Modern life cannot be imagined without electricity, the daily consumption of which seems to be a matter of course. But this achievement was also invented at one time by an inquisitive human mind, striving to make human existence more comfortable and cozy.
Invention of the three-phase system
Several scientists, including the genius of human thought, Nikola Tesla, stood at the origins of the creation of a new way of transferring energy. As in most other discoveries in electrical engineering, in this case, it was also not without the active participation of Russian scientists. Independently of the Serbian naturalist, our compatriot M. ABOUT. Dolivo-Dobrovolsky laid the foundations for the future system and put it into practice. This happened after he had been dealing with the transmission of energy over long distances for many years.
Difficulties in the transmission of electrical energy
They first tried to do this at an exhibition in Vienna, held in 1873. On it, engineer I. Fongong supplied power to a conventional electric motor through a 1 km line. A year later, an engineer from Russia F. Pirotsky, who experimented with lines from 0.2 to 1 km long. However, the low voltage used by the experimenters and the limited conductor cross-section led to huge power losses.
To reduce them, it was proposed to transmit electric current along steel rails. A couple of years later (in 1876) this idea was implemented on one of the railway branches of the city of St. Petersburg. The magnitude of the losses decreased significantly, but this method was not suitable for the transmission of electricity. The experiment resulted in the emergence of electrified transport systems.
A significant breakthrough in solving the problem was the proposal of M. Despres to increase the voltage, which, according to his calculations, would lead to a decrease in losses in the conductors. To confirm his idea, the engineer demonstrated 57 km transmission at a 2 kV line voltage at the Munich Exhibition in 1882.
Discovery of a Russian scientist
Over the next years, many engineers have struggled to increase the length of the lines with a minimum of losses, trying to control the AC motor from a distance. Over time, direct current was completely abandoned. This was due to the following reasons:
- With increased stress, bringing it back to its original form was very costly.
- It was much cheaper and easier to lower the AC voltage with a transformer.
- Losses with this type of electricity were less.
It was at this time that our compatriot came up with a brilliant idea. In recent years, he was engaged in alteration of a DC machine in a form convenient for receiving electricity. This allowed him to pay attention to the possibility of organizing branches from three equally distant anchor points.
The result is exactly what he has been puzzling over in recent years. Instead of a unipolar supply of constant amplitude, the machine was now controlled by three shifted sinusoids with varying polarity. It only remained to transfer this scheme from the electric motor to the generator. This is how the well-known three-phase power transmission system appeared.