About Transformer silicon steel

Commonly used transformer core is generally made of silicon steel sheet. Silicon steel is a kind of silicon (silicon is also called silicon) steel, its silicon content in 0.8 ~ 4.8%. The core of the transformer is made of silicon steel because silicon steel itself is a kind of magnetic material with strong magnetic conductivity, and it can produce large magnetic induction intensity in the energized coil, which can reduce the size of the transformer. As we know, the actual transformer is always working in AC condition, the power loss is not only in the resistance of the coil, but also generated in the core under the magnetization of alternating current. Usually the power loss in the iron core called “iron loss”, iron loss caused by two reasons, one is “hysteresis loss”, one is “eddy current loss”. Hysteresis loss is the core in the magnetization process, due to the existence of hysteresis phenomenon and the iron loss, the size of this loss and the hysteresis line of the material surrounded by the size of the area is directly proportional to the size of the hysteresis loop. Silicon steel hysteresis line is narrow, with it to do the transformer core hysteresis loss is small, can make its degree of heat is greatly reduced. Since silicon steel has the above advantages, why not use the whole piece of silicon steel core, but also to process it into a sheet? This is because the piece of iron core can reduce another kind of iron loss – “eddy current loss”. When the transformer works, there is alternating current in the coil, and the magnetic flux produced by it is of course alternating. This variable magnetic flux generates an induced current in the iron core. The induced current generated in the iron core, perpendicular to the direction of the magnetic flux in the plane of the circulation, so called eddy current. Eddy current losses also heat up the iron core. In order to reduce the eddy current loss, the transformer core with each other insulated silicon steel sheet stacked, so that the eddy current in the narrow loop, through a smaller cross-section, in order to increase the resistance of the eddy current path; at the same time, silicon in the silicon steel to make the material’s electrical resistivity increase, also play a role in reducing the role of eddy current. Used as a transformer core, generally choose 0.35mm thick cold rolled silicon steel sheet, according to the size of the required core, it will be cut into long pieces, and then stacked into the “day” or “mouth” shape. Reasonably speaking, if the eddy current is reduced, the thinner the thickness of the silicon steel sheet, splicing the narrower the strip, the better. This not only reduces the eddy current loss, reduces the temperature rise, but also saves silicon steel sheet material. But in fact the production of silicon steel core. Not only from the above side of the favorable factors, because that the production of iron core, to greatly increase the working hours, but also reduces the effective cross-section of the core. Therefore, the use of silicon steel sheet transformer core production, to start from the specific circumstances, weigh the pros and cons, choose the best size. Transformers are made according to the principle of electromagnetic induction. There are two windings, a primary winding, and a secondary winding, wound on top of a closed core column. When the original winding false on the AC supply voltage. The original group of alternating current, and the establishment of the magnetic potential, the role of the magnetic potential in the iron core will produce alternating flux. As for why it can be boosted, and will pressure it? That will need to use corrugated law to explain the flux generated by the induction current, always impede the change of the circular flux, when the original flux increases when the flux generated by the induction current and the original flux is opposite, that is, the secondary winding of the induction flux generated by the original winding and the main flux generated by the opposite, so the secondary winding of the alternating voltage appeared at a low level. Therefore, the core is the magnetic circuit part of the transformer. Silicon steel sheet for electricians is commonly known as silicon steel sheet or silicon steel sheet. As the name suggests, it is containing silicon as high as 0.8% -4.8% of the electrical silicon steel, hot and cold rolled. General thickness of 1mm or less, so called sheet. Silicon steel sheet is broadly speaking the plate class, because of its special purpose and independent of a branch. Silicon steel sheet for electrical engineering has excellent electromagnetic properties, is indispensable in the electric power, telecommunications and instrumentation industry, an important magnetic material. (1) classification of silicon steel sheet A, silicon steel sheet can be divided into low-silicon and high-silicon two kinds according to its different silicon content. Low silicon containing silicon 2.8% or less, it has a certain mechanical strength, mainly used in the manufacture of motors, commonly known as motor silicon steel sheet; high silicon containing silicon 2.8% -4.8%, it has a good magnetic, but more brittle, mainly used in the manufacture of transformer core, commonly known as transformer silicon steel sheet. Both in actual use and no strict boundaries, commonly used high silicon manufacturing large motors. B, according to the production process can be divided into two kinds of hot-rolled and cold-rolled, cold-rolled and can be divided into grain non-orientation and grain orientation of two kinds. Cold rolled sheet thickness uniformity, good surface quality, high magnetic, therefore, with the development of industry, hot rolled sheet is cold rolled sheet to replace the trend (China has explicitly requested to stop using hot rolled silicon steel sheet, that is, the pre-said “cold instead of hot”). (2) silicon steel sheet performance indicators A, low iron loss. The most important indicators of quality, the world’s countries are divided into grades of iron loss value, the lower the iron loss, the higher the grade, the quality is also high. B. High magnetic induction strength. In the same magnetic field to obtain a higher magnetic induction of silicon steel sheet, with which the size and weight of the motor or transformer core manufactured smaller, relatively speaking, can save silicon steel sheet, copper wire and insulation materials. C. High stacking coefficient. Silicon steel sheet surface smooth, flat and uniform thickness, manufacturing core stacking coefficient increased. D, good punching. For the manufacture of small, miniature motor core, this is more important. E, the surface of the insulating film adhesion and weldability is good. F, magnetic aging G, silicon steel sheet shall be delivered after annealing and pickling. (A) electrical hot-rolled silicon steel sheet (GB5212-85) electrical hot-rolled silicon steel sheet with low carbon loss of ferrosilicon soft magnetic alloy as a material, hot rolled into a thickness of less than 1mm sheet. Hot rolled silicon steel sheet for electrician also known as hot rolled silicon steel sheet. Hot rolled silicon steel sheet can be divided into low silicon (Si ≤ 2.8%) and high silicon (Si ≤ 4.8%) two kinds of steel. (B) electrical cold-rolled silicon steel sheet (GB2521-88) with silicon 0.8% -4.8% of the electrical silicon steel as the material, cold rolled and become. Cold rolled silicon steel sheet grain non-orientation and grain orientation of the two steel strip. Cold rolled electrical steel strip has a flat surface, thickness uniformity, high stacking coefficient, good punch sheet, etc., and is higher than the magnetic susceptibility of hot-rolled electrical steel strip, low iron loss. With cold strip instead of hot-rolled strip manufacturing motor or transformer, its weight and volume can be reduced by 0% -25%. If you use cold-rolled oriented strip, better performance, use it instead of hot-rolled strip or low-grade cold-rolled strip, can reduce transformer power consumption by 45% -50%, and transformer performance is more reliable. Used in the manufacture of motors and transformers. Usually, grain non-oriented cold rolled strip is used as the state of motor or welding transformer, etc.; grain oriented cold rolled strip is used as the core of power transformer, pulse transformer and magnetic amplifier. Steel plate specifications size: thickness of 0.35, 0.50, 0.65mm, width of 800-1000mm, length of ≤ 2.0m. (C) home appliances with hot-rolled silicon steel sheet (GBH46002-90) home appliances with hot-rolled silicon steel sheet grade to JDR, JDR after the number of iron loss value * 100, the number after the line for the thickness of the steel plate (mm) * 100. home appliances with hot-rolled silicon steel sheet for the electromagnetic properties of the requirements of the electromagnetic can be a little lower, the iron loss value (P15/50) the lowest value of 5.40W/kg. generally do not match the wash Delivery. Used for all kinds of electric fans, washing machines, vacuum cleaners, range hoods and other household appliances such as differential motors and so on.