Milestone-Proposal:Long distance transmission of electrical power using three-phase alternating current, 1891-1912

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Docket #:2021-20

This proposal has been submitted for review.

To the proposer’s knowledge, is this achievement subject to litigation? No

Is the achievement you are proposing more than 25 years old? Yes

Is the achievement you are proposing within IEEE’s designated fields as defined by IEEE Bylaw I-104.11, namely: Engineering, Computer Sciences and Information Technology, Physical Sciences, Biological and Medical Sciences, Mathematics, Technical Communications, Education, Management, and Law and Policy. Yes

Did the achievement provide a meaningful benefit for humanity? Yes

Was it of at least regional importance? Yes

Has an IEEE Organizational Unit agreed to pay for the milestone plaque(s)? Yes

Has an IEEE Organizational Unit agreed to arrange the dedication ceremony? Yes

Has the IEEE Section in which the milestone is located agreed to take responsibility for the plaque after it is dedicated? Yes

Has the owner of the site agreed to have it designated as an IEEE Milestone? Yes

Year or range of years in which the achievement occurred:


Title of the proposed milestone:

Long distance transmission of electrical power using three-phase alternating current, 1889-1912

Plaque citation summarizing the achievement and its significance:

In 1891 (till 1912), Michał Doliwo-Dobrowolski working at AEG in Berlin, Germany, carried out the world’s first long distance (175 km), high voltage (15 kV), highly efficient (75 %) electrical energy transmission of 300 HP, using the three-phase alternating current (he named “Drehstrom” i.e. “turning-current”) and the by him invented: generator (1890), squirrel cage motor (1889) and triangle or star windings transformer (1889). Already in 1896, they were adapted in Zielona Góra, Poland, then globally guided modern electrical engineering.

In what IEEE section(s) does it reside?

Poland Section and Germany Section (Poland and Federal Republic of Germany)

IEEE Organizational Unit(s) which have agreed to sponsor the Milestone:

IEEE Organizational Unit(s) paying for milestone plaque(s):

Unit: Poland Section
Senior Officer Name: Professor Adam Dabrowski

Unit: Germany Section
Senior Officer Name: Professor Jan Haase

IEEE Organizational Unit(s) arranging the dedication ceremony:

Unit: Poland Section
Senior Officer Name: Professor Adam Dabrowski

Unit: Germany Section
Senior Officer Name: Professor Jan Haase

IEEE section(s) monitoring the plaque(s):

IEEE Section: Poland Section
IEEE Section Chair name: Professor Adam Dabrowski

IEEE Section: Germany Section
IEEE Section Chair name: Professor Jan Haase

Milestone proposer(s):

Proposer name: Professor Adam Dabrowski
Proposer email: Proposer's email masked to public

Proposer name: Professor Mariusz Malinowski
Proposer email: Proposer's email masked to public

Proposer name: Professor Krzysztof Sozański
Proposer email: Proposer's email masked to public

Proposer name: Professor Jan Haase
Proposer email: Proposer's email masked to public

Proposer name: Dr. Frank Dittmann
Proposer email: Proposer's email masked to public

Proposer name: Dr.-Ing. Joachim Wiest
Proposer email: Proposer's email masked to public

Please note: your email address and contact information will be masked on the website for privacy reasons. Only IEEE History Center Staff will be able to view the email address.

Street address(es) and GPS coordinates of the intended milestone plaque site(s):

It is planned to install and expose two IEEE Milestone plaques, i.e., in two locations in two countries: Germany and Poland. The first site is the at TU Berlin, Ackerstrasse 76, Germany, GPS (latitude, longitude): 52.538750, 13.38497235. The second site is the Winne Hill at water cascade on a frequently visited observation deck with a direct view of the former Wool Factory powered by the world's first three-phase 50 Hz power line, Wrocławska Street 12, 65-001 Zielona Góra (Grünberg), Poland, GPS (latitude, longitude): 51.9378718,15.511018

Describe briefly the intended site(s) of the milestone plaque(s). The intended site(s) must have a direct connection with the achievement (e.g. where developed, invented, tested, demonstrated, installed, or operated, etc.). A museum where a device or example of the technology is displayed, or the university where the inventor studied, are not, in themselves, sufficient connection for a milestone plaque.

Please give the address(es) of the plaque site(s) (GPS coordinates if you have them). Also please give the details of the mounting, i.e. on the outside of the building, in the ground floor entrance hall, on a plinth on the grounds, etc. If visitors to the plaque site will need to go through security, or make an appointment, please give the contact information visitors will need. Germany: It is the former AEG building which is a historic building. No other historical markers are already installed. In Poland, the plaque site on Winne Hill at water cascade in Zielona Góra is a publicly accessible and a frequently visited representative place.

Are the original buildings extant?


Details of the plaque mounting:

In Germany, the plaque will be placed at the TU Berlin, Ackerstrasse 76, Berlin in the courtyard of the building, i.e., in the previous AEG (Allgemeine Elektricitäts-Gesellschaft) laboratory area, where Michał Doliwo-Dobrowolski invented the three-phase alternating current technology and apparatus: generator, transformer, and induction motor. In Poland, the plaque will be placed on a specially designed stone plinth on Winne Hill at water cascade on a frequently visited observation deck with a direct view of the former Wool Factory powered by the world's first three-phase 50 Hz long distance power line, Wrocławska Street 12, 65-001 Zielona Góra (Grünberg). This electricity was produced from 1895 in a hydroelectric power plant in Nowogród Bobrzański (Naumburg am Bober) on the Bóbr (Bober) River and sent to Zielona Góra (Grünberg) for a distance of 25 km.

How is the site protected/secured, and in what ways is it accessible to the public?

The plaque site in Berlin at the TU Berlin (previously AEG area) is publicly accessible (there is open access for the public free entrance). In Poland, the plaque site on Winne Hill at water cascade in Zielona Góra is a publicly accessible and a frequently visited representative place.

Who is the present owner of the site(s)?

Germany: HIH Property Management GmbH, Gertrudenstraße 9, 20095 Hamburg, Poland: President of the town Zielona Gora

What is the historical significance of the work (its technological, scientific, or social importance)? If personal names are included in citation, include justification here. (see section 6 of Milestone Guidelines)

In 1889, a discussion arose over the choice of the proper electrification system for Frankfurt am Main in Germany. Therefore, in 1891, the worldwide electrical exhibition was organized there and various systems of production, transmission, and distribution of electricity were presented. The right decision was, however, very difficult to make, because, on one side, at that time (i.e., in the late 1880s and in the 1890s) the quite well developed and widely used direct current (DC) electricity production and distribution technology limited the transmission distances to single kilometers and required the construction of many local low-power plants, supplying consumers divided into separate networks, forming isolated islands. This practically excluded the use of the hydroelectric power, which needed to be transmitted over long distances. On the other hand, the new alternating current (AC) technology, which due to a possibility of transformation the energy to high voltages for the long distance transmission, was not yet accepted and met with strong resistance both in the USA and in Europe. This very determined movement was called “the battle for the current” or “the transformer-battery war”. The greatest supporters of further development of the DC based electrical energy were Thomas Alva Edison in the USA and Rookes Evelyn B. Crompton with Ernst Werner von Siemens in Europe. The methods they applied were sometimes quite brutal, including attempts to legally ban further development of the AC technology [1, 4]. A breakthrough was an event on August 25, 1891 at the mentioned Frankfurt exhibition, which was the world’s first transmission of the three-phase electric energy of 300 HP from the hydroelectric power plant in Lauffen am Neckar to Frankfurt am Main at a quite long distance of 175 km. With the used high voltage of 15 kV and frequency of 25 Hz, the overall efficiency of this line exceeded 75 %, which was an almost unbelievable success at that time. The designer and main organizer of this project was Michał Doliwo-Dobrowolski, the “Chefelektriker” at the Allgemeine Elektricitäts-Gesellschaft (AEG) company in Berlin, Germany. He designed 100 kVA dry and 150 kVA oil-filled transformers and a 100 HP induction motor for the voltage of 65 V and a rotational speed of approx. 600 revolutions per minute. All this equipment was based on his pioneering concept of the three phase symmetric alternating current (with phases shifted mutually by 120 degrees, named by him “Drehstrom” i.e. “turning-current”, because of its usefulness for the implementation of a rotating magnetic field and thus for the convenient realization of the rotary motion. Michał Doliwo- Dobrowolski invented the respective three-phase apparatus: in 1890 the mature three-phase generator (British patent No. 19554, October 18, 1890, filed in August 27, 1890), in 1889 the three-phase squirrel cage induction motor (AEG patent given in April 19, 1890), and the three-phase dry and oil-filled transformer (German patent No. 56359 given in August 29, 1889 and US patent No. 422746, filed in January 8, 1890) [1, 2, 3, 7, 8]. It should be noted that another poly-phase AC current pioneer was Nikola Tesla but he suggested to use an asymmetric two-phase (e.g., cosine and sine) system in contrast to the newer Doliwo-Dobrowolski’s three-phase system. The concept of Tesla in the language of the linear algebra was based on the use of the so-called “basis”, i.e. the minimum set of components necessary to represent a two-dimensional rotating vector (of the rotating magnetic field) while the Doliwo-Dobrowolski’s concept was based − again in the contemporary algebra language − on the so-called “frame representation” i.e. on a set of a slightly larger number (in this case three) of symmetrically distributed components. In both cases, the apparatus connection required three wires, but the Doliwo-Dobrowolski’s idea led to better configurations of electric and magnetic circuits of respective devices and therefore

the three-phase electricity won and revolutionized the whole further development of the electrical power engineering [1, 6, 7, 8]. It is curious that after the end of the Frankfurt exhibition, the Doliwo-Dobrowolski’s high- voltage line was turned off and the decision to choose the electrification system for Frankfurt am Main was not made until 1893. To the surprise of Michał Doliwo-Dobrowolski, a single- phase AC system was eventually chosen, i.e., a quite wrong decision and costly to correct was made. However, the three-phase power plant in Lauffen and an 11 km long initial section of the Doliwo-Dobrowolski’s line were used to supply electricity to Heilbronn and worked until 1912. Already in 1896, the Michał Doliwo-Dobrowolski’s system was adapted in Poland to produce hydroelectric energy with the power of 466 kW and with contemporary frequency of 50 Hz in Nowogród Bobrzański (Naumburg am Bober) on the river Bóbr (Bober) and to transmit it to Zielona Góra (Grünberg) over distance of 25 km [7]. It should be mentioned that Michał Doliwo-Dobrowolski invented also various measuring instruments, incl. wattmeter, phasemeter, and frequency meter. He introduced a concept and notion of the commonly used “power coefficient” known also as “cos φ”. Moreover, he dealt with the issues of electric arc by developing the so-called extinguishing chambers in high- voltage circuit breakers. This is an idea of great practical importance and it remains fully valid up to now. Michał Doliwo-Dobrowolski was born in 1862 in the Polish family as the son of Józef, Doliwa coat of arms in the beautiful town of Gatczyna near Saint Petersburg. In this time, Poland was divided into parts and did not exist as an independent country. Especially in the Russian part Poles have to emigrate even deep into Russia. In 1881, during his student period he, as a Pole, was expelled from the Polytechnic Institute in Riga due to the repression to Poles after the attack of the Polish student on Tsar Alexander II. As a result, Michał Doliwo- Dobrowolski left for Germany and completed his studies in Darmstadt at the newly opened Electrical Engineering Faculty, where he then started working as an assistant with the Professor Erasmus Kittler’s team. Step by step he began to gain fame on the global scale. Unfortunately, after the World War 1 Dobrowolski's health continued to deteriorate. A flu epidemic was undergoing at that time. A three-week stay at the university clinic in Heidelberg did not help. He died on October 15, 1919. His grave is located in Darmstadt. In the monograph [3], devoted to Michał Doliwo-Dobrowolski, G. Niedhöfer wrote on pp. 235-236: “In 2001 in the Polish city Szczecin the 5th International Conference on Unconventional Electromechanical and Electrical Systems (UEES) was organized by the University of Technology in Szczecin. A special occasion was the 110th anniversary of the world’s first long-distance power transmission using high voltage three-phase current (1891- 2001). A seminar was held at the beginning of this conference about the life and work of Michał Doliwo-Dobrowolski, with particular emphasis on the fact that this great and outstanding pioneer of electrical engineering and the creator of the three-phase system was of Polish origin. The program included papers and carefully prepared exhibition about the pioneer of the three-phase current and − as a crowning achievement − unveiling a monument in honor of Michał Doliwo-Dobrowolski. Moreover, the City Council of Szczecin decided to name one of the squares near the Institute of Electrical Engineering after Doliwo- Dobrowolski. With this, Poland honored this great Polish inventor for the first time in an extremely dignified manner.”

Due to the Michał Doliwo-Dobrowolski’s inventions of the three-phase apparatus and technology the right way for the development of the whole contemporary electrical energy engineering was paved and the transformers won the fight against batteries.

What obstacles (technical, political, geographic) needed to be overcome?

To our knowledge, there are no technical, political, or geographical obstacles to be overcome.

What features set this work apart from similar achievements?

Polyphase power systems were independently invented by Galileo Ferraris, Michał Doliwo- Dobrovolski, Jonas Wenström, John Hopkinson, and Nikola Tesla in the late 1880s [1]. The first AC motor in the world invented by Italian physicist Galileo Ferraris was a two-phase machine and required 4 wires, which is evidently less efficient then the three-phase motors and generators developed by Michał Doliwo-Dobrovolski who used additional coils and new ways of connecting them (in a triangle or a star) [7]. Michał Doliwo-Dobrowolski for the first time in the world implemented a complete three- phase AC system and led to the transmission of electricity over a distance of 175 km with at that time very high efficiency of 75 %. In addition, he invented efficient three-phase transformers and built an induction motor with a squirrel-cage rotor, which was 10 times more powerful than other AC motors known at that time [2, 3]. The dispute over who was the actual pioneer, inventor and developer of the three-phase current system technology and apparatus was definitely resolved by the special VDE (Verband der Elektrotechnik Elektronik Informationstechnik e.V., Germany) commission established in 1957 under the leadership of Ph.D. Franz Hildebrand [6]. This commission clearly defined the fundamental contribution and pioneering significance of the Michał Doliwo-Dobrowolski's work, discoveries, inventions, and other related achievements [2, 6].

Supporting texts and citations to establish the dates, location, and importance of the achievement: Minimum of five (5), but as many as needed to support the milestone, such as patents, contemporary newspaper articles, journal articles, or chapters in scholarly books. 'Scholarly' is defined as peer-reviewed, with references, and published. You must supply the texts or excerpts themselves, not just the references. At least one of the references must be from a scholarly book or journal article. All supporting materials must be in English, or accompanied by an English translation.

[1] B. Lawson, Woodbank Communications Ltd.’s Electropaedia: “History of Batteries (and other things)”,

[2] G. Neidhöfer, “Early three-phase power. Winner in the development of polyphase AC”, IEEE Power and Energy, Vol. 5, No. 5, 2007, pp. 88-100

[3] G. Neidhöfer, “Michael von Dolivo-Dobrowolsky und der Drehstrom, Anfänge der modernen Antriebstechnik und Stromversorgung”, VDE Verlag, Berlin 2004

[4] T. P. Hughes, “Networks of power. Electrification in Western Society 1880-1930”. The Johns Hopkins University Press, Baltimore/London 1993

[5] P. S. Thompson, “Polyphase Electric Currents and Alternate-Current Motors”. E. & F. Spon Eds., London 1895

[6] F. Hillebrand, “Zur Geschichte des Drehstroms”, Elektrotechnische Zeitschrift-Ausgabe A, 1959, Vol. 80, pp. 457-458

[7] Chronik der Elektrotechnik,

[8] M. Doliwo-Dobrowolski, “Aus der Geschichte des Drehstromes”, Elektrotechnische Zeitschrift 1917, (part 1) Vol. 26, pp. 341-344, (part 2) Vol. 27, pp. 354-357, (part 3) Vol. 28, pp. 366-369, (part 4) Vol. 29, pp. 374-377

Supporting materials (supported formats: GIF, JPEG, PNG, PDF, DOC): All supporting materials must be in English, or if not in English, accompanied by an English translation. You must supply the texts or excerpts themselves, not just the references. For documents that are copyright-encumbered, or which you do not have rights to post, email the documents themselves to Please see the Milestone Program Guidelines for more information.

Please email a jpeg or PDF a letter in English, or with English translation, from the site owner(s) giving permission to place IEEE milestone plaque on the property, and a letter (or forwarded email) from the appropriate Section Chair supporting the Milestone application to with the subject line "Attention: Milestone Administrator." Note that there are multiple texts of the letter depending on whether an IEEE organizational unit other than the section will be paying for the plaque(s).

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