What is the difference between a box-type substation and a traditional substation?

What are the characteristics of a box-type substation?

Box-type substations are characterized by light weight, easy installation and maintenance, and beautiful appearance. They are particularly suitable for power transformation in industrial and mining enterprises, urban power distribution, parks, residential areas, and other places. Box-type substations are mainly composed of a multi-circuit high-voltage switch system, armored busbar, substation integrated automation system, communication, telecontrol, metering, capacitor compensation, and DC power supply. They are installed in a moisture-proof, rust-proof, dust-proof, rodent-proof, fire-proof, anti-theft, heat-insulated, fully enclosed, movable steel structure box. They are mechatronic and fully enclosed. They have the following main characteristics:

(1) Advanced technology, safe and reliable.

The box body adopts the current domestic leading technology and process. The outer shell is generally made of aluminum-zinc-coated steel plate, and the frame adopts standard container materials and manufacturing process. It has good anti-corrosion performance and will not rust for 20 years. The inner sealing plate is made of aluminum alloy buckle plate, and the interlayer is made of fireproof and heat-insulating materials. Air conditioning and dehumidification devices are installed in the box. The operation of the equipment is not affected by the natural climate environment and external pollution, and can ensure normal operation in the harsh environment of -40℃～+40℃. The primary equipment in the box adopts fully enclosed high-voltage switchgear (such as XGN type), dry-type transformers, dry-type mutual inductors, vacuum switches, spring operating mechanisms, rotary disconnectors and other equipment. The product has no exposed live parts and is a fully enclosed and fully insulated structure. It can completely achieve zero electric shock accidents and high safety. The secondary adopts a microcomputer integrated automation system, which can be unmanned.

(2) High degree of automation. 

The whole station is intelligently designed. The protection system adopts the substation microcomputer integrated automation device, which is installed in a decentralized manner. It can realize the "four remotes", namely telemetry, telesignaling, remote control and remote adjustment. Each unit has independent operation function and complete relay protection function. It can remotely set the operating parameters, control the humidity and temperature inside the box, and remotely set the smoke alarm to meet the requirements of unmanned operation. It can also realize image remote monitoring as needed.

(3) Factory prefabrication. 

During the design, as long as the designer makes a main wiring diagram and the design of the external equipment according to the actual requirements of the substation, the specifications and models of the box transformer provided by the manufacturer can be selected. All equipment is installed and debugged in the factory at one time, which truly realizes the factory construction of the substation and shortens the design and manufacturing cycle. On-site installation only requires box positioning, cable connection between boxes, outgoing cable connection, protection setting value verification, transmission test and other debugging work. The entire substation takes only about 5 to 8 days from installation to commissioning, which greatly shortens the construction period. 

(4) Flexible combination method.

The box-type substation has a relatively compact structure, and each box constitutes an independent system, which makes the combination method flexible and changeable. The user unit can freely combine some modes according to the actual situation to meet the needs of safe operation. 

(5) Low investment and quick results.

 The box-type substation reduces the investment by 40% to 50% compared with the conventional substation of the same size. Due to the selection of advanced equipment, especially the operation of oil-free equipment, the equipment leakage problem in the conventional substation is fundamentally solved. The substation can implement condition maintenance, reduce the maintenance workload, save operation and maintenance costs, and the overall economic benefits are very considerable.

(6) Small footprint. 

The box-type substation only occupies 1/10 of the area of the substation of the same size. It can make full use of the street center, square and factory corners for installation and production, which is in line with the national policy of saving land. 

(7) Beautiful appearance and easy to coordinate with the environment. 

The box shell adopts galvanized steel plate and container manufacturing technology, with beautiful appearance design. Under the premise of ensuring power supply reliability, by selecting the shell color of the box-type substation, it is easy to coordinate with the surrounding environment. It is particularly suitable for urban construction, such as urban residential areas, stations, ports, airports, parks, green belts and other densely populated areas. It can be used as both a fixed substation and a mobile substation.

The Difference Between Traditional and Prefabricated Substations

Traditional substations are a crucial component of power systems, primarily used to convert high-voltage electricity into low-voltage energy to meet varying power demands. They also ensure stable operation and optimized dispatching of power systems, ensuring reliable and stable power supply.

The following is a parameter comparison between the American Type Prefabrication Substation and the traditional substation of Zhejiang Hanya Electric Appliance Company:

How are box-type substations classified? 

(1) Assembled type. The high and low voltage complete sets and transformers are installed in a metal box, and an operation corridor is left in the high and low voltage distribution devices. This type of box-type substation is relatively large and is rarely used now. 

(2) Combined device type. Instead of using the existing complete sets of devices, the high and low voltage control and protection electrical equipment are directly installed in the box to form a whole. The design is based on maintenance-free considerations, there is no operation corridor, and the box is small. It is also called European box-type substation or ordinary box-type substation. 

(3) Integrated type. The high voltage control and protection devices are simplified, and the high and low voltage distribution devices and the transformer body are installed together in the transformer oil tank to form a whole. The volume is smaller, close to the same capacity oil-immersed transformer, and is 1/3 of the European box-type substation. It is also called American box-type substation or compact box-type substation.