Why is Westinghouse brand electricity better then Edison Brand? - Page 1
Forum section: electronics / general

author: Beamin
author_rank: Super Contributor
timestamp: September 10, 2017, 05:54:59 pm
content: Next time the electricity sales people come to the door tell them you want Edison brand electricity and watch the blank look on their face. ut why does AC transmit better over distance? High voltage works better because you can use thinner conductors because you are moving less electrons with greater potential. But why is AC better? Wouldn't you just lose energy to RF since power lines span long enough to have multiples of what ever wavelength 60hz is? Could you use 1hz AC and get the same effect?

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: September 10, 2017, 05:57:01 pm
content: Because it can be re-boosted to account for transmission line loss over great distances with transformers.

author: fubar.gr
author_rank: Unknown
timestamp: September 10, 2017, 07:38:46 pm
content: It is a tradeoff between transformer size and losses due to inductance and capacitance.At 1 Hz you would have minimal losses, but the transformer would be HUGE (more materials, more expensive) compared to a 60 Hz transformer of the same VA rating.At higher frequencies transformers would be even smaller for the same VA rating, but the wire inductance combined with the capacitance to ground would effectively act as a low-pass filter and there would be a huge voltage drop a few miles down the road.Also higher frequencies are more dangerous with regard to electrocution

author: StillTrying
author_rank: Super Contributor
timestamp: September 10, 2017, 08:35:32 pm
content: Next time the electricity sales people come to the doorask them how they manage to keep their electricity separate from other companies' electricity when it all comes down the same wires.

author: Vtile
author_rank: Super Contributor
timestamp: September 10, 2017, 08:38:15 pm
content: The difference were ability to manipulate the electricity efficiently. Not that much of an problem today, but back then the difference were hugely to Teslas favour.

author: IconicPCB
author_rank: Super Contributor
timestamp: September 10, 2017, 09:07:41 pm
content: DC is better for long line transmission...it is only at the user level where AC is more appropriate

author: Ian.M
author_rank: Super Contributor
timestamp: September 10, 2017, 09:21:13 pm
content: Just tell them you wont have Edison brand electricity in your house because of animal cruelty!https://en.wikipedia.org/wiki/Electrocuting_an_Elephant

author: Richard Crowley
author_rank: Super Contributor
timestamp: September 10, 2017, 10:18:43 pm
content: AC ("Westinghouse") is easier/more efficient to transport and distribute at regional and local levels. Mainly because you can exchange voltage/current passively with transformers. That allows stepping up or down depending on the particular requirements. This is impossible to do passively with DC.DC ("Edison") is preferred for long-distance transmission or other specialized interconnections like between two uncorrelated regions. But it requires large, specialized equipment that is much more expensive than what is used for "ordinary" AC distribution.Example 1: The "Pacific DC Intertie" which carries 3.1GW between the Columbia River (between Oregon and Washington) and Los Angeles. There is a bi-directional conversion station in Celilo (just south east of The Dalles, Oregon where there is a large Google server farm). And at the other end of the line is another bi-directional conversion station in Sylmar, California, a northern suburb in the vast Los Angeles basin. In the summer, excess hydro power is shipped from the northwest down to Los Angeles to keep their air conditioners running. And conversely, in the winter, power is shipped from LA back up north to keep us warm. Over distances like that (1362km) you start making an effective transmitting antenna @ 60Hz.Example 2: The Acaray HVDC Back-to-Back installation which interconnects Brazil (60Hz) with Paraguay (50Hz) on either side of the river.Example 3: Many undersea transmission cables that power islands like Vancouver or Mallorca. Or the connection between New Zealand's northern and southern island. Because of the high capacitance of undersea cable, DC is preferred to AC.

author: razberik
author_rank: Frequent Contributor
timestamp: September 11, 2017, 08:31:45 am
content: Quote from: StillTrying on September 10, 2017, 08:35:32 pmThis is hilarious !My recommendation is to ask sales agent how many volts they provide, but separation question is a blast.

author: Berni
author_rank: Super Contributor
timestamp: September 11, 2017, 10:05:07 am
content: With these new fangled switching power supplies, popularity of brushed motors in small appliances and popularity of inverter driven async motors in washing machines you could actually run a house on Edison electricity just fine.Tho some of the switches like bimetal thermostats or cirucit breakers might be a bit more fond of Westinghouse.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 11, 2017, 10:14:14 am
content: I don't think switching tech is quite ready for taking over existing infrastructure. One often overlooked reason comes down to: fusing!DC is very troublesome to fuse. Arcs need to be quenched with a combination of cooling air blast and pinching magnetic fields. AC's zero crossings make switch opening (under load) and fuse clearing much simpler.I suppose you could argue that all those systems could be semiconductorified as well, but things get really out of hand, really quickly. Instead of merely replacing transformers with DC-DC converters, you're also adding protection circuits (that have to be at least as large -- because they have to handle the same power, or more), switches, current limiters and so on.And you still need transient protection, because remember, while all of this stuff is going on, you still need to withstanddirect lightning strikes!So the combination that we have today: AC, transformers, fuses, switches and so on, really is a remarkably robust and efficient system, even if we scrutinize it with current technology.If, a century ago, someone had said, "they'll never improve on this stuff", they might be a fool for saying so. But as it turns out, they would've been startlingly correct!Tim

author: Richard Crowley
author_rank: Super Contributor
timestamp: September 11, 2017, 01:00:32 pm
content: The Pacific DC Intertie is ground-referenced, so there is a substantial grounding system at each end of the line. In Oregon there are "1,067 cast iron anodes buried in a two-foot trench of petroleum coke, which behaves as an electrode, arranged in a ring of 2.02 mi (3,250.87 m) circumference at Rice Flats (near Rice, Oregon), which is 6.6 mi (10.6 km) SSE of Celilo." Essentially buried under a potato field.At the Los Angeles end, the "ground" travels ~27km south from Sylmar through 644 mm2 ACSR (aluminum conductor, steel reinforced) conductor overhead lines to a former distribution station in a posh neighborhood (Brentwood) where it goes underground and out to "a line of 24 silicon-iron alloy electrodes submerged in the Pacific Ocean at Will Rogers State Beach suspended in concrete enclosures about one meter above the ocean floor."Literally a few meters from the spot where millions of amps go underground are several large swimming pools. I wonder if the neighbors know what is next-door?https://www.google.com/maps/place/34%C2%B004'05.0%22N+118%C2%B029'18.5%22W/@34.0679917,-118.4883718,104m/data=!3m1!1e3!4m5!3m4!1s0x0:0x0!8m2!3d34.068053!4d-118.488472?hl=en

author: BradC
author_rank: Super Contributor
timestamp: September 11, 2017, 01:26:26 pm
content: Quote from: Richard Crowley on September 11, 2017, 01:00:32 pmSo my "after a few beers" maths calculates that out at about 1 1/8" (~28.6mm). Did I get that right? That seems pretty small.Also, is it wrong that I pushed my digital calipers to 28.6mm and then used that to translate to imperial fractions rather than think it out?

author: forrestc
author_rank: Unknown
timestamp: September 11, 2017, 01:34:39 pm
content: Quote from: Beamin on September 10, 2017, 05:54:59 pmAs others have stated, AC is 'easier'. It can be stepped up and down with a simple transformer, the generators are simpler, it's easier to fuse, switch, etc., especially with the technology available in at the time of the "War of the Currents". But the main advantage was the ability to be easily stepped up to high voltage for transmission, reducing I*I*R losses (If you double the voltage you end up with half the current for the same power = this means you lose only 1/4 as much power to resistive losses). This one technology mad long distance distribution possible. DC wasn't able to be as easily stepped up and down, so it could only travel a short distance from generator to consumption point.I find that some of the arguments Edison made for DC were more based in causing hysteria instead of any reality. Like AC was not as safe as DC, and so on. I somehow wonder if DC would have won in today's "beliefs are facts" climate.I will say that a lot of the benefits of AC are slowly diminishing. More and more things are running on various forms of straight DC nowadays - PoE lighting for instance is apparently really taking off. We all charge more and more things with USB-C (which is capable of up to 100W), and so on. But I don't think enough things have changed for DC to 'win' on technical benefits if the War of the Currents was replayed today. Large transformers are still significantly cheaper than similar sized DC-DC coverters, and there are a LOT of transformers needed in a typical power grid.

author: krystian
author_rank: Contributor
timestamp: September 11, 2017, 01:42:30 pm
content: DC is better for power transmission because impedance of the cable consists only of resistance without reactance part (cable inductance and cable-earth capacitance)AC is better for voltage conversion because simple and very efficient transformers can do it. Semiconductor based converters are still too fragile to handle power lines, without huge costs of maintenance.DC arc-quenching is not as simple as AC. And costs of protection devices for DC are very high.Poland for example is connected with Sweden by HV DC power line, placed on the bottom of baltic sea.

author: Richard Crowley
author_rank: Super Contributor
timestamp: September 11, 2017, 01:55:59 pm
content: Quote from: BradC on September 11, 2017, 01:26:26 pmThere appear to be several conductors in parallel. At least two and probably four or maybe even six.

author: Vtile
author_rank: Super Contributor
timestamp: September 11, 2017, 02:35:36 pm
content: Quote from: krystian on September 11, 2017, 01:42:30 pmMm.. I feel compelled to say that above is generalisation and in reality there is reactance as the consumed power ( energy for pedantic persons) is not constant, but noisy (kW / kA level), which creates a situation of DC with AC ripple. Splitting the hair here, but such a words like 'only' are dangerous.@R.Crowley. How the reinforced concrete structures like bridges etc. hold against the earth currents (speeded up electrochemical corrosion) along that transmission link?

author: Richard Crowley
author_rank: Super Contributor
timestamp: September 11, 2017, 03:16:55 pm
content: Quote from: Vtile on September 11, 2017, 02:35:36 pmVirtually all of the length of the PDCI is out in vast wilderness where there is little or no infrastructure. But there are probably other HVDC paths that cross over populated territories with infrastructure.OTOH, many of the bridges that were constructed along the Pacific Coast Highway have been retired or demolished because of electrolytic corrosion. But they attributed that to the proximity of the ocean, salt air, etc. According to some recent YouTube videos I saw, they are applying some kind of zinc spray-on layer and reverse-charging both the external/coating and even the internal re-bar metal to reduce or eliminate the phenomenon.I am only a dilettante fascinated with Celilo and HVDC. I am in no way an expert nor have any experience or knowledge except what I see on the interweb.

author: RoGeorge
author_rank: Super Contributor
timestamp: September 11, 2017, 03:36:05 pm
content: Quote from: Beamin on September 10, 2017, 05:54:59 pmThat would be childish, there is no such thing as "Edison brand" electricity. That would not be technically possible for the power distribution system. If you want "Edison brand" electricity, just use the electricity coming out from your phone charger.Quote from: Beamin on September 10, 2017, 05:54:59 pmThis question is wrong, because it assumes that AC is better over distance, and that is why we use AC for power distribution.The main reasons for using AC in the power distribution system are- the electricity is generated by huge electric generators. At huge power and huge dimensions, AC electric generators are much easier to build, operate and maintain when compared to DC electric generators of similar power.- the current need to be lowered while transporting the power.The main losses when transporting power are by Joule effect, Q = I*I*r*t, so it's critical to lower the current as much as possible. To lower the current (for a given power), you need to boost the voltage. If you boost the voltage, then this will be a great danger for the electrical generators and for the end user. So you will need transformers to boost the voltage, then transport the power over long distances, then you will ned transformers again to lower the voltage at the end user side.Why we don't use lower frequencies, like 1.5 mHz?Because the transformers for 50/60 Hz in the power distribution system are already huge (like the size of a big room huge). The lower the frequency, the bigger the transformer for a given power. Nobody will want a transformer the size of a shopping Mall.(That is the same reason we are using switched power supplies, SMPS, because the transformers are much smaller at the switching frequency of many KHz than it would be at 50 or 60 Hz mains frequency.)

author: Beamin
author_rank: Super Contributor
timestamp: September 11, 2017, 10:12:54 pm
content: Quote from: RoGeorge on September 11, 2017, 03:36:05 pmThat would be what is called a joke, which is a type of humor.I should also ask them if they can sell me a service plan or a warranty for lost or damaged electricity excluding of course normal wear and tear. And I will tell them I don't want my electricity mixed with inferior brands of "unregulated"( in the legislation sense) of electricity. With that they can sell me HD digital extension cords and filters that only allow their brand of electricity to pass. I could get a triple play bundle that consists of hot, neutral, and ground. Which will save me from buying just hot and neutral. Also they could sell "electrolock" that puts encryption on my electricity to stop hackers from stealing it. All of this will come with a 2 year contract with a pro rated $500 disconnect fee and a 30 free look period where I can try out their brand of electricity to see if I like it. Don't forget the option to go green where stray electrons are recycled at an additional fee. * A 2.99 per addition outlet fee applies (each wall plug counts as two) and a 4.99 per use convenience fee would apply for use between 9 am and 5 pm. Black out insurance is optional which pays up to $5.00 for lamp batteries and generator gas. Proof of receipt required additional term may apply see an certified senior electricity sales artist associate for details.

author: Vtile
author_rank: Super Contributor
timestamp: September 11, 2017, 11:52:19 pm
content: Hmm. Since this did go to greenwashing machine. I propose that next IEC standard will include norms for waste current threatment procedures. This is important since the current returns to factory and today it is not cleaned, but released to ground. Model can be taken from water distribution as is common in electric modeling, atlast we should start to think about returning waste currents as is common with waste water these days. There is also great opportunity for business in form of waste current disposal fees.