EMC filter assembly for power converter and power converter

Abstract

An EMC filter assembly (1, 23, 27) for a power converter, comprising a first electrical connection adapted to connect a first output terminal of the battery with a first power supply terminal of the power converter, at least one first inductor (7) as part of the first electrical connection, at least one first class Y capacitor (11, 12, 34, 35) connected between the first electrical connection and ground, a second electrical connection adapted to connect a second output terminal of the battery with a second power supply terminal of the power converter, at least one second inductor (10) as part of the second electrical connection, at least one second class Y capacitor (13, 14, 36, 37) connected between the second electrical connection and ground, at least one class X capacitor (15, 33), at least one first class Y capacitor (11, 12, 34, 35), at least one second inductor (10), at least one second class Y capacitor (13, 14, 36, 37) and at least one class X capacitor (15, 33) connected between the first and second electrical connections are housed and pre-assembled in a housing (17, 24, 30).

Description

Technical Field

[0001] The present invention relates to an EMC filter assembly for a power converter, comprising: a first electrical connector adapted to connect a first output terminal of a battery to a first power supply terminal of the power converter; at least one first inductor, which is part of the first electrical connector; at least one first Y-type capacitor connected between the first electrical connector and ground; a second electrical connector adapted to connect a second output terminal of the battery to a second power supply terminal of the power converter; at least one second inductor, which is part of the second electrical connector; at least one second Y-type capacitor connected between the second electrical connector and ground; and at least one X-type capacitor connected between the first electrical connector and the second electrical connector. Background Technology

[0002] Modern electric vehicles include power converters, particularly inverters, which are connected to batteries and generate alternating current (AC) to drive one or more electric motors. There is a trend to place inverters near the electric motors. However, this creates harsh environmental conditions for the inverter components. Therefore, it is necessary to employ EMC filter assemblies for the power converters. Conventional EMC filter assemblies typically include a first electrical connection, a first inductor, at least one first Y-type capacitor connected between the line and ground (“line-to-ground”), a second electrical connection, at least one second inductor, at least one second Y-type capacitor, and at least one X-type capacitor connected between the first and second electrical connections (“line-to-line”).

[0003] Typically, several specific EMC filter components are used for different inverters. However, when different housings with different EMC filter components are used, for example, the diversity of components makes manufacturing difficult.

[0004] In addition, some EMC filter components have shown to be susceptible to vibration. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide an EMC filter assembly that can be easily manufactured and is mechanically robust.

[0006] This objective is achieved by an EMC filter assembly having the features of claim 1.

[0007] In the EMC filter assembly of the present invention, at least a first inductor, at least one first Y-type capacitor, at least a second inductor, at least one second Y-type capacitor, and at least one X-type capacitor are housed and pre-assembled in a housing.

[0008] Specifically, at least a first inductor, at least one first Y-type capacitor, at least a second inductor, at least one second Y-type capacitor, and at least one X-type capacitor are arranged in the same housing.

[0009] For example, a housing is a single component such as a molded part.

[0010] The present invention is based on the idea that all components of the EMC filter assembly can be pre-assembled, making the EMC filter assembly a prefabricated component that can be easily installed as a single part in a power converter, particularly in an inverter.

[0011] Tests have shown that the EMC filter assembly of the present invention does not have vibration problems; on the contrary, it is very robust against vibration. The pre-assembly of different parts of the EMC filter assembly has a further advantage: the individual EMC filter components can have greater tolerances without causing problems.

[0012] In the EMC filter assembly of the present invention, the first and / or second inductors are formed as magnetic cores, nanocrystal cores, or ferrite. The specific type of electronic component used as the inductive element is selected according to the requirements of the corresponding application for which the EMC filter assembly is intended.

[0013] In this invention, it is particularly preferred that at least a first inductor, at least one first Y-type capacitor, at least a second inductor, at least one second Y-type capacitor, and at least one X-type capacitor are glued and / or encapsulated in a housing with resin. Encapsulating the components in the housing with resin ensures that all EMC filter components are embedded, thus providing them with mechanical protection against damage. If they are surrounded and embedded in the resin, vibration is automatically suppressed.

[0014] In this invention, it is also conceivable that the first electrical connector and / or the second electrical connector extend through an opening in the magnetic core (preferably a nanocrystal core). This assembly ensures the presence of the desired EMC filtering effect.

[0015] Preferably, the first electrical connector and / or the second electrical connector are formed as busbars, preferably having a rectangular cross-section. The busbars are used to connect the battery's output terminals to the power supply terminals. If necessary, the busbars can be bent to adapt to different installation environments.

[0016] In the EMC filter assembly of the present invention, the housing is preferably made of an electrically insulating material, preferably of a plastic material. When a plastic material is used for the housing, it automatically insulates the contained electrical components, thereby avoiding unwanted or dangerous electrical contact and flashover.

[0017] To facilitate mounting the housing onto the substrate, it is preferable that the housing includes at least one through-hole and / or at least one lug having a through-hole for fastening the housing. The housing can then be mounted with screws or rivets, which are inserted through the through-hole and / or the lug.

[0018] According to a preferred embodiment of the invention, the first electrical connector includes at least two first inductors and / or the second electrical connector includes at least two second inductors, wherein each of the two first or second inductors is connected in series. When two inductors connected in series are used, the corresponding inductances are added together. Accordingly, two small inductors can be used instead of one large inductor, which can be an advantage regarding installation space requirements.

[0019] A series connection of at least two first or second inductors means that these inductors are directly electrically connected to each other, with no other components or electrical paths branching off between them. This also means that they are subjected to the same current. Furthermore, the voltage drop across both inductors is equal to the sum of the voltage drops across each individual inductor.

[0020] Preferably, at least two inductors are physically adjacent to each other. This means that no other functional components are placed between them. This proximity of similar components allows for compact assembly within the housing.

[0021] This invention can specify that at least one first inductor, at least one first Y-type capacitor, at least one second inductor, at least one second Y-type capacitor, and at least one X-type capacitor are arranged on a printed circuit board (PCB) or leadframe. Alternatively, all electronic components of the EMC filter assembly can be pre-assembled on the PCB or leadframe. Subsequently, the pre-assembled PCB or leadframe is mounted in a housing. Pre-assembled electronic components help simplify and accelerate the manufacturing and assembly process.

[0022] For example, at least one first Y-type capacitor, at least one second Y-type capacitor, and at least one X-type capacitor are electrically connected to a first electrical connector and a second electrical connector, respectively, via a PCB. Direct assembly of components on the PCB allows for greater stability during operation and enhances robustness against vibration.

[0023] Preferably, the at least one first Y-type capacitor, the at least one second Y-type capacitor, and the at least one X-type capacitor are physically and electrically directly connected to the printed circuit board.

[0024] Furthermore, according to a preferred embodiment, the first and second electrical connectors include means for electrical and mechanical connection to the PCB. The aforementioned capacitor is then connected to the electrical connection via the PCB.

[0025] For example, an X-class capacitor is arranged along a length direction perpendicular to the length direction of at least one Y-class capacitor. The length of the capacitor corresponds to the line including the two connection terminals of the capacitor.

[0026] For example, all Y-type capacitors are arranged in the same length direction.

[0027] For example, Class X capacitors are arranged between Class Y capacitors.

[0028] For example, all capacitors are arranged on the same side of the first inductor and the second inductor.

[0029] For example, all capacitors are arranged in an adjacent manner.

[0030] For example, an EMC filter assembly may consist of only one Class X capacitor and several Class Y capacitors, such as four Class Y capacitors.

[0031] Furthermore, the present invention relates to a power converter for electric motors, particularly an inverter.

[0032] The power converter of the present invention includes a DC link capacitor, power electronic devices, and the EMC filter assembly of the present invention as described above. Attached Figure Description

[0033] The invention is explained with reference to the accompanying drawings, using preferred examples. The drawings are schematic and illustrate:

[0034] Figure 1 This is a perspective view and a partial cross-sectional view of a first embodiment of the EMC filter assembly of the present invention.

[0035] Figure 2 yes Figure 1 Another view of the EMC filter assembly shown.

[0036] Figure 3 This is another embodiment of the EMC filter component of the present invention.

[0037] Figure 4 This is another embodiment of the EMC filter component of the present invention.

[0038] Figure 5 These are examples of equivalent circuit diagrams for various embodiments of EMC filter components. Detailed Implementation

[0039] Figure 1A first embodiment of an EMC filter assembly 1 is shown, which includes a first electrical connector formed as a busbar 2. The busbar 2 has a rectangular cross-section and is configured to connect a first output terminal of a battery to a first power supply terminal of a power converter. The power converter may be, for example, an inverter. The EMC filter assembly 1 also includes a second electrical connector, which is also formed as a busbar 3 with a rectangular cross-section. Through-holes 4 are provided at the ends of both sides of the busbars 2 and 3, allowing easy connection of the busbars 2 and 3 to the electrical terminals. Figure 1 As shown, the central sections of the two busbars 2 and 3 extend in parallel. On one side of the EMC filter assembly 1, the end sections 5 and 6 of the busbars 2 and 3 are bent to accommodate specific installation environments.

[0040] The end sections 5 and 6 of busbars 2 and 3 are adapted to be connected to Figure 1 The printed circuit board (PCB) is not shown. This allows for electrical connections between busbars 2 and 3 and other electrical components of the EMC filter assembly, which will be given below.

[0041] exist Figure 1 In the example, the end sections 5 and 6 of busbars 2 and 3 include connecting portions with a perforated plate shape extending parallel to the PCB. The connecting portions are then secured to the PCB with screws, ensuring both electrical and mechanical connections.

[0042] The central sections of busbars 2 and 3 are surrounded by a first inductor 7, which is formed as a nanocrystal core. The first inductor 7 has a cuboid shape and two rectangular through-holes 8 and 9 arranged parallel to each other. Furthermore, a second inductor 10 of the same shape (also formed as a nanocrystal core) is positioned alongside the first inductor 7 along the longitudinal axis of busbars 2 and 3. Both busbars 2 and 3 extend through the nanocrystal core, generating an EMC filtering effect.

[0043] In addition, the EMC filter assembly 1 includes a number of Y-type capacitors (Cy capacitors) placed around the first inductor 7 and the second inductor 10. Figure 1 The lower side of the Cy capacitor is shown, with its terminals extending upwards. In the mounted state, the Y-type capacitor is arranged on a printed circuit board (PCB). For clarity, the PCB is not shown. Figure 1As shown in the diagram, Cy capacitors 11 and 12 are arranged parallel to the longitudinal axes of busbars 2 and 3. On opposite sides of busbars 2 and 3, additional Cy capacitors 13 and 14 are arranged transversely to busbars 2 and 3. Between Cy capacitors 13 and 14, a Class X capacitor (Cx capacitor) 15 is arranged parallel to the longitudinal axes of busbars 2 and 3. Each Cy capacitor 11, 12, 13, and 14 is connected between one of the busbars 2 and 3 and ground. The Cx capacitor 15 is connected between the first busbar 2 and the second busbar 3. Each Cy capacitor 11, 12, 13, 14a and the Cx capacitor 15 are housed in a socket 16, which is a box with an open side. The socket 16 is mounted in a housing 17 surrounding the EMC filter assembly 1. Figure 1 It is a cross-sectional view that exposes the interior. Two inductors 7 and 10 are housed in sockets 18 and 19, depicted with dashed lines, making their interiors visible. When the PCB is mounted with the housing 17, all capacitors arranged on the printed circuit board are pushed into their respective sockets.

[0044] Figure 2 yes Figure 1 A similar view of the EMC filter assembly 1 shown is presented, except that the complete housing 17 is depicted. It can be seen that the housing 17 comprises a lower housing portion 20 and an upper housing portion 21, which are separated approximately midway. Several lugs 22 are provided on the outer side of the housing 17, allowing the EMC filter assembly to be mounted to the structure using screws or rivets. In this embodiment, the housing 17 is made of plastic material.

[0045] Figure 3 Another embodiment of the EMC filter component 23 is shown, which has the same characteristics as... Figure 1 and Figure 2 The illustrated embodiment has a similar structure. The EMC filter assembly 23 includes a housing 24 through which busbars 25 and 26 extend. Two nanocrystal cores, serving as first and second inductors, are disposed within the housing 24. Two first Cy capacitors 11 and 12 are arranged adjacent to a Cx capacitor 15. Two second Cy capacitors 13 and 14 are arranged on opposite sides of the housing 24. The terminals of the Cx and Cy capacitors are exposed externally. In the mounted state, they penetrate the PCB, and all electronic components are mounted on the PCB. During the manufacture of the EMC filter assembly 23, the inductors and all Cx and Cy capacitors are pre-assembled and housed within the housing 24. These electronic components are encapsulated in resin within the housing 24, ensuring a secure attachment to prevent any problems caused by vibration.

[0046] Figure 4Another embodiment of the EMC filter assembly 27 is shown. For clarity, the PCB on which the electronic components are mounted is not shown. Two inductors, formed as nanocrystal cores 28 and 29, are housed in a housing 30. Figure 4 In the diagram, housing 30 is shown in cross-section. Busbars 31 and 32 extend through housing 30, connecting to the battery output terminal on one side and the power converter supply terminal on the other side. A Cx capacitor 33 is located between a first Cy capacitor 34 and 35 on one side and a second Cy capacitor 36 and 37 on the other side. [The diagram shows...] Figure 4 The EMC filter assembly 27 of all the components shown is pre-assembled. In this pre-assembled state, it can be installed on the power converter or inverter structure.

[0047] In this embodiment, the ends 38, 39, 40, and 41 of the busbars 31 and 32 are shaped as connection pins, thereby allowing electrical connection between the busbars 31 and 32 and the PCB above them.

[0048] Figure 5 Several embodiments suitable for EMC filters are shown (such as...) Figures 1 to 4 The equivalent circuit diagram of the EMC filter in the image is shown. It mainly shows the series connection between the two first inductors 42 and 43 and the two second inductors 44 and 45.

[0049] Cx capacitor 46 is connected to a first electrical connector 47 between one of the first inductors 42, 43 and the output terminal 49 of the battery, and to a second electrical connector 48 between the other of the second inductors 44, 45 and the output terminal 50 of the battery.

[0050] The first Cy capacitor 51 is connected to ground and the first electrical connector 47 between one of the first inductors 42, 43 and the battery output terminal 49. The second Cy capacitor 52 is connected to ground and the second electrical connector 48 between the other of the second inductors 44, 45 and the battery output terminal 50.

[0051] The third Cy capacitor 53 is connected to ground and the first electrical connector 47 between the first inductors 42 and 43 and one of the power supply terminals 55 of the power converter. The fourth Cy capacitor 54 is connected to ground and the second electrical connector 48 between the second inductors 44 and 45 and the other of the power supply terminals 56 of the power converter.

Claims

1. An EMC filter assembly (1, 23, 27) for a power converter, comprising: A first electrical connector is adapted to connect a first output terminal of the battery to a first power supply terminal of the power converter. At least one first inductor (7) is part of the first electrical connection. At least one first type Y capacitor (11, 12, 34, 35) is connected between the first electrical connector and ground. The second electrical connector is adapted to connect the second output terminal of the battery to the second power supply terminal of the power converter. At least one second inductor (10) is part of the second electrical connector. At least one second type Y capacitor (13, 14, 36, 37) is connected between the second electrical connector and ground. At least one Class X capacitor (15, 33) is connected between the first electrical connector and the second electrical connector. The feature is that the at least first inductor (7), the at least first Y-type capacitor (11, 12, 34, 35), the at least second inductor (10), the at least second Y-type capacitor (13, 14, 36, 37) and the at least X-type capacitor (15, 33) are received and pre-assembled in the housing (17, 24, 30).

2. The EMC filter assembly according to claim 1, wherein the first inductor (7) and / or the second inductor (10) are formed as a magnetic core or a nanocrystal core (28, 29) or ferrite.

3. The EMC filter assembly according to claim 1 or 2, wherein at least a first inductor (7), at least one first Y-type capacitor (11, 12, 34, 35), at least a second inductor (10), at least one second Y-type capacitor (13, 14, 36, 37) and at least one X-type capacitor (15, 33) are glued and / or potted in the housing (17, 24, 30) with resin.

4. The EMC filter assembly according to any one of the preceding claims, wherein the first electrical connector and / or the second electrical connector extends through an opening in the magnetic core, wherein the magnetic core is preferably a nanocrystal core (28, 29).

5. The EMC filter assembly according to any one of the preceding claims, wherein the first electrical connector and / or the second electrical connector are formed as busbars (2, 3, 25, 26, 31, 32), preferably having a rectangular cross-section.

6. The EMC filter assembly according to any one of the preceding claims, wherein the housing (17, 24, 30) is made of an electrically insulating material, preferably a plastic material.

7. The EMC filter assembly according to any one of the preceding claims, wherein the housing (17, 24, 30) includes at least one through hole for securing the housing (17, 24, 30) and / or at least one lug (22) having the through hole.

8. The EMC filter assembly according to any one of the preceding claims, wherein the first electrical connector comprises at least two first inductors (7) and / or the second electrical connector comprises at least two second inductors (10), wherein the two first inductors (7) or the second inductors (10) are each connected in series.

9. The EMC filter assembly according to any one of the preceding claims, wherein the at least one first inductor (7), the at least one first Y-type capacitor (11, 12, 34, 35), the at least one second inductor (10), the at least one second Y-type capacitor (13, 14, 36, 37) and the at least one X-type capacitor (15, 33) are arranged on a printed circuit board (PCB).

10. The EMC filter assembly of claim 9, wherein the at least one first Y-type capacitor (11, 12, 34, 35), the at least one second Y-type capacitor (13, 14, 36, 37), and the at least one X-type capacitor (15, 33) are electrically connected to the first electrical connector and the second electrical connector, respectively, via the printed circuit board (PCB).

11. The EMC filter assembly according to any one of claims 1 to 8, wherein the at least one first inductor (7), the at least one first Y-type capacitor (11, 12, 34, 35), the at least one second inductor (10), the at least one second Y-type capacitor (13, 14, 36, 37) and the at least one X-type capacitor (15, 33) are arranged on a lead frame.

12. A power converter for an electric motor, particularly an inverter, comprising a DC link capacitor, power electronics, and an EMC filter assembly (1, 23, 27) according to any one of claims 1 to 11.

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