Electromagnetic compatibility EMC filter, circuit device, and power management system

Abstract

The invention relates to an electromagnetic compatibility (EMC) filter, a circuit device and a power management system. Provided is an electromagnetic compatibility (EMC) filter (1000), comprising an EMC filter body (1); an EMC filter includes an EMC filter body (1), a busbar (2) serving as a carrier carrying a current passing through the EMC filter body (1), a heat dissipation pad (3) having a first surface (31) for contacting the busbar (2), and a holder (4) attached to the EMC filter body (1) and configured to support the heat dissipation pad (3). In an EMC filter, a holder is used to hold contact between a busbar and a heat dissipation pad so that the heat dissipation pad may be integrated with the EMC filter and improve heat dissipation performance. In addition, the retainer disclosed by the invention can also be used for meeting a creepage distance requirement so as to improve electrical protection.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to power management systems, and according to more particular, to an electromagnetic compatibility filter. BACKGROUND

[0002] An electromagnetic compatibility filter (EMC filter) is a component used to suppress electromagnetic interference (EMI). In a typical scenario where an EMC filter is applied, a heat sink pad is required to be provided on a base carrying the EMC filter, which is used to mechanically contact a busbar (e.g., a copper bar) electrically connected to the EMC filter, so as to achieve heat dissipation of the busbar and prevent the EMC filter from being affected by the overheated busbar, to ensure the normal operation of the components in the EMC filter. SUMMARY

[0003] It is desirable to improve the design of an electromagnetic compatibility (EMC) filter, so that the structure of the EMC filter is more compact.

[0004] According to an embodiment in accordance with the first aspect of the present disclosure, an electromagnetic compatibility (EMC) filter is provided. The EMC filter comprises an EMC filter body, a busbar, a heat sink pad, and a retainer. The busbar serves as a carrier to carry current through the EMC filter body. A first surface of the heat sink pad is configured to contact the busbar. The retainer is attached to the EMC filter body and is configured to support the heat sink pad.

[0005] The inventors of the present application have found that the size of the heat sink pad used in conventional EMC filter applications also takes into account the creepage distance requirement, so that the heat sink pad has a larger size. Specifically, in the case of considering both the heat dissipation function and the creepage distance requirement, that is, in the conventional EMC filter application, the size of the heat sink pad needs to be set to be larger than the size of the busbar (e.g., a copper bar). While in the case of only considering the heat dissipation function, the size of the heat sink pad can be set to match the size of the busbar (e.g., a copper bar). It is desirable to be able to reduce the size of the heat sink pad, because the size of the heat sink pad beyond the heat dissipation function occupies more space, and therefore such a heat sink pad results in a larger volume of the EMC filter.

[0006] The EMC filter provided by the present disclosure uses a retainer to maintain the contact between the heat sink pad and the heat sink pad, so that the heat sink pad can be integrated with the EMC filter. The retainer of the present disclosure can also be used to meet the creepage distance requirement, because the material and size of the retainer can also be considered when designing the arrangement that meets the creepage distance, especially in combination with the heat sink pad. In addition, the retainer of the present disclosure allows the heat sink pad to be pre-installed on the retainer, which facilitates the rapid assembly of the EMC filter.

[0007] According to some embodiments, the EMC filter further comprises a base. The base is configured to support the EMC filter body. During the heat dissipation pad is supported by the retainer, a first portion of a second surface of the heat dissipation pad opposite to the first surface is in contact with the retainer and a second portion of the second surface is in contact with the housing. In this way, heat of the heat dissipation pad can also be transferred to the housing, thereby facilitating the heat dissipation effect.

[0008] According to embodiments in accordance with the second aspect of the present disclosure, a circuit arrangement is provided. The circuit arrangement comprises the EMC filter described in accordance with the first aspect.

[0009] According to embodiments in accordance with the third aspect of the present disclosure, a power management system of a vehicle is provided. The circuit arrangement described in accordance with the second aspect is comprised. The vehicle for example comprises an electric vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0010] For better understanding of the technical solutions of the present disclosure, and in order to more clearly illustrate how the technical solutions of the present disclosure are achieved, reference will now be made to the accompanying drawings, only by way of examples, in which:

[0011] Figure 1 A schematic diagram of the EMC filter provided by the present disclosure is provided in terms of the connection relationship of various components of the EMC filter;

[0012] Figure 2 An example of the EMC filter body is provided;

[0013] Figure 3 A top view of the EMC filter provided by the present disclosure is shown;

[0014] Figure 4 A first side view of the EMC filter of Figure 3 is shown;

[0015] Figure 5 A second side view of the EMC filter of Figure 3 is shown;

[0016] Figures 6A-6B A first example of the combination of the heat dissipation pad and the retainer is provided;

[0017] Figures 7A-7B A second example of the combination of the heat dissipation pad and the retainer is provided; and

[0018] Figures 8A-8B A third example of the combination of the heat dissipation pad and the retainer is provided. DETAILED DESCRIPTION

[0019] The subject matter described herein will now be discussed in relation to several example embodiments. These embodiments are discussed in order to enable better understanding of the subject matter described herein and to enable practice of the subject matter described herein, and are not intended to limit the scope of the subject matter described herein.

[0020] The terms "including" or "comprising" and variations thereof, are to be interpreted in an open-ended manner such that they are to mean "including, but not limited to". The term "or" is to be interpreted as "and / or" unless expressly indicated otherwise. The term "based on" is to be interpreted as "based, at least in part, on". The term "one embodiment" and "an embodiment" are to be interpreted to mean "at least one embodiment". The term "another embodiment" is to be interpreted to mean "at least one other embodiment".

[0021] Unless otherwise defined or limited, the terms "connected" and "coupled" and variations thereof are used broadly and encompass both direct and indirect connections and couplings. Further, "connected" and "coupled" are not restricted to physical or mechanical connections or couplings. In the following description, identical or similar components and / or steps are denoted by identical reference numerals and designations. Further explicit and implicit definitions can be included below.

[0022] It has been found that the size of the EMC filter in existing designs has a large size due to the conventional design of the arrangement of the heat sink pad. Specifically, in the conventional arrangement, the heat sink pad is not only used for heat dissipation to the busbar, but also used as part of the arrangement to form the creepage distance protection, such that the heat sink pad is usually designed to have a large size. This inevitably leads to the need for more space to be provided in the EMC filter to accommodate such heat sink pad. This is disadvantageous for optimization, in particular, reduction of the space occupied by the power management system in which the EMC filter is applied, for example, in a vehicle.

[0023] The present disclosure provides an EMC filter which is optimized and improved, in particular, in the arrangement of the heat sink pad, and which is capable of reducing the space occupied by the arrangement of the heat sink pad. In addition, the arrangement of the heat sink pad according to the embodiments of the present disclosure also has improved heat dissipation capability.

[0024] Figure 1 A schematic diagram of the connection relationship of the various components of the EMC filter provided by the present disclosure is provided. Reference is made to Figure 1The EMC filter 1000 may include an EMC filter body 1, a busbar 2, a heat dissipation pad 3, and a retainer 4. The busbar 2 may be mechanically and electrically connected to the EMC filter body 1. The busbar 2 may serve as a carrier for current flowing through the EMC filter body 1. The heat dissipation pad 3 is configured to contact the busbar 2 for heat dissipation. The retainer 4 is attached to the EMC filter body 1 and configured to support the heat dissipation pad 3. Additionally, the EMC filter 1000 may include a base 5 and a cover 6. The base 5 and cover 6 may be used to form an enclosed space to accommodate the EMC filter body 1, the busbar 2, the heat dissipation pad 3, and the retainer 4. The retainer 4 is used to maintain reliable contact between the heat dissipation pad 3 and the busbar 2. Furthermore, the retainer 4 may also be used to form creepage distance protection. This improves electrical protection for the busbar 2.

[0025] The EMC filter body 1 can be supported by a base 5 or a portion 52 of the base 5. The portion 52 can be disposed on the bottom or side of the base 5. In some embodiments, the base 5 may also include a protruding portion 51. The protruding portion 51 can be configured to partially contact the heat sink 3, allowing heat from the heat sink 3 to be transferred to the base 5. Reference will be made below. Figures 2-5 Describe the connection relationships between these components in more detail.

[0026] Figure 2 An example of an EMC filter body 1 is provided. (Reference) Figure 2 The EMC filter body 1 may include a housing 10 and electrical components. The housing 10 is used to fix and support electronic devices and to protect the electrical components, such as by providing waterproofing and / or protection against solid particles. The electrical components may include magnetic cores 12-1, 12-2, 12-3; capacitors 13-1, 13-2, 13-1, 13-2; and circuit boards 14-1, 14-2. In some embodiments, the magnetic cores 12-1, 12-2, 12-3; capacitors 13-1, 13-2, 13-1, 13-2; and circuit boards 14-1, 14-2 may be mounted inside or on the housing 10, and the magnetic cores 12-1, 12-2, 12-3; capacitors 13-1, 13-2, 13-1, 13-2; and circuit boards 14-1, 14-2 may be connected according to a circuit for suppressing electromagnetic interference (EMI), for example, one of the electrical components may be connected in series or in parallel with other electrical components.

[0027] In one embodiment, busbar 2 can be mechanically and electrically connected to electrical components. One end 2-1 of busbar 2 can be used for connection to terminals or wires of a first additional device and for receiving input (e.g., current) from an external source. Busbar 2 can be arranged to extend across the length of housing 10. The opposite ends of busbar 2 (in... Figure 1The second additional device (not visible, near the left side) can be connected with the terminals or wires of the busbar 2. The opposite end of the busbar 2 can be used to receive the output from the EMC filter body 1 and provide it to the second additional device. The output is the output (processed current) after being processed by the electrical components of the filter body 1. In a power supply system, the EMC filter helps to reduce high-frequency conducted interference. This enables sensitive equipment to function properly without malfunctioning.

[0028] Figure 3 A top view of the EMC filter provided by the present disclosure is shown, in which reference is made to Figure 2 The EMC filter body 1 is shown. Reference is made to Figure 3 The EMC filter can further comprise a base 5. The EMC filter body 1 can be mounted on the base 5, for example by the housing 10 being mounted to the base 5. A combination of a heat sink pad and a retainer (to be described in more detail below in connection with Figures 4-8B ) is provided between the EMC filter body 1 and the base 5. With such an arrangement, the arrangement of the heat sink pad can be made more compact.

[0029] Figure 4 A first side view of the EMC filter of Figure 3 is shown, Figure 5 A second side view of the EMC filter of Figure 3 is shown. Reference is made to Figures 4-5 and can be made continuously to Figure 3 The retainer 4; 4-1, 4-2, 4-3 is attached to the EMC filter body 1, for example the housing 10 of the EMC filter body 1. The retainer 4 can be configured to support the heat sink pad 3 such that the first surface 31 of the heat sink pad 3 contacts the busbar 2. The heat sink pad 3 can be used to conduct heat from the busbar 2 and dissipate the heat. The heat sink pad 3 can be formed of or comprise a thermally conductive medium. In one embodiment, the heat sink pad 3 can comprise a thermally conductive silicone gasket, and the heat sink pad 3 is insulated from the busbar 2.

[0030] In some embodiments, the holder 4 can be made of plastic. In one embodiment, the holder 4 comprises a base portion 41 and a wall portion 42 extending from the base portion 41. The wall portion 42 encloses the heat sink 3 in a direction of an outer periphery of the heat sink 3. The size of the wall portion 42 enclosing the heat sink 3 is arranged in a manner to meet the requirement of the creepage distance. In one embodiment, the size of the wall portion 42 in a direction perpendicular to the base portion 41 can be larger than the thickness of the heat sink 3. As an example, the wall portion 42 can extend vertically in a direction perpendicular to the base portion 41. Alternatively, the wall portion 42 can be arranged to extend at a predetermined angle with respect to the direction perpendicular to the base portion 41, for example, to extend obliquely. Alternatively or additionally, the wall portion 42 can also extend curvedly. This facilitates to provide a safe arrangement beyond the general creepage distance requirement, thereby being able to guard against the current flowing through the busbar 2 to the base 5 under special circumstances, such as an electrical surge.

[0031] The base portion 41 can comprise an aperture 411. The aperture 411 will be described in more detail below in connection with Figures 6A-8B More specifically. With continued reference to Figure 4 and Figure 5 A first portion 321 of a second surface 32 of the heat sink 3 opposite the first surface 31 is in contact with the holder 4. The size of the first portion 321 can be delimited by the aperture 411. The base 5 can comprise a protruding portion 51. The protruding portion 51 of the base 5 can be in contact with a second portion 322 of the second surface 32 of the heat sink 3 through the aperture 411. The protruding portion 51 can be used to receive heat transfer of the heat sink 3, such that the heat of the heat sink 3 can be dissipated faster.

[0032] Figures 6A-6B A first example of a combination of a heat sink and a holder is provided. The wall portion 42 of the holder 4-1 encloses the heat sink 3 in a direction of an outer periphery of the heat sink 3. The shape of the base portion 41 can be arranged to match the shape of the heat sink 3. In some embodiments, the base portion 41 is arranged to define the orientation of the heat sink 3 together with the wall portion 42. This can facilitate the heat sink 3 to be installed onto the holder. Additionally, the aperture 411 of the base portion 41 can be arranged at the center of the base portion 41. This facilitates the alignment of the aperture 411 with the protruding portion 51 and facilitates the holder 4 to be installed onto the base 5.

[0033] The retainer 4-1 can further include protrusions 421. The protrusions 421 can include a protruding portion for forming a snap connection, and can be disposed on the wall portions 42. The protrusions 421 can be configured to be received by recesses of the EMC filter body 1 to secure the retainer 4-1 in place relative to the EMC filter body 1. In some embodiments, the recesses of the EMC filter body 1 can be present on the housing 10 of the EMC filter body 1. With the cooperation of the protrusions 421 of the retainer 4-1 and the recesses of the EMC filter body 1, the retainer 4-1 can be conveniently mounted to the EMC filter body 1, and the heat dissipation pad 3 supported by the retainer 4-1 can be kept in contact with the busbar 2. In one embodiment, the protrusions 421 can be disposed on the first wall portion 42-1 and the second wall portion 42-2. Additionally, the protrusions 421 can also be disposed on the third wall portion 42-3 and the fourth wall portion 42-4. During the process of mounting the retainer 4-1 to the EMC filter body 1, some or all of the protrusions 421 in the wall portions 42-1, 42-2, 42-3 and 42-4 can be used to achieve the positioning and securing of the retainer 4-1 relative to the EMC filter body 1. In one embodiment, the first wall portion 42-1 and the second wall portion 42-2 opposite to each other have the same size and configuration, and the third wall portion 42-3 and the fourth wall portion 42-4 opposite to each other have the same size and configuration. In this way, during use, the user does not need to pay attention to the front and back directions of the retainer, which is conducive to improving the efficiency of the user in mounting the retainer 4-1 to the EMC filter body 1.

[0034] Figures 7A-7BA second example of a combination of a heat dissipation pad and a holder is provided. Similar to the holder 4-1, the holder 4-2 can also be provided with the protruding portion 421. The holder 4-2 differs from the holder 4-1 in that the first wall portion 42-1 and the second wall portion 42-2 among the wall portions 42 of the holder 4-2 can have different sizes, but the third wall portion 42-3 and the fourth wall portion 42-4 have the same and smaller sizes, wherein the protruding portion 421 is arranged on the first wall portion 42-1 and the second wall portion 42-2 having the larger sizes. Such an arrangement takes into account a situation where the shape of the EMC filter body 1 at the position where the heat dissipation pad 3 contacts the EMC filter body 1 or in the vicinity thereof can hinder the holder from being installed to the EMC filter body 1. By providing the first wall portion 42-1 and the second wall portion 42-2 among the wall portions 42 of the holder 4-2 to have different sizes and the third wall portion 42-3 and the fourth wall portion 42-4 to have smaller sizes, the holder 4-2 can be made to match the shape of the EMC filter body 1 at the position where the heat dissipation pad 3 is used, thereby facilitating the attachment of the holder 4-2 to the EMC filter body 1. In addition, with such an arrangement, the structural complexity of the holder 4-2 can be reduced, and a reduction in manufacturing cost is facilitated.

[0035] Figures 8A-8B A third example of a combination of a heat dissipation pad and a holder is provided. Similar to the holder 4-1, the holder 4-3 can also be provided with the protruding portion 421. The wall portions 42 are continuous. The sizes of the wall portions 42 vary linearly or nonlinearly in the outer peripheral direction of the base portion 41. With reference to Figures 8A-8B , the first wall portion 42-1 of the wall portions 42 can have a stepped profile, that is, have varying heights. For example as Figures 8A-8B shown, the first wall portion 42-1 has two heights with respect to the base portion 41. Similarly, the third wall portion 42-3 and the fourth wall portion 42-4 can also have a stepped profile. Unlike the first wall portion 42-1, the third wall portion 42-3 and the fourth wall portion 42-4, the second wall portion 42-2 can have a uniform size, that is, have only one height with respect to the base portion 41. In addition, the second wall portion 42-2 can be arranged curvilinearly along the outer peripheral direction of the base portion 41. In a case where the shape of the base portion 41 matches the shape of the heat dissipation pad 3, such a configuration facilitates the cooperation of the base portion 41 and the second wall portion 42-2 to restrict the orientation and / or movement of the heat dissipation pad 3.

[0036] It should be noted that, by Figures 6A-8BThe provided combination of heat sink and holder is merely exemplary. Other variations of the shape and configuration of the holder are also possible. The number of apertures 411 on the base portion 41 of the holder 4 can also be two or more. The number of protrusions 421 of the wall portion 42 can also be one or more, and the position of the protrusions 421 can be set according to the position of the recess of the EMC filter body 1.

[0037] The provision of various configurations of the holder makes it possible to apply the improved combination of heat sink and holder to existing EMC filters. This advantageously reduces the cost of updating EMC filters to have the advantages described in the present disclosure, by avoiding the need to re-manufacture and configure the EMC filter body including the circuit arrangement substantially for suppressing electromagnetic interference.

[0038] Furthermore, the EMC filter according to embodiments of the present disclosure can also be applied to a circuit arrangement. Further, the circuit arrangement including the EMC filter can be applied to a power management system of a vehicle. Such circuit arrangement, power management system also therefore have the advantages described above with respect to the EMC filter. For brevity only, these are not described again here.

[0039] Other variations of the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0040] The fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0041] Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. An electromagnetic compatibility, EMC, filter (1000), comprising: an EMC filter body (1); a busbar (2) serving as a carrier to carry current through the EMC filter body (1), a heat dissipation pad (3) having a first surface (31) for contacting the busbar (2), and a holder (4) attached to the EMC filter body (1) and configured to support the heat dissipation pad (3).

2. The EMC filter (1000) according to claim 1, further comprising: a base (5) configured to support the EMC filter body (1); wherein a first portion (321) of a second surface (32) of the heat dissipation pad (3) opposite the first surface (31) is in contact with the holder (4) and a second portion (322) of the second surface (32) is in contact with the base (5) during the support of the heat dissipation pad (3) by the holder (4).

3. The EMC filter (1000) according to claim 2, wherein the holder (4) comprises a base portion (41) in contact with the first portion (321) of the second surface (32) of the heat dissipation pad (3) and a wall portion (42) extending from the base portion (41) to enclose the heat dissipation pad (3) in a peripheral direction of the heat dissipation pad (3).

4. The EMC filter (1000) according to claim 3, wherein a dimension of the wall portion (42) in a direction perpendicular to the base portion (41) is greater than a thickness of the heat dissipation pad (3).

5. The EMC filter (1000) according to claim 3, wherein a shape of the base portion (41) matches a shape of the heat dissipation pad (3), and an orientation and movement of the heat dissipation pad (3) are defined by the base portion (41) and the wall portion (42).

6. The EMC filter (1000) according to claim 3, wherein the base portion (41) comprises an aperture (411) and the base (5) comprises a protruding portion (51), the protruding portion (51) of the base (5) being in contact with the second portion (322) of the second surface (32) of the heat dissipation pad (3) through the aperture (411).

7. The EMC filter (1000) according to any one of claims 3-6, wherein the holder (4) comprises a protrusion (421) provided on the wall portion (42) and configured to be received by a recess of the EMC filter body (1) to fix the holder in place relative to the EMC filter body (1).

8. The EMC filter (1000) according to any one of claims 3-6, wherein the wall portion (4) comprises a first wall portion (42-1) having a stepped profile and a second wall portion (42-2) arranged curvilinearly along an outer circumferential direction of the base portion (41).

9. A circuit arrangement comprising: The EMC filter (1000) according to claims 1-8.

10. A power management system for a vehicle, comprising the circuit arrangement according to claim 9.

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