Hebei Yueyang Electric Power Technology Co., Ltd. belongs to Beijing Beikai Zhongdian Group (established in 2005). It is a manufacturer of high and low voltage electrical equipment that integrates R&D, production, and sales. The company's main products include isolation switches, switchgear, vacuum circuit breakers, transformers, Drop Out Fuse, lightning arresters, and other series of products, which are widely used in ports, rail transportation, new energy, power systems, and infrastructure construction. These products are exported to over 60 countries and regions worldwide
Our Advantages
Strong Production Capacity
Our company covers an area of about 20,000 square meters, has 30 factories and two branches, and has more than 100 employees. More than 20 years of production experience enable us to meet the diverse production needs of users.
Focus on Product Innovation
We continue to adhere to product innovation and technological innovation, established a technology research and development center, and obtained more than 60 utility model patents.
Advanced Production Equipment
Our company is equipped with 20 lathes, 10 universal cleaning machines, 8 drilling and washing machines, 5 punching machines, 9 experimental benches, 5 detectors, etc., to provide a guarantee for the high-precision production of products.
Recognized Product Quality
Our company has passed ISO9001 series system certification and has also established a product testing center. Reliable products have been sold to many countries and regions such as Europe, Africa, Southeast Asia, and the Middle East, and have been well received.
Oil-filled or oil-immersed transformers are voltage conversion devices that use oil to keep the transformer cool. This type of transformer structure is mounted in a welded steel oil tank filled with oil.
Types of Oil-Filled Transformers
Single-Phase Transformers use one pair of windings. It’s used in lower-load situations, such as rural areas.
Three-Phase Transformers are made up of three pairs of windings. The windings typically go around a core sectioned into three parts. Three-phase transformers are used in higher-load areas and can supply three circuits with energy.
Power Transformers are designed to handle much higher loads. They can step voltages up or down and transmit a current from one place to another.
Distribution Transformers transmit lower voltages from the electrical grid to homes and businesses. They are much smaller than power transformers.
Pole-Mounted Transformers are connected to an electrical pole.
Pad-Mounted Transformers are mounted to a concrete pad on the ground.
Low Cost
The cost of procuring an oil transformer is usually 1.5 to 2 times lower than a dry transformer for the same capacity.
Good Heat Dissipation Performance
Dry transformer' epoxy resin has poorer heat dissipation performance than mineral oil. In general, the dry transformer's heat dissipation is inferior to that of the oil transformer, so the capacity of the dry transformer usually only meets the need for power distribution from the intermediate station to the end-consumption site. Also, on the grid system, oil transformers are more versatile (including transmission and distribution transformers).
Wide Application Scope
The dry-type transformer is usually suitable for voltages below 35kV, while oil-immersed are unlimited. The temperature monitoring of the dry transformer depends on the temperature sensor mounted inside the machine's body, so the obtained temperature is the temperature of a particular location, the temperature reflected by the screen is not the exact mean temperature. The transformer insulation oil conducts heat relatively evenly. The temperature reflected by the monitor can be considered the average temperature.
Long Service Life
Because of the monolithic casting structure of the dry transformer, compared with the ability to repair, recover, utilize, the oil transformer is more dominant. The insulating material of the machine dries out over time will age, and defects will accumulate. In the event of a failure, the dry transformer will be rejected entirely. The dry machine components, including copper (or aluminum) and the magnetic core, are nearly non-recyclable.
Application of Oil-Filled Transformers
Power Distribution and Conversion
Oil-immersed transformers are used for power distribution and conversion in construction and residential settings. They transmit power from transmission lines to buildings or residences and transform high voltages into lower voltages suitable for various equipment and systems. Oil-immersed transformers ensure that the power supply meets the requirements of different electrical appliances in buildings and residences, providing stable power conversion and appropriate voltage levels for safe equipment operation.
Power Protection and Safety
Oil-immersed transformers contribute to power protection and safety in the construction and residential sectors. They incorporate features such as overload protection, short-circuit protection, and earthquake protection. These transformers can detect and isolate faulty circuits promptly, preventing equipment overload and circuit short circuits to safeguard the electrical systems of buildings and residences. Additionally, oil-immersed transformers provide ground insulation protection, reducing the risk of electric shocks and ensuring electrical safety in construction and residential environments.
Power Stability and Power Factor Improvement:
Oil-immersed transformers help maintain power stability and improve power factor in construction and residential applications. They balance power loads, adjust current and voltage levels, ensuring power supply stability and avoiding excessive or inadequate voltage fluctuations. Moreover, oil-immersed transformers can correct power factors, enhancing power transmission efficiency and reducing energy waste.
Noise and Electromagnetic Interference Reduction
Oil-immersed transformers also contribute to noise and electromagnetic interference reduction in construction and residential settings. They isolate and suppress noise and interference within the power system, providing clean and stable power supply. This contributes to improved comfort and quietness in the building and residential environments while ensuring the proper functioning of electronic devices.
Working Principle of Oil-Filled Transformers
Substations and power distribution areas use oil-immersed transformers. An oil-immersed transformer is similar in design to a regular transformer. It’s made up of three main parts: a magnetic core at the center that is surrounded by coils and bushings. The magnetic core and windings create a magnetic field, allowing the current to pass through. Windings are insulated, with higher voltages needing thicker insulation. Bushings transmit the electricity to its next destination, typically a substation.
Oil-filled transformers change a current to a higher or lower voltage using the principle of induction. This process creates a surplus of heat. The oil helps to keep the transformer from overheating. The windings and core are submerged in transformer oil. It acts as a cooling agent and an insulator. Convection moves the oil through the windings, coils, and core, keeping the transformer from overheating. Oil is further cooled externally at lower voltage and in an air-cooled radiator with higher voltages.
Daily
Day-to-day transformer maintenance routines include oil and temperature checks. You should ensure the ambient, winding, and oil temperatures are within the typical range. Moreover, you should check whether the oil level gauge adapts to temperature changes. If your oil-filled transformer doesn’t accomplish one of these things, it’s time to replace the indicator. Additionally, you will have to compare the load voltage and current to the rated statistics as part of your daily power transformer maintenance routine. Pro tip: you can avoid electrical failure by keeping your overcurrent, differential, and ground voltage relay in good working order. It is unlikely for oil-filled transformers to make a lot of noise, but if yours does, you need to figure out what’s causing it. Most of the time, there is an issue with the transformer core, cooling system, and coils.
Weekly and Monthly
You need to check several transformer components on a weekly or monthly basis. These include checking the oil’s dielectric strength, inspecting your cable box, cleaning your transformer’s auxiliary circuits, etc. Here is a list of things you should include in your weekly transformer maintenance schedule:
● Determining the oil level: examine the oil level indicator and compare it to the oil temperature.
● Visually inspecting the transformer’s outside: look for any deterioration or chipped paint.
● Ensuring that the gasket joints and radiators are secure: check to see if there is no evidence of oil leakage.
● Ensuring appropriate sealing: Inspect any pressure relief device vent fitted on the cap.
● Check for signs of proper operation on the pressure release device.
Yearly
Your annual transformer maintenance schedule will include all the previous tasks mentioned in the daily and weekly schedules. Plus, it will include less frequent checks and complex tasks. The tasks to include in your yearly oil-immersed transformer maintenance plan include:
● Inspect the temperature indicators and off-circuit selector, and replace them if necessary.
● Check the weatherproof seals on the marshaling boxes.
● Measuring the insulation resistance of the transformer’s protection relays.
● Examining the resistance of the fan or oil pump motors.
● Assuring that there are no leaks around the pressure relief tank.
Consider the following tips to ensure cost-effective purchases of oil-cooled transformers:
Evaluate Multiple Suppliers
Obtain quotes from different suppliers and compare prices, quality, and after-sales service to make an informed decision.
Consider Energy Efficiency
Opt for transformers with higher efficiency ratings that may lead to long-term energy cost savings.
Assess Longevity and Reliability
Choose reputed brands or manufacturers known for their durable and reliable transformer solutions to minimize maintenance and replacement costs.
Seek Expert Advice
Consult with electrical professionals or engineers to determine the appropriate capacity and specifications required for your specific applications, ensuring you’re not overspending on unnecessary features.
Factors to Consider Before Choosing a Oil-Filled Transformer
The rated capacity of the transformer, measured in KVA, impacts the price. Higher capacity transformers generally come at a higher cost.
Transformers with higher efficiency and energy-saving ratings may be priced higher due to their advanced technology and performance capabilities.
Different manufacturers and suppliers may have varying pricing strategies based on their brand reputation, quality standards, and production costs.
Transformers with additional features like enhanced cooling systems or specialized customizations may have higher price points.
Our Certificate
Multiple certifications and product patents mean excellent product quality.
Ultimate FAQ Guide to Oil-Filled Transformers
Q: What is transformer oil?
Q: What is the difference between oil filled and dry type transformers?
Q: Where are oil filled transformers used?
Oil-immersed power transformers have many benefits, particularly their efficient cooling capabilities. They are used in many industries and can be found at both electrical substations and power distribution centers.
Q: What are the advantages of oil transformers?
Q: How do transformers work?
Q: What is the life of transformer oil?
Q: How much oil is in a 100 kVA transformer?
Q: What are the different types of oils used in transformers?
Q: How is transformer oil tested?
Q: What is an oil-immersed transformer?
Q: What are the advantages of oil immersed transformer?
First, oil-filled transformers are more affordable. They are often up to half the price of a dry-type transformer with the same capacity.
Oil-immersed transformers tend to be more successful at cooling the transformer than a dry type. Oil is a better cooling medium. They also have a higher voltage capacity. Dry-type transformers operate below 35 kV, while there are no limits with oil-immersed. Oil transformers are more versatile.
Dry-type can typically go from an intermediate location to the power consumption source. Oil-immersed can function as both power and distribution transformers.
Oil-filled transformers are better for the environment, as they are much easier to recycle than dry-type. They are also smaller and work best in outdoor environments in case of an oil spill or other accident.
Q: What are the maintenance and safety precautions for oil-immersed transformers?
You should perform regular visual inspections and cleanings. Check the transformer to ensure that all parts are in good condition and that there is no threat of leaks. Make sure that all fittings are tight. Clean the exterior and interior of the transformer to remove dust, dirt, and other debris.
It’s also essential to check the oil frequently. Make sure that the oil is at its proper level. You should also take samples of the oil and have it tested. You don’t want to use contaminated oil. Finally, keep an eye on the temperature and air pressure. You want to be sure that the transformer is within the suggested levels.
As with any electrical equipment, there is always a risk of fire. In the event of a fire, it’s important to ensure that the oil doesn’t leak out from the transformer. Oil can cause the fire to spread, making a hazardous situation even more dangerous.
Q: What is the purpose of oil in oil-filled transformers?
Q: What are some common applications of oil-filled transformers?
Q: How long do oil-filled transformers last?
Q: What is the maintenance of oil filled transformer?
Q: What are some common causes of oil leaks in an oil-filled transformer?
Q: How can you detect an oil leak in an oil-filled transformer?
Q: How do you cool an oil-filled transformer?
● (Mineral) Oil Natural Air Natural (ONAN) – The core and coils are cooled by surrounding oil. Heat transfer of oil by natural air convection.
● (Non-Mineral) Oil Natural Air Natural (KNAN) – The core and coils are cooled by surrounding synthetic oil. Heat transfer of oil by natural air convection.
● Oil Natural Air Forced (ONAF) – Cooled by surrounding in oil. Forced air circulation using pumps, fans, and blowers.
● Oil Forced Air Forced (OFAF) – Forced oil and air circulation using fans and blowers.
● Oil Natural Water Forced (ONWF) – Cooled by surrounding in oil. Forced water circulation using heat exchanges.
● Oil Forced Water Forced (OFWF) – Forced oil and water circulation using oil-to-water heat exchanges.
Q: What are some safety precautions to follow when working with oil-filled transformers?
● Keep the power off when working on the transformer. Make sure there is zero electrical leakage or continuity between the current source and the system.
● Use protective equipment and pay close attention to specific ratings for the transformer's voltage output. Keep over current protection of conductors and circuits set to the manufacturer's standards.
● Learn the maximum voltage requirements of your transformer. Be careful of system overload from a single transformer, with the understanding that multiple transformers help balance the impedance of each load.
● Keep spare nuts, bolts and other objects away from your work, so that they don't touch or fall into the transformer.
● Be certain that your transformer is grounded, which will prevent static electricity and protect the coils from contacting the enclosure or core.
● Always keep your transformer and all of its components dry and free from any kind of moisture or water. To protect unskilled onlookers, set up caution signs that warn people to keep away from danger.
As one of the leading oil-filled transformer manufacturers and suppliers in China, we warmly welcome you to buy cheap oil-filled transformer for sale here from our factory. All customized products are with high quality and low price.
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