Parts of Power Transformer and Their Function | New Topic

In this note, we are going to learn about the main parts of power transformer and their function. Welcome to Poly Notes Hub, a leading destination for engineering notes.

Author Name: Arun Paul.

What is Power Transformer?

A power transformer is a static electrical device that transfers electrical energy between two or more circuits via electromagnetic induction. It is generally used in transmission networks to increase (or decrease) voltage levels between the generator and the distribution system. Power transformers, which operate at high voltage levels, are frequently used in substations and power plants.

They include primary and secondary windings, a magnetic core, insulating fluid, cooling systems, and other safety and monitoring mechanisms. Power transformers, unlike distribution transformers, are built to withstand extremely high voltages (over 33kV) and significant power loads.

Applications of Power Transformer

• Used in power generation plants.
• Used in electrical transmission substations.
• Used in distribution network and industrial plants.
• Used in HVDC (High Voltage Direct Current) Stations.
• Also used in data centers, railway stations, parts, buildings etc.

Parts of Power Transformer and Their Function

Here we have listed the main parts of the power transformer and their function –

• High Voltage Bushing: This is the point where high voltage current enters the transformer. It insulates and safely conducts high voltage between the transformer windings and the external circuit.
• Low Voltage Bushing: This is the terminal where low-voltage current leaves or enters the transformer. It provides insulation as well as a route for low voltage electrical flow, similar to the high voltage bushing.
• Rating Plate: The rating plate contains crucial information about the transformer, such as capacity (kVA or MVA), voltage ratings, frequency, cooling method, and manufacturer details.
• Main Tank: The main tank holds the transformer’s core and windings. It is filled with insulating oil, which provides both cooling and insulation. The tank guarantees the integrity and endurance of interior components.
• Drain Off Valve: This valve drains the insulating oil for maintenance or inspection. Proper oil management is critical to the transformer’s optimal operation.
• Cooling Tubes: Cooling tubes improve the available surface area for heat dissipation. As the transformer works, the oil heats up. These tubes help to keep the oil at an ideal temperature.
• Oil Tank (Conservator Tank): The oil tank, located above the main tank, allows the insulating oil to expand and contract in response to temperature changes. It regulates the oil level and avoids overflow.
• Tank Gauge: This gauge shows the level of oil in the conservator tank. Monitoring the oil level is critical for ensuring safe operation and early detection of any problems.
• Buchholz Relay: This is a gas-actuated relay used to detect internal faults. It detects gas buildup and sends out alarms or shuts down when a fault occurs.

Advantages of Power Transformer

Here we have listed some power transformer advantages –

• It is efficient to power transfer in long distance.
• It is improve voltage regulation as well.
• It does not have any moving parts. So, it is reliable and has low maintenance cost.
• Power transformers offer high efficiency (up to 98–99%).
• They offer electrical isolation between various areas of the grid.