History of 3-phase Electricity & Distribution

Who invented 3-phase electrical distribution? Nikola Tesla? Mikhail Dolivo-Dobrovolsky? In this video I go through the detailed history from primary sources of this important EE discovery, how it works, and why it is important.
Links:
My mailing list (with a link for a video on the history of 2 phase)
kathylovesphysics.ck.page/wel...
My Patreon Page:
www.patreon.com/user?u=15291200
As usual, a big thank you to the fabulous Kim Nalley for singing "electricity" and some background music. www.kimnalley.com
Citations:
Alfred, R “Aug 14, 1888: I Sing the Meter Electric” Wired Magazine (Aug 14, 2008)
Thompson, S Polyphase Electric Currents and Alternate-current Motors (1900) p. 444
“Mr. Nikola Tesla on Alternating Current Motors” The Telegraphic Journal and Electrical Review vol. xxiv (June 7, 1889) p. 648
Carlson, W Tesla: Inventor of the Electrical Age (2013) p.113
Tesla, N “Tesla’s Tribute to Westinghouse,” The Age of Steel LXXXVIII, no. 10 (September 1900), 9.
William Stanley “The Induction Motor” Engineering News (Oct 2, 1902) vol. XLVIII No. 14 p. 279
Frank Sprague to Sprague Executive Board (leaked to Edison) (April 29, 1890) Edison Papers Digital Edition [X120CBN]
Jonnes, J Empires of Light (2003) p. 223
Leupp, F George Westinghouse: His Life and Achievements (1919) p. 159
Skrabec, Q George Westinghouse: Gentle Genius (2007) p. 130
“Mikhail Dolivo-Dobrowolsky (1862-1919)” [in Russian] Vavilov, S People of Russian Science: Essays on Outstanding Figures of Natural Science [Люди русской науки: Очерки о выдающихся деятелях есте- ствознания и техники] (1948)
Dolivo-Dobrowosky, M "Transmission of power by rotary-phase alternate currents", Electrical Engineer (London), vol. 7, p 369, (April 10, 1891)
“The invention of the electric motor 1856-1893” Elektrotechnisches Institut (ETI) www.eti.kit.edu/english/1390.php
Thompson, S Polyphase Electric Currents (1900) p. 173
Thompson, S Elementary Lessons in Electricity and Magnetism, (1894) p. 507
Ushakov, V “Electrical Power Engineering” (2017) p. 16
Allerhand, A “The Earliest Years of Three-Phase Power” Proceedings of the IEEE vol. 108 (Jan, 2020) p. 215-6
Herausgegben vom Vorstand der Ausstellung Offizieller Bericht über die Internationale elektrotechnische Ausstellung in Frankfurt am Main, 1891 (1894) p. 324
Lightning: Volume 1 (April 28, 1892) p. 509
“The Transmission of Power at Frankfort” The Electrical Engineer (Sept 18, 1891) p. 286
Brown, C “Reasons for the Use of the Three-Phase Current in the Lauffen-Frankfort Transmission” The Electrical World (Nov 7, 1891) vol. XVIII No. 19 p. 345
Nikola Tesla patent US 382,280 “Electrical Transmission of Power” (May 1, 1888)
“Mr. Tesla’s Experiments” (April 6, 1892) Electrical Engineer vol 13-14, p. 350
Lamme, B “The Story of the Induction Motor” (March 1921) Electrical Engineering (New York) vol. XL p. 205
Tesla’s patent was co-owned by supporters Alfred Brown and Charles Peck, according to Carlson, B Tesla: Inventor of the Electric Age p. 130 “Since they had shrewdly handled the business negotiations and assumed all of the financial risk in developing the motors, Tesla gave Peck and Brown five-ninths of the proceeds from the deal while retaining four-ninths for himself”
Lamme, B Benjamin Garver Lamme, Electrical Engineer, An Autobiography (1926) p. 61
Lamme, B “The Story of the Induction Motor” (March 1921) Electrical Engineering (New York) vol. XL p. 212
Davis, L Fleet Fire: Thomas Edison and the Pioneers of the Electrical Revolution (2012)
“Westinghouse paid Tesla $216,600” “Annual Report of the Board of Directors of the Westinghouse Electric” Electricity (June 30, 1897) p. 387
Gordenker, A “Japan’s incompatible power grids” Japan Times vol. 19 (July, 2011) p. 9
Dolivo-Dobrowolsky “Transmission of Power by Rotary-Phase Alternative Currents” The Electrical Engineer (April 3, 1891) p. 336

[@deaniegarcia5694]

I am a retired EE, and never paid much attention to power systems, preferring information and computation,but you make this stuff compelling! I watch your videos often, and it, almost makes me want to go back to work! Keep up the great work!

[@andyo1872]

I didn't know about Dolivo-Dobrovolsky's greatest inventions until today( I never heard about him either). Thanks to you Kathy now I know who really invented the most practical and efficient 3-phase AC. Dolivo-Dobrovolsky is so under rated ! 3-Wire 3-Phase !! What a genius !

[@LucIan-er2ir]

it depends of which sponsorig have 🙂

[@raymondgarafano8604]

YUP, but is it a Y or Delta (meaning a triangle) which came first? Is the Y better for lighting or motors? A Delta can have a center tap in the midst of a winding to give 120 volts while a Y will give 1.732 X the voltage from phase to phase as compared to the voltage from the neutral or one side of the three windings to a phase conductor.

[@BPo75]

@@raymondgarafano8604 With the D-configuration you will have the main voltage across the windings at all times (centre tap to 120V is an abomination that offers no real advantage except an insignificant reduction of insulation needed), but you won't have a neutral point.

[@rogerw9840]

Fun fact: The 18th of December 1893 the worlds first commercial 3-phase power transfer was inaugurated. The transfer line ran between Hällsjön (the source, water turbine IIRC) and Grängesberg (at the time one of the largest iron ore mines in Europe) in southern Dalarna, Sweden. The distance of the transfer was 13 kilometers and transferred up to 9300 Volt. Remains of the facilities can be seen to this day. A testing and demonstration facility connecting Lauffen and Frankfurt in Germany had been in operation for a few years before.

[@BPo75]

Jonas Wenström is sadly unknown outside Sweden.

[@robs2203]

Thanks to your presentations Kathy, as a retired electrical engineer, I am still exited about the beginnings of the sciences and their industrial implementation.

[@colmcillegardner2144]

Excited vs exited 😊

[@robs2203]

@@colmcillegardner2144 thank you ☺

[@seeratlasdtyria4584]

Simply put, this is a better explanation of these events, than I heard in my EE Engineering classes at UCLA, LOL. Kathy, I do not know your history, but you were, imho, born to teach:) Thumbs up across the board.

[@Kathy_Loves_Physics]

Thanks so much

[@Dennisaj]

If a KZbin content creator Does a better job at explaining electrical engineering, Then a professor at UCLA… Than why the heck is college so expensive???

[@seeratlasdtyria4584]

@@Dennisaj excellent question, the answer is something called 'tenure' :)

[@HyperactiveNeuron]

I 100% agree. This is like 4 or 5 different lectures and probably more than 2 or 3 classEs. Power systems and electromechanics was my favorite subject and I never heard all of this together or this organized.

[@ohboy4784]

Well, There is a huge difference between teaching "History of science " and actually doing or teaching science ...huge difference.

[@chrisnurczyk8239]

Not only do I now understand the history of this form of energy distribution, I finally have a better working understanding of the manner in which AC works in modern systems. Great job, Kathy. As a retired middle-school Natural Sciences teacher and junior college Horticultural Adjunct, it's wonderful to see someone explaining science in such a meaningful manner, using original sources. Pray, continue!

[@coolcat23]

You always create exactly the right mix between illuminating personal motivations and technical background that makes following the subject not only a breeze but very enjoyable.

[@KeritechElectronics]

As a Polish electrician and electronics hacker, I'm proud of Dolivo-Dobrovolsky and absolutely delighted with this episode :) Oh, and there are a few other important Polish inventions in electrical engineering: a FW bridge rectifier (or, as Electroboom would call it, FULL BRIDGE RECTIFIER!) and an electrolytic capacitor - both invented by Karol Pollak. How would electronics look now if not for him? I guess we'd still go with the centertapped windings. To think that most of the principles and inventions lied out by him are the mainstay of modern electrical distribution systems, though now that we've got highly efficient DC/AC converters, we may be seeing some DC power system resurgence especially in the international ultra high voltage networks, not to mention the solar installations. DC switching on the other hand, arc quenching in particular... makes me wonder if it can be easily solved using IGBTs or FETs (thyristors won't do, they stay latched until power is cut off, making them useless for this purpose).

[@krishnaprasadlama9432]

Dobrovolsky's contribution in the development of 3-wire 3-phase electricity was really an eye opener for me as I had all along thought that Tesla was the sole inventor.I had known of the contribution of Steinmetz however.

[@europoamerico7605]

This is all bull. Specially coming from a woman. Tesla invented ac period

[@angrydoggy9170]

@@europoamerico7605 Nope he didn’t. It was invented years before he was born.

[@bwfvc7770]

@@europoamerico7605 from memory the first ac was generated by a French woman using a Faraday designed machine. The commutator was introduced to this machine by Andre-Marie Ampere, thus producing the first generated, rudimentary dc.

[@scamper_van8470]

It doesn't change much whom invented what. Tech should be available to everybody,but now days Tech has become only profits and no benefits for everyone, but the end results its the same. Tech make rich some and screw over the rest,a truly excellent tech is the one that once built last over time and not break after 1 2 years due to the fact that Markets need something new every few months to make more profits... In the facts is the human kind greed that is driving today's world,along with non stop pollution of the planet. On which we all live and when the planet dies we all will die with the planet.. Capitalism and Political Corruption... 🤣🤣🤣🤣🤣🤣🤣🤣🤣

[@jourwalis-8875]

@@europoamerico7605 This is sex discrimination!

[@marcosfingerhut3011]

Kathy, the difference you're pointing that Tesla's three phase motor needed 6 connecting wires and Dolivo´s had only 3 makes a world of difference and thanks to you I can see where these two inventors differ and the huge Dolivo-Dobrovolsky´s breakthrough. How elegant is Dolivo´s 3 wires solution; I'm in awe !. Thank you for helping me see it so clearly !

[@mikelang4853]

Invention is needed in order for refinement to occur.

[@Bialy_1]

"Doliwa - is a Polish coat of arms. It was used by several szlachta families in the times of the Polish-Lithuanian Commonwealth." Dobrowolski is the family name and you can translate it as "Goodwill". But i agree that is very well made video and amazing work made by Kathy.

[@gordongecko9405]

@@Bialy_1 O tym że system 3-fazowy to wynalazek Polaka to wiedziałem, i tą wiedzę propagowałem. Ale co to jest 'doliwa' to już nie. Dzięki.

[@costiqueR]

In fact, this is a key observation, I just saw the full episode and I was angry on so many years of misinformation. Tesla added his 3 coils variant as a variant of the 2 phases device, no study really in the background. As a filling of possibilities in the patent. He did not know the huge difference between 2 and 3 phases. In fact, all that we use today is the AEG system, so is clear for me in one moment the Americans understood but was no way for them to recognize it... Tesla himself probably knew it best.

[@marcosfingerhut3011]

@@costiqueR Exactly. Tesla did not know the HUGE difference between 2 phases and the REAL (Dovrowolsky´s) three phase with only three wires.

[@jimkillen1065]

I worked at a power plant for 35 years and studied the basics classes back then. At the first power plant i worked at it was very old unit . The equipment worked well but has long since been removed. Glad i ran onto this channel. I certainly watch more of your videos . I remember i think that air craft were a lot higher frequency . Thanks for the history lesson..

[@macalmy6750]

I don't know why the KZbin algorithm sent you my way last week, but I'm glad it did. The level of detail and citation you go into is wonderful, and you're a great story teller. Too much of what gets taught in science classes about the history of science seems to be more like folklore, so it's wonderful to find someone who digs in to get the details right.

[@Jvs-eq3iy]

She is a great teacher.

[@juliofoolio2982]

Thank you Kathy. I am so grateful for your work. There are many excellent science educators on KZbin but your thoroughness and uninhibited passion set you apart. Your videos will play a part in my child’s education.

[@alfabsc]

I thought I knew this history. The Westinghouse+Tesla vs Edison story is very familiar to me. I had never heard of Dolivo-Dobrovolsky. Thanks for clearing up the details of how 3-phase became dominant electrical distribution system.

[@kevinmithnick9993]

X2. I thought Tesla was the only one and the creator of virtually everything

[@ktaragorn]

Same! Feels like his innovation was more impactful than either of edisons or teslas.. and impressive that it has stood the test of time as well!

[@clivebaxter6354]

There was no Tesla V Edison

[@wiadroman]

@@kevinmithnick9993 Well, you were wrong. Tesla invented only 50% of everything, the other 50% was invented by Da Vinci.

[@kevinmithnick9993]

@@wiadroman Well, 50% of everything is still a lot. Is sad nowadays we are more worried who is taking more attention than who is doing more. Yes, there is a difference. Good to see at least 0.000001% of world population devotes their lives to human adavancing as civilization. Unfortunatelly that number is in decline

[@NONFamers]

Thanks for yet another exciting video! Thank you for researching so deeply into the topics you cover. I had never heard of Mikhail Dolivo-Dobrovolsky before. Way back in my youth I was an intern for two weeks at an electrical motor servicing workshop, where my first, and main, task during my internship was to re-wire a three-phase motor. This was no easy task; I remember having to remove the - very scorched and burnt - coils from the stator (a dirty, smelly job), count the number of turns in each coil , measure the wire gauge (to ensure I matched the correct electrical properties), wind the individual coils, mount them without damaging the laquering, having a 'grown-up' weld the wires together in the correct configuration, and dip-coating the stator with insulating laquer before it could be tested. I was thrilled that it ran! I had, in fact, re-wired a three-phase motor! BTW, I like that purple shirt.

[@garryclelland4481]

Kathy thanks so much for putting this up , ive been in electrical / mechanical engineering for 40 + years and you've taught me stuff i did not know ( i double checked ) , thanks for putting me right , liked and subbed , thanks again .

[@ephemeralvapor8064]

This is the best video per minute of time I've seen on the history of this subject by far - good job and thank you.

[@Kathy_Loves_Physics]

Thank you for the lovely comment. Made my day. 😊

[@chuckthebull]

@@Kathy_Loves_PhysicsIll have to agree with mr or mrs Vapors,,, I have been an electronics engineer repair guy tinkerer and instrument maker and now in my 60s still doing work in film and i have to say your videos are really enjoyably to watch and this old dog has even leaned a few new tricks ( or at least history) of a few things even i did not know.. Thanks for taking the time and effort to do these vids and research all this wonderful history. I love your style and enthusiasm telling these stories. keep it up!

[@Matlockization]

@@Kathy_Loves_Physics Nicola Tesla is not serbian. When asked by a reporter where he was from, he said Austro-Hungarian which the area is current day Croatia.

[@dennishillman3502]

I have worked on and designed 3 phase systems for 30 years. I cant count how many books and papers I have read on the subject and this video had me rethinking a lot of what I have learned. Thanks for all the hard work researching this.

[@mobilemcsmarty1466]

I will second that opinion. thanks Kathy! I just found your channel and will go to watch the rest of your vids. may I humbly suggest to wear a microphone I can better hear your lovely voice and content 🙂

[@xtalvt]

Awesome job !!!!!! I build electrical control panels for several clients including Westinghouse Nuclear (worked as an engineer for them a decade ago). Your timeline is sooooo much clearer than any I had read. I also did not know where the 50 vs 60 Hz came from ... loved that part of the story! Thanks so very much !!!!!!

[@SH-th4wy]

I really like listening to someone who is so comfortably versed explain a topic. Thank you.

[@straighttalking2090]

Love Kathy's enthusiasm. Didn't think I would watch a video on this subject to the end but she carried me to it. Well done.

[@edshave]

Haven't watched this video yet as I've just discovered your channel and am slowly working my way through from the beginning. But I couldn't wait to let you know, I absolutely love both your content and style. You make it look easy but I know an awful lot of work goes into each one. Thank you so much for taking the time.

[@jimprice1959]

Kathy - A very informative video. I love the history and reasons behind what we use today. I used to be a volunteer at the Folsom Historic Powerhouse in Folsom, CA. It was built in 1995 and we told our visitors that it was the first long distance 3-phase powerhouse in the US. It was built just a bit before the Niagara Fall powerhouse was put online. Niagara used Westinghouse 2-phase generators. I believe that GE got the power transmission contract to Buffalo and used Scott-Tee connected transformers to convert to 3-phase. It's interesting that the Folsom powerhouse has four 3-phase generators and used 12 wires to send the power 26 miles down to Sacramento. This was because the original governors were not stable enough to allowed the generators to be synchronized. The AC was converted to DC in Sacramento with M-G sets and then paralleled in order to power streetcars. The change to Lombard governors in around 1906 allowed the paralleling of the generators. Folsom used GE generators. I believe this was because the Livermore Brothers used financing by GE in order to build the powerhouse.

[@Kathy_Loves_Physics]

That is fascinating! I read somewhere, I think Allerhand, A “The Earliest Years of Three-Phase Power” Proceedings of the IEEE vol. 108 (Jan, 2020), that Westinghouse lost out on the Folsom gig because he refused to use 3-phase! It is fascinating to me that Westinghouse was so advanced and adventurous with AC versus DC and then so resistant to 3-phase.

[@jimprice1959]

@@Kathy_Loves_Physics As a Professional Control Systems Engineer, and powerhouse docent, I'm familiar with some of the older technology but never learned much of the history. Thanks for combining the two in an interesting way.

[@triggerfish6619]

Hi Jim, Well now I'll have to visit, if still open, I'm in Citrus Heights and driven by often. Thank you for reminding me of fascinating things right near me.

[@angelstevens2782]

@@Kathy_Loves_Physics Follow the money trail where a reason might be for this (his) reluctance.

[@pliedtka]

My sis lives in Orangevale. The first time I was visiting years ago and biked on the bike trail along the American River I noticed the 'strange' building. Then I found the web site about Folsom Power Station. Now I recognize the face of the man who runs the site - very informative, and big thank you. I had no clue it's one of oldest hydro power houses in North America. As for the 3 phase system the one used in Europe (at least in Poland and German speaking countries) is a bit different from North American, that most of the buildings like farms, small shops, receive 3 phases 380V, in order to run 3 phase motors equipment. Most new houses are also 3 phase ready. No need for strange rotary phase converters or transformers in order to run lathe or milling machine in garage ;) - thanks to Dobrovolski and AEG. I guess two phase residential system is cheaper to build and that is main reason it remains in use until today. BTW, in Canada from time to time I see 230-240V European single phase devices run from 2 phase system: other than speed in case of motors, no real issues such as overheating.

[@richardsleep2045]

Wow these stories are always more complicated than one hears. Thanks for telling me about the amazing contributions of Dobrovolsky et al. There's such a lot of Tesla hype ;) Great stuff, subscribed, thanks.

[@RANDALLOLOGY]

In all my 50 years being in electronics with a bachelor's degree in electronic engineering, I never knew the information you just presented. I'm impressed ,and decided to subscribe.

[@TCPUDPATM]

Kathy, I’m brand new here, but the research and delivery of information is nothing short of AMAZING! I love that you don’t waste our time with wasted B-roll videos and other stuff. Your information and expertise is why we are here. Thank you, Thank you, Thank you! (One for each phase :P)

[@Kathy_Loves_Physics]

You’re welcome you’re welcome you’re welcome… and thank you for the nice comment

[@eepower]

Your contribution and work to link history to science certainly make us well informed. Thank you for making these videos.

[@Shuhua1999]

I am an electrician and I recently discovered your channel. As a person who considered Tesla a personal hero of mine I thank for this information. Now and forever a fan.

[@rdkeyser]

Great video, Kathy! I, too, stumbled upon this video while browsing something unrelated. (Thank you Google!) Previously I had a vague understanding of the 3-wire, 3-phase system, but now I see it clearly. The history is fascinating, as well. Thank you for presenting such an interesting lesson.

[@ai4px]

You should do a video about the frequency of the line. Motor users wanted lower frequencies, and lighting wanted higher frequencies. Various grids were from 16hz to 100hz over the years and finally settled on 60hz after WW2. Also there' a national time keeper to keep track of the number of 60hz transitions per day and run the grid a little faster or slower at night to "catch up" so our bedside clocks stay accurate. Lots of stuff about this that would be right up your alley!!

[@BBQDad463]

Thanks for this eye-opening and highly informative video. I do not recall ever having heard of Mr. Dolivo-Dobrovolsky prior to watching this video. Keep up the great work!

[@tomsayen9295]

I really enjoy the way you explain and present. I'm glad we have you on You Tube as a lover of physics and history.

[@surendraraju5754]

Dear Kathy, Thanks so much for your amazing compilation of videos on the history of science. I understand that the amount of research that goes into making these is immense. Keep the great work going!! Glad that I came across your channel.🙏

[@Kathy_Loves_Physics]

Thank you so much for your kind words.

[@colmcillegardner2144]

One of my buddies in HS in 1964 and I built a 12v DC motor from nails and Cu wire for Science Fair. He went down in Vietnam January 1970 as a helicopter Army Warrant Officer. 58,479 brothers and sisters never made it back. May they rest in peace.

[@maxironpaw]

I am so glad that I happened upon your channel. Back in the 70s, my uncle, who had been a printer since the 1920s, called me for help. He had an ancient printing press that was needed for an important production run. There was something wrong with its motor and control system - its two-phase motor and control system! This was the first I had heard about two-phase as I only knew about single-phase and three-phase. This ancient machinery looked like you would expect early 1900s devices and controls to look like. Somehow I figured out what was wrong and got it all working. That was my first and only exposure to two-phase power. Thank you so much for this terrific history lesson. You have a new subscriber!

[@rayoflight6220]

You can create the second phase - which has a 90 degree phase shift - with a capacitor.

[@Farm_fab]

I was surprised a number of years ago that I noticed a 2 phase motor at the scrap yard. It was for sale, but I obviously had no use for it. Two phase can be made from single phase, but I'm not an engineer to discuss this. Lancaster Pennsylvania had been wired for 2 phase many years ago, and this motor was evidently from that era.

[@davidberry8431]

@@Farm_fab interesting . So there's a scrap yard where one can browse in Lancaster? I'm in nearby Palmyra, could tell me where this is? Thankee

[@markhook499]

7

[@dougdoug2165]

Thank you for your video. You do an amazing job of tying loose ends together. When one gets more pieces of the puzzle fitted it make it much easier to comprehend the subject.

[@mikelevero]

That was so well explained. Congratulations on your exactness and concise message

[@OneShotOT]

Just stumbled across your channel, the algorithm picked a good one for me! You do such a great job laying out the step by step defining events that lead to great breakthroughs. Loved your demonstration setting fire to alcohol by pointing to it! Keep up the good work. I'm sure you'll keep growing your channel.

[@itsevilbert]

8:57 Thank you, great video as always. I can remember long ago asking (pre-internet) who created this crazy star delta stuff (which is brilliant) - now I know Mikhail Dolivo-Dobrovolsky.

[@Kathy_Loves_Physics]

It really is amazing isn’t it?

[@georgestyer2153]

Thanks Kathy...great reserch..loved every minute

[@awaitingthetrumpetcall4529]

Mikhail Dolivo-Dobrovolsky. Wow. Kathy is an absolute gem. Kathy, thank you so much for sharing your wonderful knowledge.

[@reconglobal1311]

Kathy, I really enjoyed your videos. I travelled to the UK often 30 years ago and, for lack of anything other than BBC on TV, watched James Burke's "Connection" and it became on of my favorite shows. Your show delivers that same mix of education, technology, people, and most interestingly the times and intrigue of the era that gave us the inventions we know today. Thank you.

[@Kathy_Loves_Physics]

I love the show James Burke “connections” and it is a very big compliment to tell me that I remind you of him. Thanks

[@rgmoses2189]

I have never said this lightly but I love you! Your channel lit a fire in my heart over a year ago by showing me that electricity isn't as complicated as it looks on the outside while still having a close to limitless amount of uses that people would believe was just a load of fiction if they didn't see it with their own eyes. Because of you I am currently halfway through my freshman year in college majoring in electrical engineering followed by big plans based on the future uses and generation of electricity

[@Kathy_Loves_Physics]

That makes me so happy. I’m sure you are going to do amazing things and I am honored to be a part of your story. Cheers, Kathy

[@andys9678]

Thanks!!! If young students were tought all these stories we would have more engineers... and we need them

[@jerrypender9019]

This was an outstanding presentation, and had me riveted to the screen for the entire time, which seemed more like 3 minutes than the actual time. I had no idea that the evolution of the electric power design was so complex, with so many players.

[@Kathy_Loves_Physics]

Thanks

[@buenosairesam]

I've been binge watching your videos the whole week. They are entertaining and the knowledge sticks, is so much easy to remember who did or discover what, when put in context. Plus your love for the subject shows at every second. So glad I found your channel

[@in2minutesorless64]

You're a great editor. Thank you Kathy for all your hard work and diligence! What an informative video. Keep it up!!

[@Kathy_Loves_Physics]

Thanks 😊

[@sethlavinder]

@@Kathy_Loves_Physics I absolutely agree! This is my first time here! I’m feeling very informed on a subject I happen to find very interesting, you have a very natural gift for teaching! I will be back for more!

[@bookoobeans]

Thank you Kathy! Outstanding presentation and research as always. Love your channel.

[@jdillon8360]

Great video Kathy, thanks for sharing your knowledge with us!

[@ryanroberts1104]

Very well done. People usually think I'm a weirdo when I start talking about 3 phase power...I think "most" people literally don't even know it's a thing. I used to have a big old warehouse building that was fully electric in 1910, it had modern power service but all of the original 1910 3 phase knob and tube stuff was in place and disconnected. Incredible to look at and see how advanced it was for the time. The distribution board with the slate back and live knife switches looked like something from a movie set. At over 100 years old, add some plastic insulation and change fuses for breakers and it's an almost identical system to what we are still using today. The original light switches were all rotary - this is why we say *turn* on the lights when we mean flip a switch. They have a neat little window with the word on or off when you turn it.

[@AnbroBR]

As an industrial electrician for over 40 years, I routinely worked with 240 volt and 480 volt 3-phase systems. The 3-phase systems were not all the same. Some were configured as "wye" and the others were configured as "delta." To top that off, in one factory in which I worked, they used a 240 volt 3-phase system with one of the "phases" (conductors) grounded. This was called a "grounded B-phase system." Most factories do not use this system. Excellent videos, Kathy!

[@RecordProduction]

480v ?

[@TantalumPolytope]

@@RecordProduction American 3 phase system

[@AnbroBR]

No, the grounded B-phase system was 240 volts. The factory also had 480 volt, 3-phase systems that had the normal ungrounded conductors. Thank you.@@RecordProduction

[@AnbroBR]

Yes, 480 volts. Some of their 480-volt, 3-phase systems were 480 volt / 277 volt, wye connected systems.@@RecordProduction

[@helder4u]

The more of your posts I see and hear, the more I love them, You are addictive

[@teksight9714]

Wow. Really great video. I have a short attention span and get bored easily but I couldn't stop watching this story and the exciting way you told it. Thank you. I learned a lot.

[@alanparkinson549]

Fascinating stuff, especially as I worked as a design and test engineer for a transformer manufacturing company way back in the 1970s. I couldn't do history to save my life at school, but I love the history of science and technology.

[@1945jlee]

Wow, clarified that mystery for me...!!! Love it Kathy!

[@cajun3197]

Really glad I found this channel. Great videos!

[@bobsaturday4273]

excellent presentation , I don't often watch yt video from beginning to end in one sitting but you know how to keep the audiences attention , thanx for clearing up some vague points of history for me Kathy , very educational !

[@Kathy_Loves_Physics]

Glad you liked it.

[@parameciumbrains]

A little bit of Clarification at 15:29 The picture of Tessa's 3 phase six wire transmission, is a standard motor found in the market today. The wires ends are labeled U1, V1, W1; U2, V2, W2. Because of this you can make this motor a Delta or Star or other motor, At the time of installation depending how you jump the connections. Some systems change these jumpers while running but it's rare nowadays. When you see one it's a real delight, especially when you see a person see it for the first time. The picture of M. Von Dolivo is not showing that he made 3phase but that he was working on an Improvement on his Transformer, on the right half of that picture. On the left half of his picture is a 3-phase Delta Dyno that uses slip rings. Motor with slip rings are not used very often anymore but were in the early days to help adjust the resistance of a motor dynamically. This was to help produce better running torque. In the illustration he is not dynamically changing the resistance of the slip rings. But this is something he is given credit for. Vons motor is set up as a delta.

[@qkitselectronics5415]

Great video, excellent details, giving credit where credit is due. We have sort of been mislead thinking Tesla recognized the use of 3 phase. Thanks for taking the time to do this, awesome! Have a great day everyone!

[@Kathy_Loves_Physics]

Thanks, you have a great day yourself

[@cemprotecta]

An amazing story, Kathy. Thanks for briging this topic out and explaining it in such an entertaining manner. I hope to see the release of your forecoming book very soon! Subscribed already!

[@reeswbandley2094]

I'm not only amazed by the amount of information that you share but also by the work you have done to reveal the misinformation we engineers have been taught all our lives. I like your presentation style, and I like purple!! I've been playing/working with electricity since I was a little boy, I never tire of its awesomeness. Thx!

[@keithdaniel6028]

I'm surprised I wasn't taught this in grade school, but I learn it 50 years later from this wonderful lady who loves physics & history.

[@Trucmuch]

I'm not. As interesting as it is, it's not really something you learn in school. I do not know what you studied. But if you studied history, that's a bit too electricity-specific to be learned. If you study physics, it's more a historical thing than an electric thing. Now, if you study the history of electricity, I'm with you, you should have learned that!

[@PlayNowWorkLater]

That was fascinating! I love your passion for history and electricity! And, you are capable of delivering this message like a University professor. I’m sorry, I haven’t checked to see what your creed are, but I loved this and it took me back to some of my favourite classes and professors whilst I attended University. It is rare for a KZbin video to be so engaging without a tonne of video editing. Your ideas and flow of content are concise, and engaging. Thank you for doing what you do. So looking forward to checking out your other videos.

[@Kathy_Loves_Physics]

Thanks David.

[@laneburgess1643]

I love these videos. Great work and thanks for sharing them.

[@mikesellers1879]

Excellent information ! Many thanks Kathy !

[@edcooper5841]

Wow! What a brilliant person and a great speaker. Looking forward to your book. I have been an electrical engineer for 45 years and didn't know the connections Kathy made with the history. How could you not love math, science, and engineering?

[@woodydameron5561]

Really interesting and explained so well!! All of those guys were geniuses - where would we be without them? 🤔

[@tomwaldenofficial]

"Thanks for taking the time and effort in making this video. I really enjoyed watching and learning." -Tom

[@ScottMcCulloughBmax419]

Thank you for this fascinating and exquisitely researched history of polyphase power. I'm an instant fan. Subscribed!

[@krivokucavladimir]

Long live Dolivo Dobrowolski, Forget Nikola Tesla. This great discovery. Even greater than all the discoveries of Nikola Tesla. Well done, dear lady, for opening our eyes.

[@aramboodakian9554]

Kathy I love your videos, love how you love physics and history! There is more to be learned here than meets the eye and ear. Your passion and enthusiasm for the subject is infectious!

[@peters-adventure]

I'm glad to discover your channel! I wanted to understand 3-phase to discuss with my son who does theater lighting. This video helps make sense of electrical distribution and evolution. I liked, subscribed and plan to view more episodes. I love your enthusiasm! Thank you for the research and well organized presentation.

[@greenbudkelly2820]

Wonderful, informative video delivered with passion and enthusiasm

[@yosuto5810]

Great video! I'm electrical engineering student and there is a lot of talk about Michał Doliwo-Dobrowolski at my university. There is even a statue of him near the building. I wonder how many underrated scientists there are, who didn't have the political circumstances to become globally known.

[@laurendoe168]

With all the videos you've done, I am amazed this is a topic that hasn't been covered.

[@Kathy_Loves_Physics]

I know, it is a bit embarrassing that this is my 83rd video! Well, better late than never

[@laurendoe168]

@@Kathy_Loves_Physics I'm just grateful you did!

[@TimothyWorel-xj9he]

Very interesting video. Thank you for explaining the concept so simply.

[@RockPolitics]

I rarely ever subscribe to channels. This one was an easy exception. Very nice work in gathering facts, and putting them into perspective. The significance of three wires vs six for power distribution cannot be overstated.

[@petermacinnes5313]

I like two things about this channel. 1) The willingness to have a balanced view about history, eschewing the common practise of fixating on just the well known players (ie Tesla/Edison etc) whilst ignoring the contributions of others who were pivotal especially from a practical perspective. 2) The presenter - Kathy, you are just so damn watchable !

[@DonaldJUnruh]

Don Unruh Amen to that!!!

[@ronkirk5099]

As an engineer (retired) I've always been interested in science and technology history. Thanks for bringing to our attention some of the lessor known, but very important contributors to developing the electrical systems of our modern world.

[@Kathy_Loves_Physics]

Glad you liked it.

[@ronsnow2015]

Great video, enjoyed. Your presentation was also great. Thanks for posting.

[@clintstinytrailerconversio5560]

Very informative and well presented, Kathy.

[@Debraj1978]

I work on 3 phase field oriented motor control and hence pretty much into 3-ph for past 18 years or so. But have never heard of "Dobrovolsky". Thanks for the great video.

[@placiduzzu]

Hey Debraj, nice to see you around. I subscribe to your comment.

[@FlorinSutu]

Very interesting. Here I learned some things for the first time. And that comes from a guy who learned in university how to design electric motors, electric generators and electric transformers. The teachers told us in university about Mr. Dolivo-Dobrovolsky, and he was very shortly mentioned in specialty books, maybe because I graduated in Romania.

[@kurtlysne9220]

Excellent talk; you have me hooked. I'm a 1965 EE graduate followed by an MS in Geophysics. It is great to be back in school.

[@brostelio]

This was fascinating, and the presentation was first class. Amazing channel.

[@sammyk7024]

This has to be one of the best science channels on YT, and probably the most underrated. Informative, accurate, educational, and brilliantly entertaining. Kathy, you are such a wonderful story teller! It is nothing but a privilege to have free access to the contents you make. Thank you so much!

[@hominidaetheodosia]

This is absolutely brilliant work thank you so much for this video! I love how well researched this was and that it highlighted a completely unsung hero of electrification that I was totally unaware of.

[@Kathy_Loves_Physics]

Thank you - so glad you liked it

[@Mrtheoldteacher]

Your best video so far, thanks a lot!!!

[@sparkytas]

Absolutely brilliant and entertaining explanation. Thank you! I have shared this with a lot of my electrician colleagues!

[@steveremington]

Hi Kathy, As a former electrician who worked in the electricity distribution sector and a person who has an interest in the history of science and engineering, your channel is my new KZbin happy place. Thanks for the putting in the effort to create interesting and informative videos. No it's back to binge watching the rest of your videos. I look forward to buying and reading your books when they are published.

[@l00k4tstuff]

Thank you for the full history. In the US, so much is US-centric, other contributions being brushed off as inconsequential. It's good to know the full history of technological development when trying to understand the technology.

[@hansvetter8653]

Wow! ... your research investigations are really impressive! What a useful combination of physics & history! Thanks!

[@dr.w.w.daniels7203]

Best explanation of such a convoluted history of a complex phenomenon. Well done.

[@pasixty6510]

Another great video…again! Thank you! I went to grammar school in Lauffen, from where the first 3 Phase long distance power transmission was made and I am happy that you pay so much attention to the meaningful experiment of those brave engineers to transmit huge amounts of power over more than 100km. I can say that much of the electric history is still alive. There still is a water turbine running in the place where they had run it then. There is an ‚Oskar von Miller Street‘ running down to the cement factory. The factory still exists and AEG, the firm Dobrowolski worked for, still exists, as well as Brown‘s firm, former BBC (Brown Boveri Cie), today ABB (Asea Brown Boveri). All of them managed to be enough innovative to make it into the 21st century.

[@Kathy_Loves_Physics]

Wow that is so cool.

[@bpomowe224]

@@Kathy_Loves_Physics , ASEA claimed to have the first *commercial* three-phase long distance transfer system up and running by 1893. Perhaps worth looking into how they fit into the grand scheme of things?

[@andyfeimsternfei8408]

Check out the Lower Pelzer hydroelectric power plant. It went online in 1894 and still in operation. First AC powered textile plant with a 3.5 mile 3300v transmission line. Three 750kw units, one 250kw and one 1100kw. The first four were designed and built by GE and specifically Steinmetz at Mechanicsville. Four units have stationary magnetic poles with rotating AC armature and three 3300v slip rings. I believe this to be the oldest continuously operating power plant in the world.

[@williamdebreau5769]

Thank you Kathy! Very informative, interesting, as well as entertaining. Looking forward to checking out more of your content. 🤩 😁

[@jennysquibb7440]

Wow! This is so much more awesome in the details of how it all happened than the various books about Tesla that I have read. This clears away a bunch of the marketing hype and showmanship!

[@jimdecamp7204]

Great video! I am an EE and took a power systems course as an undergraduate, but I never appreciated this history. Thank you so much!

[@TheEvertw]

Great exposition! Personally, I believe one key advantage of the 3-phase system over all other systems is that not only is the summed current zero at all times (which a two-phase, 180 degrees system also has, or a 4-phase system), the power transmitted over the wires is also constant at all times (assuming a linear load). This means there is much less vibration in 3-phase systems compared to other systems of similar power, allowing much lighter construction. Contrast e.g. the noisy, vibrating hand-drill operating on 1 phase for a measly 700W, with the near-silent operation of a 3-phase motor. This is because the power delivered to that drill varies between 0 and almost 1000W, 50 (or 60) times per second.

[@Kathy_Loves_Physics]

Good point

[@joee8417]

@@Kathy_Loves_Physics That hand drill is not using a 3 ph motor . It is using a "brushed" 'universal motor'. No where near the same. Also the brand and the price range of the drills vary immensely. A commercial drill has a commutator with many small bars vs a 'homeowner" drill which has a few larger ones. Much rougher and less efficient. Properly designed large dc motors are quite smooth and have much more torque that ac motors. The downside is maintenance. The new ac drives are catching up but if you need 300 percent starting torque, a wound rotor dc can't be beat. I'm retired now, ex Elevator mechanic. A humorous note, as they change out the older DC drive elevator systems, the power bill just went up. As the elevator slows down the mg set rpm changes from 1725 rpm (60 cycle 3 ph incoming) to 1875 rpm. As it slows down it pumps power back into the grid and the building draws less thru the meter. As long as there is not to much idle time the parasitic losses aren't too bad. The static drives all have resistor banks with fans to dissipate the heat generated by slowing down the load. Now the new code compliant air conditioned machine rooms have to have the tonnage for the load. Lol Joe

[@shahalammuhammedulla]

Excellent video. Thank you very much for the work you did. ❤

[@alexkije]

Fantastic story! Thanks for sharing! Very well told.

[@michaelschalck]

Great video :) Just a shame that Jonas Wenström was not mentioned, since he created a 3 phase transmission system on 9,5 kV in 1893 for the Swedish mining industry. And this was the initiator for placing the small town of Ludvika in Sweden on the map as a world leading center for power transmission.