Box-type Substation: A Compact "Mobile Substation"

Box-type substation, also known as prefabricated substation, is a compact integrated power distribution assembly. It integrates core power distribution equipment—including high-voltage switchgear, distribution transformers, low-voltage switchgear, electric energy metering devices, and reactive power compensation units—into one or more enclosed enclosures following a predetermined wiring scheme. Serving as a miniaturized, movable complete substation, it fulfills the full-process power distribution function from high-voltage incoming power, voltage conversion to low-voltage outgoing power.Classified by design standards, it is divided into European-style box-type substations and American-style box-type substations. The European-style type features separate compartments for the high-voltage chamber, transformer chamber, and low-voltage chamber, while the American-style type integrates the transformer and high-voltage components into a common oil tank, delivering a more compact structure.

Its core advantages lie in integration and convenience: all equipment is installed, wired, and commissioned at the factory. On-site commissioning only requires foundation construction, enclosure positioning, and cable connection before operation. Compared with conventional civil-constructed substations, the construction period can be shortened by more than 60%, and its small footprint makes it suitable for urban areas with limited land resources.Meanwhile, the enclosure is fabricated from steel plate, aluminum alloy, glass fiber reinforced cement, or similar materials, featuring wind resistance, rainproofing, dustproofing, flame retardancy, and a high protection grade. An intelligent monitoring system can be integrated as required to enable remote data acquisition, fault alarm, remote control operation, and other functions, aligning with the development needs of smart grids.

Constrained by enclosure volume and heat dissipation conditions, the transformer capacity of box-type substations generally does not exceed 1250 kVA. The compact internal layout also results in limited operating space for inspection and maintenance.Nevertheless, thanks to its flexibility and mobility, it is widely deployed in urban road lighting power supply, residential community power distribution, construction site temporary power supply, industrial park power distribution, rural power grid renovation, and other scenarios. Some units can also be aesthetically designed as "landscape box-type substations" to meet the visual requirements of urban environments.