What are the types of transformers?

Transformers are divided into two categories: voltage transformers and current transformers.

1. Voltage Transformer
The basic structure of a voltage transformer is very similar to that of a transformer. It also has two windings, one called the primary winding and the other called the secondary winding. Both windings are installed or wound on the iron core. There is insulation between the two windings and between the winding and the iron core, which provides electrical isolation between the two windings and between the winding and the iron core.
When the voltage transformer is in operation, the primary winding N1 is connected in parallel to the line, and the secondary winding N2 is connected in parallel to the instrument or relay. Therefore, when measuring the voltage on high-voltage lines, although the primary voltage is high, the secondary voltage is low, which can ensure the safety of operators and instruments.

2. Current Transformer

A current transformer is an instrument that converts high primary current into low secondary current based on the principle of electromagnetic induction for measurement. Composed of a closed iron core and winding.
Its primary winding has very few turns and is connected in series in the line where the current needs to be measured, so it often has all the current flowing through the line. The secondary winding has a relatively large number of turns and is connected in series in the measuring instrument and protection circuit. When the current transformer is working, its secondary circuit is always closed, so the impedance of the measuring instrument and protection circuit series coil is very small, and the working state of the current transformer is close to a short circuit. When using transformers, the following aspects should be noted:
1. The rated primary current of a current transformer is generally selected based on 1.2 to 1.4 times the current of the line. This is mainly to ensure that the current transformer and electrical equipment such as ammeters or energy meters will not be burned out when the line is overloaded.
2. The rated primary current of the current transformer cannot be selected to be too different from the actual working current of the line, which will affect the measurement accuracy of the current transformer.
3. The accuracy of the transformer can only be guaranteed within the rated secondary output load range. Therefore, both the secondary line load and the load of the metering device are the actual working loads of the transformer. When the secondary actual output load of the transformer is greater than the secondary rated output load, the accuracy of the transformer will decrease, and in severe overload, the transformer will be burned out.
4. When the actual secondary output load of the transformer is lower than the rated secondary output load of the transformer, the accuracy of the transformer will decrease.
5. Choose appropriate transformer products according to different usage scenarios.
6. Outdoor transformers and indoor transformers should not be mixed.