What are Transformers
In 1831, Michael Faraday, a British scholar, conducted a famous experiment at the Royal Society of London. According to historical records, he demonstrated that rotating a copper disc between the poles of a “horseshoe magnet” could generate a continuous current. Shortly after, he discovered that in a closed circuit, if the magnetic flux changes, the current must be generated. Based on these phenomena, he formulated the famous “Faraday’s law of electromagnetic induction.”
A few months later, Faraday invented the “induction ring”—the world’s first electric transformer. However, it was not until the 1880s that transformers began to be practically used.
Transformers are a type of equipment that can change alternating current (AC) voltage. In the power grid, transformers are commonly used for voltage step-up or step-down, impedance matching, and safe isolation.
So, how does this equipment work?
A Typical Workday of Transformers
Research indicates that a transformer consists of three main components: the primary coil, the secondary coil, and the core. The primary coil, located on the input side, is made of electrical conductor coils. It converts input voltage or current into magnetic energy through electromagnetic induction, which is then transferred to the secondary coil. Positioned on the output side, the secondary coil is typically connected to the load. The core's main function is to conduct magnetic flux. It converts the electrical energy from the primary circuit into magnetic energy and then converts the magnetic energy back into electrical energy in the secondary circuit.
The transformer operates based on Faraday’s law of electromagnetic induction: the rate of change of magnetic flux is directly proportional to the induced electromotive force (EMF).
The formula is as follows:
ε=N (Δϕ/Δt)
ε is the average EMF;
N is the number of coils turned in the conducting circuit;
ΔΦ is the magnetic flux;
Δt is the time.
(Source: Bitesize)
Therefore, the EMF is directly proportional to the rate of change in magnetic flux. The number of turns in the coil also influences the induced EMF. When a transformer begins operation, the primary voltage drives AC through the primary coil, generating magnetic flux. The core then acts as a bridge, transferring the current to the secondary winding. The output voltage is determined by the ratio of turns between the secondary and primary coils.
According to Faraday’s law, the current affects the magnetic flux density. A stronger current results in a stronger magnetic field. If the number of turns in both coil windings is equal, the currents will be similar. However, if the number of turns in the secondary winding increases or decreases, the secondary current and voltage will be higher or lower than those in the primary winding.
This describes the basic operation of a transformer. Based on the change in output voltage, transformers are classified as either step-up or step-down. These types are commonly used in power grids for power distribution and transmission
Cooling Methods of Transformers
Therefore, it's crucial to install a cooling system in transformers. Transformers can be divided into two main types based on the cooling method: oil-immersed transformers and dry-type transformers.
In oil-immersed transformers, the oil tank serves as the transformer's shell, containing the core and windings, and filled with mineral oil. This transformer oil provides insulation and cooling. Oil-immersed transformers are known for being low-loss, high-capacity, and cost-effective.
The dry-type transformers use air-natural or natural convection cooling methods. Compared to oil-immersed transformers, dry-type transformers are relatively more environmentally friendly, safer, and more reliable.
Additionally, it is worth mentioning that epoxy resin transformers have high mechanical strength, strong short-circuit resistance and strong overload capacity. Their features are significantly superior to other types of dry-type transformers.
Future of Transformers
After more than a hundred years of development, transformer technology has become increasingly mature, and various types have emerged to suit different applications. In the future, driven by trends such as intelligence, greening, and efficiency, the transformer industry will embrace new development opportunities. Companies need to enhance technological innovation and industrial upgrading, improve product quality and environmental performance, and actively expand international markets to achieve sustainable development. At the same time, the governments of many countries and all sectors of society should give more attention and support to jointly promote the healthy development of the transformer industry.
In the coming years, driven by global low-carbon policies, the main factors driving the demand for transformers include the growth in electricity demand, grid replacement cycles, and new energy installations. For instance, according to reports from CNBC and the U.S. Department of Energy, most of the U.S. power grid was built in the 1960s and 1970s, meaning over 70% of the transmission system is more than 25 years old. Europe’s continuous efforts to expand renewable energy are expected to sustain the demand for transformers. According to Global Market Insight, the overall transformer market is projected to experience continuous growth. In 2022, the total market size was approximately $54 billion, and from 2023 to 2032, the market is expected to grow at a CAGR of 7.2%, reaching an estimated market value of around $109.5 billion by 2032.
With the steady development of the global economy, especially the continuous increase in power generation, industrial activities, and electricity consumption, the market demand for dry-type transformers is on the rise. This trend is driven by several factors: firstly, the superior feature of dry-type transformers—and secondly, the promotion of energy policies. Many countries encourage the use of high-efficiency and energy-saving equipment to reduce energy consumption and carbon emissions, making dry-type transformers an important choice. Thirdly, technological innovation has led to continuous improvements in manufacturing processes and material applications, enhancing the performance of dry-type transformers and further expanding market demand.
CEEG Transformers
CEEG, as a skilled and experienced transformer manufacturer, has sold its products worldwide over the decades. Our products include dry-type transformers such as the SG series dry-type transformers and amorphous alloy dry-type transformers; oil-immersed transformers such as the S series oil-immersed transformers and 220kV oil-immersed transformers; prefabricated substations such as the YBF series wind/photovoltaic substations and European-style prefabricated substations; and special-type transformers such as the KBSG series mining explosion-proof dry-type transformers and non-encapsulated dry-type transformers. These products are widely used in various international projects.
CEEG has built long-term strategic partnerships with companies such as DuPont, ABB, and Siemens. Guided by the green concept of “safety, energy-saving, and environmental protection,” we are committed to making CEEG into a modern enterprise that integrates R&D, manufacturing, and sales. If you are interested in our products, please contact us as soon as possible, and we will provide you with the highest quality products and the best services!