There are many different types of transformers used in different systems and equipment. One of the most commonly used is an autotransformer. An autotransformer is like any other type of electrical transformer, but it only has one winding and not two. It is possible to use a single phase autotransformer, but there is also the option to use a three phase autotransformer as well.
It is common for people to hear the term autotransformer and assume the “auto” indicates some type of automation or control. Instead, the “auto” is the clear indication of the design using one winding which acts as both the primary as well as the secondary aspects of the transformer.
Practical Considerations
In many different systems, and to provide a consistent output, it may be important to link three autotransformers together. This can be a bulky configuration and to save space, as well as to create a more compact element, a 3 phase autotransformer can be used.
The 3 phase autotransformer can be used to step up or step down the power, which is essential for many different systems. It is important to keep in mind that these types of transformers, due to the single winding, do not provide isolation. To create isolation between the primary and secondary windings, a standard type of transformer, also known as an isolation transformer, must be selected.
The 3 phase autotransformer offers high levels of efficiency. With the more compact design, it is also less costly to manufacture, which means a lower overall cost for the equipment manufacturer.
While there are limitations to this type of autotransformer, this is no different from other types of electronic components. When in doubt, be sure to talk directly to the manufacturer to ensure the custom design and the three phase autotransformer is the right match for the specific application.