Cylindrical Winding of Transformer and Types of Transformer Winding

Q. Draw neat sketches and discuss the special features of following windings used for 3 phase transformer : Cylindrical winding, Helical winding, Crossover winding, Disc winding. List the typical voltage and current ranges over which they are used.

• Different type of windings are used depending upon voltage, current and capacity of transformer.
• Transformers with core type construction uses concentric type of windings. Both primary and secondary winding coils are wound on the limb concentrically. Generally LV winding is placed near the core (Due to less insulation requirement).
• Depending upon voltage, current, temperature rise, short circuit strength following types of windings are used for core type of transformer :

Types of Transformer Winding
      1. Cylindrical winding of Transformer

• Use These windings are used normally for low voltage winding. Rectangular conductors are used in cylindrical winding for the LV winding upto 6.6 KV of upto 750 KVA rating, while circular conductors are used in the cylindrical winding for HV winding upto 33 KV and upto 1000 KVA rating.

• Conductors are wound with either on longer side or on shorter side. Also depending upon current rating either single rectangular conductor or parallel conductors are used.

      2. Helical winding of Transformer
      3. Double helical winding of Transformer
      4. Multilayer helical winding of Transformer
      5. Cross over winding of Transformer
      6. Disc and continuous disc winding of Transformer