Distribution Transformer

Distribution Transformer

Distribution Transformer an Electrical. This Transformer is Convert high voltage electricity to lower voltage. Difference types Distribution Transformer of :-

1. Single Phase

2. Three Phase

3. Pad mounted

A distribution transformer is a transformer that provides the final voltage transformation in the electric power distribution system, stepping down the voltage used in the distribution lines to the level used by the customer. The invention of a practical efficient transformer made AC power distribution in a system using distribution transformers was demonstrated as early.

If mounted on a utility pole, they are called pole-mount transformers. If the distribution lines are located at ground level or underground, distribution transformers are mounted on concrete pads and locked in steel cases, thus known as distribution tap pad mount transformer.

Distribution transformers normally have ratings less than 200 KVA, although some national standards can allow for units up to 5000 kVA to be described as distribution transformers. Since distribution transformers are energized for 24 hours a day, reducing iron losses has an important role in their design. As they usually don't operate at full load, they are designed to have maximum efficiency at lower loads. To have a better efficiency voltage regulation in these transformers should be kept to a minimum. They are designed to have small leakage reactance.

Its Uses

Distribution transformers are normally located at a service drop, where wires run from a utility pole or underground power lines to a customer's premises. They are often used for the power supply of facilities outside settlements, such as isolated houses, farmyards or pumping stations at voltages below 30 kV. Another application is the power supply of the overhead wire of railways electrified with AC. In this case single phase distribution transformers are used.

The number of customers fed by a single distribution transformer varies depending on the number of customers in an area. Several homes may be fed from a single transformer in urban areas. Rural distribution may require one transformer per customer, depending on mains voltage. A large commercial or industrial complex will have multiple distribution transformers. In urban areas and neighborhoods where the primary distribution lines run underground, padmount transformer transformers in locked metal enclosures mounted on a concreted pad, are used. Many large buildings have electric service provided at primary distribution voltage. These buildings have customer-owned transformers in the basement for step-down purposes.

Distribution transformers are also found in the power collector networks of wind farms where they step up power from each wind turbine to connect to a substation that may be several miles kilometres distance.

Smaller core size could mean higher flux density. This can cause core temperatures to be higher, stressing the inter-laminar insulation.