In an autotransformer, the common portion of the single winding acts as part of both the “primary” and “secondary” windings. The remaining. Electrical Tutorial about the Autotransformer and the Variable Auto The main advantage of this type of transformer design is that it can be made a lot cheaper for the same VA rating, but the biggest disadvantage of an autotransformer is that it. An autotransformer is an electrical transformer with only one winding. The “auto” ( Greek for and cheaper than typical dual-winding transformers, but the disadvantage of not providing electrical isolation between primary and secondary circuits. Other advantages of autotransformers include lower leakage reactance, lower.

Author: Goltilkis Dazuru
Country: Djibouti
Language: English (Spanish)
Genre: Travel
Published (Last): 12 January 2007
Pages: 31
PDF File Size: 20.68 Mb
ePub File Size: 16.60 Mb
ISBN: 171-4-44067-458-5
Downloads: 17522
Price: Free* [*Free Regsitration Required]
Uploader: Dirisar

In railway applications, it is common to power the trains at 25 kV AC. Neglecting voltage avvantages in the windings. Ordinary Two Winding Transformer. Figure 1 shows the schematic representation of buck connection while figure 2 shows the boost connection. Asa result, an autotransformer is much smaller than a conventional transformer of the same rating.

The current ratings of the windings are given by. In fact, a part of the single continuous winding is common to both primary and secondary. Retrieved from ” https: It consists of a winding of ends A and D, which has been made a derivation in the intermediate point B.

In audio applications, tapped autotransformers are used to adapt speakers to constant-voltage audio distribution systems, and for impedance matching such as between a low-impedance microphone and a high-impedance amplifier input. Autotransformers can be used as a method of soft starting induction motors. Also, a break in the part of the winding that is used as both primary and secondary will result in the transformer acting as an inductor in series with the load which under light load conditions may result in near full input voltage being applied to the output.

The operating principle is the same as that of the common transformer, so the transformation ratio between voltages and currents advantgaes the number returned is maintained.

At full or rated load, the primary and secondary terminal currents are. If an alternating voltage is applied between points C and D, and the output voltage is measured between points A and B, the autotransformer is said autotansformer be a voltage booster.


Autotransformer Advantages and Disadvantages – LORECENTRAL

The primary voltage is applied across two of the terminals, and the secondary voltage taken from two terminals, almost always having one terminal in common with the primary voltage. The manual type is applicable only autotrasnformer relatively low disadvanatges and is known as a variable AC transformer often referred to by the trademark name Variac.

In an autotransformer part of the current flows directly from the input to the output, and only part is transferred inductively, allowing a smaller, lighter, cheaper core to be used as well as requiring only a single winding. Because it requires both fewer windings and a smaller core, an autotransformer for power applications is typically lighter and less costly than a autotransforme transformer, up to a voltage ratio of about 3: Because the primary and secondary windings of the autotransformer are physically connected, the supply and output voltage are not insulated from each other.

As in a two-winding transformer, the ratio of secondary to primary voltages is equal to the ratio of the number of turns of the winding they connect to. Dlsadvantages 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.

For connections between the two systems at very high voltage, where advantsges 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. Now, from the above figure B shown of the auto transformer, the weight of copper required in an auto transformer is.

Autotransformer: Working, Advantages, Disadvantages | Electrical Academia

On load condition, a part of the load current is obtained directly from the supply and the remaining part is obtained by transformer action. Improving your life knowledge health and family. These are often used in repair shops for testing devices under different voltages or to simulate abnormal line voltages. You can find new Free Android Games and apps. Auto Transformer also recognized as an auto step down transformer which is similar to any regular transformer but the only difference is that it shares only one winding for transmitting the power.


The autotransformer has a single winding on an iron core. This means that a greater amount of power can be transferred without exceeding the current rating of the windings of the transformer.

Circuit Globe All about Electrical augotransformer Electronics. One end of the winding is usually connected in common to both the voltage source and the electrical load. 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. 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.


Therefore, the resulting current flowing through section BC is I 2 — I 1. The voltage can be smoothly varied between turns as the brush has a relatively high resistance compared with a metal contact and the actual output voltage is a function of the relative area of brush in contact with adjacent windings. The apparent power transformed by conduction is. Equation 4 may also be written as. Electrical Transformers and Power Equipment. Since part of the winding does “double duty”, zutotransformer have the advantages of often being smaller, lighter, and cheaper than typical dual-winding transformers, but the disadvantage of not providing electrical isolation between primary and secondary circuits.

By using this site, you agree to axvantages Terms of Use and Privacy Policy.

Advantages and disadvantages of the autotransformer

Did you find apk for android? An A uto Transformer is a transformer with only one winding wound on a laminated core. Hence, saving in copper increases as the transformation ratio approaches to unity. A special form of autotransformer called a zig zag is used to provide grounding on three-phase systems that otherwise have no connection to ground. Views Read Edit View history.