Double-Winding Transformer
Transformers with high capacity maybe sometimes have three windings (In particular cases more, for e.g. split winding transformer). Each phase of three-winding transformer has three windings. When one winding is connected to alternating current power supply, the other two windings induct different electric potential. This kind of transformer is used in load needing two different voltage classes and compared to using two common transformers, it is economic , space saving and easy to maintain and manage.
High-low pressure winding of double-winding transformer is winded separately. High-low pressure of each phase is installed to the same iron core pillar but is insulted between each other. Electric power transmittion is achieved by electromagnetic induction between two windings.