Dry type transformers are a type of transformer that is commonly used in life. They are not only rich in variety, but also simple in design and construction. You can also choose some other parts according to the actual application. The following words will discuss in detail the fields, advantages, and choices of dry type transformers in daily use. I hope this post may bring you more inspiration.
LTEC Dry Type Transformers
Dry type transformer is a type of transformer that uses air or other gases as the insulation and cooling medium for windings and cores. It is safe, reliable, environmentally friendly, and has a wide range of uses. It can operate normally and smoothly under conditions of high humidity, fire risk, earthquake, etc., and is stable and powerful.
Dry type transformers are safe, reliable, environmentally friendly, and unaffected by the environment, so their scope of use is very wide.
Chemical, oil, and gas industry
Chemical, oil and gas industry-sourced: anchinv
Dry type transformers are often used in various equipment and process power supplies in chemical, oil, and gas industries involving flammable and explosive substances. For example, they are often used in refineries, petrochemical plants, pipelines, and offshore platforms.
Environmentally sensitive areas
Environmentally sensitive areas-sourced: utbtransformers
Dry-type transformers are made of environmentally friendly materials and can be used to protect the environment, prevent oil leaks, and prevent water sources, soil, and other areas. They can be specifically used in various water sources, soil, forests, wetlands, and other protected areas.
Areas with high fire risks
Areas with high fire risks-sourced: transformermfg
Dry type transformers can be used in various areas with strict requirements for fire or firefighting to prevent fire or minimize the impact of fire, including indoor substations, underground substations, hospitals, schools, hotels, shopping centers, or sports centers.
Renewable energy generation
Renewable energy generation-sourced: maddox
Dry type transformers can be connected to other renewable energy sources to form a grid to a load, such as wind turbines, solar panels, hydroelectric power plants, etc., which can help the development and utilization of renewable energy.
Other applications
For example, including traction systems, ship systems, mining systems, data centers, etc., it can play a high-performance, low-maintenance function.
There are many advantages of dry type transformers, including
High safety
High safety-sourced: redmetal
Compared with other types of transformers, dry type transformers do not use flammable or toxic liquids, which improves safety during use and reduces the risk of leakage or fire of toxic or flammable substances.
Easy to install
Dry type transformers do not require any oil storage tanks or other special low-level foundation requirements, and can be installed for long distances or low-voltage cables as long as they are close to the load.
No maintenance required
No maintenance required-sourced: compraco
During use, dry and wet transformers do not require any special maintenance.
Sturdy structure
Sturdy structure-sourced: olsun
Made of special materials, dry type transformers have a sturdy structure and can withstand the maximum vibration and impact during use, so they can also maintain stable output in the event of an earthquake.
High impedance and mechanical strength
Using high-quality insulation materials, it can withstand high temperature environments, with high impedance, high mechanical strength, and excellent short-circuit current characteristics. It is resistant to moisture and corrosion.
Quiet and cool operation
Quiet and cool operation-sourced: monolithicpower
Dry type transformers make almost no noise during use and can ensure that vibration is minimized after installation.
Long service life
Dry type transformers are made of high-quality materials and exquisite craftsmanship, which can ensure a sufficiently long service life and guarantee long-term stable operation.
The main disadvantages of dry type transformers include:
High cost
High cost-sourced: loanscanada
The high cost of dry type transformers is mainly reflected in the materials and manufacturing processes used.
Heavier weight
Compared with other types of transformers, dry type transformers have larger gaps and thicker insulators. Therefore, at the same power and voltage level, it is larger and heavier.
Easily damaged
Easily damaged-sourced: penbaypilot
Dry type transformers use an open ventilation design. Therefore, it is easy to cause a short circuit due to the entry of foreign matter or particles during use.
Noisier
Dry type transformers use a higher magnetostriction coefficient, so the noise generated during use will also be greater.
There are two main types of dry type transformers: cast resin dry-type transformers and vacuum-pressure impregnated transformers.
Cast resin dry type transformer
Cast resin dry type transformer-sourced: squarespace
Cast resin dry type transformer, also called CRT, is a transformer that uses epoxy resin material to encapsulate the primary and secondary windings. This encapsulation method can protect the windings from moisture, dust, pests, and other external factors.
Its advantages mainly include:
Its advantages mainly include-sourced: hanleyenergy
- Non-hygroscopic and maintenance-free. It is suitable for installation and use in high-humidity environments, indoors, and in dangerous areas such as fires.
- Low loss and partial discharge can also withstand overload, so as to achieve high efficiency and long life.
- Insulation grade is F grade.
Vacuum pressure impregnated transformer
Vacuum pressure impregnated transformer-sourced: tirupatitransformer
Vacuum pressure impregnated transformer, also called VPI, is a transformer made of H-grade polyester resin, in a vacuum and pressure environment, for stationary winding. This production method can eliminate the air gap in the insulation layer while improving the mechanical strength, dielectric strength, and thermal stability.
Its advantages include:
Its advantages include-sourced: goodtransformer
- Strong structure, and the shell is moisture-proof and heat-resistant, suitable for outdoor installation, and can be used in special environments, such as earthquakes or environments with large temperature fluctuations.
- Easy to maintain and strong ability to resist short-circuit current;
- Its insulation level is also F or H.
The dry type transformer is mainly composed of the following parts:
Iron core
Iron core-sourced: semiconductorforu
The iron core is mainly made of staggered silicon steel sheets. Its main function is to form a magnetic circuit, thereby reducing eddy current loss. The insulating layer is formed by coating the surface of the silicon steel with insulating paint and oxidizing it. At the same time, the iron core is also composed of the iron core body, fasteners, and insulating parts.
Winding
Winding-sourced: baumueller
Most of the windings are made of high-strength enameled wire with a fireproof grade of h. This ensures winding with excellent heat dissipation. Through a tight and uniform arrangement, the windings are mostly cylindrical, and the low-voltage windings are close to the iron core to facilitate the formation of iron core insulation.
DC reactor
DC reactor-sourced: ato
The DC reactor can also be called a smoothing reactor. It is mainly used in the DC part of the transformer. Limiting the AC component of the superimposed DC to a certain specified value can ensure the continuous and stable output of the current, thereby improving the input power factor.
AC Reactor
AC Reactor-sourced: ato
Unlike the DC Reactor, the AC Reactor is mainly used to limit the sudden change of power grid voltage and the current impact caused by voltage during operation. Since the power supply and voltage contain spike pulses, the AC in the whole circuit can not only prevent the interference of the power grid but also reduce the influence of harmonics.
EMI Filter
EMI Filter-sourced: elcom
The function of EMI filter is to reduce the radio interference generated by the inverter.
Dry type transformers and liquid type transformers are two different types of transformers. Their main differences are:
|
Dry type transformers
Dry type transformers-sourced: vietnamtransformer |
Liquid type transformers
Liquid type transformers-sourced: eaton |
|
|
Different use environments |
Dry type transformers are made without using harmful liquids or fluids. They do not release harmful gases into the environment during use and do not contain flammable liquids, so there is no risk of explosion or fire. Therefore, dry type transformers have stable reliability and are the first choice for indoor use. They are generally used in schools, hospitals, or other public facilities. |
The liquid used in liquid type transformers is flammable and explosive. You need to be careful during use, and it will also damage the environment, so it is not suitable for indoor use. When choosing a liquid type transformer, you need to consider silicone or hydrocarbon liquid transformers first. |
|
Ease of maintenance |
Dry type transformers are easy to maintain. They are mainly air-cooled and only require standard visual inspection. The specific inspection requirements need to be adjusted according to your own equipment and the frequency of use. Because of its anti-pollution ability, there is no need to consider the impact on the external environment during use. |
Liquid type transformers require more maintenance. Mainly including the environment in which they are used and the detailed requirements for use. During use, it is necessary to collect and analyze the equipment's instruments or any signs of leakage. |
|
Equipment size requirements and capacity |
Dry type transformers have a larger footprint and are limited in size and power rating, suitable for small and medium voltage needs. |
While liquid type transformers have a smaller footprint, they can handle higher voltages and capacities. |
During use, it is inevitable to have doubts about dry type transformers and oil-filled transformers. To understand their performance, you can mainly analyze the following aspects:
|
Dry type transformers
Dry type transformers-sourced: phase-a-matic |
Oil-filled transformers
Oil-filled transformers-sourced: googleusercontent |
|
|
Cooling medium |
Transformers will overheat during use or under load, so they need a cooling medium to prevent overheating, thereby avoiding fire or other risks. Dry type transformers mainly use air as a cooling medium. |
While oil-filled transformers mainly use oil. |
|
Maintenance |
Dry type transformers do not require additional maintenance. |
Oil-filled transformers have higher maintenance costs and require extra attention and regular testing of the oil in the equipment, and whether there is chemical contamination. |
|
Operating costs |
Dry type transformers have higher energy consumption and, therefore, higher operating costs. They may be replaced more frequently during use. |
Oil-filled transformers have lower operating costs. They mainly use traditional energy efficiency, reliability, and durability. |
|
Recyclability |
After the end of their service life, the coils of dry type transformers are limited in recycling. |
The cores of oil-filled transformers are easier and more environmentally friendly to recycle. |
|
Efficiency |
Although dry type transformers are larger in size, they are rated for lower voltage. |
Therefore, oil-filled transformers are more efficient than dry type transformers. |
|
Installation location |
The manufacturing process of dry type transformers uses non-toxic and safe materials, so they are more suitable for indoor installation and use. |
Oil-filled transformers are often installed outdoors. Because they may release harmful substances during use and pollute the environment. |
The design of dry type transformers depends on efficiency, performance, durability, etc. Among them, when designing, you need to consider the following factors:
Insulation type
Insulation type-sourced: thegundcompany
The insulation type affects the rated temperature, dielectric strength, mechanical strength, and thermal shock resistance of the transformer. Common dry type transformers generally use F or H grade insulation materials. Their high temperature resistance is 155°C and 180°C, respectively. These two insulation materials have good electrical and mechanical properties. Common insulation materials include varnish, epoxy resin, polyester resin, etc.
Winding material
Winding material-sourced: lucas-nuelle
The winding material affects the conductivity, resistance, loss, and mechanical strength of the transformer. Common dry type transformers use copper and aluminum as winding materials. This may enhance conductivity and reduce costs.
Core material
Core material-sourced: maddox
You can choose a core material with low hysteresis loss. This material can reduce no-load losses and improve the efficiency of the transformer. Because the core material determines the flux density, magnetic permeability, hysteresis loss and eddy current loss of the transformer. Common core materials on the market include silicon steel, cold rolled grain-oriented silicon steel (CRGO), amorphous metal, etc.
Regulation
Regulation refers to the ratio of the full load voltage drop to the no-load voltage in the transformer. It depends on the impedance and resistance of the transformer and can reflect the ability of the transformer to stabilize the voltage output under different load conditions.
Life expectancy
Life expectancy-sourced: depositphotos
The life of the transformer is easily affected by the temperature, humidity, dust, and corrosive liquids of the environment. Therefore, the insulation grade and quality of the dry type transformer should be considered in the design to withstand high temperatures or a harsh environment.
Loss
The losses of the transformer mainly include no-load loss and load loss. No-load loss refers to the loss of the core and eddy current loss. Load loss refers to copper loss or stray loss. These losses affect the efficiency, heating, or cooling of the transformer. Therefore, when selecting the core winding and insulation material, the best performance and related design parameters should be considered.
Overload
Transformer overload occurs when the transformer operates beyond its rated capacity or temperature. This can cause the transformer to overheat or the insulation to break down, the line to short circuit, or a fire. Therefore, a fan cooling or air conditioning system is required in the design.
K factor
K factor-sourced: slideserve
The K factor refers to the influence of heat generated by non-sinusoidal current in the winding that the transformer is subjected to during operation. This influence will generate harmonics, which will increase the loss or heating, and distortion of the transformer.
Before choosing a dry type transformer, you need to consider:
Is it installed indoors or outdoors?
Is it installed indoors or outdoors-sourced: media
Different dry type transformers are used in different environments. Air-cooled transformers are more suitable for indoor installation and use, including hospitals, universities, office buildings, and residential areas. Other dry type transformers are more suitable for use in extreme environments and areas, including environmentally sensitive areas, high fire risk areas, performance halls and conference centers, petrochemical and natural gas industry areas, etc.
During the later installation of the transformer, it is necessary to strictly follow the manufacturer's requirements. These include:
Handling after delivery
Handling after delivery-sourced: radiusgroup
The gravity center of transformer is relatively high, so special attention should be paid during the later handling process. Do not place it in a humid environment. If it needs to be used outdoors or in harsh environments, moisture-proof protection should be done in advance.
Storage
The storage environment of the transformer should be as dry as possible, and the temperature should be kept constant. The packaging should be as intact as possible, and the equipment and environment must be kept dry before installation and power on.
Installation conditions
Installation conditions-sourced: media
The installation conditions must take into account the ventilation conditions, noise levels, etc., of the indoor and outdoor environments. The installation area of the dry type transformer should be dry, dust-free, and free of excessive moisture, fertilizers, chemicals, and other corrosive fumes or vapors.
Isolation from flammable materials
Isolation from flammable materials-sourced: adobe
During the installation process, the transformer should try to avoid contact with flammable materials, and the passages in the installation area must be loose enough to facilitate the change, adjustment, or movement of the transformer.
Ventilation
The transformer has a normal cooling system, which can maintain normal circulation and circulation of air in the transformer environment and ensure that the temperature can be kept within the rated value.
During use, the equipment should be maintained and tested in strict accordance with the maintenance requirements, including:
Temperature log
Temperature log-sourced: thermometer
You need to read and record the temperature controller range of the transformer regularly. Under normal load conditions, record the data, compare and correct it with historical data, and adjust it at any time if there is a problem.
Maintenance in the power-off state
Inspect, clean, repair, or test the transformer in a power-off state. You need to wear arc protection clothing and disconnect the line for the first and second time. All terminals must be grounded.
Visual inspection
Visual inspection-sourced: getmaintainx
Through visual inspection, you can check whether the parts of the transformer are loose or falling off. The operating area, whether the ambient temperature is suitable, and the ventilation effect should be recorded.
Equipment cleaning
To achieve the highest efficiency of the equipment, for safety reasons, you need to clean the equipment regularly. Use a vacuum cleaner to absorb and clean dust and dirt on the cooling fan or the inside of the equipment. Do not use chemical cleaners to clean the surface of the equipment during the process.
Check for potential problems or defects
When inspecting the transformer, you should check its core for rust. Check for signs of carbonization on windings and insulation, and loose electrical connections, pitting, corrosion, or discoloration. Check for cracks, discoloration, or loose insulation.
In addition to routine maintenance, cleaning, and commissioning, transformers also need to be tested during operation. These tests can avoid various emergencies. Therefore, you need to pay attention to the following points:
Transformer turns ratio(TTR)
Transformer turns ratio(TTR)-sourced: testguy
The transformer turns ratio mainly refers to the condition of the transformer windings and core. You can test whether the actual voltage ratio between the primary and secondary windings is consistent with the ratings on the nameplate or the manufacturer's certification.
Insulation resistance test(IR)
Insulation resistance test(IR)-sourced: keystone-cable
Test the integrity of the insulation between the coil winding conductors. Each transformer rating has a minimum resistance requirement. Therefore, if the actual resistance is lower than the minimum requirement, the transformer has a potential fault.
Winding resistance test(WR)
Winding resistance test(WR)-sourced: tytorobotics
Before the transformer is tested at the factory or used daily, it is necessary to measure the resistance of the coil winding of each voltage tap. Compare and debug according to the range of ratings set by the manufacturer.
Other tests
You can perform ELSCO series certification tests on each device and record the results in the accompanying certificate. This can help with device diagnosis during later use.
The advantages of dry-type transformers are many, including stable output, safety and reliability, environmental friendliness, high efficiency, long service life, and low maintenance cost. This type of transformer is well adapted to the market. If you have more questions, you are welcome to consult us.
