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As a buyer of power equipment, you are likely to find a common feature in the industry during the selection process: the vast majority of power transformers on the market are AC-type, not DC-type. This inevitably makes you wonder: why is the power transformer always dominated by AC in the core link of power transmission and distribution in the increasingly widespread application of DC power in electronic devices and new energy systems?
This article will take the second-person perspective, combined with the core advantages of Chuanli products, to comprehensively answer this industry problem for you, and at the same time, help you sort out the key points of selecting power transformers, so as to assist you in making more accurate and efficient purchasing decisions.
A power transformer is a stationary piece of electrical equipment that works based on the principle of electromagnetic induction. The core function is to realize the voltage level conversion of electric energy exchange, maintain the frequency of electric energy unchanged during the conversion process, and complete the efficient transmission of electric energy, which is the core equipment in the whole power system of power generation, transmission, and distribution.
The power transformers produced by Chuanli not only include 110V and 220V low-voltage power transformers, such as 110v power transformers and 220v to 110v transformers, but also large-scale power transformers of 110kV and 220kV high-voltage levels, which fully meet the needs of various scenarios from equipment compatibility to power grid construction.
The types of power transformers are rich, and the products of different types have significant differences in function, voltage range, and application scenarios. Familiarity with these classifications can help you quickly locate suitable products when faced with specific needs and avoid selection deviations.
The core function is to raise the low-voltage AC to a high-voltage level, and the core application scenario is the export of power plants and long-distance transmission links. The 6.3 kV, 10.5 kV, and other medium and low-voltage electricity output by the power plant generator cannot meet the long-distance transmission requirements. After being raised to 110 kV, 220 kV, or even higher voltage by the step-up transformer, the energy loss of the transmission line can be greatly reduced.
In contrast to the function of the step-up transformer, the core is to reduce the high-voltage AC to a low-voltage level that can be directly used by the user, which is the core equipment of the distribution link. They range from low-voltage transformers that convert 220V to 110V or 110V to 220V for imported electrical appliances, to power grid distribution transformers that reduce 110kV high-voltage electricity to 10kV or 0.4kV, all of which belong to the category of step-down transformers. Chuanli‘s power transformer 220V to 110V and power transformer 110V to 220V series adopt precision winding design, voltage conversion accuracy is controlled within ±1%, suitable for industrial equipment, imported instruments, and other low-voltage adaptable scenarios.
The core function is to realize the electrical isolation between the primary circuit and the secondary circuit. The primary and secondary windings are not electrically connected, and only the magnetic field coupling transmits the electric energy. It can effectively suppress the harmonic interference in the power grid and ensure the safe and stable operation of the precision electrical equipment.
The main feature is that the primary and secondary windings share the same coil, and there is no independent secondary winding, so the structure is more compact, the manufacturing cost is lower, and the energy transfer efficiency is higher. The core is suitable for conversion scenarios with similar voltage levels, such as 110 kV to 66 kV and 35 kV to 60 kV.
These are the two mainstream types divided by cooling mode, and it is also the core choice dimension when purchasing, which directly determines the installation environment and operating characteristics of the product:
Dry-type transformer: The cooling medium is air or inert gas; there is no risk of leakage, it is fire-proof and explosion-proof, and the core is suitable for indoor scenes, such as urban substations, subway control rooms, shopping malls, factory workshops, etc.
Oil-immersed transformer: With high-quality insulating oil as the cooling medium, the heat dissipation efficiency is high, the capacity is large, and the overload capacity is strong. The core is suitable for outdoor large-scale scenes, such as power plants, outdoor substations, and industrial park main distribution.
| Transformer Types | Core Functions | Typical Voltage Range | Core Applicable Scenarios |
| Step-up Transformer | Low voltage → high voltage, reducing transmission losses | Input 6.3kV/10.5kV, Output 110kV/220kV | Power plant voltage step-up, long-distance power transmission |
| Step-down Transformer | High voltage → low voltage, adapting to power demand | Grid level: 110kV → 10kV/0.4kV; Low voltage level: 220V↔110V | Urban distribution network, industrial park, compatibility with imported electrical appliances |
| Isolation Transformer | Electrical isolation, harmonic interference suppression | 0.4kV/10kV voltage level conversion | Medical equipment, precision electronic instruments, and laboratories |
| Autotransformers | Voltage level conversion between similar voltage levels, high efficiency, and energy saving | 66kV↔110kV, 35kV↔66kV | Voltage regulation in power distribution networks, large industrial power distribution |
| Dry-type Transformer | Safe indoor power supply, no leakage risk | Subways, shopping malls, factory workshops, and laboratories | 10kV epoxy-cast dry-type transformer |
| Oil-immersed Transformer | Large-capacity outdoor power supply, excellent heat dissipation | Input 110kV/220kV, output 10kV/35kV | Power plants, outdoor substations, and large industrial parks |
The core principle of a power transformer is electromagnetic induction, which requires changing the magnetic field, and changing the magnetic field is produced by changing the current.
The size and direction of the alternating current change periodically with time. After passing through the primary winding, it will form a changing magnetic field in the iron core, and an induced voltage will pass through the secondary winding. By adjusting the ratio of the number of turns of the primary and secondary windings, the voltage can be accurately changed. No auxiliary equipment is needed, the structure is simple, and the energy transmission is direct.
The DC current is constant and only produces a constant magnetic field, which cannot trigger electromagnetic induction. Even if it is rectified, inverted, converted to AC, and then stepped up, it will increase complexity, cost, and energy consumption, which is not worth it.
When choosing power equipment, the long-term operating cost is the core consideration factor, and the advantage of the AC power transformer in energy efficiency is particularly prominent.
The energy loss of the AC power transformer is concentrated in two aspects: the eddy current loss of the iron core and the copper loss of the winding. Both types of losses can be effectively controlled by mature techniques, such as the non-crystalline alloy iron core used by Chuanli, which can reduce the no-load loss by more than 30%, and the precise vacuum impregnation and winding process, which can reduce the resistance loss of the winding. The DC transformer or “DC-AC-DC” conversion system requires additional electronic devices such as rectifiers, inverters, and filters, which themselves generate a lot of energy loss, resulting in a significant reduction in the overall energy efficiency of the system, usually only 90% to 95%.
The voltage requirements of the power system are highly diverse, and the voltage requirements of different scenes are greatly different. The AC power transformer can perfectly adapt to this diversified demand.
The voltage conversion of the AC power transformer can only be achieved by adjusting the number of turns of the primary and secondary windings, the number of turns is proportional to the voltage ratio, the design and production difficulty is low, and the precise conversion of any voltage level can be achieved. For example, a 110V to 220V transformer and a 220V to 110V transformer, the corresponding turns ratio is 1:2 and 2:1, respectively, which can be customized quickly and at a low cost.
In contrast, the conversion of DC voltage needs to be achieved through complex DC-DC electronic circuits, with a narrow adjustment range, difficult customization, and high cost, which cannot meet the one-stop needs of all scenarios and buyers.
The safety and reliability of power equipment are directly related to the normal operation of the project and the safety of personnel, which is also the core consideration of buyers, and the advantages of the AC power transformer in this regard are very obvious.
First of all, the structure of the AC power transformer is extremely simple, with only an iron core, winding, and cooling system as the core components, no complex electronic components, few fault points, and high operating stability. Secondly, AC has a zero-crossing characteristic, and the current will periodically return to zero. When a fault, such as a short circuit, occurs in the equipment, the arc will naturally extinguish at the zero-crossing of the current, which can effectively reduce the safety risks of short circuits and fires.
As a buyer, when selecting products, you should not only pay attention to the product itself, but also consider factors such as industry standards and supply chain maturity.
At present, AC power transformers have clear international standards (IEC 60044 series) and domestic standards (GB 1093 series), which make detailed provisions on voltage level, capacity, energy efficiency, safety performance, test methods, etc., so buyers can accurately evaluate product quality according to the standards.
In contrast, the DC transformer has not yet formed a unified global industry standard; the technical route is diverse, the supply chain is relatively immature, the quality of products on the market is uneven, and the procurement risk is relatively high.
| Comparison Dimensions | AC Power Transformer | DC Transformer |
| Working Principle | Based on electromagnetic induction, a simple structure, and no additional auxiliary equipment | Based on electronic circuit conversion, requires rectifiers, inverters, and other supporting equipment |
| Overall Energy Efficiency | High | Low |
| Voltage Conversion Flexibility | Extremely high, any voltage conversion can be achieved by adjusting the turns ratio | Low, limited voltage adjustment range |
| Operational Safety | High | Low |
| Industry Standards | Complete, with unified IEC and GB standards | There are no universal standards |
| Initial procurement cost | Lower initial investment, no supporting equipment costs | Higher cost, 30%-50% higher than AC products |
| Post-maintenance costs | Extremely low cost | Extremely high compatibility |
| Supply Chain Maturity | Globally mature, spare parts readily available, and comprehensive after-sales service | Immature |
| Compatibility Scenarios | Full-scenario compatibility, including power generation, transmission, distribution, and 110V/220V equipment adaptation | Only compatible with small electronic devices and specific new energy applications |
First of all, it is necessary to accurately determine the input voltage and output voltage, which is the basis of selection. Chuanli can provide customized services for all voltage levels, whether it is 110v power transformers, 220V/ 110V low-voltage transformers, or 110kV, 220kV high-voltage transformers. We can accurately design the winding number ratio according to your needs to ensure voltage conversion accuracy.
The rated capacity of the transformer (kVA) determines the maximum load power it can carry. When selecting, it is necessary to follow the principle of maximum load power + 20% redundancy to avoid equipment overheating and burning due to insufficient capacity, as well as to prevent waste of initial procurement costs and reduced energy efficiency due to excessive capacity.
The energy efficiency class directly determines the energy consumption level of the transformer and is also the core factor that affects the long-term electricity bill.
All of the communication power transformers of Chuanli meet the national level 1 energy efficiency standard, and the loss index of some products is far lower than the national standard requirements.
Different installation environments have different noise requirements for transformers. Indoor scenes, such as workshops, laboratories, and subway control rooms, usually require an operating noise of ≤55dB, while outdoor scenes can be appropriately relaxed.
The choice of cooling method directly determines the installation environment and operation stability of the transformer, and the core is determined according to the installation scene and capacity size:
Indoor, closed space, small capacity (≤1000 kVA): choose a dry-type transformer, no leakage risk, fireproof, and explosion-proof;
Outdoor, large capacity (≥1000 kVA), industrial park/power grid distribution: choose an oil-immersed transformer, high heat dissipation efficiency, strong overload ability.
At the same time, the installation method (vertical/horizontal) and protection class (choose IP65 for outdoor scenes, dustproof and waterproof) should also be considered. Choose IP54 indoor scene, installation space (Chuanli can provide a compact design, suitable for a small space).
Power transformers are heavy-asset, long-cycle-use equipment. The technical strength, product quality, and after-sales service of the brand are directly related to the long-term stable operation of the project. Therefore, when purchasing, it is necessary to choose professional brands with a good reputation and in-depth industry experience.
As an old manufacturer in the field of power equipment, With a standardized production base of 20,000 square meters and a team of more than 150 professional engineers, the products have been tested in many national and large-scale projects such as the Three Gorges Dam and the West-to-East Power Transmission, far exceeding the industry average, and can completely solve your concerns about the later operation.
In addition to the above core points, when purchasing, you also need to combine the actual needs of the project and pay attention to the following detailed parameters. Chuanli will also provide you with full-dimensional parameter customization and matching:
Short-circuit impedance: Usually 4% to 10.5%, needs to be selected according to the short-circuit current level of the power grid to ensure the stability of the power system.
Insulation grade: It is recommended to choose ≥F grade, which can adapt to the high temperature and high pressure operating environment, and improve the service life of the equipment.
Delivery time: The delivery time of Chuanli‘s regular products is 20-35 days, and the customized high-voltage products are 30-40 days, which can precisely match your project schedule.
Overload capacity: The transformer supports 120% of the rated load for continuous operation for 2 hours, which can meet the temporary load demand during the peak load period.
The following two real procurement cases vividly demonstrate the core advantages of the Sichuan Electric Power Transformer, which is also the core reason why buyers choose Sichuan Electric Power Transformer:
Case 1: Foreign-funded electronic factory 220V to 110V imported equipment adapter project
Case 2: 110 kV to 10 kV distribution network upgrade project in the old city
As a buyer of power equipment, you no longer need to worry about why most power transformers are AC instead of DC. Whether it is the low-voltage 110V / 220V conversion or the high-voltage 220kV / 110kV power grid conversion, the AC power transformer is the most cost-effective and reliable choice.
The procurement of power transformers is essentially the procurement of “stable, efficient, and reliable power conversion capabilities,” and choosing Chuanli can make your power project more stable, more energy-saving, and more convenient, and achieve the dual optimization of short-term procurement cost and long-term operating cost.
Q1: Can the 110V to 220V and 220V to 110V transformers from Chuanli be used with imported equipment?
A: The power transformer 110V to 220V and the power transformer 220V to 110V series of Chuanli can be adapted to all imported 110V / 220V equipment, and can be customized according to the load characteristics of the equipment to ensure the stable operation of the equipment.
Q2: How long is the service life of an AC power transformer?
A: The normal service life of an AC power transformer is 20 to 30 years, depending on the use environment and maintenance level.
Q3: If there are both 110V and 220V equipment on site, can Chuanli provide an integrated power supply solution?
A: Sure. Chuanli can design customized combination transformers according to your project requirements, providing a one-stop solution for the power supply requirements of different voltage equipment and reducing the number of equipment purchases and installation space.
Q4: Can the Sichuan Electric Power Transformer adapt to extreme environments such as high altitude and low temperature?
Chuanli can provide customized high-altitude and low-temperature transformers to ensure that the product can still operate stably in extreme environments. At present, this type of product has been widely used in power projects in Xizang, Xinjiang, and other regions.
