In an autotransformer, the common portion of the single winding acts as part of both the “primary” and “secondary” windings. The remaining. Auto-transformer Advantages: Auto-transformers in comparison with the double winding transformers are generally advantageous of the. ADVANTAGES OF AUTO TRANSFORMER STARTER: a) On the 65% tapping the line current is approximately equal tp that of a Star-Delta.

Author: Gushura Jubar
Country: Guadeloupe
Language: English (Spanish)
Genre: Life
Published (Last): 26 December 2008
Pages: 214
PDF File Size: 12.83 Mb
ePub File Size: 16.21 Mb
ISBN: 258-8-91966-762-3
Downloads: 5889
Price: Free* [*Free Regsitration Required]
Uploader: Baran

If the same duty is performed with an ordinary two winding transformer shown above in the figure A. A large part is merely transferred electrically by conduction. An A uto Transformer is a transformer with only one winding wound on a laminated core. Auto-transformers in comparison with the double winding transformers are generally advantageous of the voltage ratio is favorable from the point of view of the equivalent size.

The length of the conductor is proportional to the number of turns, and the cross section is proportional to the product of current and number of turns. Leave this field empty. Surge Arrester protection is required As the short circuit impendace values of the auto-transformer are low, short circuit currents can reach higher critical values.

In order to avoid the occurrence of this phenomenon must be high, medium voltage on both sides of the outlet side can one set of valve type arrester. The primary and secondary currents are in opposition and the total current flowing through the coils in common is equal to the difference of the current of the low voltage winding and the high voltage winding. Autotransformer is a transformer, common with a primary and secondary winding, which is common with a zero line, the transformation ratio have both fixed and adjustable.

The construction of Auto transformer is shown in the figure below. There are also autotransformers in which the adantages intake is achieved through a sliding brush, allowing a continuous range of secondary voltages ranging from zero to the voltage of the source.

In this way we have a more effective AC machine. Advertisements fund this website. In the same way as transformers, autotransformers can also be equipped with automatic tap changers and used in transmission and distribution systems to regulate the voltage of the electric network.

  ASTM D6760-08 PDF

Its shortcomings are as follows: It consists of a winding of ends A and D, which has been made a derivation in the intermediate point B. Because transformer silicon steel sheet and copper is and an inductive winding rated voltage and rated current, and related to the capacity of the winding, autotransformer winding capacity reduced material consumption is reduced, and low cost.

This situation must be taken into account when od to use an autotransformer for a certain application.

Advantages and disadvantages of autotransformer

For now we will call primary to the complete section AD and secondary to the portion BD, but in practice it can be the other way round, when you want to raise the primary tension.

The single —phase, a two-winding transformer is reconnected as an autotransformer as shown in Fig. The secondary voltage is less than the primary. These disadvaantages methods are not only manufacturing difficulties, not disadvantxges, and also has disadvantages in the running such as the disaevantages windings of voltagethe solution is less than ideal. Autotransformer and General transformer of the same capacity in comparison, has a simple structure, the materials used, the advantages of small size.

Therefore the auto-transformer requires much highs standard of insulation compared to normal transformer.

Advantages and disadvantages of autotransformer | Simply Buy(Shanghai)Co., Ltd. Blog

Similarly, the output apparent power is given by. Find Free WordPress Themes and plugins. The apparent power transformed by induction is. Largely because of its high and medium voltage winding autotransformer due to electrical contact may surge in three ways, the first is internal autotransformer winding installation changing the position of head pressure regulating device with load; the second is the high-voltage and medium-voltage lines to install additional transformers.

Some of the disadvantages of an autotransformer are: Advantages Step-down starter of auto-transformer transformation ratio is fixed, contact the transformation ratio of voltage regulator is variable. It has a single coil wound on the core, but has four terminals, two for each circuit, and therefore has points in common with the transformer. The tapping may be fixed or variable. In an autotransformer, the total power transmitted from the primary to the secondary does not actually pass through the whole winding.


You can find new Free Android Games and apps. When a load is connected to the secondary of the autotransformer, a current I 2 flows in the direction shown in Fig. However, not all of the 50 kVA is transformed by electromagnetic induction. The content is copyrighted to ElectricalAcademia. For connections between the two systems at very high voltage, where the power is to be transmitted in the order of GVA Giga Volt-amperesthe use of auto transformer make it possible for high power equipment and can be easily transportable.

Circuit Globe Transformer Auto Transformer. Especially in the occasion seem special economic of the transformation ratio is close to 1, so the voltages used by similar high-power transmission transformers more, in addition to the above kilowatt are widely used in the asynchronous motor starter. This last design was commercialized in the United States under the generic name of Variac and in practice it works as a source of alternating current in tension.


The apparent power transformed by conduction is. An auto transformer is similar to a two winding transformer but differ in the way the primary and secondary winding are interrelated. Neglecting voltage drops in autotransfomer windings. In short, we say that there is a wide range of advantages of autotransformers. In general practice, auto transformers are only used on distribution systems where the neutral is connected to the earth Auto-transformers are particularly sensitive to the atmospheric over-voltages.

At full or rated load, the primary and secondary terminal currents are. As a step-up, it is often referred to as a boost, and as a step-down, it is called a buck connection.