Power transformer is an indispensable part of the power system. It is responsible for converting electrical energy from one voltage level to another voltage level to meet the needs of different electrical equipment. In the structure of a power transformer, the iron core can be called the "heart" of the transformer. It is the key magnetic circuit part of the transformer. It is usually made of hot-rolled or cold-rolled silicon steel sheets with a high silicon content. The surface Coated with insulating paint. The iron core and the coils wound around it form a complete electromagnetic induction system, which together realize the transmission and conversion of electrical energy.
Working principle and function of power transformer core
01 . Working Principle
In working principle, the magnetic conductor of the iron core is the magnetic circuit of the transformer, which is like a connecting bridge, converting the electrical energy of the primary circuit into magnetic energy, and transforming the electrical energy of the secondary circuit by its own magnetic energy, and is the medium of energy conversion.
02 Functions
The main function is to fix and support the transformer winding, and to provide a path that can transfer the magnetic flux as much as possible. When the alternating current passes through the transformer winding, an alternating electromagnetic field is generated, and the iron core conducts the magnetic field based on the principle of electromagnetic induction, thereby improving the transformer ratio and efficiency.
Varieties of Core Materials
Cold Rolling
To bolster the durability of silicon steel during core assembly, a technique known as cold rolling is employed, which fortifies the metal by enhancing its strength.
Annealing
Through annealing, the core steel undergoes a high-temperature treatment to eliminate impurities, thereby augmenting the metal's malleability and ductility.
Grain-Oriented Steel
While silicon steel boasts inherently high permeability, its efficacy can be heightened by aligning the grain of the steel in a singular direction. This process, known as grain orientation, can amplify flux density by up to 30%.
Power transformer core composition and classification
01 ,Components
Power transformer core is mainly composed of core body, fastener and insulation parts.
The core body is a magnetic conductor, usually composed of hot or cold rolled silicon steel sheets with a high silicon content, which are coated with insulating paint to form a core stack. The core laminates are stacked or wound in a specific way to form a closed path, which is not only the magnetic path of electromagnetic induction, but also the skeleton of the coil.
In addition, according to the different structure, the core can also be divided into two parts: the core column and the iron yoke. The core column is where the windings are set, and the yoke connects the various parts of the core to form a closed magnetic circuit. This structure helps to enhance the strength and stability of the magnetic field and improve the efficiency of the transformer.
02 ,Classification
The surface of the core is usually coated with a thin layer of oxide to prevent eddy current losses. According to the shape and structure, the transformer core can be divided into E, I, C and other different types, in addition to triangular, pentagonal, ring and other shapes of the core.
The difference of the iron core is also a basis for transformer classification. According to the winding in the iron core layout, the transformer is divided into core transformer and shell transformer; According to the phase number and capacity of the iron core, power transformers can be divided into single-phase transformers and three-phase transformers.
Application Fields
In addition to power transformers, iron cores are also widely used in inductors and magnetic materials. In the inductor, the iron core can improve its induction and quality factor, making the inductor better able to store electrical energy. In magnetic materials, the iron core can enhance the strength and stability of the magnetic field by improving the permeability of the magnetic circuit.
In summary, while the landscape of transformer manufacturing has evolved significantly over time, the fundamental concepts have endured. Should you have any inquiries regarding transformer core design or require a quotation for a particular transformer, kindly complete the form provided below.
