The working principle of a dry-type transformer is based on the fundamental principles of electromagnetic induction. When an alternating current (AC) flows through the primary winding of the transformer, it creates a changing magnetic field in the core. This changing magnetic field induces a voltage in the secondary winding through electromagnetic induction, transferring electrical energy from the primary to the secondary circuit.

The core of the transformer, typically made of high-grade silicon steel laminations, helps to efficiently transfer the magnetic flux generated by the primary winding to the secondary winding. The windings, usually made of copper or aluminum conductors, carry the alternating current and facilitate the transfer of electrical energy.

The insulation system, often composed of epoxy resin or cast resin, provides electrical insulation and protection for the windings, ensuring safe operation. The enclosure houses all the components and provides mechanical support and protection from external elements.