Sulfur Hexafluoride Transformer, abbreviated as GIT, is a type of transformer with promising development prospects. Currently, transformers are mainly developing in two directions: one is towards extra-large ultra-high voltage, and the other is towards energy-saving, miniaturization, low noise, high impedance, and explosion-proof types. The former is generally used in large power stations or power transmission, while the latter mainly focuses on small and medium-sized products. With the urbanization development in China, the population in large cities is becoming more dense, high-rise buildings are springing up, electricity consumption is increasing sharply, and the number of transformers is also increasing. Traditional large-capacity oil-immersed transformers have a large amount of oil, and once a fire occurs due to a fault, it will pose a serious threat to high-rise buildings and people's life and property safety. Therefore, people are paying more and more attention to the research and application of non-flammable transformers. Non-flammable transformers can be divided into silicon transformers, epoxy resin cast transformers, complex sensitive insulating liquid medium transformers, and sulfur hexafluoride gas-insulated transformers according to their different insulating media. Among them, GIT has attracted people's attention due to its unique advantages and has been widely applied and developed in Japan and Europe since the 1960s. Currently, China is also developing rapidly.

  According to different cooling media, GIT can be divided into two major types: gas-insulated, gas-cooled and gas-insulated, liquid-cooled. GIT with a capacity of less than 60MVA has small heat loss and generally adopts the heat dissipation method of sulfur hexafluoride gas circulation cooling. This type of GIT has many similarities in structure with traditional oil-immersed transformers and can be referenced in design. GIT with a capacity greater than 60MVA mostly adopts a liquid-cooled and gas-insulated separate structure. The structure of such products is very different from oil-immersed transformers, usually being layered-cooled, foil-wound GIT.

  Compared with traditional oil-immersed transformers, GIT has the following advantages. First, it has good insulation performance and cooling effect. Sulfur hexafluoride has excellent electrical characteristics, mainly manifested in its insulation characteristics and arc extinguishing characteristics. Due to the electronegativity of sulfur hexafluoride (i.e., the ability to adsorb electrons), it has excellent dielectric insulation performance. In a uniform electric field, the insulation strength of sulfur hexafluoride is about 2.5 times that of air; when the gas pressure is 0.2MPa, the insulation strength of sulfur hexafluoride gas is equivalent to that of insulating oil. At the same time, sulfur hexafluoride has excellent heat exchange characteristics in the temperature range of arc extinguishing and instantaneous discharge (1500～5000K). Therefore, GIT has good insulation performance and cooling effect. Second, it is not flammable or explosive. Sulfur hexafluoride gas is an inert gas, colorless, odorless, non-toxic, and non-flammable, and its molecular structure is very stable. At room temperature, it will not undergo chemical changes with the substances it contacts, thus greatly simplifying the configuration of fire extinguishing facilities; when GIT is combined with GIS, the entire substation is in a gas-insulated environment, which enhances the non-flammability of the entire substation. In terms of explosion-proof, when an arc phenomenon occurs inside the transformer, the increased internal pressure will be offset by the volume change of sulfur hexafluoride gas, so GIT does not need additional pressure release equipment. Third, it is easy to install and flexible in layout. GIT is fully assembled at the factory, and sulfur hexafluoride gas is also injected into it. There is no need for vacuuming at the installation site, and sulfur hexafluoride gas is directly input from the gas tank to the transformer tank, basically without any tools, so the loading is clean and fast. At the same time, since the density of sulfur hexafluoride gas is only 1/60 of the density of insulating oil and the viscosity is low, the pressure drop in the cooling pipe is very small, so the cooler can be installed horizontally or vertically away from the transformer, making its layout quite flexible. Fourth, it is simple and lightweight. GIT does not need oil pillows and pressure release equipment, and these accessories do not need isolation walls. At the same time, the density of sulfur hexafluoride gas is much higher than that of transformer oil, making it simple and lightweight. In addition, GIT also has the advantages of low noise, easy maintenance and inspection, and less floor space, especially when GIT is used in conjunction with GIS, these advantages are more obvious.

  Reprint statement: This article is reprinted from online resources, and I am not responsible for any consequences of this article. If anyone is harmed by this article, including but not limited to profit damage, personal injury, and all other damages, all consequences shall be borne by the original author (I cannot find out, please cooperate with the public security and network supervision authorities to find out).