How to connect the transformer core to ground

2022-07-22
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With the development of our science and technology, we have produced a series of scientific and technological products. Their appearance has changed our life, improved our work efficiency and quality of life, and so on. Today I bring you the introduction of transformer core. Iron core is the main part of magnetic circuit in transformer. It is usually made of hot-rolled or cold-rolled silicon steel sheets with high silicon content and coated with insulating paint. The iron core and the coil wound on it form a complete electromagnetic induction system. The transmission power of the power transformer depends on the material and cross-sectional area of the iron core

transformers, I believe you have also seen, large, small, square, round, row color transformers fill all corners around us. From small components in household appliances to large transformers in power supply stations of power plants. As the saying goes, although the sparrow is small, it has five internal organs. The principle of transformer is the same regardless of its size. It uses the principle of electromagnetic induction to change the current, and is composed of primary coil, secondary coil and iron core. It is often used for voltage rise and fall, safety isolation and other fields. But we will find a problem, why should the transformer core be grounded? Now let me explain the relevant knowledge of transformer core grounding for you

transformer core introduction

transformer core, which is mainly responsible for the magnetic circuit part of the circuit. Most transformer cores in the market today are made of silicon chips, but a small part of them are made of magnetic chips (chips made of magnetic chips are gradually eliminated)

the role of transformer core

the role of transformer core is mainly in two aspects: hysteresis loss and eddy current loss

1. Hysteresis loss refers to the iron loss caused by hysteresis when the transformer works in AC state, and the use of transformer core can change this phenomenon to a certain extent. And it can also alleviate the rise of the surface of the transformer during operation

2. Eddy current loss refers to the alternating current generated by the transformer during operation. It will change with the induced current generated by the magnetic flux in the iron core. This change is called eddy current. When eddy current is lost, the temperature of the iron core surface will rise, but because of the material of the iron core (silicon), our resistivity will increase in this process, which can reduce the role of eddy current

classification of transformer iron cores

it can generally be divided into the following four categories: shell and core iron cores, single-phase and three-phase iron cores, three-dimensional and plane iron cores, as well as stacked and rolled iron cores

composition of transformer core

it is mainly composed of three parts, namely body, fastener and insulator

calculation of transformer core section

the calculated power of transformer is calculated according to the cross-sectional area of core central column, the size of core window, as well as input voltage and output voltage. First, calculate the number of turns according to the cross-sectional area of the core and the input voltage. Then calculate the outlet gauge (wire diameter of enameled wire) according to the size of the window and the number of turns, and then calculate how much current can be passed according to the wire diameter. To calculate his power. According to the formula:

turn left | turn right n=4.4fbs/10 4

in the formula, n= turns, f is the frequency, B is the magnetic flux density of silicon steel sheet, generally 10000 Gauss is taken as the standard, and S is the voltage. The calculated turns are calculated step by step

calculation of transformer core power

p (W) =s (mm) 2=19*19=361w. The transformer with single-phase 220V and capacity of 300VA can be manufactured. It is known that the cross-section of the coin core is 19 square millimeters. The coin core takes silicon steel sheet with a silicon content of 9000 Gauss to select anzabi. 45/19=2.37 takes 3 turns per volt, the primary winding 3*220=660 turns, and the secondary winding 3*12=36 turns. The cross-sectional area of the primary wire is selected, and the current is 300va/220=1.36a. Considering that the safe passing current per square millimeter is 5A =1.36/5=0.28mm2, the enameled wire with a diameter of 0.6mm can be selected. The sectional area of secondary wire is 300/12=25a, 25/5=5 mm2, and the enameled wire with wire diameter of 2.6mm can be selected. If there is surplus at the iron core mouth, the diameter of the primary and secondary wires can be larger

transformer core grounding

during the use of the transformer, the iron core and the parts and components around the iron core are in a strong electromagnetic field, so the iron core itself will have a high potential to the ground affected by the electric field. If there is no wire connected between the iron core and the ground, there will be a potential difference between the iron core and the ground, resulting in intermittent discharge. And there will be a strong electromagnetic field near the winding. In this way, the iron core and parts are in an unequal magnetic field, and there is a potential difference between them. Maybe the potential difference is not very large, but it is enough for it to break through a small insulation gap, so there will be a continuous discharge phenomenon. This is absolutely not allowed in power management, and it is difficult to check this phenomenon if you want to stop it, because some small insulation gaps are invisible to our naked eyes. Therefore, we must connect the iron core with the ground

how to connect the transformer iron core grounding

the iron core grounding is usually one-point grounding, and the steel sheets in the iron core are not electrified with each other, so for the sake of safety, we must not ground all the steel sheets. When the iron core is grounded, we only need to connect one of the steel sheets to the ground, not all of them, because although there is no electricity between the steel sheets, if the steel sheets are connected to the ground, the ground will become a conductor, so that the steel sheets can conduct electricity, thus disturbing the eddy current. Therefore, one-point grounding can not only flow current to the earth, but also not disturb the eddy current, which plays the purpose of iron core grounding

transformer core manufacturer

Guangdong Haihong Transformer Co., Ltd. specializes in the production of three-dimensional wound core transformer cores, and is currently the largest three-dimensional wound core manufacturer in China. The single-phase coil core distribution transformer produced by our company is a single-phase three wire product, and has passed the full type test and other tests. The low voltage combination of the transformer is 2-times; 0.23kV, its principle and use are different from ordinary single-phase two-wire transformer. The low-voltage current of this kind of transformer is only half of the rated current of ordinary single-phase transformer (the voltage of a1-a2 is twice 230V, so the current is only half). The biggest advantage is that the line loss of the former is only 1/4 of the latter when used, which is the main reason why most foreign countries use this kind of single-phase transformer. The product complies with the national standards GB1094 "Power Transformers" and gb/t6451 "technical parameters and requirements of three-phase oil immersed power transformers" and jb/10317-02 "technical parameters and requirements of single-phase oil immersed Distribution Transformers"

Shandong Liaocheng Transformer Co., Ltd. is quite good. It is a manufacturing enterprise that mainly produces power transformers, dry-type transformers, American box transformers, European box transformers and other transmission and distribution equipment as well as high and low-voltage complete sets of power equipment. The company is located in Liaocheng City, Shandong Province, where China's famous historical and cultural city, Jiangbei Shuicheng and Liaocheng University are located. It is 90 kilometers away from Jinan, the provincial capital, and is connected by highways and railways, Beijing Kowloon Railway and Ji Han railway intersect here, and the transportation is very convenient

editor's summary: it is one of the indispensable machines in industrialization, and after our above introduction, you should know that the most important thing in transformer is the quality of iron core. Therefore, we must pay attention to check whether the iron core in the transformer is qualified when purchasing

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