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Principle Of Box Substation

Dec. 19, 2019

Box-type substations are compact power distribution devices that combine high-voltage switchgear power distribution transformers, low-voltage switchgear, power metering equipment, and reactive power compensation devices in one or more boxes according to a certain wiring scheme. It is suitable for three-phase AC systems with a rated voltage of 10 / 0.4KV and is used for line and power distribution. Substations Low Voltage Electric Panel Factory shares with you.

Compared with European-style box transformers of the same capacity, the structure of American-type box transformers is more reasonable. Since the European-style box transformer is a transformer and ordinary high-voltage electrical equipment are installed in the same metal shell box, the transformer's room temperature is very high, which causes difficulty in heat dissipation and affects output; on the other hand, ordinary high-voltage load switches and fuses are used in the box And low-voltage switchgear, so the European-style box becomes larger. The American box transformer is different in structure from the European box transformer. From the perspective of layout, the low-voltage room, transformer room, and high-voltage room are not mesh-shaped layouts but are character-shaped layouts. From a structural point of view, this box type is divided into front and rear parts with high and low voltage operation intervals. The operation interval includes high and low voltage terminal blocks, load switch operating handles, no-load voltage regulating section switches, and plug-in fuses. Oil level gauge, etc .; the rear part is the fuel tank and heat sink, put the transformer winding, iron core, high voltage load switch and fuse into the transformer oil tank. We can provide Power Plant Indoor Electrical Switchgear for you.

Frequency Conversion Cabinet

Lightning arresters also use oil-immersed metal oxide arresters. The transformer eliminates the oil pillow and adopts the principle of a constant volume of oil plus the air gap to design a sealed fuel tank. The fuel tank and radiator are exposed to the air and there is no difficulty in heat dissipation. Low-voltage circuit breakers use molded case circuit breakers as main circuit breakers and outgoing circuit breakers. Due to the simplified structure, the floor space and volume of this box-type substation are greatly reduced. Due to its small size and only one door opening, its required area is only 1/4 of that of European-style box-type transformers, and its volume is only It is 1 / 5-1 / 3 of European box transformer with the same capacity. The high-voltage side of the American box transformer is protected by a fuse, and the low-voltage side is protected by a plastic case automatic air circuit breaker, which is the same as the protection method of the 10kV distribution transformer in China. The high-voltage fuse protects the internal fault of the transformer, and the automatic air circuit breaker protects the over-current, short-circuit and under-voltage faults of the low-voltage line. Disadvantages of the American box. Because the load switch is immersed in oil, the oil is carbonized and decomposed by the arc, and harmful gases such as acetylene are generated, which reduces the performance and an accident has occurred. No obvious disconnection is visible, and maintenance is inconvenient. Because the American low voltage protection and measurement method are different from China, the American box transformer itself does not have low voltage protection and measurement. In order to meet the needs of domestic users, domestic box transformers are equipped with low-voltage distribution cabinets on the low-voltage side. Because the box-type transformer is exposed to direct sunlight for a long time, it affects the heat dissipation of the plastic case circuit breaker, which makes the circuit breaker cannot open the load and short-circuit current normally, which easily causes high-voltage side failure.

Our company also supplies Frequency Conversion Cabinet.

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