Autotransformers By C.g.l.

We offer a wide range of products for single phase as well as three phase transformers considering transport limitations in some countries and also as per customer requirements.

Autotransformers are frequently used in power applications to interconnect systems operating at different voltage classes, for example 400 kV to 220 kV for transmission. They are also often used for providing conversions between the two common domestic main voltage bands in the world (400, 200, 66 kV). The links between the UK 400 kV and 275 kV `SuperGrid` networks are normally three-phase autotransformers with taps at the common neutral end. Autotransformers are built with common main winding and a separate low voltage winding.

Auto transformers are tailor-made products and the design varies with the impedance levels (constant Ohmic and constant percentage), transmission voltage and cooling requirements. These are normally provided with on load tap changer for voltage variation. For long distance rural power distribution lines, special autotransformers with automatic tap-changing equipment are inserted as voltage regulators, so that customers at the far end of the line receive the same average voltage as those closer to the source. The variable ratio of the autotransformer compensates for the voltage drop along the line.