Urumqi Nantianya Electrical Complete-sets Equipment Co.,Ltd.
Add : 366 Tongbaishan Street, Economic and Technological Development Zone, Urumqi
Phone : 86-:13809951165
Service Phone :0991-4653766


Principle of box type substation

Box type substation is a compact complete set of power distribution device which combines high-voltage switchgear, distribution transformer, low-voltage switchgear, electric energy metering equipment and reactive power compensation device in one or several boxes according to a certain wiring scheme. It is suitable for the rated voltage of 10 / 0.4kV three-phase AC system, as line and distribution of electric energ

Compared with the European box type substation of the same capacity, the structure of the American box type transformer substation is more reasonable. Because the European box transformer installs the transformer and common high-voltage electrical equipment in the same metal enclosure box, the room temperature of the transformer is very high, which causes heat dissipation difficulty and affects the output; on the other hand, the common high-voltage load switch, fuse and low-voltage switch cabinet are used in the box, so the European style box type transformer substation is of European type The volume of the box type transformer substation is relatively large. The structure of the American type box transformer substation is different from that of the European type box transformer substation. From the layout, the low-voltage chamber, transformer room and high-voltage chamber are not arranged in the shape of an eye, but in the shape of a product. From the structure, this box type transformer is divided into two parts: the front part and the back part. The front part is the high-voltage and low-voltage operation interval. The operation interval includes high-voltage and low-voltage wiring terminals, load switch operating handle and no-load voltage regulation Section switch, plug-in fuse, oil level gauge, etc.; at the back is the oil filling box and heat sink, and the transformer winding, iron core, high-voltage load switch and fuse are put into the transformer oil tank.

The oil immersed metal oxide arrester is also used in the arrester. The transformer cancels the oil conservator and adopts the principle of constant volume of oil and air gap to design the sealed oil tank. The oil tank and radiator are exposed to the air, so there is no heat dissipation difficulty. The low-voltage circuit breaker uses molded case circuit breaker as the main circuit breaker and outlet circuit breaker. Due to the simplified structure, the floor area and volume of this box type substation are greatly reduced Due to its small size and only one side door opening, the floor area required is only 1 / 4 of that of European box type transformer, and its volume is only 1 / 5-1 / 3 of that of European box type transformer with the same capacity. The high-voltage side of American box transformer is protected by fuse, and the low-voltage side is protected by molded case automatic air circuit breaker, which is the same as that of 10kV distribution transformer in China. The high-voltage fuse protects the internal fault of transformer and automatic air break Over current, short circuit and under voltage faults of low-voltage side line are protected by the circuit breaker. The disadvantages of American box type transformer substation are that the load switch is immersed in oil, the oil is carbonized and decomposed by arc, and harmful gas such as acetylene is produced, which makes the performance decline. There have been accidents, no obvious disconnection point can be seen, and the maintenance is not convenient. Because the low-voltage protection and measurement method in the United States is different from that in China, the American box transformer does not have low-voltage protection and measurement. In order to meet the needs of domestic users, the domestic box transformer is installed with a low-voltage distribution cabinet at the low-voltage side. As the box type transformer is exposed to the direct sunlight for a long time, the heat dissipation of the molded case circuit breaker is affected, and the circuit breaker can not normally cut off the load and short-circuit current, which is easy to cause high-voltage side fault 。

Previous:What are the uses of the distribution box
Next:Box type substation for sale