(1) For simple lighting and public power distribution, high-voltage metering is not required in the high-voltage wiring scheme of the prefabricated substation; only low-voltage metering or no metering is needed, and compensation is unnecessary. There are 4-6 outgoing circuits, controlled and protected by plastic circuit breakers.
(2) For power and lighting public power distribution, the number of outgoing circuits in the prefabricated substation increases to 8-12. In addition, reactive power compensation should be provided.
(3) Self-maintained power supply and special circumstances.
Prefabricated substations have a small footprint. Generally, a prefabricated substation occupies only 5-6 square meters, and can even be reduced by 3-3.5 square meters. Suitable for densely loaded industrial and mining enterprises, ports, and residential areas, it extends high-voltage power supply to the load center, reduces the low-voltage power supply radius, and lowers losses. Fewer low-voltage power lines are required, generally 4-6. This shortens the on-site construction period and reduces investment.
When using new equipment such as fully sealed transformers and SF6 switchgear, the equipment maintenance cycle can be extended, and even maintenance-free requirements can be achieved. The appearance is novel and aesthetically pleasing, harmonizing with the surrounding environment of the substation. Urban power supply departments require high-voltage metering for self-maintained transformer substations (250kVA or 315kVA and above). In some cases, there are multiple outgoing circuits, including backup circuits. In these situations, designers combine actual power consumption with reference to samples from manufacturers to optimize the design.
