Master the basic knowledge: Understand dry type transformers

Time：2024-10-15    Auther：ZTelec-www.ztelectransformer.com

What is a dry type transformer?

A dry type transformer is an electrical device that is used in AC power distribution systems to safely “step up” or “step down” voltages to meet the incoming power requirements of connected equipment. Dry type transformers achieve this goal without modifying the frequency or amount of electrical power to help ensure connected devices can operate reliably.

Dry type transformers are static devices, meaning they contain no continuously moving mechanical parts. This contributes to their long lifecycle and minimal maintenance requirements. They can range in size from enormous devices that weighs several tons, commonly used in power substations, to very small devices that weigh only a few ounces and are commonly found in compact electrical equipment.

Thanks to their design flexibility and critical role in the electrical system, transformers are used in nearly every power distribution system application including commercial buildings, schools, healthcare & institutions, water/wastewater, industrial, oil & gas and data centers.

How does a dry type transformer work?

The working principle of dry transformer is to realize voltage transformation through electromagnetic induction. When the input current passes through the main winding, the resulting magnetic field passes through the core and is induced to the secondary winding. Because the number of turns of the primary and secondary winding is different, according to the law of electromagnetic induction, the secondary winding will produce a different voltage than the main winding. In this way, the input voltage to the output voltage transformation is realized.

Classification of dry type transformers

The classification of dry type transformers is based on their use, structure and working principle.

First of all, according to the use, dry type transformers can be divided into distribution transformers and special transformers. Distribution transformers are mainly used in urban and rural distribution systems to convert high-voltage electrical energy into low-voltage electrical energy for household, commercial and industrial facilities. Specialized transformers are designed for specific needs, such as power electronics, frequency converters, medical equipment, etc.

Secondly, according to the structure, dry type transformers can be divided into open transformers and closed transformers. The coil and iron core of the open transformer are exposed to the air and the ventilation effect is good, and it is suitable for places with small capacity. The closed transformer adopts a sealed structure, the coil and the iron core are filled in the insulation material, which has good insulation performance. It is suitable for places where dust, moisture and fire prevention are required.

Finally, according to the working principle, dry type transformers can be divided into natural ventilation transformers and forced ventilation transformers. Natural ventilation transformers rely on natural convection to dissipate heat without additional ventilation equipment, and are suitable for places where the ambient temperature is below 40 degrees Celsius. The forced ventilation transformer requires the installation of a fan or cooler for heat dissipation, and is suitable for places with high ambient temperatures or large continuous loads.

Advantages of dry type transformers：

1. Self-extinguishing, low fire hazard

A dry type transformer comes with an eco-friendly material on its insulation. So, it comfortably winds in a self-extinguishing manner, is flame retardant, and of course easy to maintain. With it, you won’t have to invest in a fire extinguisher. Plus, even under the influence of arcing, it doesn’t produce toxic gases.

2. Zero Oil Usage

As mentioned earlier, the dry transformer doesn’t need any liquid to cool. It only requires air to remain cool. So, you won’t have to incur extra expenses to get oil, or any other liquid, plus the maintenance costs attached to them. It’s safe to say that this is an almost maintenance free transformer, so you can stay worry-free.

3. Eco-friendly and safe

Since dry transformers don’t use oil or liquids for that matter, you won’t have to deal with oil leaks. Or any other form of environmental pollutants. Plus, they are self-extinguishing meaning they rarely explode. Also, the dry type transformers are widely known to withstand unexpected weather changes, making them suitable for heavily polluted and condensed environments.

4. Low cost installation and lower load losses

Due to their low risk nature, there are barely any restrictions when installing the dry type transformers. You also won’t have to deal with other environmental precautions such as groundwater protection. Also, these transformers can serve you for over 20 years, with low chances of failure.

5. Low Maintenance

We cannot insist on this enough. The dry type transformers are extremely low maintenance. Like you barely have to even maintain them. As long as they have air to cool, you won’t have to deal with built-up dirt. Also, you will never have to deal with liquid testing. However, a routine expert inspection is recommended, and that shouldn’t be too hard.

6. Sustainable

When you use a dry transformer, you are playing a key role in ensuring we save our earthly resources. With it comes low electricity usage, 90% recyclable materials, and a reliable service of 20+ years.

Application of dry type transformer

+Chemical industry, oil and gas

+Environmentally sensitive areas (e.g. water protected areas)
+Fire hazard areas (e.g. forest)

+Inner city substation

+Indoor and underground substations
+Renewable production (e.g. offshore wind turbines)

How to choose the right dry type transformer?

First, choose the right capacity according to your needs. The capacity of a dry type transformer determines the power load it can carry. When selecting the capacity, it is necessary to consider the peak and average power load to ensure that the transformer can meet the power demand. At the same time, it is also necessary to consider the possible load growth in the future, and choose a transformer with a certain margin to prevent overload.

Second, the insulation level of the transformer should be considered. The insulation grade is directly related to the safety and stability of the transformer. Under normal circumstances, the insulation level should match the insulation level of the power system to ensure the normal operation and protection of the power equipment. In addition, it is also necessary to choose the appropriate rated voltage and frequency. Power systems in different regions may have different voltage and frequency standards, so it is necessary to choose dry transformers that meet local standards to ensure the compatibility and stability of power equipment.

Third, the efficiency and energy consumption of the transformer need to be considered. Choosing high-efficiency dry type transformers can reduce energy consumption and reduce energy bills. Therefore, when choosing a transformer, you can refer to its energy efficiency rating and energy efficiency indicators, and select products that meet energy saving requirements.

Fourth, choose reliable manufacturers and suppliers. Dry type transformer is an important power equipment, its quality and reliability are related to the normal operation of power system. Therefore, when choosing a transformer, it is necessary to choose a manufacturer and supplier with a good reputation and high-quality service to ensure the quality of the product and subsequent support.

Ztelectransformer is focusing on manufacturing MV & LV power generation , transmission and distribution equipment , as well as PV equipment including flexible solar panels , energy storage , energy management devices and substations . If you need related products, please leave your contact information, we will contact you immediately.