What does the number 0+0000 mean on the hydroelectric power station pressure tunnel paper?

This should be: Yin 0+000.0

This is the station number, used to indicate the specific location of the long building. “Yin” is the abbreviation of the name, which refers to water. tunnel; the + sign in front of 0 is the number of kilometers, and the following digits are the number of meters. For example: Diversion 2+325.6 means that the diversion tunnel is 2325.6 meters from the starting point.

Bypass 0+000.0 represents the starting point of the diversion tunnel.

The 250MW unit is very large and usually uses generator-transformer group wiring, so the protection of generator and booster transformer is also together

《 Power Engineering Electrical Design Manual (Electrical Secondary)? There are drawings on 680 pages

But they are not very clear. You can do it yourself and draw it in CAD