This application claims priority to China Application Serial Number 201310147928.8, filed Apr. 25, 2013, which is herein incorporated by reference.
1. Field of Invention
The present invention relates to a magnetic component. More particularly, the present invention relates to a magnetic core.
2. Description of Related Art
A regular magnetic component, such as an inductor or a transformer, comprises a magnetic core generating a closed magnetic loop, and a set of winding coil winding on the magnetic core. Examples of traditional magnetic components 10 are shown respectively in
A conventional magnetic core 20 is often made by a uniform-filling method. The so-called uniform-filling method means that the magnetic core 20 is composed of a same magnetic material at the cross section perpendicular to the magnetic flux direction M. For example, the magnetic core 20 can be composed of a single kind of magnetic material, as shown in
Since the magnetic permeability of a magnetic material decreases with an increase of magnetic field intensity, generally speaking, the inductance of reactor or inductor would decrease along with a DC-bias current applied increasingly. In case of the DC component of load current is in a significant amount, Better DC-bias characteristics could keep a higher inductance and a less variation between the initial inductance (i.e., the inductance when a current of zero passes an inductor) and the inductance under the DC-bias current. As such, it becomes a challenge to retain the better DC-bias characteristics in the case that a DC component of a load current is in a significant amount.
The present invention provides a magnetic core to induce higher initial inductance for magnetic components and better DC-bias characteristics.
One aspect of the present invention provides a magnetic core having a magnetic flux direction. The magnetic core comprises a first magnetic material and at least one non-uniform filling section connected to the first magnetic material, in which the non-uniform filling section comprises a plurality of magnetic materials with at least two different values of initial magnetic permeability at a cross section perpendicular to the magnetic flux direction. Another aspect of the present invention provides a magnetic component that utilizes the mentioned magnetic core, comprising the magnetic core and a set of winding coil winding on a magnetic column of the magnetic core.
Yet another aspect of the present invention provides a magnetic core having a plurality of magnetic columns, a plurality of magnetic covers, and a magnetic flux direction. The magnetic core comprises a first magnetic material and a non-uniform filling section disposed at a corner of connection between the magnetic columns and the magnetic covers. The non-uniform filling section comprises a second magnetic material and a third magnetic material having values of initial magnetic permeability different to each other, and the second magnetic material and the third magnetic material are disposed at the outer and inner side of the magnetic core, respectively. Another aspect of the present invention provides a magnetic component that utilizes the mentioned magnetic core, comprising the magnetic core and a set of winding coil winding on a magnetic column of the magnetic core.
Comparing to the conventional uniform-filling magnetic core, the magnetic core of the present magnetic component utilizes the non-uniform filling design, such that the present magnetic component can provide higher initial inductance and better DC-bias characteristics; this improved magnetic component can provide higher inductance in specific loads, or less loss in a condition of the same inductance applied.
The invention can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows:
Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
Comparing to a uniform-filling magnetic core, the present invention suggests a concept of non-uniform filling section utilized in a magnetic core, which can provide higher initial inductance and better DC-bias characteristics. As opposed to the previously mentioned uniform-filling, the non-uniform filling indicated in this invention is a kind of magnetic material solely included in one cross section of the magnetic core perpendicular to its magnetic flux direction M; moreover, there are at least two kinds of magnetic material having different values of magnetic permeability in another cross section of the magnetic core perpendicular to its magnetic flux direction M. Details will be specifically described by following embodiments.
More specifically, the magnetic core 110 comprises a plurality of magnetic column 112 and magnetic covers 114, in which the magnetic columns 112 are all equal in length and parallel to each other; the magnetic covers 114 are disposed at the two ends of the magnetic columns 112 in order to form the closed magnetic loop by adhering closely with the magnetic columns 112. A set of winding coil 190 winds on the magnetic columns 112.
In this embodiment of the present invention, the magnetic cover 114 is a flat plate, and there are two in quantity for the magnetic columns 112 and the magnetic covers 114. However, in other embodiments, a shape of the magnetic core 110 can be changed according to different shapes of magnetic cover 114 and the quantity of the magnetic columns 112. For example, the magnetic core 110 can be ring-shaped, U-shaped, EE-shaped, EC-shaped, EQ-shaped, EFD-shaped, PQ-shaped, PT-shaped, RM-shaped, can-shaped, and etc.
The magnetic column 112 and the magnetic cover 114 can be connected by methods of applying adhering glue (e.g., epoxy, etc), compression, or fixture. A close-shaped formation of the magnetic core 110 configured by the magnetic column 112 and the magnetic cover 114 makes the magnetic core 110 the complete magnetic loop. The magnetic core 110 has a magnetic flux direction M, which passes a left magnetic column 112, a right magnetic column 112, an upper magnetic cover 114, and a bottom magnetic cover 114 to form the magnetic loop.
The magnetic core 110 with non-uniform filling design comprises the first magnetic part, made by the first magnetic material 120, and the second magnetic part, made by the non-uniform filling section 130. In this embodiment, the non-uniform filling section 130 is disposed at the magnetic column 112. The first magnetic material 120 is made of a single kind of magnetic material, and the non-uniform filling section 130 is made of at least two kinds of magnetic material. More specifically, there is only one kind of magnetic material discoverable in the cross section perpendicular to the magnetic flux direction M of the first magnetic material 120, as shown in
A kind of filling method is called the non-uniform filling if there is only one kind of magnetic material discoverable in the cross section perpendicular to the magnetic flux direction M of the first part of the magnetic core 110, and there are at least two kinds of magnetic material discoverable in the cross section perpendicular to the magnetic flux direction M of the second part of the magnetic core 110.
The previously cross section perpendicular to the magnetic flux direction M is a plane orthogonal to the magnetic flux direction M, meaning that a normal of this cross section is parallel to the magnetic flux direction M passing through the cross section.
Reference is made back
The first magnetic material 120, the second magnetic material 132, and the third magnetic material 134 can have different values of magnetic permeability; or, in other embodiments, the value of magnetic permeability of the first magnetic material 120 can be identical to the value of magnetic permeability of the second magnetic material or the value of magnetic permeability of the third magnetic material, as long as the second magnetic material 132 in the non-uniform filling section 130 is different to the third magnetic material 134. One should be noted that the term of “magnetic permeability” in this disclosure is a relative magnetic permeability and the term of “initial magnetic permeability” in the disclosure is also a relative initial magnetic permeability, i.e. the relative magnetic permeability when the applied current is zero.
In this embodiment, the first magnetic material 120, the second magnetic material 132, and the third magnetic material 134 possess a first, a second, and a third magnetic permeability, respectively. The first, second, and third magnetic permeability are with different values in regard to each other. The magnetic permeability of the second magnetic material 132 and the magnetic permeability of the third magnetic material 134 are more than 5. Also, a combined volume of the second magnetic material 132 and the third magnetic material 134 occupies 10% to 90% of total volume in the magnetic core 110.
According to this embodiment, if the value of magnetic permeability of the third magnetic material 134 is less than that of the first magnetic material 120 and the second magnetic material 132, and if the magnetic permeability and a size of the magnetic material are properly chosen, an initial inductance of the magnetic component 100 can be improved vastly. On the other hand, if the value of magnetic permeability of the third magnetic material 134 is more than that of the first magnetic material 120 and the second magnetic material 132, and if the magnetic permeability and a size of the magnetic material are properly chosen, an DC-bias characteristic of the magnetic component 100 can be improved vastly.
Citing a reactor with Block magnetic core produced by Magnetics, Inc., as an example, the magnetic core can be made by two kinds of magnetic material, kool-u 26 and kool-u 125, as structures shown in
Therefore, the user can manage to determine the first magnetic material 120, the second magnetic material 132, and the third magnetic material 134 according to needs in practices in order to let the magnetic component 100 with non-uniform filling section 130 provide good DC-bias characteristics, higher inductance in specific loads, or less loss in a condition of the same inductance applied.
In other embodiments, the non-uniform filling section 130 can of course comprise more than two kind of magnetic material, meaning that there are three or four kinds of magnetic material having different values of magnetic permeability comprised in the non-uniform filling section 130. Magnetic core may also has a plurality of the non-uniform filling sections 130, and the non-uniform filling sections 130 can comprises different magnetic materials satisfying the requirement of there are at least two kinds of magnetic material at the cross section perpendicular to the magnetic flux direction M.
The magnetic core 110 comprises an inner side, which faces the space between the magnetic columns 112, and an outer side, which faces away from the space between the magnetic columns 112. More specific, the magnetic core 110 has two magnetic columns 112 facing each other and has the space between the magnetic columns 112. The inner side represents the portion of the magnetic columns 112 adjacent to the space, and the outer side is the portion of the magnetic columns 112 far away from the space. The second magnetic material 132 is disposed at the outer side of the magnetic core 110, and the third magnetic material 134 is disposed at the inner side of the magnetic material 110.
In this embodiment, the magnetic core 110 comprises a fixed magnetic flux direction, in which the magnetic flux direction comprises an inner magnetic flux path M1, which is adjacent to the space between the magnetic columns 112, and an outer magnetic flux path M2, which is away from the space between the magnetic columns 112 The second magnetic material 132 is disposed at where an outer magnetic flux path M2 passes through, and the third magnetic material 134 is disposed at where an inner magnetic flux path M1 passes through. It should be noted that, according to different kinds of magnetic core 110, an amount of the magnetic flux direction would vary with the amount of the magnetic columns 112, and definitions of the inner magnetic flux path and the outer magnetic flux path would be slightly adjusted. However, it is basically described as above that the inner side of the magnetic core 110 is adjacent to the space formed by the magnetic columns, and the outer side of the magnetic core 110 is far away from the space formed by the magnetic columns.
The magnetic columns 112 and the magnetic covers 114 or the first magnetic materials 120 and the non-uniform filling sections 130 can be connected by methods of applying adhering glues, compression, or fixture. To avoid redundancy, the methods will be referenced thereafter. The first magnetic material 120, the second magnetic material 132, and the third magnetic material 134 can possess the first, the second, and the third magnetic permeability, respectively, as shown in
In this embodiment, the second magnetic material 120 and the first magnetic material 130 are identical. The value of magnetic permeability of the third magnetic material 134 is more than 5 and, at the same time, more than that of the first magnetic material. The volume of the third magnetic material 134 occupies 10% to 90% of total volume in the magnetic core 110.
As previously described, if the value of the second magnetic permeability or the third magnetic permeability is less than that of the first magnetic permeability, the non-uniform filling magnetic core 110 can provide higher initial inductance as opposed to the uniform filling magnetic core; in contrast, if the value of the second magnetic permeability or the third magnetic permeability is more than that of the first magnetic permeability, the non-uniform filling magnetic core 110 can improve DC-bias characteristics as opposed to the uniform filling magnetic core.
Reference is made to
According to the simulation result, if the first magnetic material 120 and the second magnetic material 132 is the magnetic material having the initial magnetic permeability 26, and if the third magnetic material 134 is the magnetic material having the initial magnetic permeability 60, as shown in
A cross-sectional shape of the third magnetic material 134 parallel to the magnetic flux direction M can be T-shaped as wide interior and narrow exterior, as shown in
According to
The magnetic flux direction M or M′ can include an inner magnetic flux path and an outer magnetic flux path. The inner magnetic flux path is more adjacent to the space between the magnetic columns 112 comparing to the outer magnetic flux path. For example, the inner magnetic flux path of the magnetic flux direction M passes the inner side of the upper magnetic cover 114, the left magnetic column 112, the lower magnetic cover 114, and the left side of the middle magnetic column 112; the outer magnetic flux path of the magnetic flux direction M passes the outer side of upper cover 114, the left magnetic column 112, the lower magnetic cover 114, and the middle portion of the middle magnetic column 112. The inner magnetic flux path of the magnetic flux direction M′ passes the inner side of the upper magnetic cover 114, the right magnetic column 112, the lower magnetic cover 114, and the right side of the middle magnetic column 112; the outer magnetic flux path of the magnetic flux direction M′ passes the outer side of upper cover 114, the lower magnetic cover 114, the right magnetic columns 112, and the middle portion of the middle magnetic column 112.
The third magnetic material 134 can be single in quantity and disposed at the inner side of the magnetic column 112, as shown in
In addition, the concept of the non-uniform filling method of the present invention can be applicable to a ring-shaped magnetic core 110, as shown in
It should be noted that the embodiments described above are not used to limit the present invention, indicating that the quantity of the magnetic column in the magnetic core and the shape of the magnetic cover can be adjusted with respect to different needs. The magnetic core can be made of ferrites, magnetic powders, silicon steels, and etc. The quantity, size and disposing place of the first magnetic material and the non-uniform filling section can be also adjusted by different needs. The non-uniform filling section can be disposed near to the magnetic column and magnetic cover, or at the corner of connection between the two. The magnetic permeability of the magnetic material in the non-uniform filling section and the first magnetic material can be different or partially identical. The non-uniform filling section comprises at least two kind of magnetic materials having different values of magnetic permeability, meaning that the user can manage to determine arrangements or shapes between these materials according to different needs in practices, as long as the non-uniform filling section comprises at least two kinds of magnetic material having different magnetic permeability at the cross section perpendicular to the magnetic flux direction.
Comparing to the design with uniform-filling magnetic core, the design with non-uniform filling core can provide higher initial inductance and better DC-bias characteristics; this improved magnetic component can provide higher inductance in specific loads, or less loss in a condition of the same inductance applied.
Although the present invention has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims.
Number | Date | Country | Kind |
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201310147928.8 | Apr 2013 | CN | national |