An autotransformer means that part of its winding is shared between the high-voltage side and the low-voltage side. The other part only belongs to the high-voltage side. According to the structure, it can also be subdivided into adjustable pressure type and fixed type. Autocoupling means electromagnetic coupling. Ordinary transformers transfer energy through electromagnetic coupling of the primary and secondary coils. There is no direct electrical connection between the primary and secondary sides. The primary and secondary sides of an autotransformer have direct point-to-point connections. The low voltage coil is part of the high voltage coil. In the current power grid, autotransformers are only available from the 220KV voltage level, and they are mostly used as contact transformers between power grids.
There are almost no autotransformers below 220KV. For dry-type transformers, the insulating medium is solid such as resin, and there is no insulating oil in oil-immersed transformers, so it is called dry-type. Due to poor heat dissipation conditions, the capacity of dry-type transformers cannot be very large. Generally, there are only small and medium-sized transformers with voltage levels of 35KV and below, and almost none higher than 35KV. Mainly develops, produces and sells ZSG series single and three-phase dry autotransformers. Introduction: Auto-transformer is a transformer with only one winding. When used as a step-down transformer, a part of the turns are extracted from the winding as secondary Winding; when used as a step-up transformer, the external voltage is only applied to some turns of the winding. Usually, the part of the winding that belongs to both the primary and secondary windings is called the common winding, and the remaining part is called the series winding. Compared with ordinary transformers of the same capacity, self-coupling transformers are not only smaller in size, but also more efficient, and the transformer capacity is larger. The higher the voltage. This advantage becomes more prominent. Therefore, with the development of power systems, the increase of voltage levels and the increase of transmission capacity, auto-coupling transformers have been widely used due to their large capacity, low loss and low cost.
