(1) There is no joint between layers of three-dimensional coil core, and the magnetic circuit is uniformly distributed everywhere. There is no obvious high resistance zone and no distortion of magnetic flux density at the joint.

(2) The orientation of magnetic flux is exactly the same as that of silicon steel sheet.

(3) The length of three-phase magnetic circuit is completely equal, and the sum of three-phase magnetic circuit length is the shortest.

(4) The three-phase magnetic circuit is completely symmetrical and the three-phase no-load current is completely balanced.

2. Low loss and remarkable power saving effect

(1) The magnetization direction of the three-dimensional coil core is exactly the same as the rolling direction of the silicon steel sheet, and there is no overlap between the layers of the core. The magnetic flux distribution is uniform in all parts of the magnetic circuit, and there is no obvious distortion of the magnetic flux density at the high resistance region and no joint. On the premise of the same material, compared with laminated core, the technological coefficient of iron loss of coiled core decreases from 1.3-1.5 to about 1.05. Only this one can reduce the core loss by 10-20%.

(2) Because of the special three-dimensional structure, the amount of material used in the yoke part of the core is 25% less than that of the traditional laminated core, and the reduced angular weight accounts for about 6% of the total weight of the core.

(3) Shearing treatment of silicon steel sheet will deteriorate its magnetic conductivity. The three-dimensional coil core treated by vacuum nitrogen annealing at high temperature (800 C) not only eliminates the mechanical stress of the core, but also refines the magnetic domain of the silicon steel sheet, improves the secondary recrystallization ability of the silicon steel sheet, and makes the performance of the silicon steel sheet much better than that of the silicon steel sheet when it was manufactured.

(4) The no-load loss of the three-dimensional transformer is 25-35% lower than that of the national standard, and the maximum no-load current can be reduced by 92%.

3. Low noise

The source of noise generated by transformer vibration is:

(1) Magnetostriction of silicon steel sheet causes vibration and noise of iron core.

(2) There is electromagnetic attraction between the joint of silicon steel sheet and the laminate due to magnetic leakage, which causes vibration and noise of the core.

(3) Transformer operating magnetic density is too high, close to or reach saturation point, magnetic leakage is too large, resulting in noise.

Because the three-dimensional coiling core is made of silicon steel sheet on a special coiling machine continuously and tightly without joints, it will not produce noise due to discontinuity of magnetic circuit like laminated rush. At the same time, the three-phase magnetic circuit and flux are completely symmetrical, and the design of working magnetic density is reasonable, so the product noise is greatly reduced.

The sound level of SGB10-RL-2000/10 is only 47 dB, which is 19 dB lower than the 66 dB stipulated by the national standard. It almost reaches the state of environmental protection and silence. It is most suitable for indoor and residential areas.

4. Strong overload capability

(1) The calorific value of the product itself is very low: the no-load loss and no-load current of the coil core transformer are very small, and the calorific value of the product itself is very low.

(2) As shown in the figure, the three-phase coils are arranged in the shape of "pin". A central natural gas pipeline, the "smoke pipe", is formed between the coils. As the temperature difference between the upper and lower yokes is 30-40 C, strong air convection is generated. The cold air is supplemented from below to the central channel, and the heat radiates from the inclined surface of the upper yoke. The heat generated by the transformer is quickly taken out of the natural circulation.

5. Compact structure and small area

The special three-dimensional core makes the product compact and reasonable in layout. The occupied area of the body plane is 10-15% less than that of the traditional product, and the height of the body is 10-20%. If installed in the box substation, the volume of the box can be reduced by nearly 1/4.