Power unit and high-voltage frequency converter

Abstract

The application provides a power unit and a high-voltage frequency converter, wherein the power unit comprises a control board, a power board, a unit frame, a bus capacitor and a power device, the power board is connected with the control board; the unit frame is provided with an inwardly recessed outer wall to form a capacitor insertion seat; the bus capacitor is partially inserted into the capacitor insertion seat and electrically connected with the power board; and the power device is fixed to the power board. The technical scheme can improve the power density and assembly efficiency of the power unit.

Description

Technical Field

[0001] This invention relates to the field of power electronic equipment technology, and in particular to a power unit and a high-voltage frequency converter. Background Technology

[0002] Common cascaded high-voltage frequency converter power units typically use independently packaged rectifier bridges, IGBTs, and other power devices to achieve the rectification and inversion functions of the power unit. These devices are connected by copper-aluminum busbars or cables, which leads to problems such as large size, low power density, and long assembly time for cascaded high-voltage frequency converter power units. Summary of the Invention

[0003] The main objective of this invention is to provide a power unit and a high-voltage frequency converter, which aim to improve the power density and assembly efficiency of the power unit.

[0004] To achieve the above objectives, the present invention proposes a power unit, the power unit comprising:

[0005] Control panel;

[0006] A power board, which is connected to the control board;

[0007] A unit frame, wherein the outer wall of the unit frame is recessed inward to form a capacitor insertion socket;

[0008] Bus capacitor, wherein a portion of the bus capacitor is inserted into the capacitor socket and electrically connected to the power board; and

[0009] A power device, which is fixed to the power board.

[0010] Optionally, the control board and the power board are disposed in the unit frame;

[0011] The power device is provided in a plurality of units, and the plurality of power devices are arranged side by side on one side surface of the power board.

[0012] Optionally, a terminal is formed at one end of the bus capacitor facing the capacitor socket, and a positioning hole is formed at the bottom of the capacitor socket. The terminal passes through the positioning hole to connect to the end of the bus copper bus away from the power board.

[0013] Optionally, the power unit further includes a capacitor fixing component, which covers the outside of the bus capacitor and is fixedly connected to the unit frame;

[0014] The capacitor fixing member has a fixing claw facing the top wall of the bus capacitor. The fixing claw elastically abuts against the top wall of the bus capacitor to press and fix the bus capacitor.

[0015] Optionally, the unit frame has a copper busbar via that connects to the outside, and the power unit also includes a through-wall copper busbar that passes through the copper busbar via and extends into the unit frame for electrical connection with the power board or the control board.

[0016] A sealing element is provided between the through-wall copper busbar and the wall of the through hole of the copper busbar.

[0017] Optionally, the cross-section of the copper busbar via gradually decreases from the outside towards the interior space of the unit frame.

[0018] Optionally, the unit frame is provided with a programming port, and a programming port seal is provided at the programming port, the programming port seal comprising:

[0019] A programming port cover, wherein the programming port cover is disposed on the programming port and is capable of interference fit with the programming port; and

[0020] The programming port fixing foot has one end fixedly connected to the programming port cover plate and the other end snapped to the unit frame. The programming port fixing foot can be bent to drive the programming port cover plate to open or seal the programming port.

[0021] Optionally, the unit frame is provided with an optical fiber port, and the optical fiber port is provided with an optical fiber port seal, the optical fiber port seal comprising:

[0022] A fiber optic port cover plate is provided on the fiber optic port. The cover plate has a fiber optic head through-hole for inserting the fiber optic head, and the through-hole can be interference-fitted with the fiber optic head.

[0023] The fiber optic port fixing foot is located on the side of the fiber optic port cover plate facing the fiber optic port, and the fiber optic port fixing foot is snap-fitted to the unit frame.

[0024] The present invention also proposes a power unit, the power unit comprising:

[0025] One control panel;

[0026] A power board, which is connected to the control board via a connector terminal;

[0027] Bus capacitor, the bus capacitor being electrically connected to the power board via a bus copper busbar; and

[0028] A power device, which encapsulates a rectifier module and an inverter module, is soldered to a power board, and a plurality of power devices are arranged side by side on one side surface of the power board.

[0029] The present invention also proposes a high-voltage frequency converter, comprising the power unit described in any of the preceding claims.

[0030] The technical solution of this invention integrates the rectifier module and inverter module into a single package by setting power devices. This eliminates the need for connecting copper / aluminum busbars or cables to connect the rectifier module and inverter module, making the power unit structure more compact and reducing its size, thereby increasing its power density. Furthermore, the control board and power board of the power unit can be connected via plug-in terminals, enabling a wireless design for the entire power unit. This allows for automated assembly of the power unit, thus improving assembly efficiency. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0032] Figure 1 This is an overall structural diagram of an embodiment of the power unit of the present invention;

[0033] Figure 2 for Figure 1 A partial structural diagram of the medium power unit;

[0034] Figure 3 for Figure 2 Another structural diagram of the medium power unit;

[0035] Figure 4 for Figure 1 Assembly diagram of the intermediate bus capacitor;

[0036] Figure 5 for Figure 4 Another assembly diagram of the middle bus capacitor;

[0037] Figure 6 for Figure 1 Assembly diagram of the through-wall copper busbar;

[0038] Figure 7 for Figure 6 Schematic diagram of the through-wall copper busbar;

[0039] Figure 8 for Figure 1 Enlarged view of point A in the middle;

[0040] Figure 9 for Figure 8 Schematic diagram of the structure of the recording port seal;

[0041] Figure 10 for Figure 8 A schematic diagram of the structure of the optical fiber seal.

[0042] Explanation of icon numbers:

[0043]

[0044]

[0045] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0047] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0048] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0049] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0050] This invention proposes a power unit 100.

[0051] Please refer to Figures 1 to 3 In some embodiments of the power unit 100, the power unit 100 includes:

[0052] Control board 10;

[0053] Power board 20, which is connected to control board 10;

[0054] Unit frame 50, the outer wall of which is recessed inward to form capacitor insertion socket 51;

[0055] Bus capacitor 30, wherein a portion of bus capacitor 30 is inserted into the capacitor insertion socket 51 and electrically connected to the power board 20; and

[0056] Power device 40, which is fixed to power board 20.

[0057] In this embodiment, the power unit 100 includes a control board 10, a power board 20, a bus capacitor 30, and a power device 40. The power board 20 and the control board 10 are connected. The bus capacitor 30 is electrically connected to the power board 20 via a bus copper busbar 31. The bus capacitor 30 may be, but is not limited to, a thin-film capacitor. The power device 40 is fixed on the power board 20. Further, the power unit 100 also includes a unit frame 50. The outer wall of the unit frame 50 is recessed inward to form a capacitor insertion socket 51. Part of the bus capacitor 30 is inserted into the capacitor insertion socket 51 and electrically connected to the power board 20. This arrangement allows the part of the bus capacitor 30 connected to the power board 20 to be deeply embedded and sealed inside the power unit 100, which is beneficial to the normal operation of the bus capacitor 30. It also allows the remaining part of the bus capacitor 30 to be exposed to the external air duct for heat dissipation.

[0058] It should be noted that the power unit 100 of a common cascaded high-voltage frequency converter usually uses independently packaged rectifier bridges, IGBTs and other power devices 40 to realize the rectification and inversion functions of the power unit 100. The various devices are connected by copper-aluminum busbars or cables, which leads to problems such as large stray inductance, large volume, and low power density in the cascaded high-voltage frequency converter power unit 100. In addition, the assembly time of the power unit 100 is relatively long.

[0059] Therefore, it can be understood that the technical solution of the present invention, by setting an integrated power device 40 that integrates the rectifier module and the inverter module in one package, and having the integrated power device 40 share a power board 20 and a control board 10, eliminates the need to use connecting copper and aluminum busbars or cables to connect the rectifier module and the inverter module and other power devices. On the one hand, it can effectively reduce stray inductance, and on the other hand, it can reduce the assembly cost of the power unit 100 to a certain extent, and make the structure of the power unit 100 more compact, thereby reducing the volume occupied by the power unit 100 and increasing the power density of the power unit 100.

[0060] Please refer to Figure 2 In some embodiments of the power unit 100, the control board 10 and the power board 20 are disposed in the unit frame 50;

[0061] The power device 40 is provided in a plurality of manners, and the plurality of power devices 40 are arranged side by side on one side surface of the power board 20.

[0062] In this embodiment, the control board 10 and the power board 20 are housed in the unit frame 50. The unit frame 50 can protect the internal power board 20 and control board 10 to prevent external dust or other foreign objects from entering the unit frame 50 and interfering with the normal operation of the power board 20 and control board 10. Several functional devices are provided, and several power devices 40 are arranged side by side on one side surface of the power board 20. Each power device 40 encapsulates a rectifier module and an inverter module. With this arrangement, since there is no need to use connecting copper-aluminum busbars or cables to connect the rectifier module and inverter module and other power devices, it is beneficial to make the structure of the power unit 100 more compact, thereby improving the power density of the power unit 100.

[0063] In some embodiments, the power unit 100 has two power devices 40, and each power device 40 has a heat sink on the side facing away from the power board 20 to improve the heat dissipation effect of the power unit 100. Of course, the technical solution of the present invention is not limited to this. The heat sink can also be set as one according to actual needs, and the heat sink is located between the two power devices 40 so that the two power devices 40 can share a heat sink for heat dissipation. This arrangement can further reduce the overall size of the power unit 100. The specific implementation can be set according to actual needs and is not limited here.

[0064] Please refer to Figure 4 In some embodiments of the power unit 100, the bus capacitor 30 has a terminal block formed at one end facing the capacitor insertion base 51, and the bottom of the capacitor insertion base 51 has a corresponding positioning hole 511. The terminal block passes through the positioning hole 511 to connect to the end of the bus copper busbar 31 away from the power board 20.

[0065] In this embodiment, a terminal is formed at one end of the bus capacitor 30 facing the capacitor insertion base 51. A positioning hole 511 is correspondingly provided at the bottom of the capacitor insertion base 51. The terminal can pass through the positioning hole 511 to connect with the end of the bus copper busbar 31 away from the power board 20, thereby realizing the electrical connection between the bus capacitor 30 and the power board 20. This arrangement facilitates the rapid positioning of the bus capacitor 30 during assembly, improving the assembly convenience of the bus capacitor 30. In addition, the positioning hole 511 can also limit the terminal to prevent the bus capacitor 30 from being misaligned or sliding due to external impact, thereby improving the structural stability of the bus capacitor 30.

[0066] Please refer to Figure 5 In some embodiments of the power unit 100, the power unit 100 further includes a capacitor fixing member 52, which covers the outside of the bus capacitor 30 and is fixedly connected to the unit frame 50.

[0067] The capacitor fixing member 52 is provided with a fixing claw 521 facing the top wall of the bus capacitor 30. The fixing claw 521 elastically abuts against the top wall of the bus capacitor 30 to press and fix the bus capacitor 30.

[0068] In this embodiment, the power unit 100 further includes a capacitor fixing member 52. The capacitor fixing member 52 covers the outside of the bus capacitor 30 and is fixedly connected to the unit frame 50. Through the cooperation of the capacitor fixing member 52 and the capacitor insertion seat 51, the bus capacitor 30 can be better fixed on the unit frame 50. Specifically, the capacitor fixing member 52 has a fixing claw 521 facing the top wall of the bus capacitor 30, and the fixing claw 521 is set as an elastic member. When the capacitor fixing member 52 covers the outside of the bus capacitor 30 and is fixedly connected to the unit frame 50, the fixing claw 521 can elastically abut against the top wall of the bus capacitor 30. At this time, the fixing claw 521 undergoes elastic deformation and thus has elastic potential energy. The fixing claw 521 can then apply a clamping force to the top wall of the bus capacitor 30, thereby pressing and fixing the bus capacitor 30 onto the unit frame 50.

[0069] It should be noted that since the elastic coefficients of different materials of the capacitor fixing members 52 are different, the magnitude of the clamping force applied to the top wall of the bus capacitor 30 when elastic deformation occurs is also different. The magnitude of the clamping force applied by the capacitor fixing members 52 can be adjusted by setting different elastic materials. Of course, the magnitude of the clamping force can also be adjusted by adjusting the number and size of the fixing claws 521. The specific implementation can be set according to actual needs and is not limited here.

[0070] Please refer to Figure 6 or Figure 7 In some embodiments of the power unit 100, the unit frame 50 is provided with a copper busbar through hole 53 communicating with the outside. The power unit 100 also includes a through-wall copper busbar 60, which passes through the copper busbar through hole 53 and extends into the unit frame 50 for electrical connection with the power board 20 or the control board 10.

[0071] A sealing element 61 is provided between the through-wall copper busbar 60 and the hole wall of the copper busbar through hole 53.

[0072] In this embodiment, the unit frame 50 has a copper busbar via 53 communicating with the outside. The power unit 100 also includes a through-wall copper busbar 60, which passes through the copper busbar via 53 and extends into the unit frame 50 for electrical connection with the control board 10 or power board 20 inside the unit frame 50. A sealing element 61 is provided between the through-wall copper busbar 60 and the wall of the copper busbar via 53. The sealing element 61 can be a sealant or the like. The sealant has fluidity and can not only fill the wall of the through-wall copper busbar 60 and the copper busbar via 53 well, but also... The gap between them can also improve the connection strength between the through-wall copper busbar 60 and the copper busbar through hole 53; the seal 61 can also be made of elastic material, which can be deformed under pressure to seal the gap between the through-wall copper busbar 60 and the hole wall of the copper busbar through hole 53. Compared with setting the seal 61 as a sealant, the seal 61 made of elastic material can improve the sealing performance of the power unit 100, and at the same time make the power unit 100 have better assemblability and maintainability; the specific implementation can be set according to actual needs, and is not limited here.

[0073] It should be noted that the power unit 100 is typically located within the overall air duct of the high-voltage frequency converter. Therefore, it is necessary to improve the sealing performance of the power unit 100 to prevent dust and corrosive gases from directly entering the interior of the power unit 100 and causing it to malfunction. However, in actual production, due to considerations of processing and assembly errors, the cross-sectional dimensions of the copper busbar through-hole 53 are usually designed to be slightly larger than the cross-sectional dimensions of the through-wall copper busbar 60. This results in assembly gaps in the power unit 100, creating a risk of external dust or other foreign objects entering the power unit 100. Therefore, it is understandable that the technical solution of this invention, by providing a sealing element 61 between the through-wall copper busbar 60 and the hole wall of the copper busbar through-hole 53, can improve the sealing performance of the unit frame 50, thereby improving the safety and reliability of the power unit 100.

[0074] In some embodiments, the sealing element 61 may be, but is not limited to, a sealing ring. The material of the sealing ring may be, but is not limited to, rubber. A sealing groove is provided on the through-wall copper busbar 60, which is arranged circumferentially around the copper busbar through hole 53. The sealing ring is disposed in the sealing groove and can partially protrude from the sealing groove. With this arrangement, the sealing groove can limit the sealing ring, which can improve the positional stability of the sealing element 61. In addition, the sealing ring can also be squeezed and deformed to fit tightly against the through-wall copper busbar 60 and the hole wall of the copper busbar through hole 53, thereby ensuring the sealing effect of the sealing element 61.

[0075] In some embodiments of the power unit 100, the cross-section of the copper busbar via 53 gradually decreases from the outside towards the interior space of the unit frame 50.

[0076] In this embodiment, the cross-section of the copper busbar through hole 53 gradually decreases from the outside to the interior space of the unit frame 50. Since the cross-sectional area of ​​the copper busbar through hole 53 facing the outside is larger, it is beneficial for the through-wall copper busbar 60 to be inserted and the sealing member 61 to be inserted. Since the cross-sectional area of ​​the copper busbar through hole 53 away from the outside is smaller, it is beneficial for the hole wall of the copper busbar through hole 53 to press and fix the sealing member 61, thereby improving the connection strength and sealing performance between the through-wall copper busbar 60 and the copper busbar through hole 53.

[0077] Please refer to Figure 8 or Figure 9 In some embodiments of the power unit 100, the unit frame 50 is provided with a programming port, and a programming port seal 70 is provided at the programming port. The programming port seal 70 includes:

[0078] A programming port cover 71 is provided on the programming port and can be interference-fitted with the programming port; and

[0079] The programming port fixing foot 72 has one end fixedly connected to the programming port cover plate 71 and the other end snapped to the unit frame 50. The programming port fixing foot 72 can be bent to drive the programming port cover plate 71 to open or seal the programming port.

[0080] In this embodiment, the unit frame 50 is provided with a programming port, and a programming port sealing member 70 is provided at the programming port. The programming port sealing member 70 is openable and closable. It is used to open so that programming operations can be performed between the power units 100, or to close the programming port to reduce the risk of external dust or other foreign objects entering the programming port.

[0081] Specifically, the programming port seal 70 includes a programming port cover 71 and a programming port fixing foot 72. Its material can be, but is not limited to, an elastic material, such as silicone. When the programming port cover 71 is placed over the programming port, it provides an interference fit, which helps the programming card cover better seal the programming port. One end of the programming port fixing foot 72 is fixedly connected to the programming port cover 71, and the other end is snap-fitted to the unit frame 50 via a pull-out structure. The programming port fixing foot 72 is bendable. When the programming port seal 70 is closed, the programming port fixing foot 72 bends to allow the programming port cover 71 to cover the programming card. When the programming port seal 70 is open, the programming port fixing foot 72 releases elastic potential energy and causes the programming port cover 71 to spring back to the side of the programming port, thereby opening the programming port and enabling programming operations between the power units 100.

[0082] It is understandable that by setting the programming port seal 70, the sealing performance of the power unit 100 at the programming port can be improved; by fixing the programming port fixing foot 72 of the programming port seal 70 to the unit frame 50, the risk of losing the programming port seal 70 can be reduced, thereby improving the ease of use of the power unit 100.

[0083] Please refer to Figure 8 or Figure 10 In some embodiments of the power unit 100, the unit frame 50 is provided with an optical fiber port, and the optical fiber port is provided with an optical fiber port seal 80, the optical fiber port seal 80 comprising:

[0084] A fiber optic port cover 81 is provided on the fiber optic port. The cover 81 has a fiber optic head through-hole for inserting the fiber optic head, and the through-hole is capable of interference fit with the fiber optic head.

[0085] The fiber optic port fixing foot 82 is located on the side of the fiber optic port cover plate 81 facing the fiber optic port, and the fiber optic port fixing foot 82 is snap-fitted to the unit frame 50.

[0086] In this embodiment, the unit frame 50 is provided with an optical transfer port, and an optical transfer port sealing member 61 is provided at the optical transfer port. The optical transfer port sealing member 61 is provided with an optical transfer head through hole, and the inner diameter of the optical fiber head through hole is slightly smaller than the outer diameter of the optical fiber head, so that it can be interference-fitted with the optical fiber head that has been inserted at the optical transfer port for a long time, thereby improving the sealing performance of the power unit 100 at the optical transfer port.

[0087] Specifically, the fiber optic port seal 80 includes a fiber optic cover plate and a fiber optic fixing foot, and its material can be, but is not limited to, an elastic material, such as silicone. The fiber optic port cover 81 is installed over the fiber optic port. The fiber optic port cover 81 has a fiber optic head through-hole for inserting the fiber optic head and is interference-fitted with the fiber optic head to improve the sealing effect of the fiber optic port seal 80. Furthermore, the fiber optic port cover 81 is designed with a thin-walled structure around the fiber optic head through-hole. This design reduces the outward pulling force on the fiber optic port cover 81 and the optical drive port fixing feet during fiber optic head insertion and removal, thereby improving the connection stability of the fiber optic port seal 80 and facilitating the assembly and disassembly of the fiber optic head. The fiber optic port fixing feet 82 are located on the side of the fiber optic port cover 81 facing the fiber optic port. The fiber optic port fixing feet 82 are snap-fitted to the unit frame 50 via a pull-out structure. Furthermore, multiple fiber optic port fixing feet 82 can be provided, arranged circumferentially around the fiber optic port cover 81, thereby further improving the connection strength between the fiber optic port seal 80 and the unit frame 50.

[0088] The present invention also proposes a power unit 100, the power unit 100 comprising:

[0089] One control panel 10;

[0090] A power board 20 is connected to the control board via a plug-in terminal block.

[0091] Bus capacitor 30, the bus capacitor 30 being electrically connected to the power board 20 via bus copper busbar 31; and

[0092] A power device 40 is provided, which encapsulates a rectifier module and an inverter module. The power device 40 is soldered to the power board 20. Several power devices 40 are provided, and several power devices 40 are arranged side by side on one side surface of the power board 20.

[0093] In this embodiment, the power unit 100 includes a control board 10, a power board 20, a bus capacitor 30, and power devices 40. The power board 20 is connected to the control board 10 via a plug-in terminal. The bus capacitor 30 may be, but is not limited to, a thin-film capacitor, and is electrically connected to the power board 20 via a bus copper busbar 31. Several power devices 40 are arranged side-by-side on one side surface of the power board 20 and soldered onto the power board 20. Each power device 40 encapsulates a rectifier module and an inverter module. This configuration enables a wireless design for the power unit 100, thereby improving the ease of assembly and facilitating automated assembly of the power unit 100, thus increasing the assembly efficiency of the power unit 100.

[0094] The present invention also proposes a high-voltage frequency converter, which includes the power unit 100 described in any of the foregoing embodiments, the specific structure of which refers to any of the foregoing embodiments. Since the high-voltage frequency converter proposed in this application can apply all the technical solutions in all the foregoing embodiments, it possesses at least all the beneficial effects brought by the foregoing technical solutions, which will not be elaborated upon here.

[0095] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A power unit, characterized in that, The power unit includes: Control panel; A power board, which is connected to the control board; A unit frame, wherein the outer wall of the unit frame is recessed inward to form a capacitor insertion socket; Bus capacitor, wherein a portion of the bus capacitor is inserted into the capacitor socket and electrically connected to the power board; and A power device, wherein the power device is fixed to the power board; The unit frame is provided with a programming port, and a programming port sealing component is provided at the programming port. The programming port sealing component includes a programming port cover plate and a programming port fixing foot. The programming port cover plate covers the programming port and can be interference-fitted with the programming port. One end of the programming port fixing foot is fixedly connected to the programming port cover plate, and the other end is snap-fitted to the unit frame. The programming port fixing foot can be bent to drive the programming port cover plate to open or seal the programming port. And / or, the unit frame is provided with an optical fiber port, and an optical fiber port seal is provided at the optical fiber port. The optical fiber port seal includes an optical fiber port cover plate and an optical fiber port fixing foot. The optical fiber port cover plate covers the optical fiber port and has an optical fiber head through hole for inserting the optical fiber head. The optical fiber head through hole can be interference-fitted with the optical fiber head. The optical fiber port fixing foot is located on the side of the optical fiber port cover plate facing the optical fiber port and is snap-fitted to the unit frame.

2. The power unit as described in claim 1, characterized in that, The control board and the power board are disposed in the unit frame; The power device is provided in a plurality of units, and the plurality of power devices are arranged side by side on one side surface of the power board.

3. The power unit as described in claim 2, characterized in that, The bus capacitor has a terminal block at one end facing the capacitor socket, and a positioning hole is formed at the bottom of the capacitor socket. The terminal block passes through the positioning hole to connect to the end of the bus copper bus away from the power board.

4. The power unit as described in claim 3, characterized in that, The power unit also includes a capacitor fixing component, which is mounted on the outside of the bus capacitor and fixedly connected to the unit frame. The capacitor fixing member has a fixing claw facing the top wall of the bus capacitor. The fixing claw elastically abuts against the top wall of the bus capacitor to press and fix the bus capacitor.

5. The power unit as described in claim 1, characterized in that, The unit frame has copper busbar vias that connect to the outside. The power unit also includes a through-wall copper busbar, which passes through the copper busbar vias and extends into the unit frame for electrical connection with the power board or the control board. A sealing element is provided between the through-wall copper busbar and the wall of the through hole of the copper busbar.

6. The power unit as described in claim 5, characterized in that, The cross-section of the copper busbar via gradually decreases from the outside towards the interior space of the unit frame.

7. A high-voltage frequency converter, characterized in that, Includes the power unit as described in any one of claims 1 to 6.

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