Electrical Engineering | Development of Electrical Engineeirng

Soon after FARADAY’s discovery of electromagnetic induction, the first hand-powered generator was built by PIXII in 1832. However, the first generators were useless for practical use.
The discovery of the dynamo-electric principle by SIEMENS in 1867 was of decisive importance for practical application. This enabled powerful dynamo machines to be built.
In 1881 EDISON presented the first usable incandescent lamp and in 1882 the world’s first power station went online in New York. The first power station in Europe was built in Berlin’s Friedrichstrasse in 1884.

The first generators

Soon after MICHAEL FARADAY’s discovery of electromagnetic induction and the law of induction in 1831, the first devices were built that took advantage of this discovery. This z. B. rotated coils in front of stationary permanent magnets or permanent magnets in front of stationary coils. HIPPOLYTE PIXII, the mechanic from AMPÈRE, built the first hand-operated generator in 1832. In this generator, a horseshoe magnet was turned in front of two coils with a hand crank.

The first generators were of little practical importance. Above all, their performance was too poor for practical applications. The magnetic fields for induction were mostly generated by permanent magnets, which were relatively weak and whose strength was reduced by the constant vibrations of the generators.

Generator by H. PIXII, the AMPÈRE mechanic

A new technical principle

To obtain stronger magnetic fields and greater power from the generators, electromagnets were needed. However, these had to be generated by batteries or a second generator. There was also talk of external excitation of the electromagnets. Overall, this was very complex, and so such arrangements were mainly used in research laboratories.

For the broad application of electromagnetic induction, an invention by the technician and entrepreneur WERNER VON SIEMENS (1816-1892) was of decisive importance. SIEMENS discovered the dynamo-electric principle in 1866and presented this to the Berlin Academy of Sciences on January 17, 1867. He realized that the iron core of an electromagnet retains a residual magnetic field after switching off the current. This magnetic field is sufficient to induce a small voltage in a generator. This voltage can be used to operate the electromagnet and to strengthen the magnetic field. This induces a greater voltage. So the magnetic field of the electromagnet and the induced voltage swing each other up to the full power of the generator.

WERNER VON SIEMENS with his first dynamo machine (1867)

SIEMENS called these generators, which excite their own magnetic field, dynamo machines. With this invention from Siemens, power generators could be built. A new branch of technology, electrical engineering, emerged. In 1878 Siemens & Halske was already producing 25 dynamo machines per week.

Old dynamo machine (around 1900)

Wide use of electrical energy

The further development of electrical engineering took place very quickly and is characterized by the widespread use of electrical energy in all areas of life.
So gradually electric motors for drives began to gain acceptance. In 1879 the first electric train was presented at the trade exhibition in Lichterfelde. It was the forerunner of the electric tram. The first electric elevator could be seen in Mannheim in 1881. In 1882 the first electric mine train ran in a mine in Zeukerode near Dresden and the ancestor of all-electric cars rolled over Berlin’s Kurfürstendamm.

Advances have also been made in lighting technology. In 1881 the American inventor THOMAS ALVA EDISON (1847-1931) presented a usable electric light bulb and a model of a lighting system for residential areas at an exhibition in Paris. In 1882, EDISON set up the world’s first power station in New York and a DC power network for incandescent lamps. In 1884 the first electric motors were connected to the grid.

Also in 1884, the Deutsche Edison-Gesellschaft, later the Allgemeine Elektrizitäts-Gesellschaft (AEG), and the Siemens & Halske company built Europe’s first power station at Friedrichstrasse 55 in Berlin. Two restaurants and a few shops were illuminated with four steam engines, seven dynamo machines and 100 kW power.
The first system for the remote transmission of electrical energy in Germany has put into operation in 1891 from Lauffen to Frankfurt / Main over 175 km.

Electrical engineering and energy supply in Berlin

In the 19th century, Berlin was the centre of the development of electrical engineering. In 1880 the engineer EMIL RATHENAU acquired the EDISON patents for Germany and in 1883 founded the “Deutsche Edison-Gesellschaft”, today’s AEG. This quickly developed into the largest incandescent lamp manufacturer in Europe. As early as 1884 300,000 lamps were produced, in 1891 there were more than a million.

The first “block station” with an output of 100 kW was built in 1884. The electrical engineering generated there was used to illuminate the Café Bauer Unter den Linden and several neighbouring shops. More small power plants were built in quick succession. In 1896, 166,182 incandescent lamps and 8,216 arc lamps were supplied centrally with electrical energy in Berlin. At that time, every single lamp, every machine was recorded and registered individually.

But the need for electrical energy for motors also grew steadily. While the proportion of “power” in Berlin was only 50% in 1898, by 1900 it had grown to 75%. After all, the need for drive energy increased faster than the output of the power plants. In 1906, the Berliner Elektrizitätswerke only allowed the connection of an electric motor with the consent of a power cut from 4 p.m. to 10 p.m. in winter.
In particular, the generation of direct current in central stations with voltages of 110, 220 and 440 V. It was increasingly difficult to supply the newly emerging industrial companies on the outskirts of the city. The maintenance of the generators was laborious and dangerous. A worker who had to adjust the brushes of the commutator on such a generator according to the current consumption decided: “I am a father of a family and, in the face of my conscience, I cannot take responsibility for doing service on the commutator.”
G. FERRARIS in Turin and N. TESLA in New York had already dealt with the technical application of single- and two-phase alternating currents in the 1880s. Generators, motors and transformers were tried and tested in practice and introduced. They were much lighter and safer to use than DC machines. Nevertheless, alternating current was not given a chance because the motors did not start under load.
The engineers HASELWANDER from Siemens and the Russian V. DOLIVO-DOBROWOLSKY (AEG) found a solution by introducing a three-phase alternating current. The v. Dolivo-Dobrowolsky was also the initiator of the first three-phase long-distance transmission over 175 km from Lauffen to Frankfurt / Main, which caused a sensation at the Electrotechnical Exhibition in Frankfurt in 1891. This made it possible to transmit electrical energy over long distances without any problems, “a thousand horsepowers were able to be guided through a keyhole, the thin wire”, as a French writer enthusiastically written.

In Berlin, three-phase power stations were built in Oberschöneweide (1897) and Moabit (1900), soon afterwards others, which, however, found it difficult to meet the rapidly increasing demand from industry and households. This was only possible with the construction of new large power plants such as the Klingenberg power plant and the expansion of electricity networks for the long-distance transmission of electrical energy.

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