How To Choose The Suitable 110KV Power Transformer?
There are many types of power transformers on the market. The power transformers of 110kV and below produced by various manufacturers have different models and specifications, but the key parameters are basically similar. This article will introduce Daelim Transformer 110kV oil-immersed power transformer as an example, and tell readers how to choose a suitable 110kV power transformer.
Daelim Transformer 110kV oil-immersed series power transformers have features of low partial discharge, low loss, low noise, and high-reliability products designed and produced by themselves on the basis of digesting and absorbing advanced technologies internal and abroad. It has been highly praised by the majority of power users and relevant experts. 110kV Power Transformer is also exported all over the world.
Learn more about 110 kV and 115 kV Transformer
1. What Is 110KV Power Transformer?
110kV power transformer is static electrical equipment, which is used to convert a certain value of AC voltage (current) into another or several different values of voltage (current) with the same frequency.
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When the primary winding is energized with alternating current, an alternating magnetic flux is generated, and the alternating magnetic flux induces an alternating electromotive force in the secondary winding through the magnetic permeability of the iron core. The level of the secondary induced electromotive force is related to the number of turns of the primary and secondary windings, that is, the voltage is proportional to the number of turns.
110kV power transformer is one of the main equipment in power plants and substations. The function of the 110kV power transformer is multi-faceted. It can not only increase the voltage to send electric energy to the power-consuming area, but also reduce the voltage to the voltage used at all levels to meet the needs of electricity consumption. In short, both step-up and step-down must be completed by a 110kV power transformer. For more information, pls read our article: 110kV Class Three Phase Power Transformer
In the process of transmitting electrical energy in the power system, two losses of voltage and power will inevitably occur. When the same power is transmitted, the voltage loss is inversely proportional to the voltage, and the power loss is inversely proportional to the square of the voltage. The 110KV power transformer is used to increase the voltage and reduce the power transmission loss.
2. How To Purchase 110kV Power Transformer?
No matter what product we buy, we need to clarify our requirements, and the same goes for transformers. In order to buy a suitable 110kV power transformer, we need to determine our own technical parameters first.
2.1 What Are The Main Parameters Of the 110kV Power Transformer?
Rated Capacity
The main function of the 110KV power transformer is to transmit electrical energy because the rated capacity is its main parameter. The rated capacity indicates the size of the transmitted electrical energy, expressed in kVA or MVA.
When using a transformer, the rated capacity of the transformer must be selected reasonably. This reactive power will be provided by the power supply system when the transformer is running with no load.
If the transformer capacity is too large, it will not only increase the cost but also make the transformer run without load or light load for a long time, reduce the power factor and increase the loss.
Read more: 10.5MVA-13.8/2.4kV Substation Transformer
The transformer capacity is too small, and the transformer is overloaded for a long time, which is easy to damage the transformer. Therefore, the rated capacity of the transformer should be selected according to the needs of the power load, and should not be too large or too small.
Voltage
The high voltage of the 110kV power transformer is 110kV, and the low voltage is determined according to the specific transformation requirements of the project.
Cooling Method
The cooling method of the transformer is determined by the cooling material and the circulation method, and the cooling method of the 110KV power transformer varies greatly. In power engineering, the common cooling methods of 110KV power transformers are generally divided into three types: oil-immersed self-cooling (ONAN), oil-immersed air-cooling (ONAF), and forced oil circulation (OFAF/OFWF).
The four letters of the cooling method respectively represent the cooling material in contact with the winding; the circulation method of the inner cooling material; the outer cooling material; the circulation method of the outer cooling material.
The influence of the three cooling methods on the price is forced oil circulation (OFAF/OFWF) > oil-immersed air cooling (ONAF) > oil-immersed self-cooling (ONAN).
Try for free: Surplus 15000 kVA transformer for sale!
Winding Material
The 110kV power transformer has two or more coil windings. The windings work through the connection of alternating magnetic fields according to the principle of electromagnetic induction.
Commonly used 110kV power transformer winding materials are copper and aluminum. The only difference between copper windings and aluminum windings is electrical conductivity. Copper has better electrical conductivity than aluminum, but correspondingly, the price of copper will be much higher.
If copper windings are not a mandatory requirement, Daelim's engineering team recommends using aluminum windings, because the service life of copper and aluminum windings is almost the same, but aluminum windings are less expensive and more cost-effective.
Connection Method
Do you need a Y-Y connection or △-Y connection or something else? Different connection methods have different designs and therefore also affect the price to varying degrees.
Accessories
Accessories are also a big factor in the price! The number of accessories and whether they are other than standard accessories will greatly affect the overall price level of 110KV power transformers.
Which accessories do you need from the list below? Please make a choice and tell the Dalin team, a professional sales engineer will give you a precise price reference:
| Buchholtz relay (with 2 contacts) |
| Mechanical overpressure valve without contacts |
| OTI with alarm contacts |
| WTI with alarm contacts |
| Tap changer in HV side |
| Tap changer in LV side |
| Welded or detachable radiators |
| Screwed top cover for Transformer |
| Record-Hand hole for internal inspection |
| Stainless steel nameplate |
| Protection and control equipment for the cooling system |
| Oil level indicator with contacts |
| Sudden overpressure relief |
| The auxiliary voltage of 220 Volts 1 phase 3 wires |
| Oil preservative tank with neoprene bag and silica gel |
| Manovacuometer (pressure and vacum indicator) |
| Sea Ladder with top cover protection |
| Drain and sampling valve |
| Control cabinet |
In addition to the above parameters, parameters such as temperature, altitude, impedance, and loss will also affect the price of 110kV power transformers to varying degrees. If possible, please tell Daelim's sales engineer as much as possible about your needs, so that the price you get will be more accurate.
Read more: How To Purchase The 5 MVA Power Transformers In 2022?
2.2 How much is a 110kV transformer?
The price of a 110kV transformer varies greatly according to the configuration and requirements. If your 110kVtransformer accessories require internationally famous brands, the price will be much higher. For example, the German MR tap changer, the price of this tap changer alone may be around $100,000.
Daelim's professional sales engineer advises: It is best to determine your own budget before each purchase, and after you have a budget, it can help you choose a suitable supplier. Generally speaking, the supplier whose quotation is closer to one's own budget is the best supplier to choose.
The picture below is a 115kV 20MVA transformer that Daelim produced for a customer in Mexico in 2021. According to the owner's technical requirements and budget for this transformer, the price is between 200,000 and 300,000 US dollars.
2.3 Installation And Maintenance Of 110KV Power Transformers
Many users encountered trouble again when they received the 110kV power transformer purchased from China --- They don't know how to install and maintain it.
Don't worry, the Daelim team has figured this out for you - we have a professional installation and after-sales teams in North America. Our professional team will help you install the 110kV power transformer in a safe and reliable place that is convenient for operation, maintenance, and transportation.
Here are some tips shared by our installation after-sales team for diagnosing transformer faults by sound:
When the transformer is in normal operation, it will emit a continuous and uniform "humming" sound. If the sound produced is uneven or there are other special noises, it should be considered that the transformer is not running normally, and the fault can be found according to the difference in the sound and dealt with in time. The main faults are as follows:
Overvoltage in the grid. When single-phase grounding or electromagnetic resonance occurs in the power grid, the sound of the transformer is sharper than usual. When this happens, comprehensive judgment can be made in combination with the indication of the voltmeter.
A transformer is overloaded. The load changes greatly, and due to the effect of harmonics, the intermittent sound of "wah" or "cluck" occurs instantaneously in the transformer, and the pointer of the monitoring measuring instrument swings, and the pitch is high and the volume is loud.
Transformer clips or screws are loose. If the drop-out fuse or tap changer of the transformer is in poor contact, there will be a "squeaking" discharge sound;
If the transformer bushing of the transformer is dirty, the enamel peels off or has cracks on the surface, a "hissing" sound can be heard;
If there is partial discharge or poor electrical connection inside the transformer, there will be a "squeak" or "crack" sound, and this sound will change with the distance from the fault. At this time, the transformer should be deactivated immediately.
The transformer winding is short-circuited. If the sound is mixed with the sound of boiling water, the temperature changes sharply and the oil level rises, it should be judged that the transformer winding has a short-circuit fault. In severe cases, there will be a loud roar, and then a fire may occur. At this time, the transformer should be stopped immediately and let the professional engineer inspect it.
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Transformer case flashover discharge. This sound occurs when the high voltage of the transformer winding causes the outgoing wires to flash over each other or to the casing. At this time, the transformer should be deactivated and checked.
Now, do you have an idea on how to purchase a 110kV power transformer?
If you have any questions or inquiries, welcome to consult the Daelim team!