What does distribution transformer no-load loss mean?

No-load loss refers to the active power consumed when the secondary winding of the transformer is open and the primary winding is applied with a rated voltage with a sinusoidal waveform of rated frequency. No-load losses are constant losses. It has nothing to do with the current passing through, but with the voltage that the component is exposed to. There are many factors affecting the no-load performance of the distribution transformer, such as the material properties of the silicon steel sheet, the processing technology and equipment, and the structure of the iron core.

Transformer is one of the most important electrical equipment in the power system, and reducing its power loss is of great economic significance to the power grid. No-load loss is an important parameter of the distribution transformer. As long as it is put into the power grid, no-load loss is the same regardless of whether it is no-load or how much load is carried. No-load loss has nothing to do with the load of the transformer. As long as the transformer is connected to the power supply all the year round, the no-load loss exists, and it needs to consume energy for a long time, which shows the necessity of reducing the no-load loss.

There are many factors affecting the no-load performance of the distribution transformer, such as the material properties of the silicon steel sheet, the processing technology and equipment, and the structure of the iron core. To manufacture a transformer with lower no-load loss, on the one hand, silicon steel sheets with lower unit loss are used; on the other hand, it is necessary to improve the structure and improve the manufacturing process level. However, the no-load loss cannot be reduced simply by using silicon steel sheets with lower unit losses, which will increase the core manufacturing cost. By improving the structure and improving the manufacturing process level to reduce the no-load loss, it can not only save materials, but also save costs and energy. Silicon steel sheet

Transformer no-load losses

To reduce the no-load loss of the transformer, it is necessary to understand the composition of the no-load loss and the influencing factors of each part. In view of these factors, some feasible methods are adopted to reduce the no-load loss. The no-load loss of the transformer is mainly composed of hysteresis loss, eddy current loss and additional loss in the iron core.

1. Hysteresis loss

Since the iron core is affected by the periodic change of the alternating current, the arrangement of the dipoles of the ferromagnetic material also changes periodically and produces a hysteresis phenomenon, which results in the power loss of the alternating magnetization of the iron core, which is usually called the hysteresis loss. .

2. Eddy current loss

When the magnetic flux passing through the iron core changes, eddy currents are generated in the iron core, which circulate in the plane perpendicular to the magnetic flux vector. The magnetizing force generated by the eddy current always tries to prevent the change of the original magnetizing force, thus resulting in eddy current loss.

3. Additional loss of iron core

The additional loss of the iron core is mainly determined by the following factors:

(1) Material properties. Such as the directional characteristics of the silicon steel sheet, the processing deterioration characteristics and the characteristics of the insulating film.

(2) Design structure. Such as core seam form, core stacking method, core overlap width, etc.

(3) Process processing. Such as the dimensional accuracy and burr size of punching and shearing, the handling and stacking of silicon steel sheets in the process of handling and stacking, and the stacking quality.