The existence of wave magnetic flux, the third harmonic magnetic flux in two winding core frames is exactly opposite in phase and equal in value. Therefore, the sum of the third harmonic magnetic flux vectors in each set of windings is zero. If the primary side is connected by D and there is a loop with third harmonic current, there will be no component of third harmonic voltage on the induced secondary side voltage waveform.
Ultrafine core shall be guaranteed and considered. The main body reflects the following aspects:
(1) The hardness of the amorphous alloy sheet material is very high, and it is difficult to cut with regular tools, so the design should consider reducing the amount of shear.
(2) amorphous alloy monolithic thickness is very thin, the material surface is not very flat, the iron core filling coefficient is low.
(3) Amorphous alloys are very sensitive to mechanical stress. In the structural design, the traditional design scheme of using the iron core as the main load-bearing structure must be avoided.
(4) In order to obtain excellent low-loss characteristics, amorphous alloy iron chips must be annealed.
(5) from the electrical performance. In order to reduce the amount of cutting iron chip, the iron core of the whole product is composed of four separate iron core frames in parallel, and each phase winding is set on two independent magnetic circuit frames. The magnetic flux in each box has three harmonics in addition to the fundamental flux.
amorphous alloy core distribution transformer is that the no-load loss value is extremely low. Whether the final no-load loss value can be ensured is the core issue to be considered in the whole design process. When the product structure is arranged, in addition to considering the amorphous alloy core itself is not subject to external force, at the same time, the characteristic parameters of amorphous alloy must be accurately and reasonably selected in the calculation. In addition to this design idea, the following three requirements must be followed:
(1) Due to the low saturation magnetic density of amorphous alloy materials, in product design, the rated magnetic flux density should not be selected too high, usually 1.3~1.35T magnetic flux density can be selected to obtain a better no-load loss value.
(2) the single thickness of amorphous alloy material is only 0.03mm, so its lamination coefficient can only reach 82% ~ 86%
(3) In order to enable users to obtain the benefits of maintenance-free or less maintenance, the products of amorphous alloy distribution transformers are designed as fully sealed structures.
Transformer Amorphous Alloy Structure Characteristics
the use of magnetic conductivity of the outstanding amorphous alloy, used as a core material for the manufacture of transformers, and ultimately can obtain a very low loss value. But it has many characteristics that are essential in design and manufacture.
According to the above analysis, the most reasonable structure of the ultra-fine crystal iron core three-phase amorphous alloy distribution transformer is: the iron core, which consists of four separate iron core frames in the same plane to form a three-phase five-column type, must be annealed, and with cross-iron yoke joints, the cross-sectional shape is rectangular. Winding, rectangular cross-section, can be separately wound forming, double-layer or multi-layer rectangular layer type. The oil tank is fully sealed and maintenance-free corrugated structure.
