A power assembly and a power converter

Abstract

The application discloses a power assembly and a converter, wherein the power assembly comprises a capacitor module, a power module and a plurality of groups of absorption capacitors; part of switch devices in the power module are connected with capacitor busbars in the capacitor module through wiring components, and are divided into first switches and second switches according to the connection relationship with the polar plates of different polarities on the capacitor busbars; a mounting base is parallel to the capacitor busbars, each first switch is arranged and fixed on a first mounting surface along a first direction, and each second switch is arranged and fixed on a second mounting surface along the first direction; each first switch and each second switch are correspondingly connected with a group of absorption capacitors, and the absorption capacitors connected with the first switches are located on the side of the capacitor busbars away from the mounting base, and the absorption capacitors connected with the second switches are located on the side of the mounting base away from the capacitor busbars. The power assembly can improve the effect of reducing stray inductance of the absorption capacitors by designing the positions of the absorption capacitors.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of converter, in particular to a power assembly and a converter. BACKGROUND

[0002] The converter is widely used in the fields of power system, rail transit, military industry, petroleum machinery, new energy vehicle, wind power generation, solar photovoltaic, etc. The converter is connected between the battery system and the power grid, and is used for realizing bidirectional conversion of electric energy, controlling the charging and discharging process of the battery, converting AC and DC, and directly supplying power to AC load in the case of no power grid. At the same time, the NPC (Neutral Point Clamp) or ANPC (Active Neutral Point Clamp) three-level topology can use low blocking voltage IGBT devices to increase the DC bus voltage, thereby improving the AC output voltage and expanding the system power level, so it is widely used in the converter.

[0003] Conventionally, the converter mainly includes a power assembly, which is used for realizing bidirectional conversion of DC and AC. The power assembly in the converter generally includes a DC module and a power module. The DC module mainly includes a DC capacitor bank and a capacitor busbar, and the power module mainly includes a power tube group and a heat sink. The power tube group is installed on the heat sink, and then connected with the DC busbar through an input bus. Specifically, referring to Figure 1 which shows the structure of the power assembly in the converter in the prior art. The power assembly can include a capacitor busbar 01, a DC capacitor bank 02, an input bus 03, a power tube group 04, an output bus 05, and a heat sink 06. The input bus 03, the power tube group 04, and the output bus 05 form the above-mentioned power module. The power tube group 04 is installed on the heat sink 06, and the heat sink 06 is a air-cooled heat sink with heat dissipation fins on the back, so the input bus 03, the power tube group 04, and the output bus 05 are installed on the front of the heat sink 06. Since the output of the power device is three-phase AC, the power module includes three power tube groups 04 and three corresponding heat sinks 06. Each power tube group 04 is installed on a heat sink 06, and the input buses 03 in the three power modules are connected to the capacitor busbar 01. Further, the capacitor busbar 01 includes positive plates, negative plates, and neutral plates, which are stacked and separated from each other by insulation plates. Correspondingly, the input bus 03 in each power module also includes positive plates, negative plates, and neutral plates, which are connected to the plates in the capacitor busbar 01.

[0004] Referring to Figure 2Fig. 1 shows a circuit diagram of a three-level topology in the prior art. For a power assembly adopting the three-level topology, the power tube group 04 in each complete three-level topology generally includes three IGBT devices, corresponding to Figure 2 In the circuit shown, tube 1 and tube 2 are an input tube, tube 3 and tube 4 are an input tube, and tube 5 and tube 6 are an output tube. The first end of tube 1 is connected to the positive plate of the capacitor bus, the first end of tube 2 is connected to the neutral plate of the capacitor bus, and the second ends of tube 1 and tube 2 are connected and then connected to the first end of tube 5; the first end of tube 3 is connected to the negative plate of the capacitor bus, the first end of tube 4 is connected to the neutral plate of the capacitor bus, and the second ends of tube 3 and tube 4 are connected and then connected to the first end of tube 6; and the second ends of tube 5 and tube 6 are connected to the output bus. The capacitor cell connected to the capacitor bus is also divided into two parts, corresponding to Figure 2 C1 and C2 in Fig. 1.

[0005] In the existing three-level topology circuit diagram, there is a problem of high stray inductance. Stray inductance is also called parasitic inductance. In the three-level topology, it mainly includes the stray inductance generated inside the IGBT device, the stray inductance of the capacitor bus, and the stray inductance of the capacitor in the capacitor cell. These stray inductances will affect the instantaneous voltage and current of the power assembly, and also affect the loss and heat of the power assembly. Therefore, in the prior art, an absorption capacitor with low parasitic inductance is connected in parallel at the positive and negative terminals of the IGBT. The absorption capacitor can reduce the stray inductance of the corresponding circuit. Figure 1 In the structure of the power assembly shown in Fig. 1, an absorption capacitor is provided for each input tube in each power tube group. The absorption capacitor has two connection terminals, and each connection terminal is connected to two connection terminals of the corresponding input tube connected to the input bus. However, in the power assembly shown in Fig. 1, Figure 1 Due to the arrangement mode of the power module relative to the DC module, the commutation circuit of the IGBT device far from the DC module is long and generates high stray inductance, and the commutation circuit of the IGBT device close to the DC module is short and generates low stray inductance. This leads to inconsistent requirements for reducing stray inductance for each absorption capacitor, which is not conducive to the normal use of the absorption capacitor. SUMMARY

[0006] The purpose of the present application is to overcome the above-mentioned defects or problems in the background art and provide a power assembly and a converter which can facilitate the normal use of the absorption capacitor.

[0007] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0008] A power assembly comprises: a capacitor module comprising DC capacitor banks and a capacitor busbar connected with each other; the capacitor busbar comprises several polar plates with different polarities; a power module comprising a mounting base, a power tube group and a wiring component; the power tube group comprises several switching devices, wherein part of the switching devices are connected with the capacitor busbar through the wiring component, and are divided into first switching devices and second switching devices according to the connection relationship with the polar plates with different polarities on the capacitor busbar; the mounting base is parallel to the capacitor busbar, and is provided with a first mounting surface facing the capacitor busbar and a second mounting surface away from the capacitor busbar, the first switching devices are fixed on the first mounting surface, and the second switching devices are fixed on the second mounting surface; several groups of absorption capacitors, each of the first switching devices and each of the second switching devices is correspondingly connected with a group of the absorption capacitors, and the absorption capacitors connected with the first switching devices are located on the side of the capacitor busbar away from the mounting base, and the absorption capacitors connected with the second switching devices are located on the side of the mounting base away from the capacitor busbar.

[0009] Further, the first switching devices and the second switching devices are provided with wiring ends for connecting with the wiring component, the wiring ends of the first switching devices are connected with the wiring component and the absorption capacitors in sequence; the wiring ends of the second switching devices are connected with the absorption capacitors and the wiring component in sequence, or are connected with the wiring component and the absorption capacitors in sequence.

[0010] Further, the absorption capacitors are provided with conductive sheets extending outward, the conductive sheets are connected to the corresponding wiring ends of the first switching devices or the second switching devices, so that the absorption capacitors avoid the wiring component.

[0011] Further, the wiring component comprises several first wiring posts and several second wiring posts; the wiring ends of the first switching devices are connected with the first wiring posts, and the wiring ends of the second switching devices are connected with the second wiring posts; the conductive sheets of the absorption capacitors are connected to the wiring ends of the corresponding first switching devices and / or second switching devices through the first wiring posts and the second wiring posts, or are directly connected with the wiring ends of the corresponding second switching devices.

[0012] Further, the wiring component further comprises a busbar; the first switching devices and the second switching devices are DC side switching devices; in the DC side switching devices, the wiring ends of part of the switching devices are connected to the busbar through the corresponding first wiring posts or second wiring posts, and are connected to the capacitor busbar after being converged through the busbar.

[0013] Further, the wiring ends of each of the second switching devices are connected to the busbar through the corresponding second wiring posts, and are connected to the capacitor busbar after being converged through the busbar; the wiring ends of each of the first switching devices are directly connected to the capacitor busbar through the corresponding first wiring posts.

[0014] Further, one end of the first terminal post is connected to the terminal of the corresponding first switch, and the other end penetrates the capacitor busbar and is connected to the conductive sheet of the corresponding absorption capacitor; the second terminal post starts from the terminal of the corresponding second switch, and is connected to the busbar and the corresponding absorption capacitor in sequence.

[0015] Further, the first switch and the second switch are arranged along the length direction of the mounting base, and the terminals of the first switch and the second switch are close to the same edge of the mounting base; the length direction of the mounting base is perpendicular to the current-carrying direction of the capacitor busbar.

[0016] Further, the direct-current capacitor cell comprises at least one capacitor array, the capacitor array comprises a plurality of capacitors, and the capacitors in the capacitor array are arranged in the form of a rectangular array; in each capacitor array, the unit number of capacitors in the current-carrying direction of the capacitor busbar is less than the unit number of capacitors in the direction perpendicular to the current-carrying direction.

[0017] In addition, the application also provides a converter comprising the power assembly according to any one of the above.

[0018] From the above description of the application, the application has the following beneficial effects relative to the prior art:

[0019] 1. In the power assembly provided by the application, the mounting base in the power module is parallel to the capacitor busbar, the switch device is mounted on the mounting base and connected to the capacitor busbar through the terminal component, the first switch is arranged and fixed on the first mounting surface of the mounting base along the first direction, and the second switch is arranged and fixed on the second mounting surface of the mounting base along the first direction, that is, the mounting positions of the first switch and the second switch are away from each other relative to the mounting base, and the arrangement directions of the first switch and the second switch are the same, under the position relationship, the distances from each first switch to the capacitor busbar and from each second switch to the capacitor busbar are the same, on this basis, the absorption capacitors are divided into two parts, one part corresponds to the first switch, and the other part corresponds to the second switch, each first switch and second switch is connected to a group of absorption capacitors, so that the requirements of each absorption capacitor for reducing stray inductance are consistent; and the positions of the absorption capacitors corresponding to the first switch are on one side of the capacitor busbar, and the positions of the absorption capacitors corresponding to the second switch are on one side of the mounting base, thereby, the distance between the mounting base and the capacitor busbar can be as close as possible, the length of the connection circuit of the switch device on the mounting base and the capacitor busbar is shortened, and then the commutation circuit is shortened, and the stray inductance is reduced; at the same time, the position arrangement can facilitate the disassembly, maintenance and assembly of the absorption capacitors.

[0020] 2. Both the first and second switches are equipped with terminals. These terminals can be connected not only to wiring components but also to absorption capacitors. The absorption capacitors reduce stray inductance of the switching devices by connecting to the terminals. The order in which the terminals of the first and second switches are connected to the absorption capacitors and wiring components can be adjusted according to actual needs. This change in order will not affect the effectiveness of the absorption capacitors. However, it should be noted that the absorption capacitors should be positioned as close as possible to the first and second switches to improve their effectiveness.

[0021] 4. The absorption capacitor is provided with an outwardly extending conductive plate, which is connected to the corresponding terminal. This allows the main body of the absorption capacitor, which occupies a large space, to avoid the wiring components in the power module, and also facilitates the installation of the absorption capacitor.

[0022] 5. The wiring components include a first terminal and a second terminal. The terminals can be connected to the terminals of the switching devices. The absorption capacitor can be connected to the terminals of the switching devices through the terminals or directly to the terminals of the switching devices. Depending on the positional relationship between the absorption capacitor and other components, connecting through the terminals increases the distance between the main body of the absorption capacitor and the switching devices, making it easier to avoid the wiring components and the switching devices. Directly connecting to the terminals reduces the distance between the absorption capacitor and the terminals of the switching devices, improves the effect of the absorption capacitor in reducing stray inductance, and improves space utilization.

[0023] 6. The wiring components also include a busbar, through which the first switch or the second switch is connected to the capacitor busbar. This reduces the number of openings on the capacitor busbar, improves the current carrying efficiency of the capacitor busbar, and also facilitates the installation of the wiring components.

[0024] 7. The first switch's terminals are directly connected to the capacitor busbar via the first terminal, while the second switch is connected to the capacitor busbar via the second terminal and the busbar. These two connection methods avoid the increased stray inductance in the circuit caused by the increased commutation path when using a busbar connection, and also avoid the reduced current-carrying efficiency of the capacitor busbar caused by more through-holes created by the terminals when using direct terminal connections. This achieves a balance between lower stray inductance and higher current-carrying efficiency of the capacitor busbar. Thus, the overall current-carrying efficiency of the capacitor busbar can be improved using busbars, and the overall stray inductance can be reduced using terminals. Furthermore, since the terminals do not need to pass through a busbar, the balance of each DC-side switching device's connection to the capacitor busbar is better.

[0025] 8、The first terminal post and the terminal end cooperate to clamp and connect the conductive sheet of the absorption capacitor, so that the installation and fixation of the absorption capacitor can be realized; and the second terminal post is connected with the busbar and the absorption capacitor in sequence, because the end of the second terminal post is exposed, the conductive sheet of the absorption capacitor can be conveniently connected to the second terminal post.

[0026] 9、The capacitors in the direct-current capacitor cell are arranged in a rectangular array, and the unit number of each capacitor in the capacitor array in the current-carrying direction of the capacitor bus is less than the unit number of each capacitor in the direction perpendicular to the current-carrying direction, which makes the size of the capacitor bus in the direction perpendicular to the current-carrying direction larger than that of the conventional capacitor bus, which not only facilitates the installation and arrangement of the capacitors, but also improves the current-carrying efficiency of the capacitor bus; because the first terminal post needs to penetrate the capacitor bus to connect the absorption capacitor, and the arrangement direction of each first terminal post is perpendicular to the current-carrying direction of the capacitor bus, which will result in too many openings on the capacitor bus, thereby affecting the current-carrying capacity of the capacitor bus; by increasing the size of the capacitor bus in the direction perpendicular to the current-carrying direction, and arranging each capacitor on the capacitor bus in the direction perpendicular to the current-carrying direction with a unit number greater than that in the current-carrying direction, not only can the influence of the openings on the capacitor bus on the current-carrying efficiency of the capacitor bus be reduced, but also the material cost of the capacitor bus can be reduced compared with the method of directly thickening the capacitor bus; at the same time, this arrangement of the capacitor array can also shorten the distance between the overall capacitors in the capacitor array and the power module power taking position, where the power taking position refers to the position where the wiring component is connected with the capacitor bus, and the shortening of the distance can shorten the overall commutation circuit and further reduce the stray inductance of the power assembly. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0028] Figure 1 The structure of the power assembly in the background art is shown in the figure;

[0029] Figure 2 The circuit diagram of the three-level topology structure in the background art is shown in the figure;

[0030] Figure 3 The structure side view of the power assembly provided by Embodiment 1 of the present application is shown in the figure;

[0031] Figure 4 The structure of the power assembly in the background art is shown in the figure; Figure 3 The enlarged view of part A in the figure;

[0032] Figure 5 Fig. 1 is a structural schematic diagram of a medium-power assembly according to the present application; Figure 3 Fig. 2 is a structural schematic diagram of a part of the medium-power assembly according to the present application;

[0033] Figure 6 Fig. 3 is a structural schematic diagram of a medium-power assembly according to the present application; Figure 3 Fig. 4 is a structural schematic diagram of a part of the medium-power assembly according to the present application;

[0034] Figure 7 Fig. 5 is a structural schematic diagram of a medium-power assembly according to the present application; Figure 3 Fig. 6 is a structural schematic diagram of a part of the medium-power assembly according to the present application;

[0035] Explanation of main reference numerals:

[0036] Capacitor module 10; DC capacitor bank 11; capacitor busbar 12; power module 20; mounting base 21; power tube group 22; wiring component 23; first mounting surface 211; second mounting surface 212; switching device 221; wiring terminal 2211; first switch 222; second switch 223; third switch 224; first wiring post 231; second wiring post 232; busbar 233; absorption capacitor 30; conductive sheet 31; capacitor device 32; connection busbar 41; output busbar 42. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are preferred embodiments of the present application, and should not be regarded as exclusive to other embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative effort fall within the scope of protection of the present application.

[0038] In the claims, specification, and above drawings of the present application, unless otherwise explicitly limited, the use of the terms "first", "second", or "third" etc. is intended to distinguish different objects, and is not intended to describe a particular order.

[0039] In the claims, specification, and above drawings of the present application, unless otherwise explicitly limited, the use of terms such as "center", "transverse", "longitudinal", "horizontal", "vertical", "top", "bottom", "inner", "outer", "upper", "lower", "front", "back", "left", "right", "clockwise", "counterclockwise" etc. indicates the orientation or positional relationship based on the orientation and position relationship shown in the drawings, and is only intended to facilitate the description of the present application and simplify the description, and is not intended to indicate or imply that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation, so it cannot be understood as limiting the specific protection scope of the present application.

[0040] In the claims, the specification, and the drawings of the present application, terms such as "fixedly connected" or "connected" should be construed broadly to encompass both direct connections and indirect connections, unless otherwise expressly limited by the context. For example, fixedly connected or connected can mean that two members are connected to each other in a manner that they are not easily separated under normal conditions, or that two members are connected to each other in a manner that they are not easily separated under normal conditions and relative rotation between the two members is not allowed.

[0041] In the claims, the specification, and the drawings of the present application, terms such as "including", "having", and variations thereof should be construed broadly to encompass both "consist of" and "consist essentially of" unless otherwise expressly limited by the context.

[0042] Embodiment 1

[0043] Referring to Figure 3 Embodiment 1 of the present application provides a power assembly, which mainly comprises a capacitor module 10, a power module 20 and a plurality of groups of absorption capacitors 30. The capacitor module 10 comprises a direct-current capacitor bank 11 and a capacitor busbar 12 connected to each other, and the capacitor busbar 12 comprises a plurality of polar plates with different polarities. The power module 20 comprises a mounting base 21, a power tube group 22 and a wiring component 23.

[0044] Referring to Figure 3 The direct-current capacitor bank 11 in the capacitor module 10 comprises a plurality of capacitors, which correspond to the capacitor C1 and the capacitor C2 in the figure. Referring to the figure, the capacitors in the direct-current capacitor bank 11 are connected to the capacitor busbar 12. The capacitor busbar 12 comprises a first polar plate, a second polar plate and a third polar plate arranged in layers. According to the front-rear direction in the figure, the power module 20 is located in front of the capacitor busbar 12, and the first polar plate, the second polar plate and the third polar plate are arranged in an order of gradually approaching the power module 20, so that the first polar plate, the second polar plate and the third polar plate are arranged from back to front, the first polar plate is located at the back, the second polar plate is located in the middle, and the third polar plate is located at the front. The capacitors in the direct-current capacitor bank 11 are all fixed to the back side of the capacitor busbar 12, and are all cylindrical members with their bottoms connected to the capacitor busbar 12. In this embodiment, the first polar plate is a positive polar plate, the second polar plate is a neutral polar plate, and the third polar plate is a negative polar plate.

[0045] In addition, the capacitors in the direct-current capacitor bank 11 also form capacitor arrays, and two separate capacitor arrays are formed in this embodiment. The capacitors in each capacitor array are arranged in a rectangular array, and in each capacitor array, the unit number of the capacitors in the current-carrying direction of the capacitor busbar 12 is less than the unit number of the capacitors in the direction perpendicular to the current-carrying direction. That is, in each capacitor array, the number of capacitors in the up-down direction is less than the number of capacitors in the left-right direction, thereby forming a rectangular array arrangement.

[0046] Referring to Figure 3At the upper end of the capacitor busbar 12, three terminals are extended respectively corresponding to the first, second and third polar plates, which form the input of the capacitor busbar 12. The input here refers to the input of the direct current when the power assembly is used to convert the direct current into alternating current; it should be understood that when the power assembly is used to convert the alternating current into direct current, the original input of the capacitor busbar 12 will become the actual output of the direct current. Therefore, the input of the capacitor busbar 12 is represented here only for the convenience of description, and does not mean that it can only be used as an input of electric energy.

[0047] In the power module 20, the power tube group 22 includes a plurality of switching devices 221, some of which are connected to the capacitor busbar 12 through the wiring component 23, and are divided into first switches 222 and second switches 223 according to the connection relationship with the polar plates of different polarities on the capacitor busbar 12; the mounting base 21 is parallel to the capacitor busbar 12 and is provided with a first mounting surface 211 facing the capacitor busbar 12 and a second mounting surface 212 away from the capacitor busbar 12; each of the first switches 222 is arranged and fixed in the first direction on the first mounting surface 211, and each of the second switches 223 is arranged and fixed in the first direction on the second mounting surface 212.

[0048] The first direction is the length direction of the mounting base 21, as shown in Figure 3 which shows the up-down direction and the front-back direction, and oppositely, the left-right direction not shown can be considered as the first direction described above. Moreover, the length direction of the mounting base 21 is perpendicular to the current-carrying direction of the capacitor busbar 12, and the current-carrying direction here can be considered as the extension direction of the input of the capacitor busbar 12 to the connection position of the wiring component 23 and the capacitor busbar 12, which is the up-down direction in this embodiment.

[0049] Referring to Figure 5 and Figure 6 each switching device 221 is divided into a direct current side switching device 221 and an alternating current side switching device 221 according to the connection relationship with the direct current side and the alternating current side of the power module 20, wherein the first switch 222 and the second switch 223 are the direct current side switching devices 221, and the third switch 224 is the alternating current side switching device 221, the lower end of the first switch 222, the lower end of the second switch 223 and the upper end of the third switch 224 are connected through the connection row 41, and the lower end of the third switch 224 is connected with the output row 42, which can be connected with the external alternating current electrical component. Of course, when the power assembly is used to convert the alternating current into direct current, the original output of the power module 20 will become the actual input of the alternating current. Therefore, the output of the power module 20 is represented here only for the convenience of description, and does not mean that it can only be used as an output of electric energy.

[0050] In the embodiment, the power tube group 22 includes three single-phase switch tube groups, each of which includes three switch module groups, and each switch module group includes three switch devices 221. The three switch module groups in each single-phase switch tube group are arranged along the left-right direction, and the three single-phase switch tube groups are also arranged along the left-right direction. Referring to Figure 5 In the embodiment, there are nine switch module groups arranged along the left-right direction. The switch devices 221 are IGBT modules. Among the three switch devices 221 of each switch module, there are a first switch 222, a second switch 223, and a third switch 224.

[0051] Referring to Figure 7 Each switch device 221 is provided with a connection terminal for external wiring. The connection terminals connected to the wiring component 23 in the first switch 222 and the second switch 223 are marked as wiring terminals 2211, and the first switch 222 and the second switch 223 each include two wiring terminals 2211. In the embodiment, the two wiring terminals 2211 of the first switch 222 are connected to the neutral plate and the negative plate of the capacitor busbar 12, respectively, and the two wiring terminals 2211 of the second switch 223 are connected to the positive plate and the neutral plate of the capacitor busbar 12, respectively.

[0052] The power module 20 also includes at least one mounting base 21, which forms a first mounting surface 211 facing the capacitor busbar 12 and a second mounting surface 212 facing away from the capacitor busbar 12. In the power tube group 22, part of the switch devices 221 are located on the first mounting surface 211, and part of the switch devices 221 are located on the second mounting surface 212. Specifically, referring to Figure 3 In the embodiment, the first switch 222 is located on the first mounting surface 211, the second switch 223 and the third switch 224 are located on the second mounting surface 212, the first switch 222 and the second switch 223 are located on the upper side of the mounting base 21 and close to the upper side edge of the mounting base 21, and the third switch 224 is located on the lower side of the mounting base 21. The three switch devices 221 in the same switch module each occupy a unit size of one switch device 221 width in the left-right direction, and the first switch 222 and the second switch 223 are symmetrical to each other.

[0053] Referring to Figure 3 and Figure 4The wiring component 23 comprises busbars 233, first wiring posts 231 and second wiring posts 232. The wiring ends 2211 of the first switches 222 are connected to the first wiring posts 231, and the wiring ends 2211 of the second switches 223 are connected to the second wiring posts 232. In the DC side switch device 221, the wiring ends 2211 of part of the switch device 221 are connected to the busbars 233 through the corresponding first wiring posts 231 or second wiring posts 232, and then connected to the capacitor busbar 12 through the busbars 233. In the embodiment, the wiring ends 2211 of each of the first switches 222 are directly connected to the capacitor busbar 12 through the corresponding first wiring posts 231, and the wiring ends 2211 of each of the second switches 223 are connected to the busbars 233 through the corresponding second wiring posts 232, and then connected to the capacitor busbar 12 through the busbars 233. In addition, the first wiring posts 231 all penetrate the capacitor busbar 12 and expose end portions on the side of the capacitor busbar 12 away from the mounting base 21.

[0054] In the embodiment, the busbars 233 are copper bars, and the wiring posts are conductive posts. In other embodiments, the busbars 233 can be metal busbars 233 formed by flexible metal wires, and the wiring posts can have other shapes, such as wide flat shapes, etc. The connection between the wiring posts and the wiring ends 2211 of the switch device 221 can be achieved by screwing the wiring posts into threaded holes provided on the wiring ends 2211, or by welding.

[0055] As described above, the capacitor busbar 12 is located on the rear side of the mounting base 21, and the busbars 233 extend in the left-right direction and are parallel to the plate surface of the capacitor busbar 12. Thus, in each single-phase switch tube group, each switch module is connected to the capacitor busbar 12 through the busbars 233 at the same distance, and the length of the commutation loop of each switch module is also the same, which can reduce the stray inductance and switching loss. In addition, the busbars 233 comprise two copper bars stacked together, and the two copper bars are connected to the positive plate and the neutral plate of the capacitor busbar, respectively. The stacked arrangement can reduce the stray inductance of the current loop.

[0056] In addition, in the embodiment, the first switch and the second switch in each switch module are arranged on the mounting base 21 in the vertical direction, and each switch module is arranged side by side in the left-right direction, so that the size of the power module in the left-right direction is shortened, and the size of the power module in the up-down direction is increased. In this way, the size of the power module in the left-right direction and the up-down direction is more balanced. In addition to the advantages of facilitating actual implementation and use, the mounting base 21 as a liquid cooling radiator can also be selected to pass the cooling liquid at the left end or the right end. Since the size in the left-right direction is shortened, the cooling liquid can be better released at each position of the mounting base 21, and the overall temperature uniformity of the mounting base 21 is better. In addition, the mounting base 21 also leaves a free position at the lower side of the first mounting surface, that is, the part below the first switch. When actually designing the cooling liquid flow channel, the upper half of the mounting base 21 can be designed as a cooling liquid inlet flow channel, and the lower half can be designed as a cooling liquid return flow channel. The cooling liquid in the cooling liquid inlet flow channel has a lower temperature, which can improve the cooling efficiency of the first switch 222 and the second switch 223 with higher temperature release. The cooling liquid in the cooling liquid return flow channel has a higher temperature, which has no effect on the cooling of the third switch 224 with lower temperature release.

[0057] With reference to Figure 1 , the absorption capacitor 30 includes a plurality of groups, each group of absorption capacitors 30 including at least one capacitor device 32, and each group of absorption capacitors 30 being provided with an outwardly extending conductive sheet 31, one end of the conductive sheet 31 being connected to all capacitor devices 32 in the group of absorption capacitors 30, and the other end being connected to a corresponding terminal 2211 of the first switch 222 or the second switch 223.

[0058] With reference to Figure 4 , Figure 5 and Figure 6 , each first switch 222 and each second switch 223 is correspondingly connected to a group of absorption capacitors 30, and the absorption capacitors 30 connected to the first switch 222 are located on the side of the capacitor busbar 12 away from the mounting base 21, and the absorption capacitors 30 connected to the second switch 223 are located on the side of the mounting base 21 away from the capacitor busbar 12.

[0059] The wire end 2211 of the first switch 222 and the second switch 223 is connected with the corresponding absorption capacitor 30. The wire end 2211 of the first switch 222 is connected with the absorption capacitor 30 and the wiring component 23 in sequence, or is connected with the wiring component 23 and the absorption capacitor 30 in sequence; the wire end 2211 of the second switch 223 is connected with the absorption capacitor 30 and the wiring component 23 in sequence, or is connected with the wiring component 23 and the absorption capacitor 30 in sequence. The conductive sheet 31 of the absorption capacitor 30 is connected with the wire end 2211 of the corresponding first switch 222 and / or second switch 223 through the first connecting post 231 and the second connecting post 232, or is directly connected with the wire end 2211 of the corresponding first switch 222 and / or second switch 223.

[0060] In the embodiment, referring to Figure 4 , one end of the first connecting post 231 is connected with the wire end 2211 of the corresponding first switch 222, and the other end penetrates through the capacitor busbar 12 and is connected with the conductive sheet 31 of the corresponding absorption capacitor 30; the second connecting post 232 starts from the wire end 2211 of the corresponding second switch 223 and is connected with the busbar 233 and the corresponding absorption capacitor 30 in sequence. Specifically, the conductive sheet 31 of the absorption capacitor 30 can be provided with an opening, and then the conductive sheet 31 can be fixed to the exposed end of the first connecting post 231 or the second connecting post 232 by a bolt, or the conductive sheet 31 can be directly fixed and connected to the first connecting post 231 or the second connecting post 232 by welding. Referring to Figure 4 , the conductive sheet 31 of the absorption capacitor 30 extends horizontally outward from the absorption capacitor 30 and then extends upward to form a bend. The bend can make part of the capacitor device 32 of the absorption capacitor 30 be dislocated with the first connecting post 231 and the second connecting post 232 in the up-down direction, so that the absorption capacitor 30 can avoid the wiring component 23, and the installation of the absorption capacitor 30 is facilitated.

[0061] The first connecting post 231 needs to penetrate through the capacitor busbar 12, so corresponding openings need to be provided on the capacitor busbar 12, and the openings need to be provided on the three polar plates of the capacitor busbar 12, which affects the current carrying efficiency of the capacitor busbar 12. Therefore, the arrangement of the capacitors on the capacitor busbar 12 is improved to form a rectangular array as described above, so as to increase the size of the capacitor busbar 12 in the left-right direction and reduce the influence of the openings on the capacitor busbar 12 on the current carrying efficiency of the capacitor busbar 12.

[0062] The power module 20 is provided with a mounting base 21 parallel to the capacitor busbar 12, and the switching device 221 is mounted on the mounting base 21 and connected with the capacitor busbar 12 through the wiring component 23, wherein the first switch 222 is arranged and fixed on the first mounting surface 211 of the mounting base 21 along the first direction, and the second switch 223 is arranged and fixed on the second mounting surface 212 of the mounting base 21 along the first direction, that is, the mounting positions of the first switch 222 and the second switch 223 are opposite to each other relative to the mounting base 21, and the arrangement directions of the first switch 222 and the second switch 223 are the same, under the position relationship, the distances from each first switch 222 and each second switch 223 to the capacitor busbar 12 are the same, on this basis, the absorption capacitor 30 is divided into two parts, one part corresponds to the first switch 222, and the other part corresponds to the second switch 223, each first switch 222 and second switch 223 corresponds to a group of absorption capacitors 30, so that the requirements of each absorption capacitor 30 facing to reduce the stray inductance are consistent; and the absorption capacitors 30 corresponding to the first switch 222 are located on one side of the capacitor busbar 12, and the absorption capacitors 30 corresponding to the second switch 223 are located on one side of the mounting base 21, thereby, the distance between the mounting base 21 and the capacitor busbar 12 can be as close as possible, the length of the connection circuit of the switching device 221 on the mounting base 21 and the capacitor busbar 12 is shortened, and then the commutation circuit is shortened, and the stray inductance is reduced; at the same time, the position arrangement can facilitate the disassembly, maintenance and maintenance of the absorption capacitor 30.

[0063] Embodiment 2

[0064] The embodiment 2 of the present application provides a converter, which comprises a shell and a power module arranged in the shell, wherein the power module adopts the power module provided in the embodiment 1.

[0065] The above description and the embodiment are used to explain the protection scope of the present application, but do not constitute the limitation of the protection scope of the present application. Through the inspiration of the present application or the above embodiment, the modification, equivalent replacement or other improvement of the embodiment of the present application or one part of the technical features can be obtained by the ordinary skilled in the art combining with the common knowledge, the ordinary technical knowledge and / or the prior art in the field, through the logical analysis, reasoning or limited test, which should be included in the protection scope of the present application.

Claims

1. A power assembly, characterized by, The application relates to a power supply device, which comprises: a capacitor module (10) comprising DC capacitor cells (11) and a capacitor busbar (12) connected with each other, wherein the capacitor busbar (12) comprises a plurality of polar plates with different polarities; a power module (20) comprising a mounting base (21), a power tube group (22) and a wiring component (23), wherein the power tube group (22) comprises a plurality of switching devices (221), part of the switching devices (221) are connected with the capacitor busbar (12) through the wiring component (23), and the switching devices (221) are divided into first switches (222) and second switches (223) according to the connection relationship with the polar plates with different polarities on the capacitor busbar (12); the mounting base (21) is parallel to the capacitor busbar (12), and is provided with a first mounting surface (211) facing the capacitor busbar (12) and a second mounting surface (212) facing away from the capacitor busbar (12), the first switches (222) are fixed on the first mounting surface (211), and the second switches (223) are fixed on the second mounting surface (212); and a plurality of groups of absorption capacitors (30), each of the first switches (222) and each of the second switches (223) is correspondingly connected with a group of the absorption capacitors (30), and the absorption capacitors (30) connected with the first switches (222) are located on the side of the capacitor busbar (12) facing away from the mounting base (21), and the absorption capacitors (30) connected with the second switches (223) are located on the side of the mounting base (21) facing away from the capacitor busbar (12); the first switches (222) and the second switches (223) are arranged along the length direction of the mounting base (21), and the wiring ends (2211) of the first switches (222) and the second switches (223) are close to the same edge of the mounting base (21); the length direction of the mounting base (21) is perpendicular to the current-carrying direction of the capacitor busbar (12); the DC capacitor cell (11) comprises at least one capacitor array, the capacitor array comprises a plurality of capacitors, and the capacitors in the capacitor array are arranged in the form of a rectangular array.

2. A power pack as claimed in claim 1, characterised in that the first switches (222) and the second switches (223) are provided with wiring ends (2211) for being connected with the wiring component (23), the wiring ends (2211) of the first switches (222) are connected with the wiring component (23) and the absorption capacitors (30) in sequence; the wiring ends (2211) of the second switches (223) are connected with the absorption capacitors (30) and the wiring component (23) in sequence, or are connected with the wiring component (23) and the absorption capacitors (30) in sequence.

3. A power pack as claimed in claim 1, characterised in that, the absorption capacitors (30) are provided with outwardly extending conductive sheets (31), the conductive sheets (31) are connected to the corresponding wiring ends (2211) of the first switches (222) or the second switches (223), so that the absorption capacitors (30) avoid the wiring component (23).

4. A power pack as claimed in claim 3, characterised in that, The wiring component (23) comprises a plurality of first wiring posts (231) and a plurality of second wiring posts (232); the wiring end (2211) of the first switch (222) is connected to the first wiring post (231), and the wiring end (2211) of the second switch (223) is connected to the second wiring post (232); the conductive sheet (31) of the absorption capacitor (30) is connected to the wiring end (2211) of the corresponding first switch (222) and / or second switch (223) through the first wiring post (231) and the second wiring post (232), or is directly connected to the wiring end (2211) of the corresponding second switch (223).

5. A power pack as claimed in claim 4, characterised in that The wiring component (23) further comprises a bus bar (233); the first switch (222) and the second switch (223) are both direct-current side switching devices (221); in the direct-current side switching device (221), the wiring end (2211) of part of the switching devices (221) is connected to the bus bar (233) through the corresponding first wiring post (231) or the second wiring post (232), and is connected to the capacitor busbar (12) after being connected in parallel through the bus bar (233).

6. A power pack as claimed in claim 5, characterised in that The wiring end (2211) of each second switch (223) is connected to the bus bar (233) through the corresponding second wiring post (232), and is connected to the capacitor busbar (12) after being connected in parallel through the bus bar (233); the wiring end (2211) of each first switch (222) is directly connected to the capacitor busbar (12) through the corresponding first wiring post (231).

7. A power pack as claimed in claim 6, characterised in that One end of the first wiring post (231) is connected to the wiring end (2211) of the corresponding first switch (222), and the other end penetrates through the capacitor busbar (12) and is connected to the conductive sheet (31) of the corresponding absorption capacitor (30); the second wiring post (232) starts from the wiring end (2211) of the corresponding second switch (223), and is connected to the bus bar (233) and the corresponding absorption capacitor (30) in sequence.

8. A power pack as claimed in claim 7, characterised in that In each capacitor array, the unit quantity of capacitors in the current-carrying direction of the capacitor busbar (12) is less than the unit quantity of capacitors in the direction perpendicular to the current-carrying direction.

9. A current transformer characterized by The power assembly comprises the power assembly according to any one of claims 1-8.

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