EMC filter and inverter

Abstract

The utility model relates to an EMC (Electro Magnetic Compatibility) filter, which comprises a bus copper bar (1); the at least one magnetic ring (2) is arranged on the bus copper bar (1) and is provided with a first end (21) and a second end (22) opposite to the first end; one capacitor module which is fixedly connected to the bus copper bar (1) is arranged at the position close to the first end of each magnetic ring (2); wherein each capacitor module comprises a plastic shell (30), a plurality of capacitors (31) accommodated in the plastic shell and an electric connecting piece (32) integrally formed with the plastic shell. The utility model also relates to an inverter comprising the EMC filter.

Description

Technical Field

[0001] The utility model relates to the technical field of electromagnetic compatibility (EMC) filters, in particular to an EMC filter with low cost and simple assembly, and an inverter including such an EMC filter, Background Art

[0002] With the increasing number of electronic systems equipped in automobiles, the possibility of electromagnetic interference problems is increasing, and the requirements for electromagnetic compatibility are also increasing. Especially for electric vehicles, due to the additional power electronic devices in the motor inverter, the requirements for EMC are even more stringent. The use of EMC filters provides a reliable and lightweight method to eliminate the mutual interference of dense sources.

[0003] Currently, the EMC magnetic core and the plastic shell are generally assembled by gluing; and when connecting the X and Y capacitors to the busbar copper row, one way is to first weld the capacitors to the printed circuit board, and then connect them to the busbar copper row by screws; another way is to first weld the pins of the capacitors to the copper row and then perform encapsulation. The current assembly method not only has the problems of complex assembly process and many types of materials; moreover, the change flexibility of the X and Y capacitors is relatively low. And after the EMC requirements change, the secondary injection molding molds of the busbar copper row cannot be shared. Summary of the Utility Model

[0004] In order to overcome the above problems, the utility model provides a new type of EMC filter, which adopts a modular design, is not only simple in assembly and low in cost, but also can flexibly adjust the capacitors.

[0005] To this end, the utility model provides an EMC filter, which includes: a busbar copper row; at least one magnetic ring mounted on the busbar copper row, the magnetic ring having a first end and a second end opposite to the first end; and at least one capacitor module, wherein one of the capacitor modules fixedly connected to the busbar copper row is provided near the first end of each magnetic ring; wherein each capacitor module includes a plastic housing, a plurality of capacitors accommodated in the plastic housing, and an electrical connector integrally formed with the plastic housing.

[0006] In the above utility model, it is advantageous to modularize the capacitors in the EMC filter. According to needs, capacitors with different numbers and different topological structures can be selected to be arranged in the capacitor module, so that the adjustment of the X and Y capacitors is more flexible.

[0007] In a preferred embodiment, the magnetic ring includes a magnetic ring housing and a magnetic core received within the magnetic ring housing. The magnetic ring housing is made of a plastic material and the magnetic core and the magnetic ring housing are integrally formed by injection molding. That is, the magnetic ring is formed by injection molding on the outer surface of the magnetic core. The manufacturing mold of such a magnetic ring is simple, low in cost, relatively small in volume, and can also ensure the waterproofness of the magnetic ring housing. In the present utility model, the plastic material may be a thermoplastic material, such as polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), nylon 66 with glass fiber, and the like.

[0008] According to a preferred embodiment of the present utility model, the plastic housing is formed by injection molding on the outer surface of the main body portion of the electrical connector, such that the electrical connector is covered by the plastic housing portion, thereby having a connection portion and a grounding end extending out of the plastic housing. The capacitor module is electrically connected to the bus bar through the connection portion.

[0009] According to a preferred embodiment of the present utility model, the plastic housing is molded to have a plurality of grooves adapted to receive the plurality of capacitors. Each groove has a through hole at the bottom leading to the electrical connector, wherein the number of the through holes is selected to be the same as the number of the pins of each capacitor, such that when the capacitor is installed in the groove, the pins of the capacitor can extend through the corresponding through holes and be connected to the electrical connector. In this embodiment, the number of capacitors may be the same as the number of grooves or less than the number of grooves.

[0010] In a preferred embodiment, the electrical connector is made of a copper sheet, wherein the pins of the capacitor can be connected to the electrical connector by soldering, and the capacitor module can be fixedly connected to the bus bar through the connection portion by laser welding.

[0011] According to an embodiment of the present utility model, the bus bar can be configured as a straight line. The EMC filter includes two capacitor modules and a magnetic ring mounted to the bus bar, wherein the two capacitor modules include a first capacitor module fixedly connected to the bus bar near the first end of the magnetic ring, and a second capacitor module fixedly connected to the bus bar on the second end side of the magnetic ring and spaced apart from the second end.

[0012] According to another solution of the present utility model, the busbar copper row can be configured to have a first branch portion and a second branch portion perpendicular to the first branch portion. The EMC filter includes two magnetic rings and three capacitor modules. One of the magnetic rings is mounted to the first branch portion, and the other magnetic ring is mounted to the second branch portion. The three capacitor modules include a first capacitor module whose first end close to one of the magnetic rings is fixedly connected to the first branch portion, a second capacitor module whose first end close to the other magnetic ring is fixedly connected to the second branch portion, and a third capacitor module fixedly connected to the first branch portion at a distance from the second end on the second end side of one of the magnetic rings.

[0013] According to yet another solution of the present utility model, the busbar copper row can be configured as a straight line and have a first copper row end and a second copper row end. The EMC filter includes three magnetic rings and four capacitor modules. The three magnetic rings are mounted to the busbar copper row at intervals along the direction from the first copper row end to the second copper row end. The first end of each of the magnetic rings faces the first copper row end. A first capacitor module fixedly connected to the busbar copper row is provided near the first end of each of the magnetic rings, and a second capacitor module is fixedly connected to the busbar copper row at a distance from the second end on the second end side of the magnetic ring near the second copper row end.

[0014] It should be understood that in the above solutions, depending on the electromagnetic compatibility requirements of the EMC filter, the configurations and arrangements of the first capacitor module, the second capacitor module, and the third capacitor module can be the same or different from each other. In the case of different configurations, the differences may only lie in the number of capacitors and the topological structure.

[0015] The present utility model also provides an inverter, wherein this inverter is the above-mentioned EMC filter.

[0016] Due to the adoption of the above technical solutions, the present utility model can achieve at least one of the following beneficial technical effects: Since the capacitors are modular, according to the electromagnetic compatibility requirements, the adjustment of capacitors, such as X and Y capacitors, is more flexible; Since both the capacitor modules and the magnetic rings are made by injection molding, the molds are simple and the cost is low; Both the capacitors and the magnetic rings are modular, reducing manual assembly. Description of the Drawings

[0017] Referring to the accompanying drawings, by reading the following detailed description, the further features and advantages of the present utility model will be more clearly understood:

[0018] Figure 1 A perspective view showing an embodiment of the EMC filter according to the present utility model is shown;

[0019] Figure 2 For Figure 1Exploded view of the EMC filter shown;

[0020] Figure 3 Is a perspective view of an embodiment of a capacitor module according to the present utility model;

[0021] Figure 4 Is Figure 3 Exploded view of the capacitor module shown, wherein the capacitor module includes a capacitor, a plastic housing member, and an electrical connector;

[0022] Figure 5 Shows Figure 4 An assembly in which the plastic housing member and the electrical connector in are molded together;

[0023] Figure 6 Shows an exploded view of a magnetic ring in an EMC filter according to the present utility model;

[0024] Figure 7 Shows a perspective view of another embodiment of an EMC filter according to the present utility model; and

[0025] Figure 8 Shows a perspective view of yet another embodiment of an EMC filter according to the present utility model. Detailed Description of the Invention

[0026] The EMC filter implemented according to the present utility model will be described below with reference to the accompanying drawings and by way of examples. In the following description, many specific details are set forth in order to enable those skilled in the art of the relevant technical field to more fully understand the present utility model. However, it is obvious to those skilled in the relevant technical field that some of these specific details may not be required for the implementation of the present utility model. In addition, it should be understood that the present utility model is not limited to the specific embodiments introduced. On the contrary, the present utility model can be implemented by any combination of the following features and elements, regardless of whether they relate to different embodiments.

[0027] Figure 1 Shows a perspective view of an embodiment of an EMC filter according to the present utility model, Figure 2 Is an exploded view of the above EMC filter. In the embodiment shown in the figure, the EMC filter 100 includes a busbar copper row 1, two magnetic rings 2, and three capacitor modules. The busbar copper row 1 includes a positive copper row 11 and a negative copper row 12, and the busbar copper row 1 is configured to have a first branch portion 13 and a second branch portion 14 perpendicular to the first branch portion 13, with one magnetic ring mounted to the first branch portion 13 and the other magnetic ring mounted to the second branch portion 14. In this embodiment, each magnetic ring 2 can be fitted onto the corresponding branch portion of the busbar copper row.

[0028] In this text, "magnetic ring" is also known as inductance ring or magnetic bead, which is a ring-shaped component made of magnetic conductive material. Their main function is to impede the flow of current and generate inductive reactance. This property is called inductance. By adjusting its own inductance value, the magnetic ring can achieve filtering and suppression of specific frequency components in the circuit, thereby reducing or eliminating noise. Different types of magnetic rings have different inductive characteristics and application ranges. When selecting a magnetic ring, the appropriate material should be chosen according to the requirements of the circuit and the working environment. For example, ferrite magnetic rings are suitable for filtering and suppression in the high-frequency range, while manganese-zinc ferrite magnetic rings are suitable for filtering and suppression in the low-frequency range.

[0029] Preferably, referring to Figure 6 , the magnetic ring 2 includes a magnetic ring housing 20 and a magnetic core 23 accommodated in the magnetic ring housing. The magnetic ring housing is made of plastic material, and the magnetic core and the magnetic ring housing can be integrally formed by injection molding. For example, the magnetic ring can be made by injection molding the magnetic ring housing on the outer surface of the magnetic core, thereby sealing and covering the magnetic core in the magnetic ring housing. The magnetic ring constructed in this way has no gap between the magnetic ring housing and the magnetic core, reducing the finished volume of the magnetic ring and achieving a good waterproof effect, and reducing the manufacturing cost. Optionally, a limiting structure such as a rib or a groove can be provided on the magnetic ring housing, and when the magnetic ring is mounted on the busbar copper row, it can be held in place by the limiting structure.

[0030] Referring again to Figure 1 and Figure 2 , the magnetic ring 2 has a first end 21 and a second end 22 opposite to the first end. In fact, the first end 21 can be defined as the front end of the magnetic ring, and the second end can be defined as the rear end of the magnetic ring. The front and rear of the magnetic ring are in terms of the distance of the capacitor relative to the high-voltage positive and negative connectors of the inverter. The side closer to the high-voltage positive and negative connectors is called the front end.

[0031] In Figure 1 the illustrated embodiment, the three capacitor modules include a first capacitor module 3a fixedly connected to the first branch 13 near the first end (front end) of a magnetic ring located on the first branch 13, a second capacitor module 3b fixedly connected to the second branch 14 near the first end (front end) of another magnetic ring, and a third capacitor module 3c fixedly connected to the first branch 13 at a side spaced apart from the second end of the magnetic ring located on the first branch 13. Although the configurations of the first capacitor module 3a, the second capacitor module 3b, and the third capacitor module 3c shown in the figure are different, they all include a plastic housing 30, a plurality of capacitors 31 accommodated in the plastic housing, and an electrical connector 32 integrally formed with the plastic housing (30). The difference between the capacitor modules lies only in the number of capacitors and their topological structures.

[0032] Figure 3 and Figure 4Stereoscopic views and exploded views of an embodiment of a capacitor module, namely the first capacitor module 3a, are respectively shown. Advantageously, the plastic housing 30 is made by injection molding on the outer surface of the main body portion of the electrical connector 32, whereby the electrical connector 32 is covered by the plastic housing portion, and thus has, for example, two connection portions 321 and two ground terminals (ground points) 322 extending out of the plastic housing. The first capacitor module 3a is electrically connected to the bus bar 1 through these two connection portions 322, for example, fixedly connected to the bus bar 1 by laser welding. For example, the electrical connector 32 can be made of a copper sheet. Here, the numbers of the connection portions 321 and the ground terminals 322 are merely exemplary, and appropriate numbers can be selected according to the specific structure.

[0033] Figure 5 Shown is an assembly made of the plastic housing 30 and the electrical connector 32 by injection molding. The plastic housing 30 is first molded to have five grooves 33 adapted to receive five capacitors 31. Two through holes 330 leading to the electrical connector 32 are provided at the bottom of each groove 33. Then, the plastic housing and the electrical connector are made into an integral part by secondary injection molding. Next, the capacitors 31 are placed into the corresponding grooves, and the capacitor pins and the electrical connector, such as a copper sheet, are soldered to make the capacitor module according to the present invention. Since the capacitor 31 generally has two pins 310, the number of the through holes 330 is selected to be consistent with the number of the pins of the capacitor, so that when the capacitor 31 is installed in the corresponding groove 33, the pins of the capacitor can extend through the corresponding through holes to be connected to the electrical connector.

[0034] In other embodiments of the capacitor module, referring again to Figure 2 , for example, the second capacitor module 3b can include three capacitors 31; for example, the third capacitor module 3c can include two capacitors 31. It should be understood that the configurations of the capacitor modules shown in the figure and the topological structures of the capacitors are merely exemplary. According to the electromagnetic compatibility of the EMC filter, capacitor modules with other capacitor topological structures can also be selected.

[0035] Figure 7 Another embodiment of the EMC filter 100 according to the present invention is shown, in which the bus bar 1 is configured as a straight line. The EMC filter includes a magnetic ring 2 mounted on the bus bar 1, and a first capacitor module 3a fixedly connected (e.g., by laser welding) to the bus bar 1 near the first end 21 (front end) of the magnetic ring 2, and a second capacitor module 3b fixedly connected to the bus bar at the second end side and spaced apart from the second end.

[0036] Figure 8Shows another embodiment of the EMC filter 100 according to the present utility model, wherein the busbar copper bar 1 is configured in a straight line and has a first copper bar end 1a and a second copper bar end 1b. In this embodiment, the EMC filter includes three magnetic rings 2 and four capacitor modules. Among them, the three magnetic rings are mounted on the busbar copper bar 1 at intervals along the direction from the first copper bar end 1a to the second copper bar end 1b. The first end (front end) 21 of each magnetic ring 2 faces the first copper bar end 1a. A first capacitor module 1a fixedly connected to the busbar copper bar 1 is provided near the first end of each magnetic ring 2, and a second capacitor module 3b fixedly connected to the busbar copper bar 1 at a distance from the second end (rear end) 22 is provided on the second end side of the magnetic ring 2 near the second copper bar end 1b.

[0037] In the present utility model, although the above EMC filter 100 is applicable to an inverter, especially an inverter used in an electric vehicle. However, the EMC filter according to the present utility model is also applicable to other fields. For example, the EMC filter can be widely used in consumer electronic products such as televisions, computers, mobile phones, etc. to improve the electromagnetic compatibility of the device and reduce the impact of electromagnetic radiation on the human body; the EMC filter is used to ensure the normal operation of communication devices and prevent electromagnetic interference from interfering with or distorting communication signals; the EMC filter is used to ensure the stable operation of industrial devices in a harsh electromagnetic environment and avoid equipment failures or malfunctions caused by electromagnetic interference.

[0038] Although the present utility model has been disclosed above with preferred embodiments, the present utility model is not limited thereto. Any combinations, changes and modifications made by those skilled in the art without departing from the spirit and scope of the present utility model shall be included within the protection scope of the present utility model. Therefore, the protection scope of the present utility model shall be subject to the scope defined by the claims.

Claims

1. An EMC filter, characterized in that: The EMC filter (100) comprises: Busbar copper bar (1); At least one magnetic ring (2) mounted to the busbar (1), the magnetic ring having a first end (21) and a second end (22) opposite to the first end; and At least one capacitor module, wherein a capacitor module fixedly connected to the busbar copper bar (1) is provided near the first end of each magnetic ring (2); Each capacitor module comprises a plastic shell (30), a plurality of capacitors (31) contained in the plastic shell, and an electrical connector (32) integrally formed with the plastic shell.

2. The EMC filter according to claim 1, characterized in that: The magnetic ring (2) comprises a magnetic ring housing (20) and a magnetic core (23) accommodated in the magnetic ring housing; the magnetic ring housing is made of plastic material, and the magnetic core and the magnetic ring housing are made into one piece by injection molding.

3. The EMC filter according to claim 1 or 2, characterized in that: The plastic shell is made by injection molding on the outer surface of the main body of the electrical connector, and the electrical connector (32) is partially covered by the plastic shell, thereby having a connecting portion (321) extending out of the plastic shell and a grounding terminal (322), and the capacitor module is electrically connected to the busbar copper bar (1) through the connecting portion (321).

4. The EMC filter according to claim 3, characterized in that: The plastic housing (30) is molded to have a plurality of grooves (33) suitable for receiving the plurality of capacitors (31), and the bottom of each groove (33) is provided with a through hole (330) leading to the electrical connector (32), wherein the number of the through holes is selected to be consistent with the number of pins (310) of each capacitor, so that when the capacitor is installed in the groove (33), the pins of the capacitor can extend through the corresponding through holes and be connected to the electrical connector.

5. The EMC filter according to claim 4, characterized in that: The electrical connector is made of a copper sheet, wherein the pin (310) of the capacitor is connected to the electrical connector by soldering, and the capacitor module is fixedly connected to the busbar copper bar (1) via the connecting portion (321) by laser welding.

6. The EMC filter according to claim 4 or 5, characterized in that: The busbar copper bar (1) is constructed in a straight line type. The EMC filter comprises two capacitor modules and a magnetic ring (2) mounted on the busbar copper bar (1). The two capacitor modules comprise a first capacitor module (3a) fixedly connected to the busbar copper bar (1) near the first end (21) of the magnetic ring (2), and a second capacitor module (3b) fixedly connected to the busbar copper bar (1) on the second end side of the magnetic ring and spaced apart from the second end.

7. The EMC filter according to claim 4 or 5, characterized in that: The busbar copper bar (1) is configured to have a first branch portion (13) and a second branch portion (14) perpendicular to the first branch portion, the EMC filter comprises two magnetic rings (2) and three capacitor modules, wherein one magnetic ring is mounted to the first branch portion (13) and the other magnetic ring is mounted to the second branch portion (14); wherein the three capacitor modules comprise a first capacitor module (3a) fixedly connected to the first branch portion (13) near the first end of the one magnetic ring, a second capacitor module (3b) fixedly connected to the second branch portion (14) near the first end of the other magnetic ring, and a third capacitor module (3c) fixedly connected to the first branch portion (13) at the second end side of the one magnetic ring and spaced apart from the second end.

8. The EMC filter according to claim 4 or 5, characterized in that: The busbar copper bar (1) is constructed in a straight line shape and has a first copper bar end (1a) and a second copper bar end (1b); the EMC filter comprises three magnetic rings (2) and four capacitor modules, the three magnetic rings are installed to the busbar copper bar (1) at intervals along the direction from the first copper bar end to the second copper bar end, wherein the first end of each magnetic ring faces the first copper bar end, wherein a first capacitor module (3a) fixedly connected to the busbar copper bar (1) is provided near the first end of each magnetic ring (2), and a second capacitor module (3b) fixedly connected to the busbar copper bar (1) is spaced apart from the second end on the second end side of the magnetic ring near the second copper bar end.

9. An inverter, characterized in that: The inverter comprises an EMC filter (100) according to any one of claims 1 to 8.

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