The definition of a berry type transformer is such that it is basically a shell type or distributed core type transformer. The name of the transformer is related to it’s design and its cylindrical shape.
Berry Type Transformer Construction:
The construction is like the spokes of a wheel as the magnetic core looks the same as spokes of a wheel. Magnetic cores are build in the shape of a rectangle. The number of magnetic path in berry type transformer are more than 2 which are independent i.e. It has the distributed magnetic paths. The following image shows the multiple magnetic cores and the cylindrical winding’s HV and LV as shown below:
For housing the transformer, the entire structure of the transformer is immersed in the oil. Tightly fitted metal sheets for tanks are used.The metal tanks are constructed of specific high quality steel plate structures which are cut and welded into the solid structure.The transformer is then filled with the transformer oil for insulation. Special care is taken to avoid any leaks. Tanks are sealed to be air tight so that there will be no moisture.
The Transformer oil serves the following function:
- It keeps the transformer cool by circulation of the oil.
- It provides the transformers with additional insulation.
- It avoids rusting in the transformer.
The oil should have to be free of any moisture, alkalies and sulphur.