What is a Berry Type Transformer?
A transformer with a core that looks like a spoke of the wheel is known as a berry type transformer (or “berry transformer” for short). According to the type of core, transformers can be classified into three types;
- Core type transformer
- Shell type transformer
- Berry type transformer
Sometimes, a berry type transformer is also considered a shell type transformer. But due to different core designs and shapes, it is named a berry type transformer.
It has distributed magnetic circuit with more than two magnetic flux paths. Due to a more significant number of paths, it creates more leakage flux. And hence, the efficiency of this transformer is less compared to the core type and shell-type transformer.
Generally, the berry type transformer is kept in tightly fitted metal tanks. These tanks are manufactured from specific high-quality steel plates and make a rigid structure.
The tanks are filled with transformer oil. It is used for insulation purposes. Hence, it is also known as insulation oil. All assembly of transformer is immersed in transformer oil.
The transformer oil is circulating inside the tank. Therefore, it helps to keep the coils cool. Also, transformer oil is a good insulator and provides additional insulation.
Why is a Berry Type Transformer Used?
In berry type transformer, the flux has many paths available, and it has a separate core to complete the magnetic circuit. In most cases, this type of transformer is only used to build high-capacity transformers.
Due to the unique construction of the core, the heat produced in the winding is distributed. So, in this type of transformer, the coils remain cooler than a core and shell-type transformer.
Hence, this type of transformer is used to build a large capacity of a transformer. For a small rating of transformer, this type of construction is not used.
Berry Type Transformer Diagram
The core of a berry type transformer looks like spokes of wheels. The core of this transformer is constructed in such a way that the magnetic circuit finds a number of paths to pass flux.
HV and LV windings are wound on the core, as shown in the figure below.