How to arrange box-type substation

Box-type substation is an integrated, modular and convenient distribution equipment, which is widely used in urban distribution networks, industrial parks, residential quarters, temporary construction sites and other occasions. It has compact structure, small floor space and high safety performance, and is an indispensable part of modern power system. Reasonable layout is not only related to the operation efficiency of substation, but also directly affects the stability and safety of power supply. This paper will discuss the layout method of box-type substation from the aspects of site selection, layout design, equipment configuration and safety spacing.

First, the site selection principle

The location of box-type substation is the first step of layout, and the following principles should be followed:

1. Close to the load center: In order to reduce the line loss and improve the power supply quality, the box transformer should be arranged in the center area of power load as far as possible.
2. Convenient transportation: convenient for equipment transportation, installation and daily maintenance.
3. High terrain and good drainage: avoid low-lying water accumulation and prevent rainwater from flowing backwards.
4. Stay away from flammable and explosive places: ensure the safety of the surrounding environment and meet the requirements of fire and explosion prevention.

Second, the layout design points

Box-type substation is usually composed of high-voltage chamber, transformer chamber and low-voltage chamber, which can be arranged in the shape of "mesh", "pin" or straight line according to specific use requirements.

1. "Mesh" layout: Three functional rooms are arranged in parallel, with transformer room in the middle and high and low voltage rooms on both sides. It is suitable for wide space and easy to operate and maintain.
2. Pin-shaped layout: Three function rooms are arranged in a triangle, which saves space and is suitable for long and narrow venues.
3. Linear layout: each function room is arranged along a straight line, with simple structure and suitable for small or temporary power supply projects.

Third, the equipment configuration is reasonable

Attention should be paid to the following points when arranging equipment:

-Main equipment such as high-voltage switches, transformers and low-voltage switches shall be clearly placed according to functional zones;
-Sufficient space should be reserved at the cable inlet and outlet to facilitate wiring and maintenance;
-Centralized arrangement of control and protection devices for unified management;
-Ventilation and heat dissipation systems should be set scientifically to ensure good operating environment of internal equipment.

Fourth, the safety distance and protective measures

According to the Code for Cable Design of Electric Power Engineering and other relevant standards, the box-type substation should keep a certain distance from buildings, roads, trees, etc.

-Not less than 3 meters away from the external wall of the residential building;
-Not less than 1m away from the edge of the main road;
-Fences or protective nets should be set around to prevent irrelevant personnel from approaching;
-The casing of the box should have a good protection level (generally above IP44) and strong dustproof and waterproof ability.

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In a word, the layout of box-type substation is a systematic project, which needs to comprehensively consider geographical environment, load demand, operation and maintenance and other aspects. Scientific and reasonable layout can not only improve the reliability of power supply, but also prolong the service life of equipment and ensure the safe and stable operation of power grid. In practical engineering application, it is suggested that detailed layout scheme should be made according to the characteristics of specific projects, and relevant national standards and industry norms should be followed to achieve the optimal power allocation effect.