Dry Type Transformer
ZELECT：Your Professional Dry Type Transformer manufacturer!
Baoding Zhongyi Electric Corporation. Here in short referred to as "ZELECT", located in Baoding city, Hebei province, China. Founded in 2008, our company is one of the "high-tech enterprises", which produce and sell power transformer, high and low voltage switch-gear and prefabricated substations.
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24H Online Service
Your inquiry will be replied within 24 hours.We also provide customized service and the perfect power solution to meet your requirements.
advanced equipment
We have many very advanced and complete production equipment to ensure the excellent quality of our products
professional team
There are currently 260 employees, including 18 technicians who have been engaged in the research and development of transformer products for many years, and 8 high-quality corporate managers.
global shipping
Our sales network is divided to five main regions: America, Southeast Asia, West&South Asia, Europe&Africa, Russian Market.
To begin with, a dry type transformer, also known as cast resin type transformer is solid. Meaning it doesn't have any rotating parts. Because of this, these types of transformers maximize the use of eco-friendly temperature insulation systems to function properly.
Unlike the liquid-type transformers that are dependent on other materials such as oil and fire to function, a dry transformer works through voltage changing. So, when dealing with these types of transformers it’s the air that gets cooled and not the liquid as with other types. You simply have to place the dry transformer in a well-ventilated room for the coils to cool with ease.
When using a dry type of transformer, you don't have to keep it inside fire-resistant vaults or catch basins as you would do with conventional liquid transformers. Also, they do not release any harmful gases, hence environmentally friendly, even for indoor installation.
Advantages of Dry Type Transformer
High Security
Dry transformers use dry edge materials, unlike oil-immersed transformers, it does not require oil cooling, so there is no oil leakage and oil contamination. This oil-free design not only greatly improves the safety of the equipment, but also reduces the pollution to the environment and makes it more environmentally friendly.
Low Maintenance Cost
Because dry-type transformers do not require refueling, their maintenance costs are greatly reduced. Because the insulation material of the dry transformer is not easy to age, its life is longer than that of the oil-immersed transformer, which also saves the cost of maintenance and replacement of the equipment for the user.
Wide Range of Application
The dry transformer is small in size and light in weight, and is suitable for various occasions. For example, it can be used in basements, high-rise buildings, ships and other places where space is limited. Dry transformers can also be used in explosion-proof sites and strong electromagnetic interference environments.
What are the Types of Dry Type Transformers?
There are two main types of dry type transformers: cast resin dry type transformer (CRT) and vacuum pressure impregnated transformer (VPI).
Cast Resin Dry Type Transformer (CRT)
A cast resin dry type transformer (CRT) is a type of transformer that uses epoxy resin to encapsulate its primary and secondary winding. This protects the winding from moisture, dust, corrosion, and other environmental factors that can affect their insulation and performance.
A CRT is suitable for high humidity areas, indoor installations, and fire-risk areas because it is non-hygroscopic, non-inflammable, and maintenance-free. It can also withstand overloads, partial discharges, and low losses, resulting in high efficiency and long service life.
A CRT is available in ratings from 25 kVA to 12,500 kVA, with insulation class of F (90°C temperature rise).
Vacuum Pressure Impregnated Transformer (VPI)
A vacuum pressure impregnated transformer (VPI) is a type of transformer that uses class H polyester resin to impregnate its winding under vacuum and pressure. This eliminates any air gaps or voids in the insulation, enhancing its mechanical strength, dielectric strength, and thermal stability.
A VPI is suitable for outdoor installations, seismic events, and temperature fluctuations because it has a robust construction, a moisture-resistant enclosure, and a low thermal expansion coefficient. It also has easy maintenance, low fire risk, and high resistance to short circuit currents.
A VPI is available in ratings from 5 kVA to 30 MVA, with insulation class of F (155°C) or H (180°C), and protection up to IP56.
Application of Dry Type Transformers in Other Fields
In addition to its application in power systems, epoxy resin cast dry encapsulated transformers are also widely used in industry, construction, transportation and other fields.
In the industrial field, dry transformers can be used for the production of electroplating, welding, calcium carbide, etc., to improve production efficiency and product quality.
In the field of construction, dry transformers can be used to supply power to shopping malls, hospitals, hotels and other buildings to meet a large amount of electricity demand.
In the field of transportation, dry transformers can be used for power supply of railways, subways, airports and other places to improve the safety and stability of transportation facilities.
Important Factors to Design a Dry Type Transformers
The important design parameters for a dry-type transformer are given below.
Choice of Insulation Type
The insulation classes F and H have temperature withstand capacities of 155˚C and 180˚C respectively, and generally, F and H classes of insulation are used to insulate the primary and secondary winding. The other factors like mechanical strength, thermal shock, and dielectric strength of insulation must be considered while designing the dry-type transformer.
Selection of Winding Material
Copper and aluminum are used used to make the winding or coil. Even though copper is a better conductor, the aluminum conductor wound transformer has lower cost and weight. The transformer winding with a copper conductor has less cross-section area for the same current rating as compared to the aluminum conductor. The copper coils also provide more mechanical strength compared to the aluminum coil.
Selection of Core Material of Low Hysteresis Loss
The core of the transformer must have high permeability and less hysteresis loss in order to have better efficiency. The CRGO steel is used for the core material. The CRGO steel offers higher permeability and minimum hysteresis loss.
Regulation
The leakage reactance of the transformer must be as minimum as possible to get better voltage regulation of the transformer. The regulation of the transformer shows drops in the secondary voltage with an increase in loading on the transformer. The leakage reactance is generally kept within 2 % during transformer design.
Life Expectancy
The life of the transformer depends upon the useful life of the insulation. The life of the insulation is dependent on the temperature. The rise in temperature cause deterioration in the insulation value which may further cause the breakdown of the insulation. Insulation class B, F, and H is preferred for the dry-type transformer to withstand higher temperature. The temperature rise must be calculated during the design stage of the transformer to get a higher life expectancy of the transformer.
Losses
The no-load losses of the transformer depend on the eddy current and hysteresis loss. The no-load losses can be minimized by the use of the CRGO core and by keeping the leakage reactance as minimum as possible. The load losses depend on the resistance of the conductor. Thus, by keeping the winding resistance within moderate value losses, voltage regulation and the efficiency of the transformer can be improved.
Overloading
If the load on the transformer increases above its rated kVA, the transformer is said to be overloaded. The overloading cause rise in the temperature of the transformer which reduces the useful life of the transformer. The cooling system should be designed to cater to the temporary overloading of the transformer
K-factor
If the dry type transformer is to be used for supplying the current to non-linear loads the temperature rise takes place due to harmonics in the current waveform. The transformer for such applications must be assigned K-factor.
Insulation Level
In transformer design, insulation level adjustment is an important factor. Generally, insulation level is chosen as per basic impulse level and system over-voltage. A strong insulation level increases the life of a transformer.
In order to extend life and best performance, it is strongly recommended that you carry out regular maintenance activities of dry transformers.
The following transformer checklist covers an important checkpoint for daily maintenance of dry transformers; however, be sure to check the maintenance guide for specific products to ensure that there are no detailed information that is not specific to your specific transformer. The frequency of regular transformer maintenance inspection will change according to the operating environment and the type of load applyted.
A. Check The Accumulation of Dust
1. Visually check whether the shutters, filters, and internal coil cooling pipes have dust accumulation. If you find it, wait until the transformer is powered off and then remove all panels
2. After power off, suck the dust as much as possible
3. Clean the transformer with a rag with brush or hair. Avoid using cleaning agents or cleaning products, because they may accumulate dust and accelerate the aging of the transformer
4. In a difficult area, blow dry air into the equipment
Over time, the accumulation of dust and debris may cause problems with dry transformers, resulting in short -circuit and overheating electrons.
B. When The Transformer Is Powered On
1. Verify whether ventilation is normal
2. Monitor the transformer can listen to any change in sound characteristics
C. When The Transformer Breaks The Electricity
1. Make sure that all the hardware that can be triggered is tightened
2. Clean cooling fan
3. Check whether there are any signs of discoloration or heat damage on the insulation surface
4. Monitor the isolation damper signs of deterioration
Although the charging transformer is monitored according to the instructions, the maintenance of the dry transformer is mainly composed of subjective observation. No matter how long you maintain the device, the problem may appear at any time. Be sure to pay attention to the appearance and operation of the dry transformer. If you find any abnormalities, be sure to deal with the problem immediately to avoid damage.
When Purchasing The Dry Type Transformer, The Following Factors Should Be Taken Into Consideration:
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1. Type of Load: The type of load the transformer will be supplying power to should be taken into account. This will determine the appropriate rating and specification requirements of the transformer.
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2. Input and Output Voltage: Ensure that the input and output voltage requirements of the transformer are properly matched with the power system requirements.
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3. Dimensions and Weight: The dimensions and weight of the transformer should be taken into account to ensure that it will fit within the allocated space and be easy to transport.
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4. Safety Features: Ensure that the transformer comes with the necessary safety features, such as overload protection, short circuit protection, and over-temperature protection.
Our Factory
Our factory covers an area of 33,300 square meters, with a total construction area of 6,100 square meters. There are currently 260 employees, including 18 technicians who have been engaged in the research and development of transformer products for many years, and 8 high-quality corporate managers. With the expansion of production scale and the increase of product varieties, it has now developed into a high-tech innovative enterprise that annual production capacity of more than 1000MVA, integrating the design, production and sales of open-type dry-type transformers, epoxy resin cast dry-type transformers, amorphous alloy transformers, and special transformers.
Our Certificate
Our company has passed the ISO9001-2008 international standard quality management system certification. All performance indicators of the products have reached the relevant national standards and international standards.
The oil immersed power transformers and dry-type transformers have passed the Test Report of the National Supervision and Inspection Center for Energy-saving Product Quality; Complete sets of low voltage switch-gear (GGD2) (GCK) has passed the test of China Compulsion Certification (CCC) from the State Bureau of Quality and Technical Supervision for Electrical Products; Indoor AC draw-out type metal clad switch-gear KYN28A-12 / 1250-31.5, fixed AC metal-enclosed Ring unit XGN15-12 / 1250-31.5 and XGN15 metal-enclosed switch-gears have passed the test of the National Quality Supervision and Inspection center for High-voltage Electrical Appliances Product.
FAQ
Q: What is the difference between dry type and oil type transformer?
Q: How do you test a dry-type transformer?
Q: What is DGPT in a transformer?
Q: What are the main parts of a dry type transformer?
Q: What is the inside of a dry type transformer?
Q: What is the main features of dry transformer?
Q: What is a 3 phase dry type transformer?
Q: Why is it called a dry type transformer?
Q: How many types of dry type transformer are there?
Q: How do you test a dry type transformer?
Q: What is the average life of a dry type transformer?
Q: Do dry transformers require air circulation?
Q: What is the maximum operating temperature of a dry-type transformer?
Q: Can you provide drawings and technical data?
Q: Have your products been exported?
Q: Can the products be manufactured by customer's requirement?
Q: Vi-sting factory is allowed or not?
Q: Do you looking for Agent?
Q: How to solve the equipment trouble during using ?
Q: Can dry type transformers be installed without an enclosure?
We're known as one of the most professional dry type transformer manufacturers and suppliers in China. Please rest assured to buy high quality dry type transformer for sale here from our factory. Good service and competitive price are available.
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