Noise filter and power conversion device using the noise filter

Abstract

The noise filter (3) includes a multilayer LC filter consisting of multiple inductors and multiple capacitors. The inductors have plate-shaped busbars and core members consisting of cylindrical magnetic bodies surrounding the busbars. The power conversion device (1) includes a power conversion main circuit (2) for converting power and the noise filter (3). The multiple inductors consist of a specific busbar that serves as a plate-shaped first busbar (11) connecting the external power source to the power conversion main circuit (2) on the positive side or a plate-shaped second busbar (12) connecting the external power source to the power conversion main circuit (2) on the negative side, and multiple core members surrounding the specific busbars. Multiple capacitors are disposed between the first busbar (11) and the second busbar (12).

Description

Technical Field

[0001] This application relates to a noise filter and a power conversion device using the noise filter. Background Technology

[0002] In recent years, with the increasing emphasis on fuel efficiency in automobiles, there is a growing number of vehicles that utilize idling to stop the internal combustion engine when stationary, as well as vehicles that use electric motors to assist the internal combustion engine's torque. In these vehicles, the internal combustion engine and rotating electric motor are always integrated, and generator-electric motors, which not only provide starting and torque assistance functions but also generate electricity during driving or deceleration, are becoming increasingly common. Electromagnetic noise is generated from the power conversion devices used in these vehicles, thus creating technical problems related to the suppression of electromagnetic noise.

[0003] The power conversion device used in the vehicle includes: a main power conversion circuit such as an inverter composed of multiple switching elements and multiple DC smoothing capacitors; and a noise filtering circuit. Specifically, a noise filtering circuit is disclosed, which is configured to have a common-mode noise suppression inductor to reduce the inductance of the circuit (for example, see Patent Document 1).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2019 / 064833 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] If the noise filtering circuit section in Patent Document 1 is used, common-mode noise (Japanese: コモンモードノイズ) in the electromagnetic noise generated by the pulse voltage from the switching element can be suppressed. However, the structure proposed in Patent Document 1 cannot suppress constant-mode noise (Japanese: ノーマルモードノイズ), or it does not describe any structure for miniaturizing the noise filtering circuit section. Therefore, there are technical problems of large-scale noise filters and the inability to suppress constant-mode noise in power conversion devices.

[0009] Therefore, the purpose of this application is to obtain a miniaturized noise filter and a power conversion device that suppresses constant-mode noise.

[0010] Technical solutions adopted to solve technical problems

[0011] The noise filter disclosed in this application includes a multilayer LC filter consisting of multiple inductors and multiple capacitors, wherein the inductors have plate-shaped busbars and core members consisting of cylindrical magnetic bodies surrounding the busbars.

[0012] The power conversion device disclosed in this application includes a power conversion main circuit and a noise filter for power conversion. Multiple inductors are composed of a specific busbar that is a plate-shaped first busbar on the positive side or a plate-shaped second busbar on the negative side, and multiple core components. The first busbar connects an external power source to the power conversion main circuit, the second busbar connects an external power source to the power conversion main circuit, the multiple core components surround the specific busbar, and multiple capacitors are disposed between the first busbar and the second busbar.

[0013] Invention Effects

[0014] The noise filter disclosed in this application includes a multilayer LC filter composed of multiple inductors and multiple capacitors. The inductors have plate-shaped busbars and core members composed of cylindrical magnetic bodies surrounding the busbars. Therefore, multiple inductors can have busbars as winding portions, which enables the noise filter to be miniaturized.

[0015] According to the power conversion device disclosed in this application, the noise filter comprises multiple inductors consisting of a plate-shaped first busbar on the positive side, or a plate-shaped second busbar on the negative side, and multiple core components. The first busbar connects the external power supply to the main power conversion circuit, and the specific busbar connects the external power supply to the main power conversion circuit. The multiple core components surround the specific busbar, and multiple capacitors are disposed between the first busbar and the second busbar. Multilayer LC filters are provided on the first busbar and the second busbar connecting the external power supply to the main power conversion circuit, thus suppressing the constant-mode noise of the power conversion device. Attached Figure Description

[0016] Figure 1 A diagram showing the circuit structure of a power conversion device including the noise filter of Embodiment 1.

[0017] Figure 2 This is a perspective view showing the main parts of the noise filter in Embodiment 1.

[0018] Figure 3 This is a perspective view showing the core component of the noise filter in Embodiment 2.

[0019] Figure 4 This is a perspective view showing the core component of the noise filter in Embodiment 3.

[0020] Figure 5 This is a perspective view showing the segmented core component of the noise filter in embodiment 4.

[0021] Figure 6This is a perspective view showing the core component of the noise filter in embodiment 5.

[0022] Figure 7 This is a perspective view showing the segmented core component of the noise filter according to embodiment 6.

[0023] Figure 8 This is a perspective view showing the main parts of the noise filter in embodiment 7.

[0024] Figure 9 This is a perspective view showing the main parts of the noise filter in Embodiment 7 broken down.

[0025] Figure 10 This is a perspective view showing the main parts of the noise filter in embodiment 8.

[0026] Figure 11 This is a perspective view showing the main parts of the noise filter in embodiment 9.

[0027] Figure 12 This is a perspective view showing the busbar of the noise filter in embodiment 9.

[0028] Figure 13 This is a perspective view showing the main parts of the noise filter in embodiment 9. Detailed Implementation

[0029] Hereinafter, based on the accompanying drawings, a noise filter according to an embodiment of this application and a power conversion device using the noise filter will be described. Furthermore, in the drawings, the same or equivalent components and parts will be labeled with the same symbols. In addition, unless specifically described, the materials, shapes, and arrangements of the constituent parts described in the embodiments are not intended to limit this application to those specific details.

[0030] Implementation Method 1

[0031] Figure 1 This is a diagram showing the circuit structure of the power conversion device 1, including the noise filter 3 of embodiment 1. Figure 2 This is a perspective view showing the first inductor 3L1 and the second inductor 3L2, which are the main components of the noise filter 3. The power conversion device 1 serves as an inverter unit in an inverter-integrated rotary motor 100, where the inverter unit and the rotary motor 5 are integrated. The inverter-integrated rotary motor 100 is a device that converts the power supplied from the battery 6 and outputs it to the rotary motor 5. The inverter-integrated rotary motor 100 is as follows... Figure 1The inverter-integrated rotary motor 100 shown consists of a power conversion device 1, a rotary motor 5, and a battery 6. Additionally, the inverter-integrated rotary motor 100 includes several other components, but for simplicity, only the parts necessary for explanation are described, and other parts are omitted. The inverter-integrated rotary motor 100 of this embodiment is suitable for use as an AC generator motor in engine drive assistance and power generation.

[0032] <Power Conversion Device 1>

[0033] The power conversion device 1 includes a main power conversion circuit 2 for converting electricity and a noise filter 3. The noise filter 3 suppresses electromagnetic noise generated from the main power conversion circuit 2 during power conversion operation. The main power conversion circuit 2 and the noise filter 3 are connected via a second conductor connection 8. The power conversion device 1 is connected to a battery 6, which serves as an external power source, via a first conductor connection 7. The power conversion device 1 is connected to a rotary motor 5 via an AC conductor connection 4. The main power conversion circuit 2 converts the direct current supplied from the battery 6 into alternating current and supplies the alternating current to the rotary motor 5 via the AC conductor connection 4. The rotary motor 5 generates the driving force of the motor based on the supplied alternating current. Furthermore, the rotary motor 5 also functions as a generator that regenerates the alternating current from the battery 6 when rotating under external force. The rotary motor 5 is, for example, a brushless motor composed of three-phase windings (U-phase, V-phase, W-phase).

[0034] <Power Conversion Main Circuit 2>

[0035] The main power conversion circuit 2 consists of a bridge circuit corresponding to the three-phase windings (U-phase, V-phase, and W-phase) of the rotating motor 5, and a smoothing capacitor 2C. The bridge circuit comprises six power semiconductors 2U1, 2U2, 2V1, 2V2, 2W1, and 2W2, which are, for example, MOSFETs (Metal-Oxide Semiconductor Field-Effect Transistors). The source terminal of power semiconductor 2U1 and the drain terminal of power semiconductor 2U2 are connected to the U-phase of the rotating motor 5 via AC conductor connection 4U. The source terminal of power semiconductor 2V1 and the drain terminal of power semiconductor 2V2 are connected to the V-phase of the rotating motor 5 via AC conductor connection 4V. The source terminal of power semiconductor 2W1 and the drain terminal of power semiconductor 2W2 are connected to the W-phase of the rotating motor 5 via AC conductor connection 4W.

[0036] <Noise Filter 3>

[0037] A noise filter 3 is disposed between the first conductor connection 7 and the second conductor connection 8, and suppresses electromagnetic noise generated from the power conversion main circuit 2. The noise filter 3 includes a multilayer LC filter composed of multiple inductors and multiple capacitors. Although in Figure 1 The illustrated embodiment shows an example of a two-layer LC filter, but the number of layers in the LC filter is not limited to two segments; multiple LC filters are also permissible. The noise filter 3 includes: a first inductor 3L1, a second inductor 3L2, a first capacitor 3X1, and a second capacitor 3X2 constituting the LC filter; and a first common capacitor 9Y1 and a second common capacitor 9Y2. The noise filter 3 is connected to the battery 6 via a first conductor connection 7 and to the power conversion main circuit 2 via a second conductor connection 8. Because the noise filter 3 includes a multi-layer LC filter, its attenuation characteristics are improved. Furthermore, it can suppress the constant-mode noise of the power conversion device 1.

[0038] The noise filter 3 includes: a plate-shaped first busbar 11 connecting the battery 6 to the power conversion main circuit 2 on the positive side; and a plate-shaped second busbar 12 connecting the battery 6 to the power conversion main circuit 2 on the negative side. The first busbar 11 connects the first positive conductor connection portion 7p of the first conductor connection portion 7 to the second positive conductor connection portion 8p of the second conductor connection portion 8. The second busbar 12 connects the first negative conductor connection portion 7n of the first conductor connection portion 7 to the second negative conductor connection portion 8n of the second conductor connection portion 8. A first inductor 3L1 and a second inductor 3L2 are connected in series in a specific busbar that serves as either the first busbar 11 or the second busbar 12. This embodiment shows an example where the specific busbar is the first busbar 11 and multiple inductors are disposed on the first busbar 11, but multiple inductors can also be disposed on the second busbar 12.

[0039] A first capacitor 3X1 and a second capacitor 3X2 are disposed between a first busbar 11 and a second busbar 12. One end of the first capacitor 3X1 is connected to the first busbar 11 between the first inductor 3L1 and the second inductor 3L2, and the other end is connected to the second busbar 12 between the first negative conductor connection portion 7n and the second negative conductor connection portion 8n. One end of the second capacitor 3X2 is connected to the first busbar 11 between the second inductor 3L2 and the first positive conductor connection portion 7p, and the other end is connected to the second busbar 12 between the first negative conductor connection portion 7n and the second negative conductor connection portion 8n.

[0040] The first common capacitor 9Y1 and the second common capacitor 9Y2 are connected in series at ground potential. The two ends of the series-connected first common capacitor 9Y1 and second common capacitor 9Y2 are connected in parallel with the second capacitor 3X2. The end of the first common capacitor 9Y1, connected in parallel with the second capacitor 3X2, is connected to the first busbar 11 between the second inductor 3L1 and the first positive conductor connection 7p. The end of the second common capacitor 9Y2, connected in parallel with the second capacitor 3X2, is connected to the second busbar 12 between the first negative conductor connection 7n and the second negative conductor connection 8n. By including the first common capacitor 9Y1 and the second common capacitor 9Y2, common-mode noise generated in the power conversion main circuit 2 can be reduced.

[0041] <Structure of Noise Filter 3>

[0042] The structure of the noise filter 3, which is a major part of this application, will be described. The first inductor 3L1 is as follows... Figure 2 The device shown has: a plate-shaped first busbar 11; and a first core member 3L1c, the first core member 3L1c being a square and cylindrical magnetic body surrounding the first busbar 11. The second inductor 3L2 has: a first busbar 11; and a second core member 3L2c, the second core member 3L2c being a cylindrical magnetic body surrounding the first busbar 11. The first busbar 11 is made, for example, of conductive copper. The first core member 3L1c and the second core member 3L2c are made, for example, of ferrite. The first core member 3L1c and the second core member 3L2c are fixed to the first busbar 11, for example, via a resin-formed winding tube (not shown).

[0043] The first busbar 11 includes: a first connecting end 11c1 and a second connecting end 11c2 as connecting ends disposed at both ends of the first busbar 11; and an intermediate connecting end 11c3, the intermediate connecting end 11c3 being pulled out from a portion of the first busbar 11 between adjacent first core members 3L1c and second core members 3L2c, and connected to the first capacitor 3X1 (in Figure 2 One end (not shown in the figure). The first connecting end 11c1 is connected to the first positive conductor connecting part 7p, and the second connecting end 11c2 is connected to the second positive conductor connecting part 8p.

[0044] The portion of the first busbar 11 surrounded by the first core member 3L1c is the first winding portion 11L1, and the portion of the first busbar 11 surrounded by the second core member 3L2c is the second winding portion 11L2. The first winding portion 11L1 and the second winding portion 11L2 are portions of the first busbar 11 through which current flows, and also function as windings for the first inductor 3L1 and the second inductor 3L2, respectively. The first winding portion 11L1 and the second winding portion 11L2 are winding structures that pass through the inner sides of the square and cylindrical first core member 3L1c and second core member 3L2c in one pass. The first winding portion 11L1 and the second winding portion 11L2 are configured to be linked once in a magnetic circuit equivalent to the first core member 3L1c and the second core member 3L2c. Since the magnetic flux density is proportional to the current and the number of turns, compared with an inductor whose windings are formed by multiple turns and pass through the core member, the magnetic flux density of the core, which is a magnetic body, can be reduced, and magnetic saturation of the magnetic body caused by the increase in magnetic flux density can be prevented.

[0045] When multiple inductors are used in a noise filter, each core component has a busbar portion that serves as the winding section of the inductor. However, according to Figure 2 In the structure shown, the first inductor 3L1 and the second inductor 3L2, which are two separate inductors, can share the same first busbar 11. Therefore, there is no need to connect the separate busbars to each other, and no connection parts are required, which allows the noise filter 3 to be miniaturized. In addition, the number of components can be reduced. Furthermore, since no connection process is required, the productivity of the noise filter 3 can be improved.

[0046] Furthermore, since the first winding portion 11L1 and the second winding portion 11L2 are each configured to pass through the core member only once, the magnetic flux density can be reduced, and iron losses such as hysteresis loss of the core member, which is a magnetic material, can be reduced. In addition, since the conductor portion of the winding is shortened compared to an inductor in which the winding is formed by multiple turns and passes through the core member, the impedance of the conductor portion of the winding can be reduced, copper losses caused by impedance can be reduced, and inductor heating can be suppressed.

[0047] Furthermore, when using an inductor with a winding formed by multiple turns passing through a core member for a noise filter, a process is required to form the winding around the core, which is a magnetic material. However, according to Figure 2 The structure shown can save the process of forming a winding around the core included in the inductor, thus reducing manufacturing costs and improving the productivity of the noise filter 3.

[0048] As described above, the noise filter 3 of Embodiment 1 includes a two-layer LC filter composed of a first inductor 3L1, a second inductor 3L2, a first capacitor 3X1, and a second capacitor 3X2. The first inductor 3L1 has a plate-shaped first busbar 11 and a first core member 3L1c composed of a cylindrical magnetic body surrounding the first busbar 11. The second inductor 3L2 has a plate-shaped first busbar 11 and a second core member 3L2c composed of a cylindrical magnetic body surrounding the first busbar 11. Therefore, the first inductor 3L1 and the second inductor 3L2 can share the first busbar 11 as a winding portion, which enables the noise filter 3 to be miniaturized. Furthermore, since the first inductor 3L1 and the second inductor 3L2 share a first busbar 11, the connection of the busbar is not required, which reduces the number of components and improves the productivity of the noise filter 3.

[0049] Furthermore, since the first busbar 11 includes a first connection end 11c1 and a second connection end 11c2 serving as connection ends at both ends of the first busbar 11, and a middle connection end 11c3 extending from the first busbar 11 between adjacent first core members 3L1c and 3L2c and connected to one end of the first capacitor 3X1, there is no need to further provide connection points between the noise filter 3 and the battery 6, the noise filter 3 and the power conversion main circuit 2, and the first busbar 11 and the first capacitor 3X1. Therefore, the number of components can be reduced, and the noise filter 3 can be miniaturized. Furthermore, the noise filter 3 can be easily connected to the battery 6 and the power conversion main circuit 2, improving the productivity of the power conversion device 1. Additionally, the first busbar 11 can be easily connected to the first capacitor 3X1, improving the productivity of the noise filter 3.

[0050] Furthermore, in the case of including a first common capacitor 9Y1 and a second common capacitor 9Y2 connected in series with ground potential and connected in parallel with the second capacitor 3X2 at both ends, the common-mode noise generated in the power conversion main circuit 2 can be reduced.

[0051] Furthermore, the power conversion device 1 of Embodiment 1 includes a power conversion main circuit 2 for power conversion and a noise filter 3. The noise filter 3 has multiple inductors consisting of a specific busbar that serves as a plate-shaped first busbar 11 connecting the battery 6 to the power conversion main circuit 2 on the positive side or a plate-shaped second busbar 12 connecting the battery 6 to the power conversion main circuit 2 on the negative side, and multiple core members surrounding the specific busbar. Multiple capacitors are disposed between the first busbar 11 and the second busbar 12. The first busbar 11 and the second busbar 12 connecting the battery 6 to the power conversion main circuit 2 are provided with multi-layered LC filters, thus suppressing the constant-mode noise of the power conversion device 1.

[0052] Implementation Method 2

[0053] The noise filter 3 of Embodiment 2 will be described. Figure 3 This is a perspective view showing the first core component 3L1c and the second core component 3L2c of the noise filter 3 in Embodiment 2. Figure 3 The diagram shows the removal of the first busbar 11 from the first inductor 3L1 and the second inductor 3L2, which are the main components of the noise filter 3. The noise filter 3 of Embodiment 2 is configured to include core components made of different magnetic materials.

[0054] The first inductor 3L1 and the second inductor 3L2, which are at least two inductors included in the noise filter 3, have two core members, namely the first core member 3L1c and the second core member 3L2c, surrounding the first busbar 11 at different locations. The magnetic material of the first core member 3L1c, which forms one core member, is different from the magnetic material of the second core member 3L2c, which forms the other core member. The different magnetic materials are, for example, ferrite and center tap. In addition, the different magnetic materials may also be ferrites with different mixing ratios of nickel or manganese.

[0055] As described above, in the noise filter 3 of Embodiment 2, the first inductor 3L1 and the second inductor 3L2 are configured to include core components with different magnetic materials. Therefore, they can have different frequency characteristics in their respective core components, and can efficiently suppress electromagnetic noise including multiple frequencies.

[0056] Implementation Method 3

[0057] The noise filter 3 of embodiment 3 will be described. Figure 4 This is a perspective view showing the first core component 3L1c and the second core component 3L2c of the noise filter 3 in embodiment 3. Figure 4The diagram illustrates the removal of the first busbar 11 and the components surrounding the first core member 3L1c and the second core member 3L2c from the first inductor 3L1 and the second inductor 3L2, which are the main components of the noise filter 3. The noise filter 3 of Embodiment 3 is configured to include the segmented core members.

[0058] The first core component 3L1c and the second core component 3L2c are respectively divided. The first core component 3L1c is a core component formed by combining the first divided core portion 3L1c1 and the second divided core portion 3L1c2. The second core component 3L2c is a core component formed by combining the third divided core portion 3L2c1 and the fourth divided core portion 3L2c2. The first core component 3L1c and the second core component 3L2c are respectively integrated, for example, by resin molding, and are integrated and fixed together with the first busbar 11. Figure 4 In the diagram, dashed lines represent the outer shapes of the integrated first core component 3L1c and the second core component 3L2c.

[0059] As described above, the noise filter 3 of Embodiment 3 is configured to include core components, each of the first inductor 3L1 and the second inductor 3L2, which are each segmented. Therefore, gaps can be provided between the segmented cores, and the magnetic reluctance of the gaps is greater than that of the cores, which are magnetic materials. Compared to an inductor without gaps, the magnetic flux density is lower, thus preventing magnetic saturation of the cores. Furthermore, the decrease in inductance as the current flowing through the first busbar 11 increases can be suppressed, and the decrease in attenuation characteristics of the filter can be suppressed even in current domains with large currents.

[0060] Furthermore, when using an undivided cylindrical core component, in order to ensure the insulation between the core component and the busbar, it is necessary to manage the distance between the busbar and the core while inserting the busbar into the core component to assemble the noise filter. However, when using a divided first core component 3L1c and a second core component 3L2c, there is no need for the process of inserting the first core component 3L1c and the second core component 3L2c into the first busbar 11. The distance between the first busbar 11 and the divided core can be easily managed, thus improving productivity.

[0061] Implementation Method 4

[0062] The noise filter 3 of embodiment 4 will be described. Figure 5 This is a perspective view of the segmented first core member 3L1c of the noise filter 3 according to Embodiment 4. The noise filter 3 of Embodiment 4 is configured with a structure in which each of the segmented core members has a different magnetic material.

[0063] In the first core member 3L1c, the magnetic materials forming the first segmented core 3L1c1 and the second segmented core 3L1c2, which are the individual core members being divided, are different. The different magnetic materials are, for example, ferrite and center taps. Alternatively, the different magnetic materials may be ferrites with different mixing ratios of nickel or manganese.

[0064] As described above, in the noise filter 3 of embodiment 4, the magnetic materials forming the first segmented core 3L1c1 and the second segmented core 3L1c2, which are the respective segmented core components, are different. Therefore, the first segmented core 3L1c1 and the second segmented core 3L1c2 can have different frequency characteristics, and electromagnetic noise including multiple frequencies can be effectively suppressed.

[0065] Implementation Method 5

[0066] The noise filter 3 of embodiment 5 will be described. Figure 6 This is a perspective view showing the first core member 3L1c of the noise filter 3 in Embodiment 5. The noise filter 3 in Embodiment 5 is configured to include a core member formed of different magnetic materials.

[0067] The first core component 3L1c is integrally formed from multiple different magnetic materials. The first core component 3L1c is used in conjunction with... Figure 6 The first busbar 11, which is omitted in the text, is integrally formed from two different magnetic materials, with one surface perpendicular to the plate surface as the boundary. The location where the different magnetic materials are integrally formed is not limited to this; for example, it could also be a surface parallel to the plate surface of the first busbar 11. The different magnetic materials could be, for example, ferrite and a center tap. Furthermore, the different magnetic materials could also be ferrites with different ratios of nickel or manganese.

[0068] As described above, in the noise filter 3 of embodiment 5, the first core member 3L1c is integrally formed of two different magnetic materials with a surface perpendicular to the plate surface of the plate-shaped first busbar 11 as the boundary. Therefore, the first core member 3L1c can have different frequency characteristics with this surface as the boundary, and can efficiently suppress electromagnetic noise including multiple frequencies.

[0069] Implementation Method 6

[0070] The noise filter 3 of Embodiment 6 will be described. Figure 7 This is a perspective view showing the segmented core member of the first core member 3L1c of the noise filter 3 in Embodiment 6. The noise filter 3 in Embodiment 6 is configured to include segmented core members formed of different magnetic materials.

[0071] The first segmented core 3L1c1 is integrally formed from multiple different magnetic materials. The first segmented core 3L1c1 is integrated with... Figure 7 The first busbar 11, which is omitted in the text, is integrally formed from two different magnetic materials, with one surface perpendicular to the plate surface as the boundary. The location where different magnetic materials are integrally formed is not limited to this. Furthermore, while only the first segmented core 3L1c1 may be integrally formed from multiple different magnetic materials, the second segmented core 3L1c2 may also be integrally formed from multiple different magnetic materials. Different magnetic materials include, for example, ferrite and a center tap. Additionally, different magnetic materials may also be ferrites with different ratios of nickel or manganese.

[0072] As described above, in the noise filter 3 of embodiment 6, the segmented first core 3L1c1 is integrally formed of two different magnetic materials with a surface perpendicular to the plate surface of the plate-shaped first busbar 11 as the boundary. Therefore, the first segmented core 3L1c1 can have different frequency characteristics with this surface as the boundary, and can efficiently suppress electromagnetic noise including multiple frequencies.

[0073] Implementation Method 7

[0074] The noise filter 3 of embodiment 7 will be described. Figure 8 This is a perspective view showing the first inductor 3L1 and the second inductor 3L2, which are the main components of the noise filter 3 in embodiment 7. Figure 9 This is a perspective view showing the first inductor 3L1 and the second inductor 3L2, which are the main components of the noise filter 3, broken down. The noise filter 3 in Embodiment 7 is configured to include a first busbar 11 bent into a U-shape.

[0075] The first inductor 3L1 and the second inductor 3L2, which are at least two inductors included in the noise filter 3, have a first core member 3L1c and a second core member 3L2c that surround the first busbar 11 at different locations. A portion of the first busbar 11 between the first core member 3L1c and the second core member 3L2c is bent into a U-shape. The first core member 3L1c and the second core member 3L2c are arranged adjacent to each other on their respective outer peripheral sides. The first busbar 11 is as follows... Figure 9 The diagram shows: a first connecting end 11c1 and a second connecting end 11c2 disposed at both ends of the first busbar 11; and an intermediate connecting end 11c3, the intermediate connecting end 11c3 being pulled out from a portion of the first busbar 11 between adjacent first core members 3L1c and second core members 3L2c, and connected to the first capacitor 3X1 (in Figure 9 One end (not shown in the figure). The first connecting end 11c1 is connected to the first positive conductor connecting part 7p, and the second connecting end 11c2 is connected to the second positive conductor connecting part 8p.

[0076] Figure 2 The noise filter 3 shown is configured such that the first inductor 3L1 and the second inductor 3L2 are arranged in a straight line in the same plane. According to... Figure 8 The structure shown reduces the area of ​​the plane occupied by the first inductor 3L1 and the second inductor 3L2. Furthermore, in situations where it is impossible to achieve the same level of efficiency as before... Figure 2 In situations where the arrangement of components on a plane is limited by the configuration of the first inductor 3L1 and the second inductor 3L2 arranged in a straight line on the same plane, a method can be used to address this limitation. Figure 8 The structure shown can shorten the overall length of the first inductor 3L1, the second inductor 3L2, and the first busbar 11, which extend in a plane, thus reducing the area of ​​the plane occupied by these components. Furthermore, Figure 9 The first core component 3L1c and the second core component 3L2c each have a structure with a divided core component, but it is not limited to this. The first core component 3L1c and the second core component 3L2c can also be configured to be undivided.

[0077] like Figure 9 As shown, at the portion of the first busbar 11 extending from the U-shaped section, the direction of extension of the portion of the first busbar 11 is parallel to the plate surface of the portion of the first busbar 11, and the portion of the first busbar 11 is offset in the horizontal width direction. By bending the first busbar 11 into a U-shape, the directions of the current flowing in the first inductor 3L1 and the second inductor 3L2 are opposite. Because the current directions are opposite, the magnetic flux generated around the first core member 3L1c and the second core member 3L2c occurs in mutually canceling directions. When the portion of the first busbar 11 extending from the U-shaped section is offset in the horizontal width direction, the cancellation of magnetic flux can be reduced, and the deterioration of the filter performance included in the inductor can be prevented.

[0078] As described above, in the noise filter 3 of Embodiment 7, the first inductor 3L1 and the second inductor 3L2 have a first core member 3L1c and a second core member 3L2c that surround the first busbar 11 at different positions. The portion of the first busbar 11 between the first core member 3L1c and the second core member 3L2c is bent into a U-shape. The first core member 3L1c and the second core member 3L2c are arranged adjacent to each other on their respective outer peripheral sides. Therefore, the area of ​​the plane occupied by the first inductor 3L1 and the second inductor 3L2 can be reduced. Since the first busbar 11 includes a first connection end 11c1, a second connection end 11c2, and an intermediate connection end 11c3, it can be easily connected to the first positive conductor connection portion 7p, the second positive conductor connection portion 8p, and the first capacitor 3X1. Therefore, the number of components can be reduced, and the productivity of the noise filter 3 can be improved.

[0079] Furthermore, at the portion of the first busbar 11 extending from the U-shaped section, the direction of extension from the portion of the first busbar 11 is parallel to the plate surface of the portion of the busbar 11. When the portion of the first busbar 11 is offset in the horizontal width direction, the cancellation of magnetic flux generated around the first core member 3L1c and the second core member 3L2c can be reduced, and the deterioration of the filter performance included in the inductor can be prevented.

[0080] Implementation Method 8

[0081] The noise filter 3 of embodiment 8 will be described. Figure 10 This is a perspective view showing the main parts of the noise filter 3 in Embodiment 8. The noise filter 3 in Embodiment 8 is a molded structure.

[0082] Figure 8 The first busbar 11, the first core component 3L1c, and the second core component 3L2c shown are as follows: Figure 10 The inductor assembly 17 is formed by molding an insulator 18. The first connection terminal 11c1 and the second connection terminal 11c2 of the first busbar 11 are shown. Figure 10 (Not shown in the figure) and the intermediate connection end 11c3 is the part that is connected to the first positive conductor connection part 7p, the second positive conductor connection part 8p and the first capacitor 3X1, and therefore, it is exposed from the insulator 18.

[0083] If the first core component 3L1c or the second core component 3L2c vibrates due to external factors, it may come into contact with other components and be damaged. In the event of damage to the first core component 3L1c or the second core component 3L2c, the inductance of the inductor, including the damaged core component, may decrease. By molding the first inductor 3L1c and the second inductor 3L2c with an insulator 18 such as resin, damage due to contact with other components can be prevented. Furthermore, if the first core component 3L1c, the second core component 3L2c, and the first busbar 11 are corroded by substances such as water, the inductance of the inductor, including the corroded components, may decrease. By molding the first core component 3L1c, the second core component 3L2c, and the first busbar 11 with an insulator 18 such as resin, it is possible to prevent the adhesion of corrosive elements to the first core component 3L1c, the second core component 3L2c, and the first busbar 11.

[0084] As described above, in the noise filter 3 of Embodiment 8, the first busbar 11, the first core member 3L1c, and the second core member 3L2c are molded by the insulator 18, thus preventing the first core member 3L1c and the second core member 3L2c from contacting other components and being damaged. Furthermore, it prevents corrosive elements from adhering to the first core member 3L1c, the second core member 3L2c, and the first busbar 11.

[0085] Implementation Method 9

[0086] The noise filter 3 of embodiment 9 will be described. Figure 11 This is a perspective view showing the first capacitor 3X1, the second capacitor 3X2, and their surrounding components, which are the main parts of the noise filter 3 in embodiment 9. Figure 12 This is a 3D diagram showing the multiple busbars included in noise filter 3. Figure 13 This is a three-dimensional view showing the appearance of the main parts of the noise filter 3. Figure 12 The dashed lines are used to indicate the removal of multiple busbars so that their shapes can be seen. Figure 11 A diagram showing the components of multiple busbars. Figure 11 This is a diagram showing the disassembly of the resin cover 10. Figure 13 The figure shows the resin cover 10 mounted on the resin housing 19. The noise filter 3 of embodiment 9 is configured to house the first capacitor 3X1 and the second capacitor 3X2 within the resin housing 19.

[0087] <First capacitor 3X1, second capacitor 3X2>

[0088] The noise filter 3 includes a first connecting bus 13 and a second connecting bus 15 as connecting busbars. The first connecting bus 13 and the second connecting bus 15 connect one end of each of the first capacitor 3X1 and the second capacitor 3X2 to one side of the first busbar 11 extending to both sides from the portions of the first busbar 11 surrounded by the first core member 3L1c and the second core member 3L2c, respectively. The first capacitor 3X1 and the second capacitor 3X2 are as follows: Figure 11 The resin housing 19 shown is an integral part of the first connecting busbar 13 and the second connecting busbar 15, and is made of an insulator. The resin housing 19 is as follows... Figure 13 The device shown is enclosed by a resin cover 10. The resin housing 19 is a housing that, in addition to the first connecting busbar 13 and the second connecting busbar 15, also has a negative conductor connection busbar 14 and a ground potential connection busbar 16 embedded in it.

[0089] One end of the first capacitor 3X1 is connected to the first connecting busbar 13 via solder, and one end of the second capacitor 3X2 is connected to the second connecting busbar 15 via solder. The portion of the first connecting busbar 13 exposed from the resin housing 19 is as follows... Figure 1 The portion of the first busbar 11 shown is connected between the first inductor 3L1 and the second inductor 3L2. The portion of the second connecting busbar 15 exposed from the resin housing 19 is connected to the portion of the first busbar 11 between the second inductor 3L2 and the first positive conductor connection portion 7p. Because it includes the first connecting busbar 13 and the second connecting busbar 15, the first capacitor 3X1 and the second capacitor 3X2 can be easily connected to the first busbar 11. Furthermore, the connecting busbar and the first busbar 11 can also be connected using through holes provided at their ends and by threaded fastening, etc.

[0090] The other ends of the first capacitor 3X1 and the second capacitor 3X2 are connected to the negative conductor connection busbar 14 by solder. The portion of the negative conductor connection busbar 14 exposed from the resin housing 19 is connected to the second busbar 12, which is connected to the first negative conductor connection portion 7n and the second negative conductor connection portion 8n. The other ends of the first capacitor 3X1 and the second capacitor 3X2 are connected to the first negative conductor connection portion 7n and the second negative conductor connection portion 8n via the negative conductor connection busbar 14 and the second busbar 12.

[0091] The resin housing 19 and the resin cover 10 are sealed, for example, by silicone bonding. If liquid adheres between the terminals of the first capacitor 3X1 or the second capacitor 3X2, the first capacitor 3X1 or the second capacitor 3X2 becomes short-circuited, thus causing damage to either capacitor. Sealing the first capacitor 3X1 and the second capacitor 3X2 within the resin housing 19 and the resin cover 10 prevents the intrusion of liquids into the resin housing 19, thus preventing damage to the first capacitor 3X1 and the second capacitor 3X2. Furthermore, by housing the first capacitor 3X1 and the second capacitor 3X2 within the resin housing 19, it prevents the first capacitor 3X1 and the second capacitor 3X2 from swaying due to vibrations, etc., and thus prevents the terminals of the first capacitor 3X1 and the second capacitor 3X2 from breaking.

[0092] Furthermore, while the first capacitor 3X1 and the second capacitor 3X2 are enclosed in a resin housing 19 in this embodiment, the embodiment is not limited to this. Alternatively, the first capacitor 3X1 and the second capacitor 3X2 may be molded from an insulator as part of the first connecting busbar 13 and the second connecting busbar 15. Moreover, although the first capacitor 3X1 and the second capacitor 3X2 are included as a plurality of capacitors and are enclosed in a resin housing 19, the embodiment is not limited to this. It is also possible to configure a plurality of capacitors to be enclosed in a resin housing 19.

[0093] <First shared capacitor 9Y1, second shared capacitor 9Y2>

[0094] The first common capacitor 9Y1 and the second common capacitor 9Y2, together with the first capacitor 3X1 and the second capacitor 3X2, are housed in a resin housing 19. The noise filter 3 includes the first common capacitor 9Y1 and the second common capacitor 9Y2, which are connected in series at ground potential. The two ends of the series connection are connected in parallel with the second capacitor 3X2. The first common capacitor 9Y1 and the second common capacitor 9Y2 are housed in a resin housing 19 made of an insulator, which is integral with a portion of the first connecting busbar 13, the second connecting busbar 15, the negative conductor connection busbar 14, and the ground potential connection busbar 16.

[0095] One end of the first common capacitor 9Y1 is soldered to the second connecting bus 15. The portion of the second connecting bus 15 exposed from the resin housing 19 is connected to a portion of the first bus 11 between the second inductor 3L2 and the first positive conductor connection 7p. One end of the first common capacitor 9Y1 is connected to the first positive conductor connection 7p and the second positive conductor connection 8p via the second connecting bus 15 and the first bus 11. One end of the second common capacitor 9Y2 is soldered to the negative conductor connection bus 14. The portion of the negative conductor connection bus 14 exposed from the resin housing 19 is connected to the second bus 12, which is connected to the first negative conductor connection 7n and the second negative conductor connection 8n. One end of the second common capacitor 9Y2 is connected to the first negative conductor connection 7n and the second negative conductor connection 8n via the negative conductor connection bus 14 and the second bus 12.

[0096] The other ends of the first common capacitor 9Y1 and the second common capacitor 9Y2 are connected to the ground potential connection bus bar 16 by soldering, and the ground potential connection bus bar 16 is connected to the ground potential, thereby connecting the other ends of the first common capacitor 9Y1 and the second common capacitor 9Y2 to the ground potential.

[0097] By including a first common capacitor 9Y1 and a second common capacitor 9Y2, common-mode noise generated in the power conversion main circuit 2 can be reduced. By housing the first common capacitor 9Y1 and the second common capacitor 9Y2 in the same resin housing 19 as the first capacitor 3X1 and the second capacitor 3X2, the number of components can be reduced, and the noise filter 3 can be miniaturized.

[0098] When liquid adheres between the terminals of the first common capacitor 9Y1 or the second common capacitor 9Y2, the first common capacitor 9Y1 or the second common capacitor 9Y2 becomes short-circuited, thus causing damage to the first common capacitor 9Y1 or the second common capacitor 9Y2. Sealing the first common capacitor 9Y1 and the second common capacitor 9Y2 with the resin housing 19 and the resin cover 10 prevents the intrusion of liquids into the resin housing 19 and prevents damage to the first common capacitor 9Y1 and the second common capacitor 9Y2. Furthermore, by housing the first common capacitor 9Y1 and the second common capacitor 9Y2 within the resin housing 19, it suppresses the swaying of the first common capacitor 9Y1 and the second common capacitor 9Y2 due to vibrations, and prevents the terminals of the first common capacitor 9Y1 and the second common capacitor 9Y2 from breaking.

[0099] In this embodiment, the first common capacitor 9Y1 and the second common capacitor 9Y2 are enclosed in a resin housing 19, but this is not a limitation. Alternatively, the first common capacitor 9Y1, the second common capacitor 9Y2, the first capacitor 3X1, and the second capacitor 3X2 may be molded from an insulator. Furthermore, the noise filter 3 may also be combined with other filters, such as a common-mode choke.

[0100] As described above, since the noise filter 3 of Embodiment 9 includes a first connecting busbar 13 and a second connecting busbar 15, which connect one end of each of the first capacitor 3X1 and the second capacitor 3X2 to one side of the first busbar 11 extending to both sides from the portion of the first busbar 11 surrounded by the first core member 3L1c and the second core member 3L2c, the first capacitor 3X1 and the second capacitor 3X2 can be easily connected to the first busbar 11, thus improving the productivity of the noise filter 3. Furthermore, when the connecting busbar and the first busbar 11 are connected by threaded fastening using through holes provided at the ends of the connecting busbar and the first busbar sleeve 11, the first capacitor 3X1 and the second capacitor 3X2 can be more easily connected to the first busbar 11. Furthermore, the first capacitor 3X1 and the second capacitor 3X2 are enclosed in a resin housing 19 made of an insulator, which is integrally formed by the first connecting busbar 13 and a portion of the second connecting busbar 15. Therefore, the intrusion of liquids or the like into the interior of the resin housing 19 can be prevented, and damage to the first capacitor 3X1 and the second capacitor 3X2 can be prevented. In addition, the swaying of the first capacitor 3X1 and the second capacitor 3X2 due to vibration or the like can be suppressed, and the breakage of the terminals of the first capacitor 3X1 and the second capacitor 3X2 can be prevented.

[0101] Furthermore, by housing the first shared capacitor 9Y1 and the second shared capacitor 9Y2 within the same resin housing 19 as the first capacitor 3X1 and the second capacitor 3X2, the number of components in the noise filter 3 can be reduced, allowing for miniaturization of the noise filter 3. Additionally, by sealing the first shared capacitor 9Y1 and the second shared capacitor 9Y2 within the resin housing 19 made of an insulator, the intrusion of liquids or the like into the resin housing 19 can be prevented, thus preventing damage to the first shared capacitor 9Y1 and the second shared capacitor 9Y2. Furthermore, by housing the first shared capacitor 9Y1 and the second shared capacitor 9Y2 within the resin housing 19, the swaying of the first shared capacitor 9Y1 and the second shared capacitor 9Y2 due to vibration or the like can be suppressed, and the breakage of the terminals of the first shared capacitor 9Y1 and the second shared capacitor 9Y2 can be prevented.

[0102] Furthermore, this application describes various exemplary implementation methods and embodiments, but the various features, methods and functions described in one or more implementation methods are not limited to specific implementation methods, and can be applied to implementation methods alone or in various combinations.

[0103] Therefore, numerous variations not illustrated are contemplated within the scope of the technology disclosed in this application. These include variations, additions, or omissions of at least one constituent element, as well as the extraction of at least one constituent element and its combination with constituent elements of other embodiments.

[0104] (Symbol Explanation)

[0105] 1 Power conversion device; 2 Power conversion main circuit; 2U1 power semiconductor; 2U2 power semiconductor; 2V1 power semiconductor; 2V2 power semiconductor; 2W1 power semiconductor; 2W2 power semiconductor; 2C smoothing capacitor; 3 Noise filter; 3L1 first inductor; 3L2 second inductor; 3L1c first core component; 3L1c1 first segmented core; 3L1c2 second segmented core; 3L2c second core component; 3L2c1 third segmented core; 3L2c2 fourth segmented core; 3X1 first capacitor; 3X2 second capacitor; 4 AC conductor connection part; 5 Rotary motor; 6 Battery; 7 First conductor connection part; 7p first positive conductor connection part; 7n first negative conductor connection part; 8 Second conductor connection part; 8p second positive conductor connection part; 8n second negative conductor connection part; 9Y1 first common capacitor ; 9Y2 Second common capacitor; 10 Resin housing; 11 First busbar; 11c1 First connection terminal; 11c2 Second connection terminal; 11c3 Intermediate connection terminal; 11L1 First winding section; 11L2 Second winding section; 12 Second busbar; 13 First connecting busbar; 14 Busbar for negative conductor connection; 15 Second connecting busbar; 16 Busbar for ground potential connection; 17 Inductor assembly; 18 Insulator; 19 Resin housing; 100 Inverter integrated rotary motor.

Claims

1. A noise filter, characterized in that, This includes a multilayer LC filter composed of multiple inductors and multiple capacitors. The inductor has a plate-shaped busbar and a core component consisting of a cylindrical magnetic body surrounding the busbar. At least two of the inductors have two core members surrounding the busbar at different locations, a portion of the busbar between the two core members is bent into a U-shape, and the two core members are configured to be adjacent on their respective outer peripheral sides. In each of the two core members extending from the U-shaped bend, the two portions of the busbar extend in the direction of their respective extension and are parallel to the respective plate surfaces of the two portions of the busbar. The two portions of the busbar are offset relative to each other in the horizontal width direction of the plate surfaces, and the two core members are offset relative to each other in the horizontal width direction of the plate surfaces.

2. The noise filter as described in claim 1, characterized in that, At least two of the inductors have two core members surrounding the busbar at different locations, and the magnetic material forming one core member is different from the magnetic material forming the other core member.

3. The noise filter as described in claim 1, characterized in that, The core component is segmented.

4. The noise filter as described in claim 3, characterized in that, The magnetic materials forming the individual core components that are divided are different.

5. The noise filter as described in claim 1, characterized in that, The core component is made of a combination of various magnetic materials.

6. The noise filter as described in claim 3, characterized in that, The segmented core component is made of a combination of various magnetic materials.

7. The noise filter as described in claim 1, characterized in that, The busbar includes a connecting end and an intermediate connecting end. The connecting end is disposed at both ends of the busbar, and the intermediate connecting end is pulled out from a portion of the busbar between adjacent core components and connected to the capacitor.

8. The noise filter as described in claim 1, characterized in that, The busbar and the core component are molded with an insulator.

9. The noise filter as described in claim 1, characterized in that, The device includes a connecting busbar that connects one end of each of the plurality of capacitors to one side of the busbar extending laterally from portions of the busbar formed by the plurality of core members. A portion or all of the capacitors are molded with an insulator along with a portion of the connecting busbar, or a portion or all of the capacitors are hermetically housed in an insulator housing integral with a portion of the connecting busbar.

10. The noise filter as claimed in claim 1, characterized in that, It includes a first shared capacitor and a second shared capacitor, which are connected in series at ground potential, and their two ends are connected in parallel with the capacitor. The first common capacitor, the second common capacitor, and the plurality of said capacitors are molded with an insulator or hermetically housed in a housing made of an insulator.

11. A power conversion device, characterized in that, include: A power conversion main circuit, which performs power conversion; as well as The noise filter according to any one of claims 1 to 10, Multiple inductors are composed of a specific busbar that serves as a plate-shaped first busbar on the positive side or a plate-shaped second busbar on the negative side, and multiple core components. The first busbar connects an external power source to the main power conversion circuit, the second busbar connects an external power source to the main power conversion circuit, the multiple core components surround the specific busbar, and multiple capacitors are disposed between the first busbar and the second busbar.

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