Magnetic core applied to reactor and reactor

Abstract

A magnetic core utilized in a reactor includes an upper yoke, a bottom yoke, and at least two core columns. The closed magnetic loop is formed by the upper yoke, the bottom yoke, and the core columns. The core columns include at least one first magnetic column. The first magnetic column includes a core body, a balance magnetic unit and an air gap. The balance magnetic unit and the adjacent air gap form a composite air gap for dividing the first magnetic column into different parts. The upper yoke, the bottom yoke, and the two core columns constitute a closed magnetic loop. The composite air gap is disposed at a side of the core body. The upper yoke, the bottom yoke, and the core body are made of planar laminated magnetic material. The magnetic permeability of the balance magnetic unit is lower than which of the planar laminated magnetic material.

Description

technical field [0001] The present invention relates to a magnetic core, in particular to a magnetic core for a reactor. Background technique [0002] At present, in the application of high-power converters, reactors are often used to suppress current ripple and improve power factor. With the development of switching elements, the switching frequency continues to increase, especially when the switching frequency reaches above 5kHz, the traditional reactors that directly use silicon steel sheet materials and open air gaps gradually become Not very applicable. Therefore, there are two new combinations of materials for the magnetic core of the reactor, one is stacked with metal powder core blocks (Block Core), and the other is stacked with planar laminated magnetic materials. Both require an air gap on the magnetic core. [0003] These two reactors have their own advantages. The reactor made of stacked metal powder core blocks can effectively reduce the high-frequency eddy c...

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Problems solved by technology

[0003] These two reactors have their own advantages. The reactor made of stacked metal powder core blocks can effectively reduce the high-frequency eddy current loss of the reactor winding due to the special dispersed air gap of the metal powder core. With soft saturation characteristics, it can effectively deal with special working conditions such as instantaneous large pulse current and overload operation; while the reactor made of planar laminated magnetic material with air gap, due to the low core loss and high saturation of the material itself Magnetic flux density, the prepared reactor is small in size and uses less copper, but relatively, due to the relatively concentrated air gap, the opening of the air gap in the planar laminated magnetic material will increase the winding loss very obviously, and the planar laminated The diffuse magnetic flux generated by the air gap of the sheet magnetic material will also cut the planar laminated magnetic material itself, resulting in an increase in the core eddy current loss of the reactor

[0004] Although the reactor made of planar laminated magnetic material increases the eddy current loss of the winding and the eddy current loss of the magnetic core due to the diffused magnetic flux, the total loss can basically be reduced due to the small amount of copper wire and magnetic core. It is equivalent to the metal powder core reactor; although the reactor made of stacked metal powder core blocks is larger in volume, due to its soft saturation characteristics, the light load inductance is lower than that of the reactor made of planar laminated magnetic materials. to be big

And users are often vacillating between these two solutions, it is difficult to choose

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