What is the difference between dry type and oil type transformer?

Dry-type transformer vs. oil-filled transformer is the most common debate in the market today. If you, too, are confused about whether to go for dry-type transformers or oil-filled transformers, then read this article till the end!

 

This post is the ultimate guide for people confused about how they differ from each other.

 

 

Transformers are becoming increasingly popular for altering the voltage in conventional power circuits. Whether you want to reduce the voltage to operate low-powered devices or raise the voltage to allow for long-distance electric power transmission, transformers are the way to go!

There are two types of transformers: dry-type transformers and oil-filled transformers. Even though they have the same objective, these transformers differ significantly. These distinctions are significant enough that the different transformer types are better suited to specific applications.

 

This article highlights the differences between dry-type transformers and oil-filled transformers. You will distinguish between their cost, maintenance, noise, energy efficiency, etc. So, let's get started, shall we!

 

 

An electrical transformer is a static electromagnetic equipment used in electrical power systems to change the value of voltage and current.

A typical electrical transformer consists of three major parts namely, a magnetic core, a primary winding, and a secondary winding.

 

The magnetic core is a piece of laminated silicon steel that provides a low reluctance path for the flow of magnetic field between primary and secondary windings.

 

The primary winding is made up of copper wires and takes input supply from the source. While, the secondary winding is also made up of copper wires and supplies the transformed electricity to the electrical load.

 

The primary function of the electrical transformer is to increase or decrease the supply voltage and current in an electrical circuit.

 

Types of Transformers

Depending on the insulating material used, the electrical transformers can be classified into the following two types

• Dry-Type Transformer
• Oil-Filled Transformer

 

 

A type of electrical transformer in which a solid insulating material is used for providing insulation between conducting components like windings, core, etc. is called a dry-type transformer.

 

In most practical dry-type transformers, epoxy resin or polyester resin is used as the insulating material. Thus, these transformers are also known as cast resin transformer or epoxy resin transformer.

 

These solid insulating materials have good thermal stability and dielectric strength. Also, these materials have non-flammable and self-extinguishing capabilities. Hence, these transformers are relatively safer from the fire safety point of view.

 

The dry-type transformers are mainly used in medium voltage applications where oil-filled transformers cannot be used. Some common examples of applications of dry-type transformers include indoor substations, commercial buildings, underground substations, etc.

 

 

A type of electrical transformer in which the core and the winding assembly is immersed in a dielectric oil to provide insulation and cooling capabilities is called an oil-filled transformer. It is also known as an oil-immersed transformer.

 

The oil-filled transformer consists of a steel tank which is filled with transformer oil and encloses the internal parts of the transformer.

When an oil-filled transformer is in operation, a significant amount of heat is generated due to losses in the transformer windings and the core. Since, the transformer is immersed in the oil, the heat is transferred to the oil and hence to the external environment.

 

The oil-filled transformers are commonly used in generating stations, distribution systems, transmission systems, outdoor substations, etc.

This is all about electrical transformer, dry-type transformer, oil-filled transformer. Let us now understand the differences between dry-type and oil-filled transformers using a comparison table.

 

 

Comparing the two transformer versions, we can gain a deeper insight into their many differences. This information is valuable when choosing between the two options, especially if the application suits either type.

 

Cooling Efficiency

The cooling efficiency of oil is higher than that of air. Liquid-immersed transformers that also use air to cool are even more efficient, running at a lower temperature and allowing higher currents in the windings without causing damage.

 

Load Capacity

Because their cooling is more effective, manufacturers can design liquid-filled transformers to convert higher voltages than the air-cooled types, typically above 2500kV, making them suitable for high-power systems involving electricity production and supply.

 

Safety and Environmental Impact

Air will not catch fire or explode. Oil can. That makes the dry transformer a safer option. An air-cooled unit also pollutes the environment less, save for its higher noise levels.

The liquid type can easily catch fire, especially if the oil has flammability properties. It can also leak and cause contamination if users do not observe proper care and maintenance.

 

Maintenance Requirements

Transformer oil requires regular checking for reduced levels, testing for quality and contamination, and scheduled changes and disposal. These requirements make liquid-cooled units more demanding to care for. The air-cooled type is less costly to keep in good condition, requiring fewer checks, inspections, or other maintenance.

 

Longevity

Because they operate more efficiently, liquid-cooled transformers last longer. Another reason for their longer lifespan is the oil's insulation, which prevents electrical damage due to faults. It also lubricates parts and prevents corrosion, which makes them last longer.

 

Price Comparison

Upfront, you will pay more for a dry transformer than a liquid-cooled type. However, its operating costs are lower since it requires less maintenance. This property makes it a more economical option in the long run. The liquid-filled type costs less upfront, but its maintenance expenses are higher.

 

Application Difference

With their many differences, the two transformers fit different applications. For instance, high-voltage electrical systems require more effective cooling. On the other hand, oil transformers, owing to their reduced safety and spillage risks, do not suit some applications, such as indoor environments.

 

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Final Wordings

 

Based on our dry-type transformer vs. oil-filled transformer analysis, oil-filled transformers appear to be a better alternative in terms of energy-saving, cost-saving, and recyclability. Dry-type transformers, on the other hand, are safer for interior operations.

 

Whether you're looking for an oil-filled or dry-type transformer, you should always deal with a trusted provider that offers the finest items on the market GNEE dry-type transformers, and oil-filled transformers are the finest choice in this case. With GNEE, you are sure to receive top-quality equipment at reasonable rates!