Let's continue our excursion around the Zhigulevskaya HPP.
The tremendous energy produced by the plant requires proper "care". That's why near every hydroelectric generator there is a substation providing such "care".
These are vacuum circuit breakers. Everyone remembers from school that if you place 2 conductors with high voltage close to each other, there will be formed an electric arc between them. The circuit breakers are used to prevent its forming.
Obsolete equipment is actively reconstructed. These are, for example, old oil switches.