The basic work of a transformer is to improve the safety and efficiency of power systems by raising and lowering voltage levels as and when needed. As by nature, every transformer is a distribution transformer. Some transformers are used to transfer electricity to residential and industrial areas so, they are located in the colonies, offices etc whereas some are used to transfer electricity generated in the power plants to the transformers located at substations.
Electrical distribution transformers being one of its kinds are machines that transfer electricity from one circuit to another with changing voltage level but no frequency change. With the advancement in the latest technology, today they are designed using AC supply, which means that fluctuation in supply voltage is impacted by the fluctuation in the current. The electrical transformer is a solid-static device which does not employ any moving parts to transfer energy which reduces the risk of friction and hence no windage losses happens. It works on the Faraday’s electromagnetic induction law which states that “Rate of change of flux linkage with respect to time is directly proportional to the induced EMF in a conductor or coil”.
Also, its physical basis lies in the mutual induction between two circuits that are linked by a common magnetic flux. It is usually equipped with two windings primary and secondary which shares a magnetic core that is laminated, and the mutual induction that takes place between these circuits helps transfer electricity from one point to another. There will be different rates of change in flux linkage depending on its amount.
Types of an electrical distribution transformer
- Core Type Transformer
These types of transformer consist of two horizontal sections along with two vertical limbs, a rectangular core and a magnetic circuit. Then cylindrical coils (HV and LV) are placed on the central limb of it.
- Shell Type Transformer
It comprises of a double magnetic circuit and a central limb with two outer limbs.
- Single Phase Transformer
A single phase transformer has only one set of windings. However, separate single-phase units can offer the same results as three-phase transfers when they are externally interconnected.
- Three Phase Transformer
Mainly used for generation, transmission and distribution of power a triple-phase transformer has three sets of primary and secondary windings to form a bank of three single-phase transformers.
- Step Up Transformer
This type is determined by the number of turns of wire. So, if the second set has a greater number of turns than the primary side, it means that the voltage will correspond to that, which forms the base of a step-up transformer.
- Step Down Transformer
As the name suggests these kinds of transformer steps down the level of voltage in the power transmission and distribution network.
- Power transformer
Use to transmit electricity and has high ratings.
- Distribution transformer
It has a comparatively lower rating and is used to distribute electricity.
- Oil cooled distribution transformer
It is designed to cool itself by the surrounding airflow and is employed in small transformers of up to 3 MVA.
- Water-Cooled Oil-Filled Transformer
In order to transfer the heat generated in the oil to the cooling water, these kinds of transformers make use of heat exchangers.
- Air-Cooled (Air Blast) Transformer
These transformers consist of blowers and fans to cool down the heat which is been generated.
How is an electrical distribution transformer helpful?
4 benefits of using electrical distribution transformer
1. Raises or lowers down the voltage level in the circuit of an AC.
2. Increases or decreases the value of a capacitor in an Ac circuit.
3. Isolates two electric circuits.
4. Steps up the voltage level at the site of power generation before the transmission and distribution take place.