Mikhail Dolivo-Dobrovolsky

At the end of the 1870s, after a series of assassination attempts and finally the murder of Tsar Alexander II in 1881, a wave of anti-Polish 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.

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.

There he published several smaller publications and was in close contact with Carl Hering, a mechanical engineer from the USA and Kittler's first assistant.

[5][6] In 1887, Director General Emil Rathenau 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 that time, alternating current gradually attracted the attention of technicians, and engineers from Ganz Works in Budapest had designed the first transformer in today's sense 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.

[6] At AEG and the Swiss cooperation partner Maschinenfabrik Oerlikon (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 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 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.

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.

Dobrovolsky, age 22