What is a box-type substation?

Box-type substations are suitable for residential quarters, urban public transformers, bustling downtowns, construction power supplies, etc. Users can choose box-type transformers according to different usage conditions and load levels. The rapid development of China's urban modernization and the continuous update and transformation of urban power distribution networks , Will be widely used.

For box-type substations, China has introduced and imitated box-type substations from France, Germany and other countries since the late 1970s. The structure adopts high and low voltage switch cabinets and transformers. This type of box substation is called European-style box substation. , The image is likened to building a house for high and low voltage switchgear and transformers. Since the 1990s, China has introduced American box-type substations, and structurally simplified the structure of load switches, ring network switches and fuses into the transformer tank. In the oil, the lightning arrester also uses oil-immersed zinc oxide arresters, the transformer removes the oil pillow, and the fuel tank and radiator are exposed to the air. This kind of box change is called an American box change, and the image is like a box hanging next to the transformer.

The box-type substation shell is made of steel plate or alloy plate, equipped with a double-layer top cover, and has good heat insulation. The shell and frame are all anti-corrosion treatments, and have long-term outdoor use conditions. The shape and color can be coordinated with the environment, and the installation is convenient. There is a cable room under the foundation of the box-type substation, and there is a manhole in the low-voltage room to enter the cable room for work. In terms of volume, the European-style box-type substation has a larger product volume due to the installation of conventional switch cabinets and transformers inside. Because of the integrated installation, the volume is small.

The high-voltage side of the European-style box substation adopts a load switch and a current-limiting fuse for protection. When one-phase fuse is blown, the striker of the fuse is used to open the load switch at the same time to avoid phase loss operation. The load switch is required to have the ability to cut off the transfer current. The low voltage side is protected by a load switch and a current-limiting fuse. The high voltage side of the American box substation is protected by a fuse. The load switch only has the function of switching and cutting off the high voltage load current. The capacity is small. When a phase fuse appears on the high voltage side Fuse, the voltage on the low-voltage side will be reduced, and the under-voltage protection or over-current protection of the plastic case automatic air switch will be activated, and low-voltage operation will not occur. From the perspective of product cost, the European-style box becomes expensive. From the perspective of product price reduction, American style There is still room for price reduction in the box transformer. On the one hand, the three-phase five-column iron core of the American box transformer can be changed to a three-phase three-column iron core. On the other hand, the high-voltage part of the American box transformer can be modified and moved from the transformer tank to the outside , Occupy the space of the high-pressure chamber.