Box-type substations are generally referred to as box-type substations. Box-type substations include "combined" equipment including high-voltage incoming and outgoing lines, metering devices, transformers, low-voltage incoming lines, and low-voltage distribution outgoing lines, which is equivalent to a complete substation. . However, box-type substations are usually installed outside the building, so there is no special requirement for the selection of transformers, and oil-immersed transformers are generally used.
Box type substation box structure
The box of the European-style substation is composed of three parts: the base, the outer shell and the top cover. The base is generally made of channel steel, angle steel, flat steel, steel plate, etc., assembled by welding or bolted to form; in order to meet the needs of ventilation, heat dissipation and incoming and outgoing lines, strip holes and moderately sized circles should be opened at the corresponding positions. shaped hole. The box shell, top cover channel steel, angle steel, steel plate, aluminum alloy plate, color steel plate, cement plate, etc. are bent, assembled and welded or connected with screws, hinges or related special accessories.
Regardless of the material of the box, it must have five prevention functions such as sun protection, rain protection, dust prevention, rust prevention, and prevention of small animals (such as snakes) according to the standard requirements. In order to prevent the strong solar radiation in the hot summer, the shell of the European substation is generally filled with insulating materials with low thermal conductivity on the top. Commonly used fillers are: rock wool board, polystyrene foam and so on.
In the traditional "combined substation" of unified design, the shell is generally filled with thermal insulation fillers. This method is no longer adopted by most designers, because the thermal insulation fillers can prevent strong solar radiation in hot summer. At the same time, it also hinders the dissipation of a large amount of heat generated during the operation of the transformer. Therefore, in addition to retaining the method of punching louver holes on the shell, the designers also adopted the method of increasing the heat dissipation area and strengthening air convection to dissipate heat, and at the same time, it can also reduce manufacturing cost.
On the surface of European-style box-type transformers: There are many methods on the surface of European-style box-type transformers. In northern China, traditional methods such as spray painting, baking paint, and plastic spraying are used for treatment; in the economically developed areas of southern China, in addition to the above methods, there are also Paste colored tiles or veneer on the outside of the shell of the cement board structure for surface treatment, especially the box-shaped appearance placed in the residential area, which is more coordinated and unified with the style of local buildings.
Structure of high voltage power distribution device
The European-style box-type high-voltage power distribution device is divided into two types: terminal type and ring network type from the line entry method; from the line entry position, it can be divided into: overhead line entry from the top of the box (traditional box transformers use this method compared to More) and use of high-voltage cable trenches to enter and exit lines from the ground, which is a more common method of modern design.
There are many SF6 series load switches with SF6 gas as arc extinguishing medium, and their cost is higher than FN-10 series high voltage load switches. This type of switch structure includes fuses, without fuses, grounding switches, etc., but they are generally equipped with live displays; the operating mechanism is generally manual, and some are electrically operated. With a fuse, when a short circuit fault occurs in the circuit, it can automatically cut off the switch to protect the circuit and equipment such as transformers and switches.
There are also vacuum switches that use vacuum as the arc extinguishing medium. This type of switch can be used alone, or with fuses, and can also be used in series with SF6 series load switches, but this will increase the cost. Requirements do not have to be used in this way.
High-voltage metering: In the high-voltage power distribution device, if the user has high-voltage metering requirements, a high-voltage metering cabinet must be installed.
Power Supply departments across China do not have uniform requirements for high-voltage or low-voltage metering. Northwest region power supply regulations stipulate: when the transformer capacity is greater than 160KVA, high-voltage metering must be used; the switch of high-voltage metering cabinet must be controlled by the power supply department. Beijing, Tianjin and other North China power supply departments believe that the measurement of box-type substations should be on the low-voltage side, which can improve the reliability of power supply, reduce the unstable factors caused by high-voltage measurement, and reduce the loss of the transformer itself. , which is borne by the user.
The structure of the box-type substation high-voltage metering cabinet is generally composed of: CT, PT, and metering meters, remote control, and telemetry devices.
Power Supply
Power Supply,Mute Processing Power Supply,Low Ripple Power Supply,Heat Dissipation Power Supply
Guangzhou Lufeng Electronic Technology Co. , Ltd. , https://www.lufengelectronics.com