A box-type substation, also known as a pre-assembled substation or pre-fabricated substation, is a compact indoor or outdoor power distribution equipment factory-prefabricated with high-voltage switchgear, distribution transformers, and low-voltage distribution devices arranged according to a specific wiring scheme. It integrates functions such as transformer voltage reduction and low-voltage distribution into one unit, housed in a moisture-proof, rust-proof, dust-proof, rodent-proof, fire-resistant, theft-resistant, heat-insulated, fully enclosed, and movable steel structure box. It is particularly suitable for urban grid construction and renovation, representing a new generation of substations following traditional civil-built substations.

       Box-type substations are applicable in residential areas, urban public transformers, bustling downtown areas, construction power sources, etc. Users can select box-type substations based on different usage conditions and load levels. Since their introduction, box-type substations have developed rapidly, accounting for 70% of distribution transformers in developed European countries and 90% in the United States. With the rapid development of urban modernization and the continuous upgrading of urban distribution networks in China, they are poised to be widely adopted.

       Box-type substations can achieve the "four remotes": telemetry, telecommunication, remote control, and teleadjustment. Each unit operates independently with comprehensive relay protection functions, allowing remote setting of operational parameters, control of internal humidity and temperature, and remote smoke alarm capabilities to meet unmanned operation requirements. Additionally, remote image monitoring can be implemented as needed. Thanks to the use of advanced equipment, particularly oil-free devices, the issue of equipment leakage commonly found in conventional substations is fundamentally resolved. These substations enable condition-based maintenance, reducing maintenance workload and saving approximately 100,000 yuan annually in operational costs, yielding significant overall economic benefits. Pre-assembled box-type substations primarily consist of multiple high-voltage switch systems, armored busbars, integrated substation automation systems, communication, remote control, metering, capacitor compensation, DC power supply, and other electrical units. These are installed in a moisture-proof, rust-proof, dust-proof, rodent-proof, fire-resistant, theft-resistant, heat-insulated, fully enclosed, and movable steel structure box, achieving機(jī)電一體化 and fully enclosed operation.