0.08 mm silicon steel tape winding laminated core magnetic properties
26 Dec 2023
Reading Volume :
GNEE Steel Electrical Steel
In recent years, the global environment is facing more severe challenges, and it is urgent to improve motor efficiency and reduce motor loss. In addition, with the rise of new mobile technologies, the use environment and specification requirements of motors have also changed, requiring smaller and higher power output motors. In order to meet these requirements, increasing the rotation speed of the motor becomes a solution, even for small motors, by increasing the speed can also increase the output power. However, with the increase of speed, the iron loss of the motor iron core will also increase sharply, resulting in a decrease in efficiency.
The motor iron core is usually made of non-oriented electrical steel plate, common plate thickness of 0.5 mm and 0.35 mm. This material is chosen because the high-speed rotation of the motor is related to the high frequency of the magnetic field in the iron core, and the iron loss of the electrical steel plate will increase with the increase of frequency. This is mainly caused by eddy current loss. Eddy current loss can be expressed in terms of frequency, magnetic flux density and square of plate thickness. In order to suppress the increase in iron loss caused by frequency, extremely thin electrical steel plates have been developed, which can significantly reduce the eddy current loss relative to the increase in frequency while maintaining the characteristics of high saturated magnetic flux density of non-oriented electrical steel plates. It is reported that extremely thin electrical steel plates are manufactured by re-rolling existing non-oriented electrical steel plates. The development of this extremely thin electrical steel plate is expected to play an effective role in fields such as small high-speed motors.
However, it is still difficult to make wide-width ultra-thin electrical steel plate, and how to effectively use ultra-thin electrical steel plate to manufacture large-sized motor iron core has become a topic. To this end, people have developed a very thin electrical steel strip coil iron core called "winding laminated core", even if the width is narrow, it can achieve the large-scale goal of the motor iron core. The plate thickness of the core is only 0.08 mm, which is very thin and can be made into a winding shape. By increasing the number of winding, it can achieve a larger size relative to the radial direction. In general, "wound core" refers to the existing electrical steel plate is wound to make the core, and "wound laminated core" refers to the plate thickness of the thin electrical steel strip is wound to make the iron core. The core maintains insulation between layers by winding an extremely thin electrical steel strip with an insulating film.
At present, although methods have been developed to wind iron cores using amorphous materials with thinner plate thickness, it is impossible to maintain the interlayer insulation properties of iron cores because amorphous materials have no insulating coating themselves. In contrast, the wound laminated core is wound with an extremely thin electrical steel strip with an insulating film, so that the insulation between layers can be maintained.
Daisuke Wakabayashi and other researchers at the University of Arts and Science in Japan studied the changes caused by the structure of the iron core by comparing the structure of the wound laminated core with that of the traditional laminated core. At the same time, the optimum plate thickness and the manufacturing conditions for further reduction of iron loss are explored by evaluating the wound laminated core made of very thin electrical steel strips with different plate thicknesses.
Therefore, people can provide different sizes of iron cores, and further expand the effective use of extremely thin electrical steel plates. In particular, the laminated core with a plate thickness of 0.08mm can maintain the characteristics of low iron loss and high permeability in the frequency range of 50Hz to 1kHz, and is the most suitable core material for reducing hysteresis loss and eddy current loss. In the frequency range of more than 1kHz, a material of 0.05mm can be considered due to the increase in eddy current loss. The researchers plan to machine the laminated core made of extremely thin electrical steel strips into the shape of motor stators to further define the characteristics of the stators and their effects in motor applications.
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