Underwater frequency converter

Abstract

The invention discloses an underwater frequency converter, and the underwater frequency converter is used for controlling a motor, and comprises a housing and a frequency conversion unit which is disposed in the housing and is used for achieving the control of the motor. The shell comprises a shell main body with a circular cross section and an end cover which is partially inserted into the end part of the shell main body and is hermetically connected with the end part of the shell main body. The underwater frequency converter provided by the embodiment of the invention has good compression resistance and sealing performance.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of frequency converters. More specifically, the present application relates to an underwater frequency converter. Background Art

[0002] This section is intended to provide background or context for the embodiments of the present application set forth in the claims. The descriptions herein may include concepts that may be explored, but not necessarily concepts that have been previously thought of or explored. Therefore, unless otherwise noted herein, the content described in this section is not prior art with respect to the specification and claims of the present application, and is not admitted to be prior art by inclusion in this section.

[0003] With the implementation of my country's marine development strategy and the advancement of technology, the demand for electrical equipment that can adapt to underwater environments is growing. Underwater inverters are inverters that can work in underwater environments and are mainly used to drive underwater electrical equipment (such as motors).

[0004] The relevant underwater inverters are placed in a seawater environment with a depth of 300m and a pressure of 3MPa for a long time. As seawater is a conductive medium and corrosive, the sealing and pressure resistance design of underwater inverters has always been one of the primary technical problems to be solved. Once an underwater inverter fails due to improper sealing or pressure deformation, it is very difficult and expensive to bring it to land for repair. In view of this, it is urgent to provide an underwater inverter with good sealing and pressure resistance. Summary of the invention

[0005] In order to solve one or more technical problems mentioned above, the present application provides an underwater frequency converter, which is used to control a motor. The underwater frequency converter includes a housing and a frequency conversion unit arranged inside the housing and used to control the motor, and the housing includes a housing body with a circular cross section and an end cover partially inserted into the end of the housing body and sealed and connected to the end of the housing body.

[0006] In an optional scheme, the end cover includes a first end cover and a second end cover, and the first end cover and the second end cover are respectively arranged at two ends of the shell body, and the first end cover and the second end cover both include a convex ring portion inserted into the interior of the shell body, and a sealing ring is provided between the convex ring portion and the shell body.

[0007] In an optional scheme, the frequency conversion unit includes: a first interface, which is sealed on the first end cover and is used to receive a first alternating current of a fixed frequency; a rectifier module, which is arranged in the shell body and connected to the first interface, for converting the first alternating current into direct current; an energy storage module, which is arranged in the shell body and connected to the rectifier module, for storing the electric energy of the direct current and filtering the direct current; an inverter module, which is arranged in the shell body and connected to the energy storage module, for converting the filtered direct current into a second alternating current; a second interface, which is sealed on the second end cover and connected to the inverter module, for providing a second alternating current to the motor; and a control module, which is arranged in the shell body and connected to the inverter module and controls the frequency of the second alternating current; wherein the first interface, the rectifier module, the energy storage module, the inverter module and the second interface are arranged in sequence along the axial direction of the shell body, and the control module and the rectifier module are in the same position in the axial direction of the shell body, but are spaced apart in the radial direction of the shell body.

[0008] In an optional solution, the shell also includes a first mounting sleeve coaxially arranged in the shell body and used to install the rectifier module, and a second mounting sleeve coaxially arranged in the shell body and used to install the inverter module, and the fit between the first mounting sleeve and the second mounting sleeve and the shell body is an interference fit.

[0009] In an optional solution, the inner circumference of the first mounting sleeve includes a first mounting plane for mounting the rectifier module, and the inner circumference of the second mounting sleeve includes a second mounting plane for mounting the inverter module.

[0010] In an optional scheme, the inner cavity of the first mounting sleeve includes a rectification area for accommodating a rectification module and a control module. The rectification area is divided into a first part and a second part by a plane passing through the central axis of the inner cavity. The rectification module is arranged in the first part, and the second part and the unused part of the first part jointly accommodate the control module.

[0011] In an optional scheme, the rectifier module includes a first bent busbar, a first rectifier unit, a second rectifier unit and a third rectifier unit, the first bent busbar connects the first rectifier unit, the second rectifier unit and the third rectifier unit to form a three-phase rectifier bridge connected to the first interface and the energy storage module, and the first rectifier unit, the second rectifier unit and the third rectifier unit are arranged on the inner circumferential surface of the first mounting sleeve along the circumferential interval; the inverter module includes a second bent busbar, a third bent busbar, a fourth bent busbar, a first IGBT module, a second IGBT module, a third IGBT module, a fourth IGBT module, a fifth IGBT module and a sixth The IGBT module, the second bent busbar, the third bent busbar and the fourth bent busbar connect the first IGBT module, the second IGBT module, the third IGBT module, the fourth IGBT module, the fifth IGBT module and the sixth IGBT module to form a three-phase inverter bridge connected to the second interface and the energy storage module. The first IGBT module, the second IGBT module, the third IGBT module, the fourth IGBT module, the fifth IGBT module and the sixth IGBT module are arranged on the inner circumferential surface of the second mounting sleeve along the circumferential interval; the energy storage module includes at least one capacitor, and the at least one capacitor is connected to the rectifier module and the inverter module.

[0012] In an optional solution, the first bent busbar includes a first straight portion parallel to the assembly surface of the first rectifier unit, a second straight portion connected at an angle to the first straight portion and parallel to the assembly surface of the second rectifier unit, and a third straight portion connected at an angle to the second straight portion and parallel to the assembly surface of the third rectifier unit; the rectifier module also includes at least one rectifier connecting component for connecting the first bent busbar and the first rectifier unit, the second rectifier unit and the third rectifier unit; the second bent busbar includes a fourth straight portion parallel to the first IGBT module and a fifth straight portion connected at an angle to the fourth straight portion and parallel to the second IGBT module; the third bent busbar includes a sixth straight portion parallel to the second IGBT module , a seventh straight portion connected at an angle to the sixth straight portion and parallel to the third IGBT module, and an eighth straight portion connected at an angle to the seventh straight portion and parallel to the fourth IGBT module; the fourth bent busbar includes a ninth straight portion parallel to the fourth IGBT module, a tenth straight portion connected at an angle to the ninth straight portion and parallel to the fifth IGBT module, and an eleventh straight portion connected at an angle to the sixth IGBT module; the inverter module also includes at least one inverter connecting component for connecting the second bent busbar, the third bent busbar, the fourth bent busbar, the first IGBT module, the second IGBT module, the third IGBT module, the fourth IGBT module, the fifth IGBT module and the sixth IGBT module.

[0013] In an optional scheme, the rectifier connecting component includes bolts; the inverter connecting component includes a first conductive column arranged in the overlapping area of ​​the second bent busbar and the third bent busbar, and a second conductive column arranged in the overlapping area of ​​the third bent busbar and the fourth bent busbar, the two ends of the first conductive column are respectively connected to the second bent busbar and the third bent busbar by bolts, and the two ends of the second conductive column are respectively connected to the third bent busbar and the fourth bent busbar by bolts.

[0014] In an optional solution, the underwater frequency converter further includes a bracket for mounting the energy storage module and the control module, and two ends of the bracket are respectively fixed to the inner surfaces of the first mounting sleeve and the second mounting sleeve by bolts.

[0015] Through the above description, those skilled in the art can understand that the shell body with a circular cross-section can effectively improve the overall compressive strength of the underwater inverter, and the end cover partially inserted into the shell body can further improve the shell strength while forming a redundant seal with other sealing designs of the underwater inverter, thereby effectively improving the overall sealing performance of the underwater inverter. The underwater inverter provided in the embodiment of the present application has good compressive resistance and sealing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] By reading the detailed description below with reference to the accompanying drawings, the above and other purposes, features and advantages of the exemplary embodiments of the present application will become easy to understand. In the accompanying drawings, several embodiments of the present application are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0017] Figure 1 An underwater frequency converter according to an embodiment of the present application is shown;

[0018] Figure 2 Shows Figure 1 The first installation set and rectifier module of the underwater frequency converter shown in;

[0019] Figure 3 Shows Figure 1 The second installation set and inverter module of the underwater frequency converter shown in ;

[0020] Figure 4 Shows Figure 2 The rectifier unit and rectifier bent busbar of the rectifier module shown in FIG.

[0021] Figure 5 Shows Figure 3 The IGBT module and the inverter bent busbar of the inverter module shown in FIG.

[0022] Figure 6 A schematic diagram of the main circuit of an underwater frequency converter according to an embodiment of the present application is shown.

[0023] Description of reference numerals:

[0024] 100. Underwater frequency converter; 10. Shell; 11. First end cover; 12. Second end cover; D1. Protruding ring; 13. Shell body; 14. First mounting sleeve; 15. Second mounting sleeve; S1. First mounting plane; S2. Second mounting plane; 20. Frequency converter; 21. First interface; 22. Second interface; 23. Rectifier module; B1. First bent busbar; a1. First straight portion; a2. Second straight portion; a3. Third straight portion; R1. First rectifier unit; R2. Second rectifier unit; R3. Third rectifier unit; j1. First conductive trace; j2. Second conductive trace; j3. Third conductive trace; j4. Fourth conductive trace; j5. Fifth conductive trace; 24. Inverter module; B2. Second bent busbar; B3. Third bent busbar; B4. Fourth bent busbar; a4. Fourth flat portion straight portion; a5, fifth straight portion; a6, sixth straight portion; a7, seventh straight portion; a8, eighth straight portion; a9, ninth straight portion; a10, tenth straight portion; a11, eleventh straight portion; V1, first IGBT module; V2, second IGBT module; V3, third IGBT module; V4, fourth IGBT module; V5, fifth IGBT module; V6, sixth IGBT module; j6, sixth conductive trace; j7, seventh conductive trace; j8, eighth conductive trace; j9, ninth conductive trace; j10, tenth conductive trace; j11, eleventh conductive trace; j12, twelfth conductive trace; j13, thirteenth conductive trace; j14, fourteenth conductive trace; e1, first conductive column; e2, second conductive column; 25, energy storage module; 26, control module; 30, bracket. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0026] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0027] Figure 1 FIG. 1 shows an underwater frequency converter 100 according to an embodiment of the present application. Figure 1As shown, the underwater frequency converter 100 includes a housing 10 and a frequency conversion unit 20 disposed inside the housing 10 and used to realize motor control. The housing 10 includes a housing body 13 with a circular cross section and an end cover partially inserted into the end of the housing body 13 and sealed and connected to the end of the housing body 13. Among them, the housing body 13 with a circular cross section can ensure that the compressive strength of the housing body 13 in all directions is uniform and can avoid stress concentration, thereby effectively improving the compressive strength of the housing 10. The end cover is partially inserted into the housing body 13, so that the end cover can be fastened in both radial and axial directions, which is conducive to further improving the strength and reliability of the connection. At the same time, the part of the end cover inserted into the housing body 13 can form a mechanical seal, and the mechanical seal and the seal at the connection between the end cover and the housing body 13 constitute a redundant sealing design. Even if the seal at the connection between the end cover and the housing body 13 fails, the end cover can still prevent seawater from entering the interior of the housing 10 and achieve a sealing effect. In one embodiment, in order to further enhance the pressure resistance and sealing performance of the housing 10, the end cover and the housing body 13 are preferably connected by a flange. The flange connection can withstand greater pressure and has the advantages of easy disassembly, high connection strength and good sealing performance. Therefore, it is particularly suitable for the connection between the end cover and the shell body 13.

[0028] Therefore, those skilled in the art can understand that the shell body 13 with a circular cross-section can effectively improve the overall compressive strength of the underwater inverter 100, and the end cover partially inserted into the shell body 13 can further improve the strength of the shell 10 while forming a redundant seal with other sealing designs of the underwater inverter 100, thereby effectively improving the overall sealing performance of the underwater inverter 100. The underwater inverter 100 provided in the embodiment of the present application has good compressive resistance and sealing performance.

[0029] Regarding the above-mentioned end caps, the number thereof can be selected as one or two according to actual needs. In one embodiment, the number of end caps is selected as two, including a first end cap 11 and a second end cap 12. The first end cap 11 and the second end cap 12 are respectively arranged at both ends of the shell body 13. The first end cap 11 and the second end cap 12 both include a convex ring portion D1 inserted into the interior of the shell body 13, and a sealing ring is provided between the convex ring portion D1 and the shell body 13. The sealing ring has good sealing performance, simple structure, easy use and low cost. It can be understood that the number of sealing rings can be selected as one or more, and those skilled in the art can make a reasonable choice based on actual usage requirements or costs.

[0030] Regarding the frequency conversion unit 20 mentioned above, in one embodiment, the frequency conversion unit 20 includes a first interface 21, a rectifier module 23, an energy storage module 25, an inverter module 24, a second interface 22, and a control module 26. The first interface 21 is sealed on the first end cover 11 and is used to receive a first alternating current of a fixed frequency. The rectifier module 23 is arranged in the shell body 13 and connected to the first interface 21, so as to convert the first alternating current into direct current. The energy storage module 25 is arranged in the shell body 13 and connected to the rectifier module 23, so as to store the electric energy of the direct current and filter the direct current. The inverter module 24 is arranged in the shell body 13 and connected to the energy storage module 25, so as to convert the filtered direct current into a second alternating current. The second interface 22 is sealed on the second end cover 12 and connected to the inverter module 24, so as to provide the second alternating current to the motor. The control module 26 is arranged in the shell body 13 and connected to the inverter module 24 and controls the frequency of the second alternating current. Based on the above functional modules and interfaces, the underwater frequency converter 100 realizes the conversion of a first alternating current with a fixed frequency-direct current-a second alternating current with a variable frequency, and transmits the second alternating current to the motor to drive and control the operation of the motor.

[0031] The first interface 21, the rectifier module 23, the energy storage module 25, the inverter module 24 and the second interface 22 of the underwater frequency converter 100 are arranged in sequence along the axial direction of the shell body 13, so that the rectifier module 23, the energy storage module 25 and the inverter module 24 are arranged in order according to the current direction of the first alternating current received by the first interface 21 and the second alternating current output by the second interface 22. This orderly arrangement can simplify the wiring between the various functional modules and interfaces and reduce the amount of wires. At the same time, the control module 26 and the rectifier module 23 are in the same position in the axial direction of the closed shell 10 and are spaced apart in the radial direction. This arrangement can improve the space utilization rate inside the closed shell 10, making the internal structure of the underwater frequency converter 100 more compact, thereby reducing the overall volume of the underwater frequency converter 100, reducing the weight of the underwater frequency converter 100, and reducing the manufacturing cost of the underwater frequency converter 100.

[0032] Figure 2 Shows Figure 1 The first mounting sleeve 14 and the rectifier module 23 of the underwater frequency converter 100 are shown in FIG. Figure 2 The arrangement of the first mounting sleeve 14 and the rectifier module 23 shown in FIG. Figure 1 is implemented in the structure shown in Figure 1 The content described in also applies to Figure 2 . Figure 3 Shows Figure 1 The second installation sleeve 15 and the inverter module 24 of the underwater frequency converter 100 are shown in FIG. Figure 3 The arrangement of the second mounting sleeve 15 and the inverter module 24 shown in FIG. Figure 1 is implemented in the structure shown in Figure 1 The content described in also applies to Figure 3 .

[0033] like Figure 1-Figure 3 As shown, the housing 10 further includes a first mounting sleeve 14 coaxially disposed in the housing body 13 and used to mount the rectifier module 23, and a second mounting sleeve 15 coaxially disposed in the housing body 13 and used to mount the inverter module 24. The first mounting sleeve 14 and the second mounting sleeve 15 coaxially disposed in the housing body 13 can not only maximize the use of the space inside the housing body 13 to facilitate the installation of the rectifier module 23 and / or the inverter module 24, but also are not prone to eccentricity or looseness, which is beneficial to improving the overall strength of the housing 10. In addition, since the rectifier module 23 and the inverter module 24 inside the underwater inverter 100 will generate a lot of heat when the underwater inverter 100 is working, the internal temperature of the underwater inverter 100 will be too high, increasing the risk of aging or damage of the electronic components inside the inverter, and shortening the service life of the underwater inverter 100. The arrangement of installing the rectifier module 23 and the inverter module 24 on the first mounting sleeve 14 and the second mounting sleeve 15 respectively is also beneficial for the rectifier module 23 and / or the inverter module 24 to transfer the generated heat to the shell body 13 through the first mounting sleeve 14 and / or the second mounting sleeve 15, and use the external seawater as a heat transfer medium to transfer heat, so that the external seawater can take away the heat transferred to the shell body 13 when flowing through the shell 10, so as to realize the heat dissipation of the underwater inverter 100 and effectively reduce the temperature of the underwater inverter 100.

[0034] In terms of material selection, the shell body 13, the first mounting sleeve 14 and / or the second mounting sleeve 15 should be selected as a metal material with good thermal conductivity and high strength, such as aluminum or aluminum alloy. Exemplarily, the shell body 13, the first mounting sleeve 14 and / or the second mounting sleeve 15 can be selected as 6061 aluminum alloy or 7075 aluminum alloy, which has the advantages of good thermal conductivity, high strength and corrosion resistance, so it is particularly suitable for making the shell body 13, the first mounting sleeve 14 and / or the second mounting sleeve 15. In an optional embodiment, the outer wall of the aforementioned shell body 13 may also be provided with a plurality of annular heat dissipation grooves arranged at intervals along the axial direction of the shell body 13. It is understandable that the shape of the cross section of the annular heat dissipation groove can be selected by those skilled in the art according to actual needs, such as a rectangle.

[0035] During installation, the rectifier module 23 and the inverter module 24 can be installed on the first mounting sleeve 14 and the second mounting sleeve 15 respectively, and then the first mounting sleeve 14 with the rectifier module 23 installed and the second mounting sleeve 15 with the inverter module 24 installed are installed in the shell body 13. In order to facilitate the installation operation and subsequent maintenance, the position of the first mounting sleeve 14 is preferably adjacent to or against the first end cover 11, and the installation position of the second mounting sleeve 15 is preferably adjacent to or against the second end cover 12. Compared with the installation method of directly installing the rectifier module 23 and / or the inverter module 24 on the shell body 13, this installation method has very low processing requirements for the shell body 13, which not only facilitates the installation and removal of the rectifier module 23 and / or the inverter module 24, but also reduces the overall processing difficulty and processing cost of the shell 10.

[0036] Further, in a preferred embodiment, the first mounting sleeve 14 and the second mounting sleeve 15 are fitted with an interference fit. For example, the first mounting sleeve 14 and / or the second mounting sleeve 15 can be installed in the shell body 13 by a hot pressing method or a cold pressing method, and a tight fit is achieved by using the clamping force of the shell body 13, which has the advantages of simple structure, high fit and high bearing capacity.

[0037] In an optional solution, the inner circumference of the first mounting sleeve 14 includes a first mounting plane S1 for mounting the rectifier module 23. The rectifier module 23 can be fixed to the first mounting plane S1 by bolts. The first mounting plane S1 can form a larger contact area with the rectifier module 23, which is conducive to the rapid conduction of heat and further improves the heat dissipation efficiency. Exemplarily, during installation, the rectifier module 23 can be placed on the first mounting plane S1, and then the bolts are sequentially passed through the first mounting sleeve 14 and the rectifier module 23, so as to achieve the connection between the rectifier module 23 and the first mounting sleeve 14. Similarly, the inner circumference of the second mounting sleeve 15 includes a second mounting plane S2 for mounting the inverter module 24. The inverter module 24 is fixed to the second mounting plane S2 by bolts. The second mounting plane S2 can form a larger contact area with the inverter module 24, which is conducive to the rapid conduction of heat and further improves the heat dissipation efficiency. During installation, the inverter module 24 can be placed on the second installation plane S2, and then bolts are sequentially inserted through the second installation sleeve 15 and the inverter module 24, thereby achieving connection between the inverter module 24 and the second installation sleeve 15. The aforementioned first plane and / or second plane will not destroy the material stress of the entire housing 10, nor will it reduce the mechanical strength and compressive strength of the entire housing 10, and can meet the use requirements of the underwater inverter 100.

[0038] In an optional solution, the inner cavity of the first mounting sleeve 14 includes a rectifying area for accommodating the rectifying module 23 and the control module 26. The rectifying area is divided into a first part and a second part by a plane passing through the central axis of the inner cavity. The rectifying module 23 is arranged in the first part, and the second part and the unused part of the first part jointly accommodate the control module 26. Such an arrangement can improve the space utilization inside the first mounting sleeve 14, making the internal structure of the underwater frequency converter 100 more compact as a whole. As another alternative embodiment, the inner cavity of the first mounting sleeve 14 may not be provided with a clear rectifying area, and the rectifying module 23 can be flexibly arranged in the inner cavity of the first mounting sleeve 14, and located between the axial sequence positions between the first interface 21 and the energy storage module 25.

[0039] Figure 4 Shows Figure 2 The rectifier module 23 shown in FIG. It can be understood that Figure 4 The structure shown in FIG. 1 is an implementation of the rectifier module 23, which is exemplary and not restrictive. Therefore, the description of the rectifier module 23 above is also applicable to the description of the rectifier module 23 below. Figure 4 Description.

[0040] like Figure 1 , Figure 2 and Figure 4 As shown, the rectifier module 23 includes a first bent busbar B1, a first rectifier unit R1, a second rectifier unit R2 and a third rectifier unit R3. The first bent busbar B1 connects the first rectifier unit R1, the second rectifier unit R2 and the third rectifier unit R3 to form a three-phase rectifier bridge connected to the first interface 21 and the energy storage module 25. The first rectifier unit R1, the second rectifier unit R2 and the third rectifier unit R3 are arranged on the inner circumferential surface of the first mounting sleeve 14 at intervals along the circumferential direction. Such an arrangement can evenly transfer the heat generated by the first rectifier unit R1, the second rectifier unit R2 and the third rectifier unit R3 to the first mounting sleeve 14, preventing heat concentration, which is beneficial to improving the overall heat dissipation efficiency of the rectifier unit.

[0041] It should be noted that, due to the limitation of the internal assembly space of the first installation sleeve 14, the first rectifier unit R1, the second rectifier unit R2 and the third rectifier unit R3 in this embodiment each include two diodes. During installation, the first rectifier unit R1, the second rectifier unit R2 and the third rectifier unit R3, a total of six diodes, are fixed on the first installation surface, and the remaining space in the first installation sleeve 14 is used to accommodate the energy storage module 25 to improve the space utilization of the first installation sleeve 14, thereby making the overall layout of the frequency conversion unit 20 more compact. Those skilled in the art can also install the rectifier units in a reasonable manner according to the teachings of this application and in combination with actual needs, for example, each rectifier unit includes a diode and six rectifier units, a total of six diodes, are fixed on the first installation plane S1, and these methods still fall within the protection scope of this application.

[0042] As an example, Figure 2 As shown, the first bent busbar B1 includes a first straight portion a1 parallel to the mounting surface of the first rectifier unit R1, a second straight portion a2 connected at an angle to the first straight portion a1 and parallel to the mounting surface of the second rectifier unit R2, and a third straight portion a3 connected at an angle to the second straight portion a2 and parallel to the mounting surface of the third rectifier unit R3. Such a setting can simplify wiring and reduce the amount of wires used, further improve the space utilization inside the first mounting sleeve 14, and the installation method is simple and the connection is reliable.

[0043] Furthermore, the rectifier module 23 further comprises at least one rectifier connection component for connecting the first bent busbar B1 and the first rectifier unit R1 , the second rectifier unit R2 and the third rectifier unit R3 . In an optional embodiment, the rectifier connection component comprises a bolt.

[0044] Figure 5 Shows Figure 3 The inverter module 24 shown in FIG. It can be understood that Figure 5 The structure shown in FIG. 1 is an implementation of the inverter module 24, which is exemplary and not restrictive. Therefore, the description of the inverter module 24 above is also applicable to the description of the inverter module 24 below. Figure 5 Description.

[0045] like Figure 1 , Figure 3 and Figure 5As shown, the inverter module 24 includes a second bent busbar B2, a third bent busbar B3, a fourth bent busbar B4, a first IGBT module V1, a second IGBT module V2, a third IGBT module V3, a fourth IGBT module V4, a fifth IGBT module V5 and a sixth IGBT module V6. The second bent busbar B2, the third bent busbar B3 and the fourth bent busbar B4 connect the first IGBT module V1, the second IGBT module V2, the third IGBT module V3, the fourth IGBT module V4, the fifth IGBT module V5 and the sixth IGBT module V6 and form a three-phase inverter bridge connected to the second interface 22 and the energy storage module 25. IGBT (insulated gate bipolar transistor) is a composite fully controlled voltage-driven power semiconductor device composed of BJT (bipolar junction transistor) and MOS (insulated gate field effect transistor), which has the advantages of low driving power and low saturation voltage drop. The underwater frequency converter 100 can adjust the voltage and frequency of the second alternating current by controlling the opening and closing of the IGBT to meet the actual needs of the motor, thereby achieving the purposes of speed regulation, energy saving, etc. Among them, the first IGBT module V1, the second IGBT module V2, the third IGBT module V3, the fourth IGBT module V4, the fifth IGBT module V5 and the sixth IGBT module V6 are arranged on the inner circumferential surface of the second mounting sleeve 15 along the circumferential interval. Such an arrangement can make the heat generated by the first IGBT module V1, the second IGBT module V2, the third IGBT module V3, the fourth IGBT module V4, the fifth IGBT module V5 and the sixth IGBT module V6 be evenly transferred to the second mounting sleeve 15, preventing heat concentration, and helping to improve the overall heat dissipation efficiency of the inverter module 24.

[0046] As an example, Figure 3 As shown, the second bent busbar B2 includes a fourth straight portion a4 parallel to the first IGBT module V1 and a fifth straight portion a5 connected at an angle to the fourth straight portion a4 and parallel to the second IGBT module V2; the third bent busbar B3 includes a sixth straight portion a6 parallel to the second IGBT module V2, a seventh straight portion a7 connected at an angle to the sixth straight portion a6 and parallel to the third IGBT module V3, and an eighth straight portion a8 connected at an angle to the seventh straight portion a7 and parallel to the fourth IGBT module V4; the fourth bent busbar B4 includes a ninth straight portion a9 parallel to the fourth IGBT module V4, a tenth straight portion a10 connected at an angle to the ninth straight portion a9 and parallel to the fifth IGBT module V5, and an eleventh straight portion a11 connected to the sixth IGBT module V6. Such a setting method can simplify wiring and reduce the amount of wires used, further improve the space utilization inside the second mounting sleeve 15, and the mounting method is simple and the connection is reliable.

[0047] Furthermore, the inverter module 24 also includes at least one inverter connection component for connecting the second bent busbar B2, the third bent busbar B3, the fourth bent busbar B4, the first IGBT module V1, the second IGBT module V2, the third IGBT module V3, the fourth IGBT module V4, the fifth IGBT module V5 and the sixth IGBT module V6. As an example, Figure 3 As shown, the inverter connection component includes a first conductive column e1 provided in the overlapping area of ​​the second bent busbar B2 and the third bent busbar B3, and a second conductive column e2 provided in the overlapping area of ​​the third bent busbar B3 and the fourth bent busbar B4. The two ends of the first conductive column e1 can be connected to the second bent busbar B2 and the third bent busbar B3 respectively by bolts, and the two ends of the second conductive column e2 can be connected to the third bent busbar B3 and the fourth bent busbar B4 respectively by bolts. Exemplarily, the first conductive column e1 and the second conductive column e2 can be selected as nut columns. In an alternative embodiment, the aforementioned first conductive column e1 and the second conductive column e2 can also be selected as patch nut columns.

[0048] In a feasible embodiment, the underwater frequency converter 100 further includes a bracket 30 for mounting the energy storage module 25 and the control module 26 (see Figure 1 ), so as to facilitate the rapid disassembly and maintenance of the energy storage module 25 and the control module 26, the two ends of the bracket 30 are respectively fixed to the inner surfaces of the first mounting sleeve 14 and the second mounting sleeve 15 by bolts. The connection between the energy storage module 25 and the control module 26 and the bracket 30 is preferably a detachable connection, and the connection method includes but is not limited to bolt connection or clamping connection. As another example, the energy storage module 25 and the control module 26 can be directly installed in the underwater inverter 100, and the energy storage module 25 and the control module 26 are connected to the shell body 13, and the connection method can be selected as bolt connection or clamping connection.

[0049] Figure 6 FIG. 1 shows a schematic diagram of the main circuit of the underwater frequency converter 100 according to an embodiment of the present application. It can be understood that: Figure 6 The circuit configuration shown in FIG. 1 is an implementation of the underwater frequency converter 100 and is exemplary rather than restrictive. Therefore, the above description of the underwater frequency converter 100 is also applicable to the underwater frequency converter 100. Figure 6 .

[0050] Regarding the first interface 21 mentioned above, in an optional embodiment, the first interface 21 may also include a first power interface, which is connected to the rectifier module 23 and is used to provide the first alternating current to the rectifier module 23. The first interface 21 may also include a first signal interface, which is connected to the control module 26 and is used to provide a control signal to the control module 26.

[0051] As for the second interface 22 mentioned above, in an optional embodiment, the second interface 22 may also include a second power interface, which is connected to the inverter module 24 and the motor and is used to output the second AC power to the motor. The second interface 22 may also include a second signal interface, which is connected to the control module 26 and the motor and is used to input the operating parameters of the motor, such as temperature, voltage and current, into the control module 26 to realize state monitoring and protection of the motor.

[0052] It should be noted that the first interface 21 and the second interface 22 can be provided on the shell body 13, or on the first end cover 11 and / or the second end cover 12, and the present application does not limit this. In order to simplify the wiring and reduce the amount of wires, the first interface 21 should be close to the rectifier module 23, and the second interface 22 should be close to the inverter module 24. Optionally, the first interface 21 and the second interface 22 can be provided on the first end cover 11 and the second end cover 12 respectively, and one of the rectifier module 23 and the inverter module 24 can be in contact with or adjacent to the first end cover 11, and the other of the rectifier module 23 and the inverter module 24 can be in contact with or adjacent to the second end cover 12. Exemplarily, the first interface 21 is provided on the first end cover 11, and the first end cover 11 is adjacent to the rectifier module 23, which simplifies the wiring between the first interface 21 and the rectifier module 23 and reduces the length of the wire. The second interface 22 is provided on the second end cover 12, and the second end cover 12 is adjacent to the inverter module 24, which simplifies the wiring between the second interface 22 and the inverter module 24 and reduces the length of the wire.

[0053] The rectifier module 23 mentioned above is connected to the first interface 21 to convert the first AC power into DC power. In this embodiment, the rectifier module 23 includes a first rectifier unit R1, a second rectifier unit R2 and a third rectifier unit R3. Figure 6 As shown, the first rectifier unit R1 includes a diode VD1 and a diode VD2, the second rectifier unit R2 includes a diode VD3 and a diode VD4, and the third rectifier unit R3 includes a diode VD5 and a diode VD6. The anodes of the diodes VD1, VD3 and VD5 are respectively connected to the first live wire T, the second live wire S and the third live wire R of the first alternating current; the cathodes of the diodes VD2, VD4 and VD6 are also respectively connected to the first live wire T, the second live wire S and the third live wire R of the first alternating current. The cathodes of the diodes VD1, VD3 and VD5 are collected and used as the positive electrode DC+ connected to the energy storage module 25; the anodes of the diodes VD2, VD4 and VD6 are collected and used as the negative electrode DC- connected to the energy storage module 25.

[0054] After the rectifier module 23 rectifies the first AC power into DC power, the DC power output by the rectifier module 23 has certain pulsation and a large amount of harmonic interference, and the rectified DC power needs to be filtered. The energy storage module 25 can suppress pulsation and harmonic interference, making the voltage wave of the DC power smoother and providing a stable working voltage for the motor. At the same time, the energy storage module 25 is also used to store the electrical energy of the DC power. The aforementioned energy storage module 25 includes at least one capacitor, and the at least one capacitor is connected to the rectifier module 23 and the inverter module 24. For example, Figure 6 As shown, the energy storage module 25 at least includes a capacitor C1. Preferably, the energy storage module 25 also includes a capacitor C2 and a capacitor C3, and the capacitors C1, C2 and C3 are connected in parallel to each other between the three-phase rectifier bridge and the three-phase inverter bridge, and are used to store the electric energy of the direct current output by the three-phase rectifier bridge and filter the direct current. One end of the capacitor C1, the capacitor C2 and the capacitor C3 is connected to the positive electrode DC+ of the output end of the three-phase rectifier bridge, and the other end is connected to the negative electrode DC- of the output end of the three-phase rectifier bridge.

[0055] After the energy storage module 25 stores the electric energy of the DC power and filters the DC power, the filtered DC power needs to be inverted into a second AC power with variable frequency through the inverter module 24 to drive and control the motor. The inverter module 24 includes a first IGBT module V1, a second IGBT module V2, a third IGBT module V3, a fourth IGBT module V4, a fifth IGBT module V5 and a sixth IGBT module V6. For example, Figure 6 As shown, the emitter E1 of the first IGBT module V1, the emitter E3 of the third IGBT module V3 and the emitter E5 of the fifth IGBT module V5 are respectively connected to the first input terminal U, the second input terminal V and the third input terminal W of the motor; the collector C2 of the second IGBT module V2, the collector C4 of the fourth IGBT module V4 and the collector C6 of the sixth IGBT module V6 are also respectively connected to the first input terminal U, the second input terminal V and the third input terminal W of the motor. The collector C1 of the first IGBT module V1, the collector C3 of the third IGBT module V3 and the collector C5 of the fifth IGBT module V5 serve as the positive electrode DC'+ of the input end of the three-phase inverter bridge and are used to connect the positive electrode DC+ of the output end of the three-phase rectifier bridge; the emitter E2 of the second IGBT module V2, the emitter E4 of the fourth IGBT module V4 and the emitter E6 of the sixth IGBT module V6 serve as the negative electrode DC'- of the input end of the three-phase inverter bridge and are used to connect the negative electrode DC- of the output end of the three-phase rectifier bridge.

[0056] Regarding the control module 26 mentioned above, it is arranged on the bracket 30, and is connected to the above-mentioned inverter module 24 and controls the frequency of the second alternating current. The control module 26 receives the control instruction from the first signal interface, and outputs the control signal to the inverter module 24 according to the control instruction, so as to adjust the frequency, voltage, phase and other parameters of the second alternating current output by the inverter module 24, so as to realize the control of the speed and torque of the motor, so that the motor can run as needed. The control module 26 can also collect and obtain various operating parameters of the motor fed back by the second signal interface, monitor and protect the motor status, and ensure the safe and reliable operation of the motor. For example, if Figure 6 As shown, the gate G1 of the first IGBT module V1, the gate G2 of the second IGBT module V2, the gate G3 of the third IGBT module V3, the gate G4 of the fourth IGBT module V4, the gate G5 of the fifth IGBT module V5 and the gate G6 of the sixth IGBT module V6 are connected to the control module 26 so that the control module 26 can control the three-phase inverter bridge.

[0057] As for the specific implementation method, the aforementioned control module 26 of the present application can be implemented in various suitable ways. For example, the control module 26 can be implemented by a general-purpose processor ("CPU") or a special-purpose processor (such as a "graphics processing unit"), or a combination of the two. In some scenarios, the control module 26 of the present application can also be implemented by a programmable logic controller (Programmable Logic Controller, "PLC"). Therefore, the present application does not impose any restrictions on the specific implementation method of the control module 26, and those skilled in the art can implement it in a reasonable manner as needed according to the teachings of the present application, and these methods still fall within the scope of protection of the present application.

[0058] Regarding the first bent busbar B1 mentioned above, illustratively, as Figure 4 and Figure 6 As shown, the aforementioned first bent busbar B1 also includes a first conductive trace j1, a second conductive trace j2, a third conductive trace j3, a fourth conductive trace j4 and a fifth conductive trace j5 which are arranged in the first bent busbar B1 and spaced apart from each other. The first conductive trace j1 is connected to the cathode of the diode VD1, the cathode of the diode VD3 and the cathode of the diode VD5; the second conductive trace j2 is connected to the anode of the diode VD1 and the cathode of the diode VD2; the third conductive trace j3 is connected to the anode of the diode VD3 and the cathode of the diode VD4; the fourth conductive trace j4 is connected to the anode of the diode VD5 and the cathode of the diode VD6; the fifth conductive trace j5 is connected to the anode of the diode VD2, the anode of the diode VD4 and the anode of the diode VD6.

[0059] Regarding the second bent busbar B2, the third bent busbar B3 and the fourth bent busbar B4 mentioned above, illustratively, as Figure 5 and Figure 6 As shown:

[0060] The second bent busbar B2 further includes a sixth conductive trace j6, a seventh conductive trace j7 and an eighth conductive trace j8 which are arranged in the second bent busbar B2 and are spaced apart from each other, the sixth conductive trace j6 is connected to the collector of the first IGBT module V1, the seventh conductive trace j7 is connected to the emitter of the first IGBT module V1 and the collector of the second IGBT module V2, and the eighth conductive trace j8 is connected to the emitter of the second IGBT module V2;

[0061] The third bent busbar B3 further includes a ninth conductive trace j9, a tenth conductive trace j10 and an eleventh conductive trace j11 which are spaced apart from each other in the third bent busbar B3, the ninth conductive trace j9 is connected to the collector of the third IGBT module V3, the tenth conductive trace j10 is connected to the emitter of the third IGBT module V3 and the collector of the fourth IGBT module V4, and the eleventh conductive trace j11 is connected to the emitter of the fourth IGBT module V4;

[0062] The fourth bent busbar B4 also includes a twelfth conductive trace j12, a thirteenth conductive trace j13 and a fourteenth conductive trace j14 which are arranged in the fourth bent busbar B4 and are spaced apart from each other. The twelfth conductive trace j12 is connected to the collector of the fifth IGBT module V5, the thirteenth conductive trace j13 is connected to the emitter of the fifth IGBT module V5 and the collector of the sixth IGBT module V6, and the fourteenth conductive trace j14 is connected to the emitter of the sixth IGBT module V6.

[0063] In the above description of the present application, unless otherwise clearly specified and limited, the terms "fixed", "installed", "connected" or "connected" and the like should be understood in a broad sense. For example, with regard to the term "connection", it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements. Therefore, unless otherwise clearly defined in the present application, those skilled in the art can understand the specific meanings of the above terms in the present application according to the specific circumstances.

[0064] According to the above description of the present application, those skilled in the art may also understand that the terms used below, such as "up", "down", "front", "back", "left", "right", "length", "width", "thickness", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", "center", "longitudinal", "lateral", "clockwise" or "counterclockwise", etc., which indicate orientation or positional relationships, are based on the orientation or positional relationships shown in the drawings of the present application, and are only for the purpose of facilitating the explanation of the scheme of the present application and simplifying the description, rather than explicitly or implicitly indicating that the device or element involved must have the specific orientation, be constructed and operate in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms cannot be understood or interpreted as limitations on the scheme of the present application.

[0065] In addition, the terms "first" or "second" used in this application to refer to numbers or ordinals are only used for descriptive purposes and cannot be understood as explicitly or implicitly indicating relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, the meaning of "plurality" is at least two, such as two, three or more, etc., unless otherwise clearly and specifically defined.

[0066] Although multiple embodiments of the present application have been shown and described herein, it is obvious to those skilled in the art that such embodiments are provided only by way of example. Those skilled in the art can think of many changes, modifications and alternatives without departing from the thought and spirit of the present application. It should be understood that in the process of practicing the present application, various alternatives to the embodiments of the present application described herein can be adopted. The attached claims are intended to limit the scope of protection of the present application, and therefore cover equivalents or alternatives within the scope of these claims.

Claims

1. An underwater frequency converter, the underwater frequency converter (100) is used to control a motor, characterized in that: The underwater frequency converter (100) comprises a housing (10) and a frequency conversion unit (20) arranged inside the housing (10) and used to control the motor, wherein the housing (10) comprises a housing body (13) having a circular cross-section and an end cover partially inserted into an end of the housing body (13) and sealedly connected to the end of the housing body (13).

2. The underwater frequency converter according to claim 1, characterized in that: The end cover comprises a first end cover (11) and a second end cover (12), wherein the first end cover (11) and the second end cover (12) are respectively arranged at two ends of the shell body (13), and the first end cover (11) and the second end cover (12) both comprise a convex ring portion (D1) inserted into the interior of the shell body (13), and a sealing ring is arranged between the convex ring portion (D1) and the shell body (13).

3. The underwater frequency converter according to claim 2, characterized in that: The frequency conversion unit (20) comprises: A first interface (21), which is sealed on the first end cover (11) and is used to receive a first alternating current with a fixed frequency; a rectifier module (23), which is arranged in the housing body (13) and connected to the first interface (21), and is used for converting the first alternating current into direct current; an energy storage module (25), which is arranged in the housing body (13) and connected to the rectifier module (23) and is used to store the electric energy of the direct current and filter the direct current; An inverter module (24), which is disposed in the housing body (13) and connected to the energy storage module (25), and is used for converting the filtered direct current into a second alternating current; a second interface (22), which is sealingly disposed on the second end cover (12) and connected to the inverter module (24) to provide the second alternating current to the motor; and A control module (26) is arranged in the shell body (13) and is connected to the inverter module (24) and controls the frequency of the second alternating current; wherein the first interface (21), the rectifier module (23), the energy storage module (25), the inverter module (24) and the second interface (22) are arranged in sequence along the axial direction of the shell body (13), and the control module (26) and the rectifier module (23) are in the same position in the axial direction of the shell body (13), but are spaced apart in the radial direction of the shell body (13).

4. The underwater frequency converter according to claim 3, characterized in that: The housing (10) further comprises a first mounting sleeve (14) coaxially arranged in the housing body (13) and used for mounting the rectifier module (23), and a second mounting sleeve (15) coaxially arranged in the housing body (13) and used for mounting the inverter module (24), wherein the first mounting sleeve (14) and the second mounting sleeve (15) are fitted with the housing body (13) in an interference fit.

5. The underwater frequency converter according to claim 4, characterized in that: The inner circumference of the first mounting sleeve (14) includes a first mounting plane (S1) for mounting the rectifier module (23), and the inner circumference of the second mounting sleeve (15) includes a second mounting plane (S2) for mounting the inverter module (24).

6. The underwater frequency converter according to claim 5, characterized in that: The inner cavity of the first mounting sleeve (14) comprises a rectification area for accommodating the rectification module (23) and the control module (26); the rectification area is divided into a first part and a second part by a plane passing through the central axis of the inner cavity; the rectification module (23) is arranged in the first part, and the second part and an unused part of the first part jointly accommodate the control module (26).

7. The underwater frequency converter according to claim 5, characterized in that: The rectifier module (23) comprises a first bent busbar (B1), a first rectifier unit (R1), a second rectifier unit (R2) and a third rectifier unit (R3); the first bent busbar (B1) connects the first rectifier unit (R1), the second rectifier unit (R2) and the third rectifier unit (R3) to form a three-phase rectifier bridge connected to the first interface (21) and the energy storage module (25); the first rectifier unit (R1), the second rectifier unit (R2) and the third rectifier unit (R3) are arranged at intervals along the circumferential direction on the inner circumferential surface of the first mounting sleeve (14); The inverter module (24) comprises a second bent busbar (B2), a third bent busbar (B3), a fourth bent busbar (B4), a first IGBT module (V1), a second IGBT module (V2), a third IGBT module (V3), a fourth IGBT module (V4), a fifth IGBT module (V5) and a sixth IGBT module (V6); the second bent busbar (B2), the third bent busbar (B3) and the fourth bent busbar (B4) connect the first IGBT module (V1), the second IGBT module (V2), the third IGBT module (V3), the fourth IGBT module (V4), the fifth IGBT module (V5) and the sixth IGBT module (V6); An IGBT module (V3), a fourth IGBT module (V4), a fifth IGBT module (V5) and a sixth IGBT module (V6) are connected to form a three-phase inverter bridge connected to the second interface (22) and the energy storage module (25); the first IGBT module (V1), the second IGBT module (V2), the third IGBT module (V3), the fourth IGBT module (V4), the fifth IGBT module (V5) and the sixth IGBT module (V6) are arranged on the inner circumferential surface of the second mounting sleeve (15) at intervals along the circumferential direction; The energy storage module (25) comprises at least one capacitor, and the at least one capacitor is connected to the rectifier module (23) and the inverter module (24).

8. The underwater frequency converter according to claim 7, characterized in that: The first bent busbar (B1) comprises a first straight portion (a1) parallel to the assembly surface of the first rectifier unit (R1), a second straight portion (a2) connected at an angle to the first straight portion (a1) and parallel to the assembly surface of the second rectifier unit (R2), and a third straight portion (a3) ​​connected at an angle to the second straight portion (a2) and parallel to the assembly surface of the third rectifier unit (R3); The rectifier module (23) further comprises at least one rectifier connecting component for connecting the first bent busbar (B1) and the first rectifier unit (R1), the second rectifier unit (R2) and the third rectifier unit (R3); The second bent busbar (B2) comprises a fourth straight portion (a4) parallel to the first IGBT module (V1) and a fifth straight portion (a5) connected to the fourth straight portion (a4) at an angle and parallel to the second IGBT module (V2); The third bent busbar (B3) comprises a sixth straight portion (a6) parallel to the second IGBT module (V2), a seventh straight portion (a7) connected at an angle to the sixth straight portion (a6) and parallel to the third IGBT module (V3), and an eighth straight portion (a8) connected at an angle to the seventh straight portion (a7) and parallel to the fourth IGBT module (V4); The fourth bent busbar (B4) comprises a ninth straight portion (a9) parallel to the fourth IGBT module (V4), a tenth straight portion (a10) connected at an angle to the ninth straight portion (a9) and parallel to the fifth IGBT module (V5), and an eleventh straight portion (a11) connected to the sixth IGBT module (V6); The inverter module (24) further comprises at least one inverter connection component for connecting the second bent busbar (B2), the third bent busbar (B3), the fourth bent busbar (B4), the first IGBT module (V1), the second IGBT module (V2), the third IGBT module (V3), the fourth IGBT module (V4), the fifth IGBT module (V5) and the sixth IGBT module (V6).

9. The underwater frequency converter according to claim 8, characterized in that: The rectifying connection component includes bolts; the inverter connection component includes a first conductive column (e1) arranged in the overlapping area of ​​the second bent busbar (B2) and the third bent busbar (B3), and a second conductive column (e2) arranged in the overlapping area of ​​the third bent busbar (B3) and the fourth bent busbar (B4), the two ends of the first conductive column (e1) are respectively connected to the second bent busbar (B2) and the third bent busbar (B3) by bolts, and the two ends of the second conductive column (e2) are respectively connected to the third bent busbar (B3) and the fourth bent busbar (B4) by bolts.

10. The underwater frequency converter according to claim 4, characterized in that: The underwater frequency converter (100) further comprises a bracket (30) for mounting the energy storage module (25) and the control module (26), and two ends of the bracket (30) are respectively fixed to the inner surfaces of the first mounting sleeve (14) and the second mounting sleeve (15) by bolts.

Images