1. Three-phase alternating current (AC) and direct current (DC) networks

1.1 Edison-Tesla controversy

In the early 1880s, the standard for transmitting electrical energy was DC lines. This was how Edison (1847-1931) first installed electricity distribution on Wall Street in New York in 1882. The voltage distributed by the network was around 110 V, supplied by dynamos. Unfortunately, with a 110 V DC generator, it's difficult to supply a receiver beyond 1.5 km, due to voltage drops on the line.

Edison was in fierce opposition to George Westinghouse (1846-1914) and Nikolas Tesla (1856-1943), both advocates of alternating current (AC line) from 1886 onwards. Indeed, the invention of the transformer made it possible to use an alternator to create high-voltage networks, such as those seen today, by using a step-up transformer. If, after...