|Release time: 2018-03-14 Click times: 1035 times|
| Transformer is a device that uses the principle of electromagnetic induction to change the AC voltage. The main components are a primary coil, a secondary coil, and an iron core (magnetic core). The main functions are: voltage conversion, current conversion, impedance conversion, isolation, voltage stabilization (magnetic saturation transformer), etc. It can be divided into distribution transformers, power transformers, hermetic transformers, combined transformers, dry-type transformers, oil-immersed transformers, single-phase transformers, electric furnace transformers, rectifier transformers, etc. |
First, the production principle of the transformer:
In a generator, whether the coil moves through a magnetic field or the magnetic field moves through a fixed coil, the potential can be induced in the coil. In both cases, the value of the magnetic flux is unchanged, but the amount of magnetic flux interlinked with the coil is. Change, this is the principle of mutual induction. A transformer is a device that uses electromagnetic mutual induction to transform voltage, current, and impedance.
2. Classification According to the cooling method: dry-type (self-cooling) transformer, oil-immersed (self-cooling) transformer, fluoride (evaporative cooling) transformer. Classified by moisture-proof method: open transformer, potting transformer, sealed transformer.
Classified by core or coil structure: core transformer (insert core, C-type core, ferrite core), shell transformer (insert core, C-type core, ferrite core), Toroidal transformers, metal foil transformers.
Classification by power phase: single-phase transformer, three-phase transformer, multi-phase transformer.
Classified by purpose: power transformer, voltage transformer, audio transformer, intermediate frequency transformer, high frequency transformer, pulse transformer.
Third, the characteristic parameters of the power transformer Operating frequency The transformer core loss has a great relationship with the frequency, so it should be designed and used according to the frequency of use, which is called the operating frequency. With rated power at the specified frequency and voltage, the transformer can work for a long time without exceeding the output power of the specified temperature rise.
Rated voltage refers to the voltage allowed on the coil of the transformer. It must not exceed the specified value during operation. The voltage ratio refers to the ratio of the primary voltage and the secondary voltage of the transformer. There is a difference between the no-load voltage ratio and the load voltage ratio. When the secondary of the no-load current transformer is open, the primary still has a certain current. This part of the current is called no-load current. The no-load current is composed of a magnetizing current (generating magnetic flux) and a core loss current (caused by core loss). For a 50Hz power transformer, the no-load current is basically equal to the magnetizing current.
No-load loss refers to the power loss measured at the primary when the transformer secondary is open. The main loss is the core loss, followed by the loss (copper loss) caused by the no-load current on the copper resistance of the primary coil, which is very small.
Efficiency refers to the percentage of the ratio of the secondary power P2 to the primary power P1. Generally, the higher the rated power of the transformer, the higher the efficiency.
Insulation resistance indicates the insulation performance between each coil of the transformer and between each coil and the iron core. The level of insulation resistance is related to the performance of the insulation material used, the temperature level and the degree of humidity.
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