The transformer core is the core component of a power transformer. As the carrier of the magnetic circuit for electromagnetic induction, it directly affects the efficiency, volume and operational stability of the transformer. ​

In terms of materials, modern transformer cores are mostly made by laminating silicon steel sheets (with a silicon content of approximately 3% to 5%). The addition of silicon can significantly increase the resistivity of iron and reduce eddy current losses - this is the useless power consumption caused by electromagnetic induction of current in the iron core. Silicon steel sheets are usually rolled into thin sheets of 0.3mm or 0.23mm. After being coated with an insulating layer on the surface, they are stacked layer by layer to further reduce the influence of eddy currents.

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Its structure is divided into two types: core-type and shell-type. In the core-type, the windings of the core wrap around the core column and are mostly used in power transformers. Shell-type cores are wound around and are commonly found in small transformers. The geometric design of the core needs to be precisely calculated to ensure the unobstructed magnetic circuit and avoid magnetic saturation at the same time. ​

Efficient core design is the key to energy conservation in transformers. Nowadays, the application of new materials such as ultrafine crystalline alloys is driving cores towards lower losses and higher magnetic permeability, providing core support for the construction of green power grids.

The adoption of laminated structure in transformer cores is a key design in electrical engineering, which is underpinned by profound physical principles and engineering considerations.

 

The challenge of eddy current loss

When alternating current passes through the windings of a transformer, a changing magnetic field is generated in the core. According to the law of electromagnetic induction, this changing magnetic field will induce a circular current inside the iron core, which is called "eddy current". If a single iron core is used, these eddy currents will cause a large amount of energy to be lost in the form of heat, not only reducing efficiency but also possibly causing the iron core to overheat.

 

Solution for laminated structure

This design can be made by stacking thin sheets of iron cores and coating each sheet with an insulating layer.

1.Significantly increase the resistance of the eddy current path

2.Limit the flow range of the vortex within a single thin sheet

3.Effectively reduce eddy current loss by over 90%

Material and process optimization

Modern transformers typically use silicon steel sheets with a thickness of 0.23 to 0.35mm. The addition of silicon further enhances the resistivity. The stacking direction is arranged along the magnetic field lines, which not only ensures the smoothness of the magnetic circuit but also minimizes the eddy current effect to the greatest extent.

 

This seemingly simple laminated design is actually the best solution to balance efficiency, cost and reliability, and remains one of the core technologies in transformer manufacturing to this day.

Transformers are essential electrical devices that facilitate the efficient transmission and distribution of electrical energy. At the heart of every transformer lies its core, which plays a crucial role in transforming voltage levels. One commonly employed technique in constructing transformer cores is lamination. In this article, we will explore why lamination is used and delve into its significance in the design and performance of transformer cores.

 Why COGO Lamination?

The primary reason for incorporating CRGO laminations in transformer cores is to mitigate energy losses caused by magnetic characteristics while maintaining optimal performance. Laminated cores consist of numerous thin layers of a magnetic material, typically silicon steel, stacked together and insulated from each other. This technique introduces several benefits that enhance the efficiency and reliability of transformers.

 

Reducing Eddy Current Losses:

When an alternating current flows through the primary winding of a transformer, it induces a magnetic field in the core. However, this varying magnetic field can induce small circulating currents, known as eddy currents, within the solid core material. These eddy currents generate heat and consume a significant amount of energy, leading to undesirable energy losses. Lamination effectively addresses this issue by breaking up the solid core into thin insulated layers, thus interrupting the flow of eddy currents and minimizing energy dissipation as a result.

 

 

Controlling Magnetic Flux:

Lamination also helps in controlling the flow of magnetic flux within the transformer core. By dividing the core into multiple layers, each with its own magnetic path, laminations ensure that the magnetic flux follows a desired and efficient route. This controlled flux path minimizes magnetic leakage and maximizes the coupling between the primary and secondary windings, leading to improved transformer performance.

 

Reducing Hysteresis Losses:

Hysteresis loss occurs when the magnetic field within the core material repeatedly reverses its polarity with each alternating cycle. By using laminations, the size of the hysteresis loop, and thus the associated hysteresis losses, can be significantly reduced. This is achieved by carefully selecting the thickness and composition of the laminations, optimizing the magnetic properties and reducing energy losses within the core.

SO…

Lamination is a fundamental technique employed in transformer core design to enhance efficiency and reduce energy losses. By effectively controlling eddy currents, magnetic flux, and hysteresis losses, laminated transformer cores ensure optimal performance and improve the overall energy efficiency of electrical power distribution systems. As technologies continue to advance, the use of advanced laminated materials and designs will further contribute to the evolution of efficient and sustainable transformers.

In the realm of materials science, there exists a star that shines brightly in the field of electrical engineering – orientation silicon steel, or simply, oriented silicon steel. This isn't just any ordinary metal; it's a technological wonder that revolutionizes the way we think about electricity and magnetism.

Imagine a material so refined and engineered that it exhibits exceptional magnetic properties, making it the go-to choice for transformers and other electrical devices. Oriented electrical steel undergoes a complex manufacturing process involving rolling and annealing to align its magnetic domains in a specific direction. This alignment is crucial, as it significantly reduces energy loss during the transformation of electrical energy, enhancing efficiency by leaps and bounds.

But why should we care? Well, in today's world where sustainability and energy efficiency are paramount, every little bit of energy saved counts. Transformers equipped with orientation silicon steel play a pivotal role in reducing electricity wastage, thereby contributing to greener, more eco-friendly power grids.

Moreover, the material's thin gauge and high permeability allow for more compact transformer designs, making it an invaluable asset in the ever-shrinking world of electronics. From large-scale power stations to the tiny transformers inside our gadgets, orientation silicon steel is there, silently working its magic.

So, the next time you marvel at the seamless flow of electricity that powers your life, remember the unsung hero behind the scenes – orientation silicon steel. It's a material that's not just about steel; it's about innovation, efficiency, and a brighter, more sustainable future.