Prefabricated substations are the main direction for current rural power grid renovation and future substation construction. However, they still have some shortcomings, specifically:
Fire Prevention: Prefabricated substations are generally fully sealed and unattended. Although all equipment operates without oil and is equipped with a remote smoke alarm system, fire hazards still exist inside the enclosure, such as cables and compensation capacitors. In the event of a fire, ventilation and firefighting are hindered. Therefore, an automatic fire suppression system should be considered, but this would increase the manufacturing cost of the prefabricated substation.
Expansion: Due to size and manufacturing cost limitations, prefabricated substations have limited expansion margin for outgoing line bays. Adding 1-2 more outgoing line bays to the existing enclosure is difficult; additional enclosures are required.
Maintenance: Due to manufacturing cost and enclosure size limitations, prefabricated substations have limited maintenance space, hindering equipment maintenance, especially emergency repairs. This is an inherent weakness of prefabricated substations and an insurmountable drawback.
In summary, looking to the future, box-type substations will be widely used in cities, rural areas, industrial and mining enterprises and public buildings in my country. They will be used by more and more people because of their high quality and low price, which will bring my country's power grid operation level to a new level [2].
