What is the difference between autotransformer and ordinary transformer?
Writer： Hengfeng you electric Time：2023-04-19 views：times
Transformer is a static electrical equipment used to transform AC voltage and current to transmit AC energy. It realizes electric energy transmission according to the principle of electromagnetic induction. Transformers can be divided into power transformers, furnace transformers, rectifier transformers and other transformers for special purposes. It can be said that transformers have a wide variety and are widely used. Today, let Alisa, the sales manager of hengfengyou electric, introduce the difference between autotransformer and ordinary transformer in power transformer:
A. Definition of autotransformer:
It refers to the transformer whose primary and secondary windings are on the same winding, and the primary and secondary windings are directly connected in series and self coupled. According to the structure, it can also be subdivided into adjustable pressure type and fixed type. Self coupling means electromagnetic coupling. An ordinary transformer transmits energy through the electromagnetic coupling of the primary and secondary coils. The primary and secondary sides have no direct electrical connection. The primary and secondary sides of the autotransformer have direct electrical connection. Its low-voltage coil is a part of the high-voltage coil. Autotransformer and other protective equipment will also be used in the protective equipment of communication lines.
B. Definition of common transformer:
It is used to change the voltage (current and impedance) and transfer electric energy. It is composed of a primary coil, one to several secondary coils and iron core (air core coil is commonly used in high frequency). Differential transformer is mainly used as displacement sensor, which is generally composed of one primary coil, two secondary coils and iron core. For the two secondary coils of this sensor, one induced potential increases and the other induced potential decreases. The two secondary coils are connected in reverse series (connected at the same end). This wiring method is called differential voltage regulator. The displacement of the middle iron core causes the change of the output voltage of the secondary coil. After amplification, it is used to indicate the displacement
C. Difference between autotransformer and ordinary transformer:
1. The primary side and secondary side have not only magnetic connection, but also electrical connection, while the ordinary transformer is only magnetic connection.
2. The capacity of the power supply through the transformer is composed of two parts: the electromagnetic induction power between the primary winding and the common winding, and the conducted power directly conducted by the primary winding.
3. Since the autotransformer winding is composed of the primary winding and the common winding, the number of turns and height of the primary winding, the current and leakage reactance of the common winding are correspondingly reduced compared with those of the common transformer. The short-circuit reactance X of the autotransformer is (1-1 / k) times of the short-circuit reactance X of the common transformer, and K is the transformer transformation ratio.
4. If the autotransformer is equipped with a third winding, the third winding will occupy the common winding capacity and affect the operation mode and exchange capacity of the autotransformer.
5. Because the neutral point of autotransformer must be grounded, the setting and configuration of relay protection are complicated.
6. The autotransformer has the advantages of small volume, light weight, convenient transportation and low cost.
