IGCT module structure and IGCT converter

Abstract

The application discloses an IGCT module structure and an IGCT converter, which comprise four power columns; the four power columns comprise two groups, each group comprising a first power column and a second power column; the axial direction of the first power column comprises three IGCTs, and the axial direction of the second power column comprises four diodes; one-to-one correspondence between the three IGCTs and three diodes in the four diodes is achieved through copper bars in parallel connection, and the other diode in the four diodes is a diode in a buffer absorption circuit. Four power columns are adopted, the four power columns comprise two groups, each group comprising a first power column and a second power column; the axial direction of the first power column comprises three IGCTs, and the axial direction of the second power column comprises four diodes; one-to-one correspondence between the three IGCTs and three diodes in the four diodes is achieved through copper bars in parallel connection, each phase converter comprises a module structure, and since the power column is shortened, the stability of the module structure can be improved, and the module structure is not prone to collapse.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, specifically to an IGCT module structure and an IGCT converter. Background Technology

[0002] With the significant increase in the power rating of converters, integrated gate-commutated thyristors (IGCTs) have gained importance. For example, using IGCTs to construct modules of active neutral point clamped (ANPC) three-level converters can further improve the power rating of converters.

[0003] Since each IGCT requires a diode in parallel, the existing IGCT module structure in the ANPC converter includes two strings: one for the IGCT and one for the diode. This results in a long and thin IGCT module structure, which is not conducive to maintenance. Furthermore, the excessive length of the power string makes it prone to misalignment, leading to structural instability. Summary of the Invention

[0004] In view of this, this application provides an IGCT module structure and an IGCT converter, which can shorten the length of the power string, make the structure more stable, and prevent deviation.

[0005] This application provides an IGCT module structure for a three-level converter, including: four power columns;

[0006] The four power columns are divided into two groups, each group including a first power column and a second power column;

[0007] The first power column includes three IGCTs along its axis, and the second power column includes four diodes along its axis.

[0008] The three IGCTs are connected in parallel with three of the four diodes via copper busbars, and the other diode in the four diodes is the diode in the buffer absorption circuit.

[0009] Preferably, the first power column is arranged axially from bottom to top as follows: first heat sink, second IGCT, second heat sink, first insulating component, third heat sink, third IGCT, fourth heat sink, first IGCT, fifth heat sink and second insulating component;

[0010] The two groups include a first group and a second group. The directions of the three IGCTs of the first power column in the first group are opposite to the directions of the three IGCTs of the first power column in the second group.

[0011] Preferably, the second power column is arranged axially from bottom to top as follows: sixth heat sink, second diode, seventh heat sink, third insulating component, eighth heat sink, third diode, ninth heat sink, first diode, tenth heat sink, fourth diode, eleventh heat sink and fourth insulating component;

[0012] The orientation of the four diodes in the second power column of the first group is opposite to that of the four diodes in the second power column of the second group.

[0013] Preferably, the first end of the second IGCT is pressed onto the first heat sink;

[0014] The first end of the first copper busbar is connected to the first heat sink crimped by the second IGCT in the first group;

[0015] The second end of the first copper busbar is connected to the first heat sink crimped by the second IGCT in the second group;

[0016] The first copper busbar is the AC output lead of the module structure.

[0017] Preferably, the second diode is crimped onto the sixth heat sink;

[0018] The second diode is pressed onto the second copper busbar through the sixth heat sink, and the second IGCT is pressed onto the second copper busbar through the first heat sink, so that the second IGCT and the second diode are electrically connected. The second copper busbar is connected to the bottom frame of the module structure through the fifth insulating component.

[0019] The second IGCT and second diode in the first group are electrically connected to the second IGCT and second diode in the second group through the second copper busbar.

[0020] Preferably, the first end of the first IGCT is pressed onto the fourth heat sink, the second end of the second IGCT is pressed onto the second heat sink, and the first and second ends of the bent copper busbar are respectively connected to the second heat sink and the fourth heat sink, so that the first IGCT and the second IGCT are connected together.

[0021] Preferably, the first end of the first IGCT is pressed onto the fourth heat sink, the second end of the second IGCT is pressed onto the second heat sink, and the first end and the second end of the stacked busbar are respectively connected to the second heat sink and the fourth heat sink, so that the first IGCT and the second IGCT are connected together.

[0022] Preferably, the two groups include a first group and a second group;

[0023] There is a first commutation path between the first power column and the second power column in the first group;

[0024] There is a second commutation path between the first power column and the second power column in the second group;

[0025] The first commutation path and the second commutation path are different parts of the same commutation path in a three-level converter. The current direction of the first commutation path is opposite to that of the second commutation path.

[0026] Preferably, the module structure further includes: a first capacitor; the first capacitor is a capacitor in the buffer absorption circuit;

[0027] The first terminal of the first capacitor is connected to the anode of the third diode via a copper busbar, and the second terminal of the first capacitor is connected to the cathode of the fourth diode via a copper busbar.

[0028] This application also provides an IGCT module structure for a two-level converter, which includes at least the following two power columns: a first power column and a second power column;

[0029] The first power column includes two IGCTs along its axis, and the second power column includes three diodes along its axis.

[0030] The two IGCTs of the first power column are connected in parallel with two of the three diodes of the second power column via copper busbars, and the other diode is a diode in the buffer absorption circuit.

[0031] Preferably, it further includes: a third power column and a fourth power column;

[0032] The third power column includes two IGCTs along its axis, and the fourth power column includes three diodes along its axis.

[0033] The two IGCTs of the third power column are connected in parallel with two of the three diodes of the fourth power column through a copper busbar. The other diode among the three diodes is the diode in the buffer absorption circuit.

[0034] The first two-level circuit includes a first power column and a second power column, and the second two-level circuit includes a third power column and a fourth power column respectively.

[0035] The first two-level circuit and the second two-level circuit are connected in parallel.

[0036] This application also provides an IGCT converter, including any of the module structures described above.

[0037] Preferably, when the IGCT converter is a three-phase three-level clamped IGCT converter, each phase includes one or more of the module structures described herein.

[0038] Preferably, when the IGCT converter is a two-level IGCT converter, it includes one or more of the module structures described above.

[0039] Therefore, this application has the following beneficial effects:

[0040] The IGCT module structure provided in this application employs four power columns, comprising two groups, each group including a first power column and a second power column. The first power column includes three IGCTs along its axial direction, and the second power column includes four diodes along its axial direction. The three IGCTs and three of the four diodes are connected in parallel via copper busbars, corresponding one-to-one. Each phase converter includes one module structure. Due to the shortened power columns, the stability of the module structure is improved, making it less prone to collapse. Furthermore, using the module structure provided in this application, the commutation paths of the first and second groups are located at different parts of the same path within the converter, and their commutation paths are opposite to those of the second group. This can cancel magnetic field interference and reduce stray inductance, thus enabling the four-column module structure to achieve a higher power rating. Attached Figure Description

[0041] Figure 1 This is a circuit diagram of a three-level clamped IGCT converter;

[0042] Figure 2 This is a schematic diagram of a module structure in the prior art;

[0043] Figure 3 This is a circuit diagram of a two-level IGCT converter;

[0044] Figure 4 A schematic diagram of the IGCT module structure of a three-level converter provided in this application embodiment;

[0045] Figure 5 From Figure 4 The main view corresponding to direction A;

[0046] Figure 6 for Figure 4 The main views corresponding to 3 and 4 in the diagram;

[0047] Figures 7-10 Schematic diagrams of four converter paths for the module structure provided in the embodiments of this application;

[0048] Figure 11 A schematic diagram showing the current direction of the first commutation path and the current direction of the second commutation path.

[0049] Figure 12 A schematic diagram of the specific structure of the laminated busbar provided in this application;

[0050] Figure 13 This is a top view of the IGCT module structure of the two-level converter provided in the embodiments of this application;

[0051] Figure 14 for Figure 13 The corresponding front view in direction A. Detailed Implementation

[0052] To enable those skilled in the art to better understand the technical solutions provided in the embodiments of this application, the IGCT converter will be introduced below.

[0053] See Figure 1 The figure shows a circuit diagram of a three-level clamped IGCT converter.

[0054] Figure 1 The circuit diagram shown is for a single-phase IGCT converter. It should be understood that a three-phase IGCT converter would include three... Figure 1 The structure shown.

[0055] The bridge arm consists of four IGCTs connected in series: V1, V2, V3 and V4. Each IGCT has a diode connected in parallel across its two ends, i.e., V1, V2, V3 and V4 are connected in parallel with diodes D1, D2, D3 and D4 respectively.

[0056] The clamped IGCT consists of two units: V5 and V6; D5 and D6 are connected in parallel at both ends of V5 and V6, respectively. V5 and V6 are connected in series between the anode of V2 and the cathode of V3.

[0057] In addition, the cathode of V5 is connected to the midpoint of the DC-side capacitor, which is the common terminal of C3 and C4.

[0058] The IGCT converter also includes snubber circuits, with one snubber circuit corresponding to each of the upper and lower bridge arms. The first snubber circuit includes L1, R1, D7, and C1. The second snubber circuit includes L2, R2, C2, and D8.

[0059] Figure 1 The components within the dashed box 100 form a module structure, see [reference]. Figure 2 The figure is a schematic diagram of a module structure in the prior art.

[0060] from Figure 2 It can be seen that, targeting Figure 1 The device within the 100 series has two power pillars: one containing a diode and the other containing an IGCT. Because the power pillars are too long, they are prone to shifting, leading to structural instability.

[0061] In addition to three-level converters including IGCTs, two-level converters can also include IGCTs.

[0062] See Figure 3 The figure shows a circuit diagram of a two-level IGCT converter.

[0063] Figure 3The two-level converter shown has a bridge arm circuit consisting of two IGCTs: V1 and V2, which are connected in parallel with D1 and D2, respectively.

[0064] and Figure 1 The buffer snubber circuit is the same as that in the two-level converter, which also includes a buffer snubber circuit, namely L1, R1, D3, and C1. This application addresses the following: Figure 3 The structural layout of devices within the range of 200.

[0065] The IGCT module structure provided in this application embodiment is applicable to both three-level IGCT converters and two-level IGCT converters. The module structure of the three-level IGCT converter will be introduced first below.

[0066] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the embodiments of this application will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0067] See Figure 4 The figure is a schematic diagram of the IGCT module structure of a three-level converter provided in an embodiment of this application.

[0068] The IGCT module structure of the three-level converter provided in this embodiment includes: four power columns;

[0069] Figure 4 This is a top view of the module structure, including four power pillars, labeled 1, 2, 3, and 4. For a clearer understanding of the module structure, see [link to relevant documentation]. Figure 5 The image is from Figure 4 The main view corresponding to direction A.

[0070] The four power columns are divided into two groups, each group including a first power column and a second power column; Figure 5 The image shows the first group of power columns, i.e. Figure 4 See 1 and 2. Figure 6 The image is Figure 4 The main view corresponding to 3 and 4 in the diagram.

[0071] The following is combined Figure 1 , Figure 5 and Figure 6 Let me introduce it. It should be understood that... Figure 5 and Figure 6 The module structure layout is the same, only the corresponding Figure 1 The circuits are located at different positions. There are two groups: a first group and a second group. The orientation of the three IGCTs of the first power column in the first group is opposite to that of the three IGCTs of the first power column in the second group. The orientation of the four diodes of the second power column in the first group is opposite to that of the four diodes of the second power column in the second group.

[0072] Each power column separates the IGCT devices and diodes, placing them in different power columns; that is, the first power column includes three IGCTs along its axis, and the second power column includes four diodes along its axis. Figure 5 As shown, the first power column includes three IGCTs along its axis: V2, V5, and V1, corresponding to... Figure 1 The three IGCTs in the middle. The axial direction of the second power column includes four diodes: D2, D5, D1, and D7, corresponding to... Figure 1 The four diodes in it.

[0073] The three IGCTs are connected in parallel with three of the four diodes via copper busbars, and the other diode in the four diodes is the diode in the buffer absorption circuit.

[0074] like Figure 5 As shown, the first power column is arranged axially from bottom to top as follows: first heat sink 21, second IGCT (V2), second heat sink 22, first insulating component 11, third heat sink 23, third IGCT (V5), fourth heat sink 24, first IGCT (V1), fifth heat sink 25, and second insulating component 12.

[0075] It should be understood that the bottom of the module structure also includes a bottom frame 30.

[0076] The second power column is arranged axially from bottom to top as follows: sixth heat sink 26, second diode D2, seventh heat sink 27, third insulating component, eighth heat sink 28, third diode D5, ninth heat sink 29, first diode D1, tenth heat sink 210, fourth diode D7, eleventh heat sink 211 and fourth insulating component.

[0077] This application does not specifically limit the implementation of the heat sink; for example, a water-cooled heat sink can be used. Furthermore, the height of the insulating components between each IGCT can be the same; similarly, the height of the insulating components between each diode can be the same, facilitating the parallel connection of the IGCT and its corresponding diode.

[0078] V1 and D1 are connected in parallel through copper busbar P3, V5 and D5 are connected in parallel through copper busbar P3, and V2 and D2 are connected in parallel through copper busbar P3.

[0079] The module structure also includes: a first capacitor; such as Figure 5 As shown, the first terminal of the first capacitor C1 is connected to the anode of the third diode D5 via a copper busbar, and the second terminal of the first capacitor C1 is connected to the cathode of the fourth diode D7 via a copper busbar. D7 is... Figure 1 The diode in the buffer absorption circuit, and C1 is the capacitor in the buffer absorption circuit.

[0080] The top of the module structure is also fixed to the top frame 50 by a locking mechanism 40.

[0081] The system comprises two groups: a first group and a second group; the first end of the second IGCT is crimped onto the first heatsink; the first end of the first copper busbar is connected to the first heatsink crimped by the second IGCT in the first group; and the second end of the first copper busbar is connected to the first heatsink crimped by the second IGCT in the second group. Figure 2 V2 and V3 are connected by crimping, while V2 and V3 are connected by copper busbars in the technical solution provided in this application.

[0082] It should be noted that the first copper busbar can be used as the AC output terminal of the module structure, i.e., the AC output terminal.

[0083] The second diode D2 is pressed onto the sixth heat sink 26;

[0084] The first and second ends of the second copper busbar P4 are connected to the first heat sink 21 and the sixth heat sink 26 respectively, so that the second IGCT, i.e. V2, is connected to the second diode D2. The second copper busbar P4 is connected to the bottom frame 30 of the module structure through the fifth insulating component 15.

[0085] Specifically, the first group Figure 5 As shown, the cathode of the second IGCT, i.e. V2, is connected to the anode of the second diode D2 via a second copper busbar P4. The second copper busbar P4 is connected to the bottom frame 30 of the module structure via an insulating component, which is implemented by a fifth insulating component 15.

[0086] The second copper busbar P4 can be configured as a thick copper busbar. This thick copper busbar connects to the bottom frame, increasing the strength of the bottom frame and reducing the risk of module collapse due to frame deformation. It should be understood that the connection between the second IGCT and the second diode in the first group, as described above, is achieved through the second copper busbar at the bottom of the module structure. Since the second copper busbar is located on the bottom frame and is a single unit, the electrical connection between the second IGCT and the second diode in the second group is also achieved through the second copper busbar. Furthermore, the electrical connection between the second IGCT and the second diode in the first and second groups is also achieved through the second copper busbar. In other words, the second IGCT and second diode in the first group are electrically connected to each other in the second group via the second copper busbar.

[0087] In one possible implementation, the first end of the first IGCT is pressed onto the fourth heat sink, and the second end of the cathode and the anode of the second IGCT are pressed onto the second heat sink. The first and second ends of the bent copper busbar are connected to the second and fourth heat sinks respectively, so that the first IGCT and the second IGCT are connected together.

[0088] by Figure 5Taking this as an example, the cathode of the first IGCT, V1, and the anode of the second IGCT, V2, are connected by a bent copper busbar P1. Figure 6 The cathode of V3 and the anode of V4 are connected by a bent copper busbar P2.

[0089] Figure 6 and Figure 5 The structure is the same, so I will not repeat it here.

[0090] The following is combined Figures 7-10 This application introduces four commutation paths for the module structure provided in the embodiments. Among them, ① and ④ are short commutation paths, and ② and ③ are long commutation paths. They adopt a four-power column method and change the connection method between V2 tube and V3 tube from a press-fit method to a copper busbar connection method. The commutation path ② and ③ becomes longer, and the increased part is the height of a single heat sink and the copper busbar connecting the cathode of V2 tube and the anode of V3 tube.

[0091] The two sets of power columns include a first set and a second set; a first commutation path exists between the first and second power columns in the first set; a second commutation path exists between the first and second power columns in the second set; the first and second commutation paths are different parts of the same commutation path in the three-level converter, that is, the first and second commutation paths are located on the same path in the three-level converter, and the current direction of the first commutation path is opposite to that of the second commutation path. See Figure 11 for details. Taking commutation path ② as an example, during the commutation process, the current directions of columns 1 and 2 are opposite to those of columns 3 and 4, and the resulting magnetic fields partially cancel each other out, reducing the stray inductance of the path.

[0092] To reduce stray inductance generated in the commutation path, another approach is to connect the cathode of the first IGCT (V1) and the anode of the second IGCT (V2) via a multilayer busbar. Similarly, the cathode of V3 and the anode of V4 are connected via a multilayer busbar; that is, the copper busbar connecting the cathode of V1 and the anode of V2 is layered with the copper busbar connecting the cathode of V3 and the anode of V4 to form a multilayer busbar. See [link to multilayer busbar structure] for details. Figure 12 As shown.

[0093] The stacked busbar is actually a combination of the bent copper busbar of the first power column of the first group used to connect the first IGCT and the second IGCT, and the bent copper busbar of the second group used to connect the first power column of the second IGCT. It is designed and implemented in a stacked manner. Therefore, the stacked busbar has four ends, two ends for connecting the devices of the first group, and the other two ends for connecting the devices of the second group.

[0094] The IGCT module structure provided in this application uses four power columns and is suitable for clamped three-level converters. Each phase converter includes one module structure. Because the power columns are shorter, the stability of the module structure can be improved, and the module structure is less prone to collapse. In addition, using the module structure provided in this application, the commutation path of the first group is opposite to that of the second group, which can cancel magnetic field interference and reduce stray inductance. Therefore, the four-column module structure can achieve a larger power rating.

[0095] Based on the IGCT module structure of a three-level converter provided in the above embodiments, this application also provides an IGCT module structure of a two-level converter, which will be described in detail below with reference to the accompanying drawings.

[0096] See Figure 13 The figure is a top view of the IGCT module structure of the two-level converter provided in the embodiment of this application.

[0097] It should be understood that, in order to... Figure 4 Corresponding to the module architecture, Figure 13 The two-level module structure can include two two-level modules, and each pair of two two-level modules can be applied to... Figure 13 The module architecture shown. Due to... Figure 13 The copper busbars at the bottom are connected together, so two two-level converters can be easily connected in parallel.

[0098] See Figure 14 The image is Figure 13 The corresponding front view in direction A.

[0099] Figure 14 Only the middle part is shown Figure 13 A set of power columns. That is... Figure 14 for Figure 3 The structural diagram of the device within 200.

[0100] Because of the circuit layout differences between a two-level IGCT converter and a three-level IGCT converter, therefore... Figure 14 The components in Figure 5 There are few components in it.

[0101] The IGCT module structure of the two-level converter provided in this embodiment includes at least the following two power columns: a first power column and a second power column;

[0102] The first power column includes two IGCTs along its axis, namely V1 and V2, and the second power column includes three diodes along its axis, namely D1, D2, and D3. For the specific circuit details, please refer to [link to circuit diagram]. Figure 3 .

[0103] The two IGCTs of the first power column are connected in parallel with two of the three diodes of the second power column via copper busbars, respectively. Specifically, V1 is connected in parallel with D1, and V2 is connected in parallel with D2. The third diode is the diode in the buffer absorption circuit, namely C1, which is connected between the cathode of D3 and the anode of D2. C1 is specifically connected to D2 and D3 via copper busbars.

[0104] For the module structure corresponding to two two-level circuits, it also includes: a third power column and a fourth power column;

[0105] The third power column includes two IGCTs along its axis, and the fourth power column includes three diodes along its axis.

[0106] The two IGCTs of the third power column are connected in parallel with two of the three diodes of the fourth power column through a copper busbar. The other diode among the three diodes is the diode in the buffer absorption circuit.

[0107] The first two-level circuit includes a first power column and a second power column, and the second two-level circuit includes a third power column and a fourth power column respectively.

[0108] The first two-level circuit and the second two-level circuit are connected in parallel.

[0109] The embodiments in this application are not specifically limited to two-level IGCT converters. Figure 13 The number of module structures can be varied, for example, including 3 groups, corresponding to 6 two-level circuits. Adding a DC support capacitor can realize a two-level dual-PWM converter structure, suitable for low-power converter systems. Alternatively, it can include 2 groups, corresponding to 4 two-level circuits. Two groups can also be used... Figure 13 The module structure enables the parallel connection of three two-level circuits, that is, one module includes two two-level circuits, another module includes one two-level circuit, and two power pillars are not equipped with devices.

[0110] When multiple sets of two-level modules are assembled, a modular multilevel converter (MMC) topology can be formed, which can be applied to medium and high voltage DC power distribution systems. Therefore, this module structure has applicability.

[0111] Because of the IGCT module structure of the two-level converter provided in this application embodiment, the number of devices on each power column is reduced, the power column is shortened, and the structure is more stable, and there will be no instability problem caused by the power column being too long.

[0112] Based on the above embodiments, which provide an IGCT module structure for a three-level converter and an IGCT module structure for a two-level converter, this application also provides an IGCT converter, including the IGCT module structure for a three-level converter or the IGCT module structure for a two-level converter described above.

[0113] When the IGCT converter is a three-phase three-level clamped IGCT converter, each phase includes one Figure 4 The module structure shown.

[0114] When the IGCT converter is a two-level IGCT converter, the two two-level IGCT converters include one Figure 13 The module structure shown.

[0115] The IGCT converter provided in this application adopts the module structure described above. The power column is shorter and the stability is higher. Moreover, due to the use of laminated busbars and the opposite commutation paths of the two groups, stray inductance can be reduced, thereby ensuring that the IGCT converter corresponding to this module structure has a larger power rating.

[0116] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems or apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section.

[0117] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An IGCT module structure for a three-level converter, characterized in that, include: Four power columns; The four power columns are divided into two groups, each group including a first power column and a second power column; The first power column includes three IGCTs along its axial direction, and the second power column includes four diodes along its axial direction. The three IGCTs correspond one-to-one with three of the four diodes and are connected in parallel via copper busbars. The other diode among the four diodes is a diode in the buffer absorption circuit.

2. The module structure according to claim 1, characterized in that, The first power column is arranged axially from bottom to top as follows: first heat sink, second IGCT, second heat sink, first insulating component, third heat sink, third IGCT, fourth heat sink, first IGCT, fifth heat sink and second insulating component; The two groups include a first group and a second group, wherein the directions of the three IGCTs of the first power column in the first group are opposite to the directions of the three IGCTs of the first power column in the second group.

3. The module structure according to claim 2, characterized in that, The second power column is arranged axially from bottom to top as follows: sixth heat sink, second diode, seventh heat sink, third insulating component, eighth heat sink, third diode, ninth heat sink, first diode, tenth heat sink, fourth diode, eleventh heat sink and fourth insulating component; The orientation of the four diodes in the second power column of the first group is opposite to that of the four diodes in the second power column of the second group.

4. The module structure according to claim 2, characterized in that, The first end of the second IGCT is pressed onto the first heat sink; The first end of the first copper busbar is connected to the first heat sink crimped by the second IGCT in the first group; The second end of the first copper busbar is connected to the first heat sink crimped by the second IGCT in the second group; The first copper busbar is the AC output lead of the module structure.

5. The module structure according to claim 3, characterized in that, The second diode is pressed onto the sixth heat sink; The second diode is pressed onto the second copper busbar through the sixth heat sink, and the second IGCT is pressed onto the second copper busbar through the first heat sink, so that the second IGCT and the second diode are electrically connected. The second copper busbar is connected to the bottom frame of the module structure through the fifth insulating component. The second IGCT and the second diode in the first group are electrically connected to the second IGCT and the second diode in the second group through the second copper busbar.

6. The module structure according to claim 2, characterized in that, The first end of the first IGCT is pressed onto the fourth heat sink, and the second end of the second IGCT is pressed onto the second heat sink. The first end and the second end of the bent copper busbar are respectively connected to the second heat sink and the fourth heat sink, so that the first IGCT and the second IGCT are connected together.

7. The module structure according to claim 2, characterized in that, The first end of the first IGCT is pressed onto the fourth heat sink, and the second end of the second IGCT is pressed onto the second heat sink. The first end and the second end of the stacked busbar are respectively connected to the second heat sink and the fourth heat sink, so that the first IGCT and the second IGCT are connected together.

8. The module structure according to any one of claims 1-7, characterized in that, The two groups include the first group and the second group; There is a first commutation path between the first power column and the second power column in the first group; A second commutation path exists between the first power column and the second power column in the second group; The first commutation path and the second commutation path are different parts of the same commutation path in the three-level converter, and the current direction of the first commutation path and the current direction of the second commutation path are opposite.

9. The module structure according to claim 3, characterized in that, The module structure further includes: a first capacitor; the first capacitor is the capacitor in the buffer absorption circuit; The first terminal of the first capacitor is connected to the anode of the third diode via a copper busbar, and the second terminal of the first capacitor is connected to the cathode of the fourth diode via a copper busbar.

10. An IGCT module structure for a two-level converter, characterized in that, It includes at least the following two power columns: a first power column and a second power column; The first power column includes two IGCTs along its axial direction, and the second power column includes three diodes along its axial direction. The two IGCTs of the first power column and two of the three diodes of the second power column are connected in parallel via copper busbars, and the other diode among the three diodes is a diode in the buffer absorption circuit.

11. The module structure according to claim 10, characterized in that, Also includes: The third power column and the fourth power column; The third power column includes two IGCTs in its axial direction, and the fourth power column includes three diodes in its axial direction. The two IGCTs of the third power column and two of the three diodes of the fourth power column are connected in parallel through a copper busbar, and the other diode of the three diodes is a diode in the buffer absorption circuit. The first two-level circuit includes the first power column and the second power column, and the second two-level circuit includes the corresponding third power column and the fourth power column; The first two-level circuit and the second two-level circuit are connected in parallel.

12. An IGCT converter, characterized in that, Includes the module structure as described in any one of claims 1-9 or the module structure as described in any one of claims 10-11.

13. The IGCT converter according to claim 12, characterized in that, When the IGCT converter is a three-phase three-level clamped IGCT converter, each phase includes a module structure as described in any one of claims 1-9.

14. The IGCT converter according to claim 12, characterized in that, When the IGCT converter is a two-level IGCT converter, it includes a module structure as described in any one of claims 10-11.

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