Based on the type of cooling used, transformers are classified into two types; one is liquid-filled and the other one is dry type transformer.
Dry type power transformers construction basically uses high-temperature insulation that exceeds the ratings of cellulose. But now day’s modern conventional dry transformers feature insulation systems comprising carefully coordinated high-temperature (220’C) materials that are coated with a high-temperature, moisture-resistant polyester sealant. Dry type transformer’s performance under overload is demonstrably limited but by adding cooling fans can literally help in augmenting this.
These transformers find their applications in diverse commercial and industrial environments for decades. Some of the units can be exceptionally economical choice in medium voltage distribution in terms of cost. Applications where low flammability is a vital consideration, a special type of dry type transformer is designed known as gas-filled transformer dry type. N2, C2F6, and SF6 gases are the ones used in these designs, providing a dielectric medium that is external to the windings. These units are larger in size as compared to oil-filled transformers. They are commonly installed in dry-docks to provide local power for ship building. Because of reduced fire risks, some of the transformers are being successfully used successfully in special applications where the public are in close proximity, such as underground tunnels, residential apartments, oil rigs and more.
Vacuum pressure encapsulated dry type transformers are designed to meet the needs in military shipboard. These transformers typically find their applications in very harsh indoor and outdoor environments. They are highly resistant to humid and caustic environments. These transformers employ a resin made of silicone which is very thick.
farady power transformer 