CN111292930A

CN111292930A - Electronic equipment and filter inductor thereof

Info

Publication number: CN111292930A
Application number: CN201811504902.3A
Authority: CN
Inventors: 沈唐兵; 李双佳; 单亮
Original assignee: Siemens Electric Vehicle Powertrain System Shanghai Co ltd
Current assignee: Siemens Electric Vehicle Powertrain System Shanghai Co ltd
Priority date: 2018-12-10
Filing date: 2018-12-10
Publication date: 2020-06-16
Anticipated expiration: 2038-12-10
Also published as: CN111292930B; WO2020119589A1

Abstract

The invention relates to an electronic device and a filter inductor (200), wherein the filter inductor can be arranged at an input end of the electronic device; the filter inductor (200) comprises a plurality of magnetic cores including a first magnetic core (22) and a second magnetic core (55) and at least one conductor embedded in the first magnetic core (22); the second magnetic core (55) has a hollow portion for receiving the first magnetic core (22), wherein the first magnetic core (22) is made of a first magnetic material, and the second magnetic core (55) is made of a second magnetic material different from the first magnetic material.

Description

Electronic equipment and filter inductor thereof

Technical Field

The present invention relates to an electronic device, and more particularly, to a filter inductor (filter inductor) of an electronic device.

Background

A high power system is typically provided with a high power module, such as a converter (converter) module or an inverter (inverter) module. Such power modules generally do not satisfy the regulatory standards of the International commission on Radio interference (CISPR) for electromagnetic interference (EMI) and other standards in the full frequency range or at least in some frequency ranges, especially in the frequency range and/or a high frequency range required by the drive system of an Electric Vehicle (EV) or a Hybrid Electric Vehicle (HEV). Therefore, a plurality of filter inductors made of different magnetic materials are required to be disposed at the input end of the high-power module, so as to filter common-mode (CM) and differential-mode (DM) noises in the full frequency range and eliminate electromagnetic interference.

Fig. 1 is a schematic cross-sectional view of a prior art filter inductor 100. The filter inductor 100 is disposed at an input of a high power module of a high power system. The filter inductor 100 includes a housing 41, a magnetic core 26, two positive and negative bus bars (buss bars) 11, a center post 202, a side post 201, a central gap 65, and at least one side gap. Two bus bars 11 are embedded in the magnetic core 26, and divide the magnetic core 26 into a center pillar 202 and a side pillar 201. The center post 202 is located between the two bus bars 11, and the rest of the magnetic core 26 is the side post 201. The central gap 45 and the at least one side gap are respectively located in the central pillar 202 and the side pillar 201, so that one structure as shown in fig. 1, which is approximately an H-shape as viewed from the cross-section of the filter inductor 100, is formed. To facilitate the above structure and component assembly, the magnetic core 26 is composed of a plurality of independent

magnetic blocks

26a, 26b, and the

magnetic blocks

26a, 26b are assembled by using an adhesive layer 33. The adhesive layer 33 may be a one-pack type epoxy adhesive (epoxy 2089).

The housing 41 is used to accommodate the magnetic core 26 and the bus bar 11, so the volume and shape of the housing 41 are designed to match the volume and shape of the magnetic core 26 and the two bus bars 11. In addition, for convenience of component assembly, the housing 41 may be composed of a plurality of housing parts, such as an upper half 41a and a lower half 41b in this embodiment.

The material of the magnetic core 26 is a magnetic material, and can be selected from one of the following soft magnetic materials: ferrite (ferrite), amorphous soft magnetic (amorphous magnetic material), and iron powder. If core 26 is made of manganese-zinc-ferrite (MnZn ferrite), filter inductor 100 can only attenuate common mode and differential mode noise in a low frequency range (e.g., between 1K and 30 mhz) due to its high permeability suitable for use in the low frequency range. Conversely, if nickel-zinc ferrite (NiZn ferrite) is selected as the material of the magnetic core 26, the filter inductor 100 can only be used to attenuate common mode and differential mode noise and eliminate electromagnetic interference in a high frequency range (e.g., between 30M and 1000 mhz) due to its high set impedance characteristics.

Therefore, in order to eliminate common mode and differential mode noise and electromagnetic interference in a full frequency range (i.e. covering the low frequency range and the high frequency range), it is necessary to provide a plurality of filter inductors, each using different magnetic materials, at the input end of the high power module, which cannot be implemented by only a single filter inductor in the prior art; in addition, the plurality of filter inductors respectively occupy a certain space inside the high power module, so that the overall volume of the high power module cannot be reduced in product design.

Disclosure of Invention

The present invention is directed to solving the above-mentioned problems and providing a filter inductor with multiple magnetic cores for eliminating noise and electromagnetic interference in a full frequency range.

In order to achieve the purpose, the invention adopts the following technical scheme:

a filter inductor can be arranged at an input end of an electronic equipment power supply module; the filter inductor comprises a plurality of magnetic cores and at least one conductor, wherein the plurality of magnetic cores comprise a first magnetic core and a second magnetic core, and the at least one conductor is embedded in the first magnetic core; the second magnetic core has a hollow portion for accommodating the first magnetic core, wherein the first magnetic core is made of a first magnetic material, and the second magnetic core is made of a second magnetic material different from the first magnetic material.

Further, the first magnetic material and the second magnetic material may be selected from the following soft magnetic materials: ferrite (ferrite), amorphous soft magnetic (amorphous magnetic material), and iron powder.

Further, the first magnetic material can eliminate noise and electromagnetic interference in a first frequency range, and the second magnetic material can eliminate noise and electromagnetic interference in a second frequency range, wherein the second frequency range is different from the first frequency range.

Further, the union of the first frequency range and the second frequency range covers a full frequency range between 1 khz and 1000 mhz.

Further, one of the first magnetic material and the second magnetic material is a nickel zinc ferrite (NiZnferrite), and the other is a manganese zinc ferrite (MnZn ferrite).

Further, the filter inductor further comprises a housing for accommodating the plurality of magnetic cores.

Further, the filter inductor further comprises a first fastening device for fixing at least one of the plurality of magnetic cores.

Further, the first fastening device includes at least one first rib and at least one first groove opposite to the at least one first rib, wherein the at least one first rib is disposed on at least one inner wall of the housing and corresponds to the at least one first groove disposed on the surface of the second magnetic core; or the at least one first groove is arranged on at least one inner wall of the shell and corresponds to the at least one first rib arranged on the surface of the second magnetic core.

Further, the filter inductor further includes at least one conductor channel formed inside the first magnetic core for passing the at least one conductor therethrough.

Further, the filter inductor further comprises a second fastening device for fixing at least one of the plurality of magnetic cores.

Further, the second fastening device includes at least one second rib and at least one second groove opposite to the at least one second rib, wherein the at least one second rib is disposed on at least one outer wall of the at least one conductor channel and corresponds to the at least one second groove disposed on a surface of a portion of the first magnetic core contacting the at least one conductor channel; or the at least one second groove is arranged in the at least one outer wall of the at least one conductor channel and corresponds to the at least one second rib arranged on the surface of the part of the first magnetic core, which is contacted with the at least one conductor channel.

Further, at least one of the first magnetic core and the second magnetic core is composed of a plurality of independent magnetic blocks, and the plurality of magnetic blocks are bonded together by using an adhesive layer (adhesive layer).

Further, the filter inductor includes two conductors, the two conductors include two bus bars (busbars) that are positive and negative, and the at least one conductor channel includes two conductor channels.

Further, the first magnetic core includes a central pillar and a side pillar, and the central pillar is located between the two conductor channels.

Further, the filter inductor includes at least one central void, the at least one central void being located within the center post.

The invention also relates to an electronic device comprising the filter inductor.

Further, the electronic device is an inverter.

Drawings

Fig. 1 is a schematic cross-sectional view of a prior art filter inductor 100.

Fig. 2a, 2b and 2c are each a cut-away schematic view of a first embodiment of a filter inductor 200 of the present invention.

Fig. 3a and 3b are each a cut-away schematic view of a second embodiment of a filter inductor 200 of the present invention.

Fig. 4a and 4b are each a cut-away schematic view of a third embodiment of a filter inductor 200 of the present invention.

Fig. 5a and 5b are each a cut-away schematic view of a fourth embodiment of a filter inductor 200 of the present invention.

Detailed Description

The essential features and advantages of the invention will be explained in more detail below with reference to the drawings and exemplary embodiments, to which the invention is not restricted.

Fig. 2a, 2b and 2c are each a cut-away schematic view of a first embodiment of a filter inductor 200 of the present invention. The filter inductor 200 is disposed at an input end of a high power module of an electronic device, such as a high power system, and has a plurality of magnetic cores for eliminating noise and electromagnetic interference in a full frequency range. At least two of the plurality of magnetic cores are made of magnetic materials different from each other. Preferably, the electronic device is an inverter.

In the present embodiment, the plurality of magnetic cores of the filter inductor 200 include a first magnetic core 22 and a second magnetic core 55, and the second magnetic core 55 has a hollow portion for accommodating the first magnetic core 22. In another embodiment (not shown), the filter inductor 200 has three magnetic cores, including a first magnetic core, a second magnetic core and a third magnetic core at the outermost periphery from inside to outside, and the second magnetic core and the third magnetic core have a hollow portion for accommodating the first magnetic core and the second magnetic core, respectively. The present invention is not limited to the number of the plurality of magnetic cores.

Further, the filter inductor 200 further includes an outer shell 44 (as shown in fig. 2 c), at least one conductor channel 101, at least one conductor, a center pillar 202, at least one center gap 65, a side pillar 201, and at least one side gap. The at least one conductor channel 101 is formed (or embedded) inside the first magnetic core 22 for passing the at least one conductor therethrough. In the present embodiment, the at least one conductor includes two positive and negative bus bars (busbars), and the filter inductor 200 has two conductor channels 101 for passing through the two bus bars.

The housing 44 may be made of plastic. The housing 44 is configured to accommodate the plurality of magnetic cores (e.g., the first magnetic core 22 and the second magnetic core 55 in the embodiment), and is provided with the at least one conductor channel 101. The volume and shape of the housing 44 are designed to match the volume and shape of the plurality of magnetic cores and the at least one conductor channel 101. In one embodiment, the housing 44 may be configured as the housing 41 of the filter inductor 100 of fig. 1, and may be composed of a plurality of housing components, such as an upper housing half 41a and a lower housing half 41 b; however, the present invention is not limited to the implementation (e.g., material, structure, size, shape, etc.) of the housing 44.

The two conductor channels 101 of the filter inductor 200 divide the first magnetic core 22 into a central pillar 202 and a side pillar 201, the central pillar 202 is located between the two conductor channels 101, and the remaining portion is the side pillar 201. The at least one central void 65 and the at least one side void are located in the center pillar 202 and the side pillar 201, respectively, and are generally located in the middle of the center pillar 202 and the side pillar 201, respectively, so as to form a structure similar to an H-shape as seen from the cross-section of the filter inductor 200 as shown in fig. 2 a. The at least one central gap 65 may be configured to receive another component of the filter inductor 200, such as a sensor. In another embodiment (not shown), the filter inductor 200 has a plurality of central voids 65 located within the center post 202. Further, in other embodiments (not shown), the filter inductor 200 does not have the above-mentioned side voids or has a plurality of the side voids. The present embodiment is not limited to the number of the at least one central gap 65 and the at least one side gap.

Further, in order to facilitate the above-mentioned structure and component assembly, the first magnetic core 22 is composed of a plurality of independent first

magnetic blocks

22a, 22b, and the assembly is performed by using an adhesive layer (adhesive layer)33 to adhere the plurality of first

magnetic blocks

22a, 22b together to form a square block with a length, a width, and a thickness of 90 mm, 60 mm, and 50 mm, respectively, as shown in fig. 2 a. The adhesive layer 33 may be made of a one-pack type epoxy adhesive (epoxy 2089). In addition, although the first magnetic core 22 in the present embodiment is composed of two first

magnetic blocks

22a, 22b, the present invention is not limited to the number of the plurality of first magnetic blocks; in addition, in another embodiment (such as the third embodiment described later), the first magnetic core 22 can be an integrally formed magnetic core block without using any adhesive layer for bonding.

The second magnetic core 55 may be a block integrally formed and having a hollow portion for accommodating the first magnetic core 22 therein, as shown in fig. 2a and 2 b. Therefore, the shape and volume of the hollow portion of the second magnetic core 55 are determined by the shape and volume of the first magnetic core 22. Further, the size and shape of each of first core 22 and second core 55 are determined in accordance with design details regarding shape or volume of filter inductor 200. In the present embodiment, the shapes of the first magnetic core 22 and the second magnetic core 55, and the shape of the hollow portion of the second magnetic core 55 are both a square; however, the present invention is not limited to the respective sizes and shapes of the first core 22 and the second core 55.

The first core 22 is made of a first magnetic material, and the second core 55 is made of a second magnetic material different from the first magnetic material. In addition, when selecting the first magnetic material and the second magnetic material, it is necessary to consider whether the two materials can achieve good effects in a certain frequency range respectively in terms of the effect of eliminating common mode and/or differential mode noise and electromagnetic interference; that is, the first magnetic material and the second magnetic material are selected to effectively eliminate noise and electromagnetic interference in a first frequency range and a second frequency range, respectively, and the first frequency range is different from the second frequency range; preferably, the union of the first frequency range and the second frequency range is a full frequency range between 1 khz and 1000 mhz.

As for the above-mentioned embodiment (not shown) having three magnetic cores, the three magnetic cores are made of different magnetic materials, each of which can effectively eliminate noise and electromagnetic interference in three frequency ranges, and the union of the three frequency ranges is the full frequency range. In this manner, the filter inductor 200 eliminates common mode and/or differential mode noise and electromagnetic interference over the full frequency range.

The magnetic material of each of the plurality of magnetic cores, such as the first magnetic material of the first magnetic core 22 and the second magnetic material of the second magnetic core 55, can be selected from the following soft magnetic materials: ferrite (ferrite), amorphous soft magnetic (amorphous magnetic material), iron powder, and the like. In the present embodiment, the first magnetic material is nickel-zinc-ferrite (NiZn ferrite), and the first magnetic core 22 can effectively attenuate common mode and/or differential mode noise and provide good electromagnetic interference cancellation effect in the first frequency range due to its high impedance characteristic in the first frequency range (e.g., a high frequency range between 1K and 30 mhz); the second magnetic material is manganese zinc ferrite (MnZnferrite), which effectively attenuates noise in the second frequency range (e.g., a low frequency range between 30 mhz and 1000 mhz) due to its high conductivity characteristics.

Thus, by utilizing the characteristics of the different magnetic materials of the first magnetic core 22 and the second magnetic core 55 in the high frequency range and the low frequency range, respectively, the single filter inductor 200 can meet the requirements for eliminating noise and electromagnetic interference in the full frequency range (i.e. including the first frequency range and the second frequency range).

Preferably, the filter inductor 200 further comprises a first fastening device and/or a second fastening device for fixing at least one of the plurality of magnetic cores. In the embodiment shown in fig. 2c, the filter inductor 200 comprises the first fastening device and the second fastening device for fixing the second magnetic core 55 and the first magnetic core 22, respectively, and thus the mutual electromagnetic interference between the first magnetic core 22 and the second magnetic core 55 can be avoided.

Further, as shown in fig. 2c, the first fastening device includes at least one first rib 81, and at least one first groove opposite to the at least one first rib 81; the at least one first rib 81 is disposed on at least one inner wall of the housing 44 and corresponds to the at least one first groove disposed on the surface of the second magnetic core 55. The second fastening means comprises at least one second rib 82 and at least one second groove opposite to the at least one second rib 82; the at least one second rib 82 is disposed on at least one outer wall of the at least one conductor channel 101 and corresponds to the at least one second groove disposed on the surface of the portion of the first magnetic core 22 contacting the at least one conductor channel 101.

In another embodiment (not shown), the positions of the ribs and the slots are reversed, that is, at least one first slot included in the first fastening device is disposed on at least one inner wall of the housing 44 and corresponds to at least one first rib 81 disposed on the surface of the second magnetic core 55; the second fastening means comprises at least one second groove arranged in at least one outer wall of the at least one conductor channel 101 and corresponding to at least one second rib 82 arranged on a surface of a portion of the first magnetic core 22 in contact with the at least one conductor channel 101.

Fig. 3a and 3b, fig. 4a and 4b, and fig. 5a and 5b are cut-away schematic views of a second, third, and fourth embodiment of a filter inductor 200 of the present invention, respectively. The second, third and fourth embodiments have the same name and same number of elements as those in the first embodiment, and the functions of these elements are similar or identical to those described above for the first embodiment, so they are not described again in detail.

The difference between the second embodiment and the first embodiment is in the shape of the first core 22 and the second core 55. The shapes of the first core 22 and the second core 55 and the shape of the hollow portion of the second core 55 in the second embodiment are all a cylindrical shape, unlike the shapes of the square blocks in the first embodiment. In other embodiments (not shown), the hollow portions of the first magnetic core 22, the second magnetic core 55 and the second magnetic core may be an elliptic cylinder or a triangular cylinder.

The first magnetic core 22 of the third embodiment and the first embodiment has the same shape and is a square, and the difference is whether the first magnetic core 22 is integrally formed. The first magnetic core 22 of the third embodiment is an integrally formed magnetic core block, and the first magnetic core 22 of the first embodiment is formed by bonding a plurality of separated first

magnetic blocks

22a, 22b using a bonding layer 33.

The second magnetic core 55 of the fourth embodiment is identical to that of the first embodiment in shape, and is a square having a hollow portion for accommodating the first magnetic core 22. The fourth embodiment is different from the first embodiment in that the second magnetic core 55 of the fourth embodiment includes a plurality of independent second

magnetic blocks

55a, 55b, and the second

magnetic blocks

55a, 55b are bonded by using an adhesive layer 33, however, the second magnetic core 55 of the first embodiment is an integrally formed magnetic core block without using any adhesive layer. Therefore, although the second magnetic core 55 in the fourth embodiment is composed of two second

magnetic blocks

55a, 55b, the present invention is not limited to the number of the plurality of second magnetic blocks 55.

Compared with the prior art, the prior art needs to install a plurality of filter inductors at the input end of a high-power module to eliminate noise and electromagnetic interference in the full frequency range, but the invention has the advantages that the effect can be achieved only by arranging one filter inductor; on the other hand, because a high-power module does not need to have a plurality of filter inductors, the filter inductor of the present invention can reduce the manufacturing cost of the high-power module and the high-power system to which the high-power module belongs, and can reduce the volume of the high-power module, and the power density of the high-power module is higher.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A filter inductor (200) that may be installed at an input of an electronic device; the filter inductor (200) comprises a first magnetic core (22) and at least one conductor disposed within the first magnetic core (22); the filter inductor (200) is characterized by comprising:

-a plurality of magnetic cores including at least said first magnetic core (22) and a second magnetic core (55), said second magnetic core (55) having a hollow portion for receiving said first magnetic core (22), wherein said first magnetic core (22) is formed of a first magnetic material and said second magnetic core (55) is formed of a second magnetic material, said second magnetic material being different from said first magnetic material.

2. The filter inductor (200) of claim 1, wherein: the first magnetic material and the second magnetic material may be selected from the following soft magnetic materials: ferrite, amorphous soft magnetic, and iron powder.

3. The filter inductor (200) of claim 2, wherein: the first magnetic material is capable of canceling noise and electromagnetic interference in a first frequency range, and the second magnetic material is capable of canceling noise and electromagnetic interference in a second frequency range, the second frequency range being different from the first frequency range.

4. The filter inductor (200) of claim 3, wherein: the union of the first frequency range and the second frequency range covers a full frequency range, which is between 1 khz and 1000 mhz.

5. The filter inductor (200) of claim 1, wherein: one of the first magnetic material and the second magnetic material is nickel-zinc ferrite, and the other is manganese-zinc ferrite.

6. The filter inductor (200) of claim 1, wherein: the filter inductor (200) further includes a housing (44) to house the plurality of magnetic cores.

7. The filter inductor (200) of claim 6, wherein: the filter inductor (200) further comprises a first fastening device for fixing at least one magnetic core (55) of the plurality of magnetic cores.

8. The filter inductor (200) of claim 7, wherein: the first fastening means comprise at least one first rib (81) and at least one first groove opposite to the at least one first rib (81), wherein:

-said at least one first rib (81) is arranged on at least one inner wall of said casing (44) and corresponds to said at least one first groove arranged on the surface of said second magnetic core (55); or

-said at least one first groove is provided on at least one inner wall of said casing (44) and corresponds to said at least one first rib (81) provided on the surface of said second magnetic core (55).

9. The filter inductor (200) of claim 1, wherein: the filter inductor (200) further comprises at least one conductor channel (101), wherein the at least one conductor channel (101) is formed inside the first magnetic core (22) and is used for allowing the at least one conductor to pass through.

10. The filter inductor (200) of claim 9, wherein: the filter inductor (200) further comprises a second fastening device for fixing at least one magnetic core (22) of the plurality of magnetic cores.

11. The filter inductor (200) of claim 10, wherein: the second fastening means comprises at least one second rib (82) and at least one second groove opposite the at least one second rib (82), wherein:

-said at least one second rib (82) is arranged on at least one outer wall of said at least one conductor channel (101) and corresponds to said at least one second groove arranged on the surface of the portion of said first magnetic core (22) in contact with said at least one conductor channel (101); or

-said at least one second groove is provided on at least one outer wall of said at least one conductor channel (101) and corresponds to said at least one second rib (82) provided on the surface of the portion of said first magnetic core (22) in contact with said at least one conductor channel (101).

12. The filter inductor (200) of claim 1, wherein: at least one of the first magnetic core (22) and the second magnetic core (55) is composed of a plurality of independent magnetic blocks, and the plurality of magnetic blocks are bonded together by using a bonding layer (33).

13. The filter inductor (200) of claim 9, wherein: the filter inductor (200) comprises two conductors comprising two bus bars, each being positive and negative, the at least one conductor channel comprising two conductor channels (101).

14. The filter inductor (200) of claim 13, wherein: the first magnetic core (22) comprises a central pillar (202) and a side pillar (201), the central pillar (202) being located between the two conductor channels (101).

15. The filter inductor (200) of claim 14, wherein: the filter inductor (200) comprises at least one central void (65), the at least one central void (65) being located within the center post (202).

16. An electronic device, characterized in that it comprises a filter inductor (200) according to any one of claims 1 to 15.

17. The electronic device of claim 16, wherein: the electronic device is an inverter.