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How are power transformers classified?
- May 28, 2018 -

Power transformers are classified by use: boost (power plant 6.3kv / 10.5kv or 10.5kv /110kV, etc.), contact (220kV/110kV or 110kV/ 10.5kv between substations), voltage reduction (distribution 35kV/ 0.4kv or 10.5kv / 0.4kv).
Power transformers are classified by phase number: single phase, three phase.

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Power transformer windings by classification: double winding (each phase on the same core, former vice winding, winding and insulation) separately, three winding (every three phase winding, the original, vice winding winding and insulation) separately, autotransformer (among a set of winding tap as a primary or secondary output). The capacity of primary winding is greater than or equal to that of secondary winding and tertiary winding. The percentage of winding capacity is in the order of high voltage, medium voltage and low voltage: 100/100/100, 100/50/100 and 100/100/50. It is required that the secondary and tertiary windings are not fully loaded. Generally, the voltage of the third winding is low, which is mainly used for the near power supply or compensation equipment, and is used to connect the three voltage levels. Autotransformer: there are two kinds of uhv or uhv transformer, because of its small loss, light weight and economical operation, so it is widely used in uhv power grid. The common type of small autotransformer is 400V/36V (24V), which is used for power supply of safety lighting and other equipment.

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Power transformers are classified by insulation media: oil-immersed transformers (flame retardant, non-flame retardant), dry transformers, 110kVSF6 gas insulated transformers.
The core of power transformer is core structure.
The three-phase power transformer configured in general communication engineering is a double-winding transformer.