the level of a single stretch of cable,

That isn't as good as it sounds. Consider an earth cable under a street damaged during an earthquake. Do you dig up the entire street? Or do you just dig where the problem is. That can come out to a pretty big difference in terms of time (and cost). Much more so if you consider the large underground cables that are being laid down for ferrying renewable energies from costs inland.

So the system might be fast and dependable on single faults

The math presented in the article is fast and robust for many faults.

Suppose A branches to B,C - in a fault to any, everyone turns off. Then A turns on, then B turns on, then C turns on. When the power trips off again, you know that the fault must be between A-BC or behind B or C.

With the proposed method you turn nothing off (you just modulate a small pulse on the channel). No one goes without power just for a test. Much better.

Nov 12, 2015
I sure do wish more peoples would discuss this technical stuffs like anti-Skippy and Eikka-Skippy are doing right now. Good information from both even though they don't agree 100 percents.

And do you notice how they are not wasting a lot of letters saying "Skippy needs to go learn,,,,,," or "Skippy is not in the business he doesn't,,,,,,,, " or "I used to,,,,, so,,,,, "? And not talking about each others in the third person like they were on a stage giving the grand lecture?

Nov 12, 2015
"In the epilepsy case, you have a sustained signal, whereas in a grid failure you have one non-repeating signature and then the power is out."
---------------------------------

Nope. Usually, there can be multiple events before the complete loss of power. look up fault clearing on transmission lines and see how fast the breakers and reclosers can operate. It is sub-cycle.

We monitor the waveshapes at millions of times per second to see the fine points from higher frequencies, such as those in arcing. Pathology is much easier these days.

Nov 12, 2015
I could send you folk some actual graphs of different scenarios of power loss. It is interesting to see what loads and line reactances do regarding the currents injected into the system by powered devices.

Look up clamps versus crowbars, and see the progress in dealing with million-horsepower electrical loads.

Nov 12, 2015
We can use Time Domain Reflectometers to pinpoint the source of failure. They inject an RF signal and map the impedances along the entire route. I used one in 1966 to help save a mission at Edwards AFB on a special aircraft.

Sorry to include myself in the story, but I was the person who did it.

Nov 12, 2015
I noticed how both of you dodged the technical aspects of my posts
Thats because we're not qualified to address them (at least Im not), and neither are you as eikka demonstrated.

We're also not the kind of people who would pretend that we were.

You are.
You haven't provided any "technical aspects" save for the most vague hand-waving. There's almost nothing to comment on. You haven't presented any "issue" to talk about
Hes just fishing for reasons to talk about himself.
I used one in 1966 to help save a mission at Edwards AFB on a special aircraft
-See?
I could send you folk some actual graphs of different scenarios of power loss
Uh no thanks. You probably stole them from their rightful owners.

Nov 12, 2015
Therec are a number of ways to locate faults.
http://ecmweb.com...le-fault

-And TDR is not the best.

"One weakness of TDR is that it does not pinpoint faults. TDR is accurate to within about 1% of testing range. Sometimes, this information alone is sufficient. Other times, it only serves to allow more precise thumping. Nevertheless, this increased precision can produce substantial savings in cost and time. A typical result is "438 ft 5 10 ft." If the fault is located at 440 ft, you only need to thump the 20-ft distance from 428 ft to 448 ft, instead of the entire 440 ft.

"Another weakness of TDR is that reflectometers cannot see faults-to-ground with resistances much greater than 200 ohms. So, in the case of a "bleeding fault" rather than a short or near-short, TDR is blind."

-George - notice how I provided useful info without once referencing myself? TDR used on a plane is a lot more useful than on underground faults because of that 1% thing.

Nov 12, 2015
That's hilarious, otto. You do not understand a sentence of that cut-and-paste.

Nov 12, 2015
I used one in 1966 to help save a mission at Edwards AFB on a special aircraft.


I am going to make your day glam-Skippy. You do not need to thank me. Tell me about this TDR unit you used to save the special aircraft? Did you plug him directly into the aircraft? Or did you run along the side while he flew over? Who made the TDR unit and what did he look like?

Oh boy, this ought to get good, eh?

Nov 12, 2015
I could send you the story, Ira, with permission of its owner, Smithsonian Air and Space Magazine. They bought it from me.

It was an HP and looked just like an HP scope with the horizontal profile and scope on the left side. The little dial to the right and below the scope would let you dial along the length of the cable displaying the impedance along the line.

It runs on 120VAC and connects to the coax.

Try to catch somebody else. My stuff is true, to your dismay.

Nov 12, 2015
That description was from memory of an event in October of 1966. I had not seen one before that night, and not one since.

But the aircraft was the EC-135N/ARIA.

Nov 12, 2015
It was an HP and looked just like an HP scope with the horizontal profile and scope on the left side. The little dial to the right and below the scope would let you dial along the length of the cable displaying the impedance along the line.


Well your wiki warrioring got you half there but, sorry Cher. There is a reason I ask you the question, I already knew the answer, and now you did too hoping I did not know the whole story. (You ever heard about that thing they teach the lawyers in lawyering school? Never ask the witness anything that you don't already know the answer to.)

HP yessirree-roo did make the first one that combined the sampling unit and signal generator in one package for the oscilloscopes. Are you ready? It was prototyped and demonstrated in 1964,,,, but was not produced as a product for sale until,,,, 1968!!!!!!

Before then it just was not available. (Pssst, like in 1966)

Nov 12, 2015
I could send you the story, Ira, with permission of its owner, Smithsonian Air and Space Magazine.


Well that has not slowed you down from telling a good story before. Why start now.

They bought it from me.


Uuh huh. You mean that the Smithsonian Skippys bought your life stories? I just got to know Cher,, why they would want to buy them from you? You give em away for free here every day.

Nov 12, 2015
Gosh, you folk who live on the net will always be behind those of us who lived in the real world. If you could not find it, it means you can't find it. You have a real problem with that little ego, Ira. You should have someone get a big lens and look at it.

This TDR was part of the B-58 project a few years before, so your assessment of when it was produced is way off. Maybe I'll look it up.

And, yeah, they bought that story: It was a very special aircraft.

Nov 12, 2015
If you could not find it, it means you can't find it.


Well that is going to keep everybody from noticing that I found it and you could not after three hours of frantic searching.

You have a real problem with that little ego, Ira.


My little ego is not so much the problem for me non. Better my little ego who doesn't care than your great big ego that gives you so much grief and misere.

This TDR was part of the B-58 project a few years before, so your assessment of when it was produced is way off.


My assessment is part of the historical record. Yours is no more than "back in the day blah, blah, blah."

Maybe I'll look it up


If you could not find him yet to look more would a waste of your times.

It was a very special aircraft


Like everything else you never did, eh? glam-Skippy you got two special stories for every physorg article. Did you ever do anything that was not special?

Nov 12, 2015
Here you go, Big Mouth. How many references from 1966 and HP would you like?

"1966 , Volume v.17 n.10 , Issue June-1966 - HP Labs
http://www.hpl.hp...6-06.pdf

17, NO. 5 JANUARY, 1966. MEASURING ... impedance (10 megohms), while metal .... Fig. is Typical stability of -hp- Model 400E/EL AC Voltmeter is ... The ac output impedance is ..... 1 "Cable Testing with Time Domain Reflectometry," Hewlett-."

Nov 12, 2015
P.S. for glam-Skippy.

Now that I finally come to the realizations that you are the most experienced and knowledgeable Skippy who I never did see before I do not feel so bad about leaving off the fooling around now because I got some work stuffs to do me. I will try to get back so we can fool around some more.

That means you can put out your stories without having to worry about ol Ira-Skippy interrupting just when you get to the good parts.

Nov 12, 2015
Here you go, Big Mouth. How many references from 1966 and HP would you like?

"1966 , Volume v.17 n.10 , Issue June-1966 - HP Labs
http://www.hpl.hp...6-06.pdf

17, NO. 5 JANUARY, 1966. MEASURING ... impedance (10 megohms), while metal .... Fig. is Typical stability of -hp- Model 400E/EL AC Voltmeter is ... The ac output impedance is ..... 1 "Cable Testing with Time Domain Reflectometry," Hewlett-."


Psst, Skippy this is me whispering to you. You just don't know when to quite digging. That says exactly what I said. It was not on the market in 1966. It was only offered in the HP Journal as a "coming attraction".

Nov 12, 2015
Do you dig up the entire street? Or do you just dig where the problem is.


No. You would get to the end of the cable and use a signal reflectometer to estimate how far down the line the fault is.

The result will be many times more accurate anyways than what you can get from some simulation done from a listening post miles away from the actual fault. Even if you do use the simulation algorithm, you still have to measure the precise point of the fault via conventional means to get the location down to the meter, so you aren't digging up half the block to find it.

That means your response to the fault isn't really helped by the proposed system. While it could get you a probable location at some resolution - say 1/3rd of the street - it still takes the same time to actually locate the fault. You still need linemen at the scene doing actual measurements.

Nov 12, 2015
Nope. Usually, there can be multiple events before the complete loss of power.


There can, but not always. If a small tornado throws a tree at your power line, that's pretty much a one-shot event. Power goes down and a bunch of switches trip upstream to the event - now figure out where it happened.

Of course, in the case of something like a distribution transformer failure due to overload, there will be signs for a long time before it actually blows up.

look up fault clearing on transmission lines and see how fast the breakers and reclosers can operate. It is sub-cycle.


That's kind-of defeating your point. These breakers isolate the problem from the rest of the grid, thereby isolating the signal from your listening post.

Nov 12, 2015
No, they do not. By the time they operate, the entire event is already being stored. Recorders detect and record the instability the information and waveshape data of which has been run through and stored in copious buffer memory for that purpose. With multiple measurement systems running at once, many display the information graphically and dynamically on screen for immediate or later analysis.

The ones I used were from BMI and RPM.

Nov 13, 2015
That description was from memory of an event in October of 1966. I had not seen one before that night, and not one since.

But the aircraft was the EC-135N/ARIA.


" Equipped with a steerable seven-foot antenna dish in its distinctive "Droop Snoot" or "Snoopy Nose", the EC-135N A/RIA became operational in January 1968"

https://en.wikipe...g_EC-135

Nov 13, 2015
First-contact-with-aria-by-george-kamburoff

http://www.flyari...roff.htm

Nov 13, 2015
Steve, that is one short version of the story. I was disobeying repeated direct orders at the time, and had to get up early one morning to go meet the General for that Airman of the Month award. And at the time, I was sneaking out at night to violate my charge, essentially breaking the military law.

I had no idea what happened to that aircraft until I read this:

Black Fire: De-orbiting Spysats during the Cold War http://www.thespa...e/1715/1

I sent my story to Dwayne Day and he sent it to the Editor of Smithsonian Air and Space Magazine.

Nov 13, 2015
BTW, the ARIA group has a web page, but you will not find out much about it, and nothing about their real mission. They put my name on their page of acknowledgments.

Nov 13, 2015
That's hilarious, otto. You do not understand a sentence of that cut-and-paste.
How would you know? You dont know the difference between calories and BTUs.

I do understand 'One weakness of TDR...'
And also 'Another weakness of TDR'

-And I know the difference in scale between plane wiring and underground power lines.

You apparently think theyre equivalent.

Nov 13, 2015
HP yessirree-roo did make the first one that combined the sampling unit and signal generator in one package for the oscilloscopes. Are you ready? It was prototyped and demonstrated in 1964,,,, but was not produced as a product for sale until,,,, 1968!!!!!!
-Bwahaahaahaa
That says exactly what I said. It was not on the market in 1966. It was only offered in the HP Journal as a "coming attraction"
-Bwahaahaahaaaaahaaaaaaa

-George must be one of those failed psychopaths...

"We would characterize criminal psychopaths as "unsuccessful psychopaths." The implication, of course, is that many psychopaths may exist in society who cope better than do those who come to the attention of the judicial and welfare systems."

-Hes too stupid to lie here but he doesnt know it, because hes uh too stupid.

Nov 13, 2015
-And I know the difference in scale between plane wiring and underground power lines.

You apparently think theyre equivalent.


He also was hoping we would not know that wiring and cable runs in military aircraft (and naval ships too) are meant to be unplugged and removed in case of a fault, not patched up in place. Guess he over (or under) thought that little ploy to get something in about how wonderful his past was and how elite he is in the "I-Have-Done-Everything" tribe.

Nov 13, 2015
" Equipped with a steerable seven-foot antenna dish in its distinctive "Droop Snoot" or "Snoopy Nose", the EC-135N A/RIA became operational in January 1968"
-Bwahaahaaaaa george your zippers down.
I was disobeying repeated direct orders at the time, and had to get up early one morning to go meet the General for that Airman of the Month award. And at the time, I was sneaking out at night to violate my charge, essentially breaking the military law
-and, from his story;
Nothing was ever said by my boss, but it was my last hurrah on the flight line. I was immediately taken off flight line duty and put into the shop, where I could be watched
-So was this before or after you got your airman of the month merit badge?

Did they make you pay for your free dinner at the rotary then?

Bwahaahaaahaaaaaa
how wonderful his past was and how elite he is
Id like to know when that story of his was added to the website.

Yesterday?

Nov 13, 2015
Thanks for once again revealing your ignorance of how things work. Yup, I worked on the first one, the prototype, to see if they would build more. We got it ready with only minutes to spare that night, with the help of that ridiculous finding of the TDR.

It took another year to equip it with consoles and mission equipment and construct several more.

No, otto, I have no control over the ARIA website. But make sure you read the vignette at:

Black Fire: De-orbiting Spysats during the Cold War http://www.thespa...e/1715/1

Tell us what you did in the service, . . you DID enlist, didn't you? You didn't just hide, did you?

Nov 13, 2015
I see Ira does not know the difference between electronics techs and aircraft electricians. I only rewired a few aircraft, when the harnesses burned the length of the EC-121R aircraft while we were in the swamps and we had no electricians, so we got the wire and did it ourselves (Dune Moon, July, 1967).

Nov 13, 2015
We got it ready with only minutes to spare that night, with the help of that ridiculous finding of the TDR.

It took another year to equip it with consoles and mission equipment and construct several more.

No, otto, I have no control over the ARIA website. But make sure you read the vignette at:

Black Fire: De-orbiting Spysats during the Cold War http://www.thespa...e/1715/1
Uh who gives a shit??

BTW:
Yup, I worked on the first one, the prototype
-This appears to be an crucial aspect of the story. Why didnt you mention it either here or on that website until you were called on it?

Most people would be embarrassed to reveal their 'experience' in the context of so many clumsy and juvenile lies.

Youve been proven a liar so many times and still you continue to present this 'experience' as justification for it.

Your a liar no matter what you did and we all know it, do you understand that?

Youve perverted yet another thread with irrelevant stories about YOU.

Nov 14, 2015
I have never had a follower with such a grudge in my life, and most of the time it is kind of flattering to see how much influence I have on some other person. I can make otto scream, rant, rave, curse in ALL CAPS, all just by being me.

Bark!

Roll over!

I have never had a follower with such a grudge in my life
Ive never seen a poster here who thinks that he has a right to lie just about every day just because he claims to have a phony MS, and who got sick of killing while soldering wires in vietnam.
I can make otto scream, rant, rave, curse in ALL CAPS, all just by being me
Well youve already admitted that you are here to play people like cheap kazoos.

"Psychopaths make their way by conning people into doing things for them; obtaining money for them, prestige, power, or even standing up for them when others try to expose them. But that is their claim to fame. That's what they do. And they do it very well. What's more, the job is very easy because most people are gullible with an unshakable belief in the inherent goodness of man.

"Manipulation is the key to the psychopath's conquests."

-This is why most people consider them scumbags.

Barf?

Nov 16, 2015
Did otto look up the ARIA? You know he did. Bullies fold when confronted.

Nov 16, 2015
Did otto look up the ARIA? You know he did. Bullies fold when confronted.
Uh that has nothing to do with short circuits in power grids and everything to do with your puss-filled ego.

Right?

Nov 16, 2015
The techniques I used to find the RF impedance anomaly is directly applicable to this discussion.

Nov 16, 2015
The techniques I used to find the RF impedance anomaly is directly applicable to this discussion.


Not really. Time domain reflectometry in powerlines, especially undeground powerlines, have different considerations because the characteristic impedances are different and the frequency ranges these things are built to work with are vastly different. A power line is not like a 50 ohm coaxial cable - for RF frequencies a simple kink or a loop in the cable makes a reflection, whereas for AC line frequencies it does nothing, which makes it difficult to tell a fault from normal discontinuities because the cables are made of multiple strands where one or many strands may be broken along the way, and splices etc. Some faults like a bleeding ground fault can be completely undetectable.

And because of the impedance mismatches, the RF signal attenuates differently over miles and miles of cable - you may never even hear the reflection because the returning signal is too weak.

Nov 16, 2015
To make a comparison - back in the day of analog television, one way to clean up a snowy picture was to take the coax cable from the antenna and loop it around 7 or 8 times 3-4 inch in diameter as close to the reciever as possible. That created a rudimentary filter that would clean up some of the noise bleeding in from higher frequency sources like cellphone masts or nearby computers.

If you were in a building with coax network cabling, and the electrician had tucked away extra cable by looping it around and hidden the loop in the wall, that would end up causing trouble for the network administrator.

That's how sensitive cables are at RF frequencies. You can even "see" the discontinuity created by the small bit of tin between a coaxial cable and the connector at the end in the reflection, and because it is so sensitive you're drowned in all sorts of extra noise when you try to measure a power line, because they're not so nicely made and uniform in quality as coax cables.

Nov 16, 2015
A time-domain-reflectometer is basically like radar.

When the sky is clear, when you have a nice uniform quality cable that is properly terminated with the right impedance, there's no reflections from the cable itself and you can sense a fault in it easily.

When you have a decades old power line that is oxidized and mechanically stressed, frayed, possibly already repaired several times by splicing in new cable, it's like pointing your radar into a forest of trees, expecting to see something other than the trees.

It works only if you use a frequency for which the trees are invisible, which means you use similiar techniques but at different, lower frequencies, which limits the resolution of the picture you get and the types of faults you can find.

Nov 16, 2015
Eikka, you are just flapping your lips to say something.

Which techniques have you used?

Nov 16, 2015
The techniques I used to find the RF impedance anomaly is directly applicable to this discussion.
Thats a recurring delusion of yours. Anything about you is directly applicable to any discussion.

You asked if I looked up ARIA. ARIA has nothing to do with short circuits in power grids.

And so why would I want to look it up?

I provided a link to a site which describes better methods devised since 1910 when Time domain reflectometry was first conceived.

Did you visit that site?

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