Substations are very common in modern power systems. It may be located at the power generating station or at the middle of the transmission line or at the end. They mainly transforms voltage levels for transmission and distribution purposes.
Substations can be divided into different groups like
- Transmission Substation
- Distribution Substation
- Collector Substation
- Converter Substations
- Switching Substations
- Railway traction substation
One thing you might have been noticed that almost every substation surface is covered with stones and gravels. Have you ever thought what is the reason behind doing that?
well, we will discuss one by one in this article.
1.Compensate vibration: Transformers are static electromagnetic devices. As their cores are made of ferromagnetic materials they tends to vibrate at power frequency which is basically 50/60 Hz and its harmonics.The voids present between the gravels contains air pockets,which absorb the vibrations and saves the substation from mechanical structural failure.
2.Keeps surroundings Dry: Stones prevents water stagnation at the substation as well as prevents plants and weeds to grow up.
3. It increases tower footing resistance
4.Reduces step potential: When an energized high voltage power line falls on the ground ,it creates a potential gradient ring around it on ground surface. It is very dangerous for the workers in fault conditions.
The stones laid on the surface helps to reduce the step potential during fault conditions at substation.
5. Prevents Reptiles: Though it is controversial, some experts says that the vibration of transformers attracts reptiles but the gravels discourages them to enter.