Power conversion device

Abstract

Power conversion device comprising: a DC power supply terminal to which DC power is supplied from a DC power supply; a filter unit comprising a plurality of filter capacitors and removing noise from the DC power; a smoothing capacitor smoothing the DC power and feeding the smoothed DC power to a power conversion circuit unit; a first busbar module partially formed with a sealing material connecting the DC power supply terminal and the filter unit; a second busbar module partially formed with the sealing material connecting the smoothing capacitor and the filter unit; and a metal enclosure housing the DC power supply terminal, the filter unit, the smoothing capacitor, the first busbar module, and the second busbar module.The first busbar module includes: a first positive busbar connected to a positive terminal of the DC power supply; a first negative busbar connected to a negative terminal of the DC power supply; and a ground busbar thermally connected to the first positive and first negative busbars. The first positive busbar, the first negative busbar, and the ground busbar are laminated.

Description

Technical field

[0001] The present invention relates to a power conversion device. State of the art

[0002] Along with the increase in inverter power and current, heat generated by the DC bus, which serves as a power transfer path during power conversion, also increases. Furthermore, as the switching frequency increases, it is essential to add a noise filter circuit to suppress EMC noise. This noise filter circuit is located near the DC bus or elsewhere. For example, PTL 1 below discloses a technique for effectively suppressing radiated noise generated near a noise source by means of a configuration in which a ground bus is laminated between a positive bus and a negative bus, which are key circuit components. Citation list of patent literature

[0003] PTL 1: JP 2013-219919 A Summary of the invention: Technical problem

[0004] In the technique described in PTL 1, if the ground busbar is located between the positive and negative poles in the main circuit section, the cancellation of the magnetic field between the positive and negative poles is prevented, thus degrading the main circuit inductance and increasing the associated surge voltage. This causes problems such as an increase in noise sources and chip breakage. Therefore, it is necessary to implement noise suppression in a section other than the main circuit section. Solution to the problem

[0005] Power conversion device comprising: a DC power supply terminal to which DC power is supplied from a DC power supply; a filter unit comprising a plurality of filter capacitors and removing noise from the DC power; a smoothing capacitor smoothing the DC power and feeding the smoothed DC power to a power conversion circuit unit; a first busbar module partially formed with a sealing material connecting the DC power supply terminal and the filter unit; a second busbar module partially formed with the sealing material connecting the smoothing capacitor and the filter unit; and a metal enclosure housing the DC power supply terminal, the filter unit, the smoothing capacitor, the first busbar module, and the second busbar module.The first busbar module includes: a first positive busbar connected to a positive terminal of the DC power supply; a first negative busbar connected to a negative terminal of the DC power supply; and a ground busbar thermally connected to the first positive and first negative busbars. The first positive busbar, the first negative busbar, and the ground busbar are laminated. Advantageous effects of the invention

[0006] According to the present invention, it is possible to provide a power conversion device that achieves noise reduction, an improvement in heat dissipation, miniaturization, and an improvement in design freedom. Brief description of the drawings [ Fig. 1] Fig. Figure 1 is a diagram for describing an electrical circuit of a power conversion device according to a first embodiment of the present invention. [ Fig. 2] Fig. Figure 2 is a perspective overall view of the power conversion device of Fig. 1. [ Fig. 3] Fig. Figure 3 is a perspective view of a filter unit and a first busbar module of Fig. 2. [ Fig. 4] Fig. Figure 4 is a cross-sectional view along line AA' of Fig. 2. [ Fig. 5] Fig. Figure 5 is a perspective view of smoothing capacitors and a second busbar module. Fig. 2. [ Fig. 6] Fig. Figure 6 is a view to describe heat dissipation via fasteners in Fig. 4. [ Fig. 7] Fig. Figure 7 is a perspective overall view of a power conversion device according to a second embodiment of the present invention. [ Fig. 8] Fig. Figure 8 is a diagram describing an electrical circuit of the power conversion device of Fig. 7. [ Fig. 9] Fig. Figure 9 is a cross-sectional view along line BB' of Fig. 7. [ Fig. 10] Fig. Figure 10 is a perspective overall view of a power conversion device according to a third embodiment of the present invention. [ Fig. 11] Fig. Figure 11 is a diagram describing an electrical circuit of the power conversion device of Fig. 10. [ Fig. 12] Fig. Figure 12 is a cross-sectional view along line CC' of Fig. 10. [ Fig. 13] Fig. Figure 13 is an electrical circuit diagram of a power conversion device according to a fourth embodiment of the present invention. [ Fig. 14] Fig. Figure 14 is a perspective view to describe a first busbar module and a filter unit of Fig. 13. [ Fig. 15] Fig. Figure 15 is a top view of the power conversion device of Fig. 13. [ Fig. 16] Fig. Figure 16 is a cross-sectional view along line DD' of Fig. 15. [ Fig. 17] Fig. 17 is a first variation. [ Fig. 18] Fig. 18 is a second variation. Description of the embodiments

[0007] Embodiments of the present invention are described below with reference to the drawings. The following description and drawings are examples used to describe the present invention, and omissions and simplifications are made as appropriate for the sake of clarity. The present invention can be carried out in various other forms. Unless otherwise stated, each component can be singular or plural.

[0008] The positions, sizes, shapes, areas, and the like of the components shown in the drawings may not represent actual positions, sizes, shapes, areas, and the like, for the purpose of facilitating understanding of the invention. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, areas, or the like disclosed in the drawings. (First embodiment and overall configuration) (FIG. 1)

[0009] A power conversion device 1 comprises a power conversion circuit unit 4, a filter unit 20, and a smoothing capacitor 50. The power conversion circuit unit 4 is a power semiconductor module comprising switching elements that convert DC power to AC power and diode elements that return currents from a motor generator MG. The diode elements of the power conversion circuit unit 4 have a function for converting AC power to DC power during regeneration.

[0010] A high-voltage battery 2, connected to the power conversion device 1, provides DC power to a HEV or EV. The motor-generator MG, also connected to the power conversion device 1, outputs driving power for the HEV or EV based on the AC power obtained by converting the DC power input from the high-voltage battery 2 in the power conversion circuit unit 4. The motor-generator MG also acts as a generator, regenerating AC power for the high-voltage battery 2 when the motor is driven by an external force.

[0011] In the power conversion circuit unit 4, a power semiconductor module 4a is connected to a U-phase of the motor generator MG. A power semiconductor module 4b is connected to a V-phase of the motor generator MG. A power semiconductor module 4c is connected to a W-phase of the motor generator MG.

[0012] DC busbars 10 are power transmission paths connected to the high-voltage battery 2 and the power conversion circuit unit 4. A DC power supply terminal 6 is connected to the high-voltage battery 2 and is supplied with DC power. The smoothing capacitor 50 is located between the high-voltage battery 2 and the power conversion circuit unit 4. The smoothing capacitor 50 is connected to the high-voltage battery 2 and the power conversion circuit unit 4 via the DC busbars 10, smooths the DC power input from the high-voltage battery 2, and supplies the smoothed DC power to the power conversion circuit unit 4.

[0013] The filter unit 20 is a noise filter circuit arranged between the DC power supply terminal 6 and the smoothing capacitor 50 to remove electromagnetic noise from the DC power input from the high-voltage battery 2. The filter unit 20 comprises a number of filter capacitors. These filter capacitors are X capacitors 22 and Y capacitors 23 and 24.

[0014] A first busbar module 11 comprises a first positive busbar 11p and a first negative busbar 11n, each connected to a positive pole and a negative pole of the DC power supply 2 via the DC power supply terminal 6, and is partially formed with a sealing material (not shown). In the DC busbars 10, the first busbar module 11 connects the DC power supply terminal 6 and the filter unit 20.

[0015] A second busbar module 12 includes a second positive busbar 12p, which is connected to the first positive busbar 11p, and a second negative busbar 12n, which is connected to the first negative busbar 11n, and is partially formed with a sealing material. In the DC busbars 10, the second busbar module 12 connects the filter unit 20 and the smoothing capacitor 50.

[0016] In the filter unit 20, the X-capacitors 22 are connected between the first positive busbar 11p and the first negative busbar 11n and smooth the power at a frequency higher than the frequency of the power smoothed by the smoothing capacitor 50.

[0017] A ground bus 25 has high thermal conductivity and serves as the ground in an electrical circuit of the power conversion device 1. The Y-capacitor 23 is a Y-capacitor connected between the first positive bus 11p and the ground bus 25 and removes common-mode noise. The Y-capacitor 24 is a Y-capacitor connected between the first negative bus 11n and the ground bus 25 and removes common-mode noise. (FIG. 2)

[0018] A metal housing 7 is a metal housing of the power conversion device 1 and accommodates the DC busbars 10, the filter units 20, the smoothing capacitor 50, the first busbar module 11, the second busbar module 12, and the power conversion circuit units 4. Since the first busbar module 11 is an EMC filter module, the first busbar module 11 has the first positive busbar 11p, the first negative busbar 11n, and the ground busbar 25 (see Fig. 1) Although the first positive busbar 11p, the first negative busbar 11n and the ground busbar 25 are laminated together, a main circuit inductance is not affected, and it is not necessary to consider the cancellation of a magnetic flux between the positive pole and the negative pole. (FIG. 3)

[0019] The first busbar module 11 contains the first positive busbar 11p, the first negative busbar 11n, and the ground busbar 25 laminated together. The ground busbar 25 includes fastening elements 25a for connecting the first busbar module 11 to the housing 7. Consequently, the ground busbar 25 is thermally connected to the first positive busbar 11p and the first negative busbar 11n, and is also thermally connected to the housing 7.

[0020] The first busbar module 11 comprises the X capacitors 22 and Y capacitors 23 and 24. In the first busbar module 11, the strength and vibration resistance of the first busbar module 11 are improved by using the ground busbar 25 as the mounting element of the first busbar module 11. (FIG. 4)

[0021] In the first busbar module 11, the first positive busbar 11p, the first negative busbar 11n and the ground busbar 25 are laminated, and parts of the first positive busbar 11p, the first negative busbar 11n and the ground busbar 25 are formed by a sealing material 11m. Fig. Figure 4 presents an example in which the mass busbar 25 is provided between the first positive busbar 11p and the first negative busbar 11n in the lamination direction. By applying such a lamination type, heat can be dissipated substantially uniformly from both the first positive busbar 11p and the first negative busbar 11n.

[0022] The ground busbar 25 is thermally connected to the first positive busbar 11p and the first negative busbar 11n. Therefore, heat Q11p dissipated by the first positive busbar 11p and heat Q11n dissipated by the first negative busbar 11n are transferred via the ground busbar 25 to the sealing material 11m. This contributes to the cooling of the filter unit 20. Furthermore, stacking the busbars reduces the volume, thus miniaturizing the design. The ground busbar 25 also serves as a mounting and ground connection for the first busbar module to the housing 7; therefore, the surface area required for mounting the ground busbar 25 can be reduced. (FIG. 5)

[0023] In the second busbar module 12, the second positive busbar 12p and the second negative busbar 12n are laminated. A number of smoothing capacitors 50 are located on the side of the housing 7 (see Fig. 2) provided, which is the lower surface of the second busbar module 12. (FIG. 6)

[0024] The mounting parts 25a, which are components of the ground busbar 25, are attached to the metal housing 7 by means of fasteners 26, such as screws or bolts. As described above, by attaching the ground busbar 25, which has high thermal conductivity, to the metal housing 7, the heat Q11p generated by the first positive busbar 11p and the heat Q11n generated by the first negative busbar 11n can be transferred to the housing 7. This contributes to cooling the filter capacitors 21, which have a low temperature-resistant operating point, by dissipating radiant heat and improving the heat dissipation effect. Furthermore, the ground busbar 25 serves both as a mounting point and as a ground connection for the first busbar module 11 to the housing 7; therefore, this contributes to miniaturization.

[0025] The filter capacitors 21 are arranged in positions sandwiched between the multiple mounting elements 25a. The heat Q11p generated by the first positive busbar 11p and the heat Q11n generated by the first negative busbar 11n are transferred to the metal housing 7 via the ground busbar 25, which has high thermal conductivity, and the mounting elements 25a.

[0026] Heat generated Q6, which is supplied by the DC power supply terminals 6 ( Fig. 2) is dissipated via the ground busbar 25, which has high thermal conductivity, and the mounting parts 25a to the metal housing 7. As a result, the generated heat Q6 is prevented from flowing into the filter capacitors 21. In addition, generated heat Q12, which is dissipated by the second busbar module 12 ( Fig. 2) is also discharged via the mass busbar 25, which has high thermal conductivity, and the fastening parts 25a to the metal housing 7, so that the generated heat Q12 is prevented from flowing into the filter capacitors 21. (Second embodiment) (FIG. 7 to FIG. 9)

[0027] In the case of adopting an embodiment in which the filter unit 20 comprises at least one magnetic core 30 with a through-hole through which the first busbar module 11 is inserted, the magnetic core 30 is provided between the first busbar module 11 and the second busbar module 12.

[0028] As in Fig. As shown in Figure 9, the first busbar module 11 has a mounting element 25a at a position between the magnetic core 30 and the filter capacitors 21. Since the section of the first busbar module 11 through which the magnetic core 30 passes has a small cross-sectional area, the electrical resistance increases, and consequently, so does the heat Q30 generated by the magnetic core 30. Therefore, the generated heat Q30 is prevented from flowing into the filter capacitors 21 by being dissipated to the metal housing 7 via the ground busbar 25 and the mounting element 25a. (Third embodiment) (FIG. 10 to FIG. 12)

[0029] The filter unit 20 comprises magnetic cores 31 and 32, each having a through-hole through which the first busbar module 11 is inserted. A plurality of fastening elements 25a are provided at positions between the first magnetic core 31 and the second magnetic core 32. The first magnetic core 31 is inserted into the first busbar module 11 and is positioned on one side near the DC power supply terminals 6. The second magnetic core 32 is inserted into the first busbar module 11 and is positioned on one side near the second busbar module 12.

[0030] In the first busbar module 11, the parts through which the magnetic cores 31 and 32 pass have smaller cross-sectional areas, the electrical resistances increase, and more heat is generated. Heat Q31, emitted by the first magnetic core 31, is transferred to the metal housing 7 via the mounting element 25a; therefore, the generated heat Q31 is prevented from flowing into the filter capacitors 21. Similarly, heat Q32, emitted by the second magnetic core 32, is also transferred to the metal housing 7 via the mounting element 25a; therefore, the generated heat Q32 is prevented from flowing into the filter capacitors 21. (Fourth embodiment) (FIG. 13 to FIG. 16)

[0031] The filter unit 20 comprises two sets of multiple filter capacitors 21. Furthermore, the filter unit 20 comprises at least one magnetic core 30 with a through-hole through which the first busbar module 11 is inserted. The magnetic core 30 is arranged at a position between the two sets of multiple filter capacitors 21.

[0032] The two sets of first busbar modules 11, between which the magnetic core 30 is arranged, each comprise a first positive busbar 11p and a first negative busbar 11n and are each partially formed with a sealing material 11m. Each of the two sets of filter capacitors 21 comprises an X-capacitor 22 and Y-capacitors 23 and 24. The two sets of first busbar modules 11 are connected to a plurality of corresponding filter capacitors 21. The two sets of first busbar modules 11 are mounted on an intermediate busbar mounting part 110 ( Fig. 14) connected to each other.

[0033] The intermediate busbar mounting part 110 comprises a positive busbar mounting part 110p and a negative busbar mounting part 110n. The positive busbar mounting part 110p is a mounting part between two sets of the first positive busbars 11p. The negative busbar mounting part 110n is a mounting part between two sets of the first negative busbars 11n.

[0034] In the first busbar module 11, a section through which the magnetic core 30 penetrates has a smaller cross-sectional area, the electrical resistance increases, and more heat is generated. The generated heat Q30 is dissipated via the mounting elements 25a to the metal housing 7 before it reaches the two sets of filter capacitors 21, thus preventing the generated heat Q30 from flowing into the two sets of filter capacitors 21.

[0035] In the first busbar module 11, the electrical resistance of the intermediate busbar mounting part 110 increases due to fastening with screws or the like (not shown), thus generating more heat. The heat Q110 generated by the intermediate busbar mounting part 110 is transferred to the metal housing 7 via the mounting parts 25a. This prevents the generated heat Q110 from flowing into the two sets of filter capacitors 21.

[0036] Each of the two sets of filter capacitors 21 is arranged at a position between the plurality of mounting parts 25a. Heat generated Q11p, which is dissipated from the first positive busbars 11p, and heat generated Q11n, which is dissipated from the first negative busbars 11n, are dissipated through the ground busbars 25, which have high thermal conductivity, and via the mounting parts 25a to the metal housing 7.

[0037] As described above, as in the first to fourth embodiments, there is one degree of freedom in the connection positions between the X-capacitor 22 and the Y-capacitors 23 and 24 and the busbars; therefore, a change in the arrangement and sizes of the capacitors can be addressed by changing the positions at which connections are taken out of the busbars. (First variation and second variation) (FIG. 17, FIG. 18)

[0038] The first positive busbar 11p, the first negative busbar 11n and the ground busbar 25 are laminated together, but for example, as in Fig. As shown in Figure 17, the first positive busbar 11p, the first negative busbar 11n, and the ground busbar 25 can be laminated in order from top to bottom. Alternatively, as shown in Fig. As shown in Figure 18, the ground busbar 25, the first positive busbar 11p, and the first negative busbar 11n are laminated in that order from top to bottom. That is, one of the first positive busbar 11p and one of the first negative busbar 11n are positioned between the ground busbar 25 and the other busbar.

[0039] As described above, even if the lamination sequence of the busbars is different, the generated heat Q11p and Qlln can be transferred to the ground busbar 25, thus reducing the heat flowing into the X capacitors 22 and the Y capacitors 23 and 24 in the heat-sensitive filter unit 20, and protecting the filter unit 20 from heat.

[0040] The embodiments of the present invention described above provide the following actions and effects. (1) Power conversion device 1 comprises: a DC power supply terminal 6, to which DC power is supplied from a DC power supply 2; a filter unit 20, which includes a plurality of filter capacitors 21 and removes noise from the DC power; a smoothing capacitor 50, which smooths the DC power and supplies the smoothed DC power to a power conversion circuit unit; a first busbar module 11, which is partially formed with a sealing material 11m and connects the DC power supply terminal 6 and the filter unit 20; a second busbar module 12, which is partially formed with the sealing material 11m and connects the smoothing capacitor 50 and the filter unit 20;and a metal housing 7, which accommodates the DC power supply connection 6, the filter unit 20, the smoothing capacitor 50, the first busbar module 11, and the second busbar module 12. The first busbar module 11 includes: a first positive busbar 11p, which is connected to a positive terminal of the DC power supply 2; a first negative busbar 11n, which is connected to a negative terminal of the DC power supply 2;and a ground busbar 25, which is thermally connected to the first positive busbar 11p and the first negative busbar 11n. The first positive busbar 11p, the first negative busbar 11n and the ground busbar 25 are laminated. With this configuration, it is possible to provide a power conversion device 1 that achieves noise reduction, improved heat dissipation, miniaturization and improved design freedom. (2) The second busbar module 12 comprises: a second positive busbar 12p connected to the first positive busbar 11p; and a second negative busbar 12n connected to the first negative busbar 11n, wherein the second positive busbar 12p and the second negative busbar 12n are laminated. This configuration allows the main circuit inductance to be reduced. (3) The mass busbar 25 includes a number of mounting parts 25a that attach the first busbar module 11 to the housing 7, and the mounting parts 25a are attached to the housing 7 by fasteners 26. This configuration improves cooling performance. (4) The filter capacitors 21 are arranged at positions between the multiple mounting parts 25a. This configuration improves the cooling performance. (5) The filter unit 20 comprises at least one magnetic core 30 with a through-hole through which the first busbar module 11 is inserted, and the first busbar module 11 comprises the fastening parts 25a at a position between the magnetic core 30 and the filter capacitors 21. This configuration improves the cooling performance. (6) The filter unit 20 comprises two of the magnetic cores 30, each having the through-hole, and the plurality of fastening parts 25a is provided between the two magnetic cores 30. This configuration improves the cooling performance. (7) The filter unit 20 comprises two of the filter capacitors 21, and the magnetic core 30 is provided at a position between the two of the filter capacitors 21. This configuration improves the cooling performance. (8) The mass busbar 25 is provided between the first positive busbar 11p and the first negative busbar 11n in one lamination direction. This configuration makes it possible to achieve an improved heat dissipation effect, miniaturization and an increased degree of design freedom. (9) One connection between the first positive busbar 11p and the first negative busbar 11n is provided between the ground busbar 25, and the other connection between the first positive busbar 11p and the first negative busbar 11n. This configuration makes it possible to achieve an improved heat dissipation effect, miniaturization, and an increased degree of design freedom.

[0041] It should be noted that the present invention is not limited to the embodiments described above and that various variations and other configurations can be combined without departing from the core of the present invention. Furthermore, the present invention is not limited to a single embodiment that includes all the configurations described above and includes one in which part of the configuration is omitted. Reference symbol list 1 Power conversion device 2 high-voltage batteries 4 Power conversion circuit unit 4a to 4c Power semiconductor module 6 DC power supply connection 7 cases 10 DC busbar 11 first busbar module 11p first positive bus bar 11n first negative busbar 11m of sealing material 12 second busbar module 12p second positive bus 12n second negative bus 20 filter units 21 Filter capacitor 22 X-capacitor 23, 24 Y-capacitor 25 Ground bus 25a Fastening part 26 Fastening element 30 magnetic core 31 first magnetic core 32 second magnetic core 50 smoothing capacitor 110 Intermediate busbar mounting part 110p positive busbar mounting part 110n negative busbar mounting part QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2013-219919 A ​​

[0003]

Claims

[1] Power conversion device comprising: a DC power supply connection to which DC power is supplied from a DC power supply; a filter unit that includes a large number of filter capacitors and removes noise from the DC power supply; a smoothing capacitor that smooths the DC power and feeds the smoothed DC power to a power conversion circuit unit; a first busbar module, which is partially formed with a sealing material and connects the DC power supply connection and the filter unit; a second busbar module, partially formed with the sealing material, connecting the smoothing capacitor and the filter unit; and a metal housing that accommodates the DC power supply connection, the filter unit, the smoothing capacitor, the first busbar module and the second busbar module, the first busbar module includes the following: a first positive busbar connected to a positive pole of the DC power supply; a first negative busbar connected to a negative terminal of the DC power supply; and a mass busbar that is thermally connected to the first positive busbar and the first negative busbar, and The first positive busbar, the first negative busbar and the mass busbar are laminated. [2] Power conversion device according to claim 1, wherein the second busbar module comprises: a second positive busbar connected to the first positive busbar; and a second negative busbar connected to the first negative busbar, wherein the second positive busbar and the second negative busbar are laminated. [3] Power conversion device according to claim 1 or 2, wherein the mass busbar comprises a plurality of fastening parts which fasten the first busbar module to the housing, and the fastening parts are attached to the housing by fastening elements. [4] Power conversion device according to claim 3, wherein the filter capacitors are arranged at positions between the plurality of fastening parts. [5] Power conversion device according to claim 4, wherein the filter unit comprises at least one magnetic core with a through-hole through which the first busbar module is inserted, and the first busbar module comprises the fastening parts at a position between the magnetic core and the filter capacitors. [6] Power conversion device according to claim 5, wherein the filter unit comprises two of the magnetic cores, each having the through-hole, and the plurality of fastening parts is provided between the two magnetic cores. [7] Power conversion device according to claim 5, wherein the filter unit comprises two sets of the plurality of filter capacitors, and the magnetic core is provided at a position between the two sets of the plurality of filter capacitors. [8] Power conversion device according to claim 1, wherein the mass busbar is provided between the first positive busbar and the first negative busbar in a lamination direction. [9] Power conversion device according to claim 1, wherein one of the first positive busbar and the first negative busbar is provided between the ground busbar and another of the first positive busbar and the first negative busbar.

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