Mikhail Osipovich Dolivo-Dobrovolsky (russian: Михаи́л О́сипович Доли́во-Доброво́льский; german: Michail von Dolivo-Dobrowolsky or ''Michail Ossipowitsch Doliwo-Dobrowolski''; – ) was a

Russian Empire The Russian Empire was an empire and the final period of the Russian monarchy from 1721 to 1917, ruling across large parts of Eurasia. It succeeded the Tsardom of Russia following the Treaty of Nystad, which ended the Great Northern War. ...

-born

engineer Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the limit ...

electrician An electrician is a tradesperson specializing in electrical wiring of buildings, transmission lines, stationary machines, and related equipment. Electricians may be employed in the installation of new electrical components or the maintenance ...

, and inventor of Polish-Russian origins, active in the German Empire and also in Switzerland. After studying in Germany and while working in Berlin for ''Allgemeine Elektricitäts-Gesellschaft'' ( AEG), he became one of the founders (the others were

Nikola Tesla Nikola Tesla ( ; ,"Tesla"
''

Galileo Ferraris Galileo Ferraris (31 October 1847 – 7 February 1897) was an Italian university professor, physicist and electrical engineer, one of the pioneers of AC power system and inventor of the induction motor although he never patented his work. Many ...

and Jonas Wenström) of polyphase electrical systems, developing the three-phase

electrical generator In electricity generation, a generator is a device that converts motive power (mechanical energy) or fuel-based power ( chemical energy) into electric power for use in an external circuit. Sources of mechanical energy include steam turbines, g ...

and a three-phase electrical motor (1888) and studying star and delta connections. The triumph of the three-phase system was displayed in Europe at the International Electro-Technical Exhibition of 1891, where Dolivo-Dobrovolsky used this system to transmit electric power at the distance of 176 km with 75% efficiency. In 1891 he also created a three-phase

transformer A transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. A varying current in any coil of the transformer produces a varying magnetic flux in the transformer' ...

and short-circuited ( squirrel-cage) induction motor. He designed the world's first three-phase

hydroelectric power plant Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined an ...

in 1891.

Life

Mikhail Dolivo-Dobrovolsky was born as the son of the Russian civil servant and landowner of Polish descent Josif Florovich Dolivo-Dobrovolsky and Olga Mikhailovna Jewreinova from an old Russian noble family in

Gatchina The town of Gatchina ( rus, Га́тчина, , ˈɡatːɕɪnə, links=y) serves as the administrative center of the Gatchinsky District in Leningrad Oblast, Russia. It lies south-south-west of St. Petersburg, along the E95 highway which ...

near

Saint Petersburg Saint Petersburg ( rus, links=no, Санкт-Петербург, a=Ru-Sankt Peterburg Leningrad Petrograd Piter.ogg, r=Sankt-Peterburg, p=ˈsankt pʲɪtʲɪrˈburk), formerly known as Petrograd (1914–1924) and later Leningrad (1924–1991), i ...

. He spent his school days in

Odesa Odesa (also spelled Odessa) is the third most populous city and municipality in Ukraine and a major seaport and transport hub located in the south-west of the country, on the northwestern shore of the Black Sea. The city is also the administrati ...

, where his father was transferred in 1872. After secondary school he went at the age of 16 to the Riga Polytechnic, a college founded by

Baltic Germans Baltic Germans (german: Deutsch-Balten or , later ) were ethnic German inhabitants of the eastern shores of the Baltic Sea, in what today are Estonia and Latvia. Since their coerced resettlement in 1939, Baltic Germans have markedly declin ...

, teaching in

German language German ( ) is a West Germanic language mainly spoken in Central Europe. It is the most widely spoken and official or co-official language in Germany, Austria, Switzerland, Liechtenstein, and the Italian province of South Tyrol. It is als ...

. At the end of the 1870s, after a series of assassination attempts and finally the murder of

Tsar Alexander II Alexander II ( rus, Алекса́ндр II Никола́евич, Aleksándr II Nikoláyevich, p=ɐlʲɪˈksandr ftɐˈroj nʲɪkɐˈlajɪvʲɪtɕ; 29 April 181813 March 1881) was Emperor of Russia, King of Poland and Grand Duke of Fin ...

in 1881, a wave of repression broke out, with which all progressively oriented students were expelled from their university, which was equivalent to a study ban in all of Russia. Among them was Dolivo-Dobrovolsky. After his forced exmatriculation in Riga in 1881, he left his homeland in 1883 and went to

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

Mikhail Ossipovitch Dolivo Dobrovolski à 22 ans

He studied at the first chair of electrical engineering worldwide, at the Technische Hochschule Darmstadt in the German Empire Grand Duchy of Hesse from 1883 to 1884. From 1885 to 1887, he became one of :de:Erasmus Kittler's first assistants. There he published several smaller publications and was in close contact with

Carl Hering Carl Hering (Philadelphia, 19 March 1860 – 10 May 1926) was an American engineer involved in studies on electric batteries and electric furnaces. He also made discoveries on electromagnetic force. Biography He was one of the sons of Consta ...

, a mechanical engineer from the USA and Kittler's first assistant. After the inventions, Dolivo-Dobrovolsky continued his research in the field of heavy current technology, inventing the phase meter in 1892 and the ferrodynamic wattmeter in 1909. He published papers and gave numerous lectures. From 1903 to 1907 he devoted himself to scientific work in Lausanne, where he acquired Swiss citizenship with his entire family in 1906. After his return to Berlin, he continued his work at AEG and became Technical Director of the apparatus factory in 1909. On 24 October 1911, he received an honorary doctorate from the TH Darmstadt, whose Dolivo building bears his name today. During his life he obtained over 60

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...

s. In 1919, Dolivo-Dobrovolski died of a severe heart condition at the academic hospital in

Heidelberg Heidelberg (; Palatine German language, Palatine German: ''Heidlberg'') is a city in the States of Germany, German state of Baden-Württemberg, situated on the river Neckar in south-west Germany. As of the 2016 census, its population was 159,914 ...

. He was buried at the forest cemetery of Darmstadt, where his grave (grave site: R 6a 7) - located very close to the memorial of his teacher :de:Erasmus Kittler - can still be visited today. In the city centre of Darmstadt in 1969 a street was named after Dr.-Ing. E. h. Michael Dolivo-Dobrovolsky, the Dolivostraße.

Invention of the three-phase system

In 1887, Director General

Emil Rathenau Emil Moritz Rathenau (11 December 1838 – 20 June 1915) was a German entrepreneur, industrialist, mechanical engineer. He was a leading figure in the early European electrical industry. Early life Rathenau was born in Berlin, into a w ...

of the ''Allgemeine Elektricitäts-Gesellschaft AG'' ( AEG) in Berlin offered him a position, whereupon Dolivo-Dobrovolsky remained associated with the company until the end of his life. At the AEG, Dolivo-Dobrovolsky initially made an effort to further perfect direct current technology. After all, AEG's origins lay in an Edison subsidiary, and Edison, like Siemens, relied entirely on

direct current Direct current (DC) is one-directional flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor such as a wire, but can also flow through semiconductors, insulators, or eve ...

. At that time,

alternating current Alternating current (AC) is an electric current which periodically reverses direction and changes its magnitude continuously with time in contrast to direct current (DC) which flows only in one direction. Alternating current is the form in whic ...

gradually attracted the attention of technicians, and engineers from

Ganz Works The Ganz Works or Ganz ( or , ''Ganz companies'', formerly ''Ganz and Partner Iron Mill and Machine Factory'') was a group of companies operating between 1845 and 1949 in Budapest, Hungary. It was named after Ábrahám Ganz, the founder and the ...

Budapest Budapest (, ; ) is the capital and most populous city of Hungary. It is the ninth-largest city in the European Union by population within city limits and the second-largest city on the Danube river; the city has an estimated population ...

had designed the first transformer in today's sense in 1885. However, AC technology required further equipment, especially reliable and self-starting motors; AC theory was also still underdeveloped. Before Dolivo-Dobrovolsky, the Italian Galileo Ferraris drew attention to alternating current. He invented the first AC motor in 1885. After him, the German engineer Friedrich August Haselwander develops the first AC 3 phase synchronous generator in Europe which produced about 2.8 kW at 960 rev/min, corresponding to a frequency of 32 cycles per second, today known as Hertz, or Hz. The machine had a stationary, ring-shaped, three-phase armature and a rotating ‘internal-pole magnet’ with four wound salient poles, which provided the revolving field. The patent application filed in July 1887. The first AC 3 phase synchronous generator went into operation in October 1887. AC Power History and Timeline
/ref> Regardless of these events, a forward-looking solution was found at AEG in 1888. Dolivo-Dobrovolsky worked with chained three-phase alternating current and introduced the term three-phase current. The associated

asynchronous motor An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. An induction motor c ...

invented by him was the first functional solution. However, the asynchronous motor with squirrel-cage rotor had the problem of delivering only low torque at low speeds, such as when starting up. The solution was the slip ring motor, a variation of the asynchronous motor in which the short circuit of the rotor is opened and guided to the outside via sliprings. By connecting various external resistors, Dolivo-Dobrovolsky was able to introduce an asynchronous motor with high starting torque in 1891. At the beginning of 1889, the first AEG three-phase motors were in operation, and in the following year they already produced 2 to 3 horsepower. Dolivo-Dobrovolsky paid attention to well distributed windings, a low dispersion of the lines of force and as uniform a force field as possible and achieved a satisfactory result. In 1891, he also developed the first

Delta-wye transformer A delta-wye transformer is a type of three-phase electric power transformer design that employs delta-connected windings on its primary and wye/star connected windings on its secondary. A neutral wire can be provided on wye output side. It ca ...

for this purpose.

First remote transmission of electrical energy

At AEG and the Swiss cooperation partner

Maschinenfabrik Oerlikon Maschinenfabrik Oerlikon was a Swiss engineering company based in the Zürich district of Oerlikon (Zürich), Oerlikon known for the early development of electric locomotives. It was founded in 1876 by the industrialist Peter Emil Huber-Werdmü ...

(MFO), all components for a three-phase network were available, but until now they had only been in trial operation. At this time,

Oskar von Miller Oskar von Miller (7 May 1855 – 9 April 1934) was a German engineer and founder of the Deutsches Museum, a large museum of technology and science in Munich. Biography Born in Munich into an Upper Bavarian family from Aichach, he was the son of ...

made the extremely daring proposal to present the three-phase current transmission system Lauffen-Frankfurt at the International Electrotechnical Exhibition planned for 1891 in

Frankfurt Frankfurt, officially Frankfurt am Main (; Hessian: , " Frank ford on the Main"), is the most populous city in the German state of Hesse. Its 791,000 inhabitants as of 2022 make it the fifth-most populous city in Germany. Located on it ...

at the MFO, where Dolivo-Dobrovolsky and his chief electrician partner Charles E. L. Brown realized the project: A 300 HP three-phase AC generator of the MFO was to be driven by the water turbine of the cement plant in Lauffen am Neckar, generating a voltage of about 50 V and 40 Hz, transforming it up to 15 kV (later 25 kV) and then transmitting it via 175 km of overhead line to Frankfurt and transforming it down again to supply a 100 HP asynchronous motor and several small three-phase motors as well as about 1000 incandescent lamps. The power output of the motors, which had previously been in test operation, was still only 2 to 3 hp. Nevertheless, the plant was put into operation on the evening of 24 August 1891, and a test committee determined that 75% of the energy generated in Lauffen arrived in Frankfurt. This proved that, on the one hand, alternating current was profitable for a large-scale public electricity supply and, on the other hand, that the three-phase components were now of the same quality as those of direct current technology. The image-boosting effect of the demonstration at the World Expo finally led to the breakthrough of three-phase AC technology. At Siemens and Edison, however, AC technology only slowly gained acceptance, which enabled AEG to become a global company.

References

Sources

* https://web.archive.org/web/20050908025431/http://erudite.nm.ru/DolivoDobr.htm * https://web.archive.org/web/20110926231334/http://library.istu.edu/hoe/personalia/dolivo.pdf {{DEFAULTSORT:Dolivo-Dobrovolsky, Mikhail 1862 births 1919 deaths People from Gatchina People from Tsarskoselsky Uyezd Electrical engineers Emigrants from the Russian Empire to Germany Technische Universität Darmstadt alumni