Frequency converter and frequency conversion speed regulation system

Abstract

The utility model provides a frequency converter (26) and a frequency conversion speed regulation system, the frequency converter (26) comprises a power unit (28) and a busbar (30), the power unit (28) comprises an output end (32), the output end (32) comprises copper, the busbar (30) comprises a copper bar section (34) and an aluminum bar section (36) which are welded together through a welding structure, and the copper bar section (34) is in electric contact with the copper of the output end (32) and separates the output end (32) from the aluminum bar section (36). The present disclosure enables the frequency converter (26) to have a high reliability while having a high power transmission efficiency.

Description

Technical Field

[0001] The present disclosure belongs to the technical field of motor control, and particularly relates to a frequency converter and a variable frequency speed regulation system. Background Art

[0002] A variable frequency speed control system, consisting of a frequency converter (VFD) and a motor, controls the motor's speed by varying the power supply frequency. In existing VFD systems, the VFD's power unit is typically connected to the motor via a busbar.

[0003] Figure 1 The main structural diagram of a part of a frequency converter of a variable frequency speed regulation system in the prior art is shown. Figure 2 yes Figure 1 The right side structural diagram of the power unit of the inverter is shown.

[0004] Reference Figure 1 and Figure 2 The inverter 10 includes a power unit 12 and a plurality of busbars 14. The power unit 12 includes a plurality of input terminals 16 and a plurality of output terminals 18, and each busbar 14 is electrically connected to one output terminal 18 via fasteners (e.g., bolts and nuts). In order to make the inverter 10 compact and reduce the cost of the inverter 10, the busbars 14 are made of aluminum and the output terminals 18 are made of copper. However, due to the different thermal expansion coefficients and thermal conductivity coefficients of aluminum and copper, and the electrochemical corrosion reaction between the busbars 14 and the output terminals 18 that are in direct contact, non-conductive substances (e.g., copper oxide and aluminum oxide) will accumulate at the connection between the busbars 14 and the output terminals 18. Over time, these non-conductive substances will cause the resistance value of the connection position to increase, thereby increasing the circuit loss. In some cases, the excessive resistance may even cause the line contacts to burn out, resulting in line disconnection.

[0005] Figure 3 A partial structural diagram of a frequency converter of another variable frequency speed regulation system in the prior art is shown, wherein the busbar and the output end of the power unit are shown in an exploded manner.

[0006] Reference Figure 3 To address the aforementioned electrochemical corrosion problem, one solution is to apply electrical composite grease 24 (also known as conductive paste) between the busbar 20 and the output terminal 22. While the electrical composite grease 24 can separate the busbar 20 and the output terminal 22, preventing electrochemical corrosion, over time, the electrical composite grease 24 will oxidize and fall off due to overheating. Ultimately, after the electrical composite grease 24 is depleted, the busbar 20 and the output terminal 22 will come into direct contact. In other words, the use of electrical composite grease 24 can only prevent electrochemical corrosion for a short period of time and cannot serve as a long-term solution. Utility Model Content

[0007] The technical problem to be solved by the present disclosure is the electrochemical corrosion problem between the busbar and the output end of the power unit in a variable frequency speed regulation system.

[0008] To solve the above technical problems, the present disclosure provides an inverter, characterized in that it includes: a power unit, the power unit includes an output end, and the output end includes copper; and a busbar, the busbar includes a copper busbar segment and an aluminum busbar segment welded together by a welding structure, wherein the copper busbar segment is in electrical contact with the copper of the output end and separates the output end from the aluminum busbar segment.

[0009] In the present disclosure, the copper busbar segments separate the output terminals from the aluminum busbar segments, so that the aluminum busbar segments do not come into direct contact with the copper output terminals, thereby effectively avoiding electrochemical corrosion between the busbar and the output terminals, and enabling the inverter to have higher power transmission efficiency and higher reliability. Figure 3 Compared with the prior art shown, on the one hand, the present invention can save the step of applying electrical composite grease, thereby eliminating the risk of missing the application of electrical composite grease; on the other hand, when electrical composite grease is not used, the present invention does not have the problem of electrical composite grease oxidizing and falling off, so there is no need to apply new electrical composite grease regularly, thereby reducing the maintenance cost of the inverter.

[0010] Furthermore, the welding structure between the copper bar segment and the aluminum bar segment is a diffusion welding structure.

[0011] In the present disclosure, compared with other welding methods such as fusion welding, diffusion welding can make the transition portion between the copper bar segment and the aluminum bar segment have lower resistance and higher mechanical strength, thereby further improving the power transmission efficiency and reliability of the inverter.

[0012] Furthermore, the length of the transition portion between the copper bar segment and the aluminum bar segment is 3 cm to 5 cm.

[0013] In the present disclosure, the transition portion can have an appropriate length, making the inverter both economical and reliable. In other words, under this configuration, the busbar welding cost will not be too high due to the transition portion being too long, nor will the mechanical strength of the transition portion be too low due to the transition portion being too short.

[0014] Furthermore, the copper busbar segment is detachably connected to the output end.

[0015] In the present disclosure, the power unit and the busbar can be separated from each other, so that the frequency converter is easy to transport and install.

[0016] Furthermore, the copper busbar segment is connected to the output end through one or more first fasteners; the copper busbar segment includes a first base and a first end, and the first end is bent relative to the first base; the output end includes a second base and a second end, and the second end is bent relative to the second base; the first end is in electrical contact with the second end, and the first fastener passes through the first end and the second end.

[0017] In this disclosure, by bending the output terminal and copper busbar segments, the first fastener can be installed at a more user-friendly angle, such as a roughly horizontal installation angle, facilitating assembly of the power unit and busbar. In other words, at this installation angle, the first fastener can be more easily installed on the output terminal and copper busbar segments. This configuration is particularly advantageous in installation spaces with limited space. Furthermore, compared to bent aluminum busbar segments, bent copper busbar segments, which offer superior mechanical properties, help ensure the mechanical strength of the busbar, thereby further improving the reliability of the inverter.

[0018] Furthermore, the first base separates the first end from a transition portion between the copper bar segment and the aluminum bar segment, and a length of the first base is greater than or equal to 3 cm.

[0019] In the present disclosure, there can be a suitable distance between the fold between the first end portion and the first base portion and the transition portion, so that the mechanical strength of the transition portion is not easily or hardly affected by the bending.

[0020] Furthermore, the first base and the second base extend parallel to each other and are away from each other relative to the first end and the second end, the first end is bent in a first direction relative to the first base, and the second end is bent in a second direction relative to the second base, and the first direction is opposite to the second direction; the first end and the first base form a first bending angle, and the second end and the second base form a second bending angle, and the first bending angle and the second bending angle are equal.

[0021] In the present disclosure, by making the first bending angle and the second bending angle equal, the output end and the copper busbar section can be bent by the same jig, thereby reducing the manufacturing cost of the inverter. Figure 4 In the manner shown, even if there is an error between the first bending angle and the second bending angle, the first base portion and the second base portion can still extend parallel to each other.

[0022] Further, the first fastener comprises copper.

[0023] In the present disclosure, it is possible to avoid electrochemical corrosion reaction between the first fastener and the output end and the copper busbar segment, thereby further improving the reliability of the frequency converter.

[0024] Furthermore, the aluminum row segment includes a third base and a third end, and the third end is bent relative to the third base; the inverter also includes an extension conductor, and the extension conductor includes aluminum; the extension conductor includes a fourth base and a fourth end, and the fourth end is bent relative to the fourth base; the aluminum row segment is connected to the extension conductor via one or more second fasteners; the third end is in electrical contact with the fourth end, and the second fastener passes through the third and fourth ends.

[0025] In this disclosure, aluminum busbar segments can be connected to extension conductors in a similar manner to copper busbar segments, allowing the busbar to function as an adapter between the output terminals and the extension conductors. In this configuration, the busbar, acting as an adapter, can be shorter, enabling welding with smaller jigs. This makes the busbar easier to manufacture and reduces manufacturing costs.

[0026] Furthermore, the third base separates the third end from a transition portion between the copper bar segment and the aluminum bar segment, and a length of the third base is greater than or equal to 3 cm.

[0027] In the present disclosure, there can be a suitable distance between the fold between the third end portion and the third base portion and the transition portion, so that the mechanical strength of the transition portion is not easily or hardly affected by the bending.

[0028] Furthermore, the second fastener comprises aluminum.

[0029] In the present disclosure, it is possible to avoid electrochemical corrosion reaction between the second fastener and the aluminum segment and the extension conductor, thereby further improving the reliability of the inverter.

[0030] Furthermore, the third base and the fourth base extend parallel to each other and are away from each other relative to the third end and the fourth end, the third end is bent in a third direction relative to the third base, and the fourth end is bent in a fourth direction relative to the fourth base, and the third direction is opposite to the fourth direction; the third end and the third base form a third bending angle, the fourth end and the fourth base form a fourth bending angle, and the third bending angle and the fourth bending angle are equal.

[0031] In the present disclosure, by making the third bending angle and the fourth bending angle equal, the aluminum segment and the extension conductor can be bent by the same jig, thereby reducing the manufacturing cost of the inverter. Figure 7 In the manner shown, even if there is an error between the third bending angle and the fourth bending angle, the third base portion and the fourth base portion can still extend parallel to each other.

[0032] Furthermore, the copper busbar segment and the output end are integrally formed.

[0033] In the present disclosure, compared with the above-mentioned connection method using fasteners, the output terminal and the copper busbar section can be arranged more compactly, thereby facilitating miniaturization of the frequency converter. This configuration is particularly advantageous when the installation space is small.

[0034] The present disclosure also provides a variable frequency speed regulation system, characterized in that it includes: a motor; and the above-mentioned inverter, wherein the output end is electrically connected to the motor via the busbar.

[0035] The present disclosure also provides a variable frequency speed regulation system, characterized in that it includes: a motor; and the above-mentioned inverter including the extension conductor, wherein the output end is electrically connected to the motor via the busbar and the extension conductor in sequence. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings described herein are used to provide a further understanding of the present disclosure and constitute a part of the present disclosure. The exemplary embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation of the present disclosure. In the drawings:

[0037] Figure 1 This is a schematic diagram of the main structure of a part of a frequency converter of a variable frequency speed regulation system in the prior art;

[0038] Figure 2 yes Figure 1 The right side structural diagram of the power unit of the inverter is shown;

[0039] Figure 3 This is a partial structural diagram of another frequency converter of a variable frequency speed regulation system in the prior art;

[0040] Figure 4 This is a schematic diagram of the main structure of a part of a frequency converter of a variable frequency speed regulation system according to the first embodiment of the present disclosure;

[0041] Figure 5 yes Figure 4 A schematic diagram of the three-dimensional structure of a portion of a busbar of a frequency converter according to the first embodiment of the present disclosure is shown;

[0042] Figure 6 yes Figure 4 Schematic diagram of a method for manufacturing a busbar of a frequency converter according to a first embodiment of the present disclosure;

[0043] Figure 7 This is a schematic diagram of the main structure of a part of a frequency converter of a variable frequency speed regulation system according to a second embodiment of the present disclosure;

[0044] Figure 8This is a schematic diagram of the main structure of a part of a frequency converter of a variable frequency speed regulation system according to a third embodiment of the present disclosure;

[0045] Figure 9 It is a partial structural diagram of a frequency converter of a variable frequency speed regulation system according to the fourth embodiment of the present disclosure, wherein the busbar and the output end of the power unit are shown in an exploded manner.

[0046] Description of Figure Numbers:

[0047] 10. Frequency converter;

[0048] 12. Power unit;

[0049] 14. Busbar;

[0050] 16. Input terminal;

[0051] 18. Output terminal;

[0052] 20. Busbar;

[0053] 22. Output terminal;

[0054] 24. Electric compound grease;

[0055] 26. Frequency converter;

[0056] 28. Power unit;

[0057] 30. Busbar;

[0058] 32. Output terminal;

[0059] 34. Copper busbar section;

[0060] 36. Aluminum row segment;

[0061] 38. Transition section;

[0062] 40. First fastener;

[0063] 42. First base;

[0064] 44. first end portion;

[0065] 46, second base;

[0066] 48. second end portion;

[0067] 50, third base;

[0068] 52. The third end;

[0069] 54. Extended conductor;

[0070] 56, fourth base;

[0071] 58. Fourth end;

[0072] 60. Second fastener. DETAILED DESCRIPTION

[0073] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present disclosure and its application or use. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0074] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form.

[0075] Refer to the following Figures 4 to 6 A first embodiment of the present disclosure is introduced.

[0076] Figure 4 This is a schematic diagram of the main structure of a part of a frequency converter of a variable frequency speed regulation system according to the first embodiment of the present disclosure. Figure 5 yes Figure 4 The schematic diagram of the three-dimensional structure of a part of the busbar of the inverter of the first embodiment of the present disclosure is shown in FIG. Figure 6 yes Figure 4 The figure shows a schematic diagram of a method for manufacturing a busbar of a frequency converter according to the first embodiment of the present disclosure.

[0077] Reference Figure 4 and Figure 5 The present disclosure provides a frequency converter 26, comprising a power unit 28 and a busbar 30. The power unit 28 comprises an output terminal 32, and the output terminal 32 comprises copper. The busbar 30 comprises a copper busbar segment 34 and an aluminum busbar segment 36 welded together by a welding structure. The copper busbar segment 34 is in electrical contact with the copper of the output terminal 32, and separates the output terminal 32 and the aluminum busbar segment 36. Here, the copper busbar segment 34 is a connecting busbar comprising copper, and the aluminum busbar segment 36 is a connecting busbar comprising aluminum. For example, the output terminal 32 and the copper busbar segment 34 can be made of copper or a copper alloy, and the aluminum busbar segment 36 can be made of aluminum or an aluminum alloy. As an example, the output terminal 32 and the copper busbar segment 34 can be made of the same material, for example, both can be made of copper. Of course, in other examples, the output terminal 32 and the copper busbar segment 34 can also be made of different materials. Here, "different materials" can be different types of components of the material, or different ratios between different types of components. As an example, the power unit 28 can have the same Figure 1 and Figure 2 The power units 28 shown are of the same configuration. For example, in this configuration, the plurality of busbars 30 may have the same configuration, and the plurality of output terminals 32 may have the same configuration.

[0078] In the present disclosure, the copper busbar segment 34 separates the output end 32 and the aluminum busbar segment 36, so that the aluminum busbar segment 36 does not come into direct contact with the copper of the output end 32, thereby effectively avoiding electrochemical corrosion between the busbar 30 and the output end 32, so that the inverter 26 can have high power transmission efficiency and high reliability. Figure 3 Compared with the prior art shown, on the one hand, the present disclosure can save the step of applying the electrical composite grease 24, thereby eliminating the risk of missing the application of the electrical composite grease 24; on the other hand, when the electrical composite grease 24 is not used, the present disclosure does not have the problem of oxidation and shedding of the electrical composite grease 24, so there is no need to apply new electrical composite grease 24 regularly, thereby reducing the maintenance cost of the inverter 26.

[0079] Reference Figure 6 The welding structure between the copper bar segment 34 and the aluminum bar segment 36 is a diffusion welding structure (also known as ion diffusion welding). In this way, compared with other welding methods such as fusion welding, diffusion welding can make the transition portion 38 ( Figure 6 The shaded area (shaded area in the figure) has low electrical resistance and high mechanical strength, thereby further improving the power transmission efficiency and reliability of the inverter 26. Here, the transition portion 38 is the transition portion between the copper busbar segments 34 and the aluminum busbar segments 36 created by welding. For example, when the copper busbar segments 34 and the aluminum busbar segments 36 are diffusion welded together, the transition portion 38 corresponds to the diffusion layer. For another example, when the copper busbar segments 34 and the aluminum busbar segments 36 are fusion welded together, the transition portion 38 is what is commonly referred to as a weld seam. It should be understood that the copper busbar segments 34 and the aluminum busbar segments 36 are not limited to being welded together by diffusion welding; for example, they can be welded using other possible methods.

[0080] Reference Figure 6 The length of the transition portion 38 between the copper busbar segment 34 and the aluminum busbar segment 36 is 3 cm to 5 cm. As an example, the length of the transition portion 38 can be 3.5 cm to 4.5 cm, for example, 4 cm. This ensures that the transition portion 38 has an appropriate length, ensuring both cost-effectiveness and reliability for the inverter 26. In other words, with this configuration, the welding cost of the busbar 30 is neither excessively high due to an excessively long transition portion 38, nor is the mechanical strength of the transition portion 38 reduced due to an excessively short transition portion 38.

[0081] Reference Figure 4The copper busbar section 34 is detachably connected to the output terminal 32. This allows the power unit 28 and busbar 30 to be separated from each other, making the inverter 26 easier to transport and install. This configuration is particularly advantageous when the power unit 28 is large or the busbar 30 needs to extend a long length.

[0082] Reference Figure 4 The copper busbar segment 34 is connected to the output end 32 by one or more first fasteners 40. The copper busbar segment 34 includes a first base 42 ( Figure 4 The horizontally extending portion) and the first end portion 44 ( Figure 4 The output end 32 includes a second base portion 46 ( Figure 4 The horizontally extending portion) and the second end portion 48 ( Figure 4 The first end 44 and the second end 48 are bent relative to the second base 46. The first end 44 and the second end 48 are in electrical contact. The first fastener 40 passes through the first end 44 and the second end 48. As an example, the first fastener 40 may be a bolt, and the first and second ends 44 and 48 may be provided with mounting holes for receiving the first fastener 40. By bending the output end 32 and the copper busbar segment 34, the first fastener 40 can be installed at a more convenient angle, such as a substantially horizontal angle, facilitating assembly of the power unit 28 and the busbar 30. In other words, at this installation angle, the first fastener 40 can be more easily installed to the output end 32 and the copper busbar segment 34. This configuration is particularly advantageous in situations where installation space is limited. Furthermore, compared to the bent aluminum busbar segment 36, the copper busbar segment 34, with its better mechanical properties, helps ensure the mechanical strength of the busbar 30, thereby further improving the reliability of the inverter 26.

[0083] Reference Figure 4 The first base portion 42 separates the first end portion 44 from the transition portion 38 between the copper busbar segment 34 and the aluminum busbar segment 36. The length of the first base portion 42 is greater than or equal to 3 cm. For example, the length of the first base portion 42 can be 3 cm to 5 cm, for example, 4 cm. This ensures that the fold between the first end portion 44 and the first base portion 42 (i.e., the portion where the extension direction changes) and the transition portion 38 are at an appropriate distance, ensuring that the mechanical strength of the transition portion 38 is not easily or substantially affected by the fold.

[0084] Reference Figure 4 The first base portion 42 and the second base portion 46 extend parallel to each other and are spaced apart from each other relative to the first end portion 44 and the second end portion 48. The first end portion 44 extends in a first direction ( Figure 4 The second end portion 48 is bent relative to the second base portion 46 in the second direction ( Figure 4 The first direction is opposite to the second direction. The first end 44 and the first base 42 form a first bending angle, the second end 48 and the second base 46 form a second bending angle, and the first bending angle and the second bending angle are equal. As an example, the first bending angle and the second bending angle can be 60° to 280°, for example, 90°. In this way, by making the first bending angle and the second bending angle equal, the output end 32 and the copper busbar section 34 can be bent by the same jig, thereby reducing the manufacturing cost of the inverter 26. In addition, the output end 32 and the copper busbar section 34 are arranged as follows Figure 4 When the first end portion 44 and the second end portion 48 are bent in opposite directions, even if there is a difference between the first bend angle and the second bend angle, the first base portion 42 and the second base portion 46 can still extend parallel to each other. It should be understood that in other examples, the first bend angle and the second bend angle may not be equal. For example, the first bend angle and the second bend angle may be complementary.

[0085] Reference Figure 4 The first fastener 40 comprises copper. For example, the first fastener 40 can be made of the same material as the output terminal 32 or the copper busbar segment 34. This prevents electrochemical corrosion between the first fastener 40 and the output terminal 32 and the copper busbar segment 34, thereby further improving the reliability of the inverter 26.

[0086] In some examples, the variable frequency speed regulation system includes a motor and the aforementioned inverter 26 . The output terminal 32 is electrically connected to the motor via a busbar 30 .

[0087] Refer to the following Figure 7 The second embodiment of the present disclosure is introduced. The second embodiment is a modification of the first embodiment. For features that are the same or similar to those of the first embodiment, the same reference numerals are used in this embodiment and detailed descriptions of these features are omitted.

[0088] Figure 7 It is a schematic diagram of the main structure of a part of a frequency converter of a variable frequency speed regulation system according to the second embodiment of the present disclosure.

[0089] Reference Figure 7 , the aluminum row segment 36 includes a third base 50 ( Figure 7 The horizontally extending portion) and the third end portion 52 ( Figure 7 The third end portion 52 is bent relative to the third base portion 50. The frequency converter 26 further includes an extension conductor 54, which includes aluminum. The extension conductor 54 includes a fourth base portion 56 ( Figure 7 horizontal portion in the middle) and the fourth end 58 ( Figure 7The fourth end 58 is bent relative to the fourth base 56. The aluminum busbar segments 36 are connected to the extension conductor 54 via one or more second fasteners 60. The third end 52 is in electrical contact with the fourth end 58, and the second fastener 60 passes through the third and fourth ends 52, 58. For example, the second fastener 60 may be a bolt, and the third and fourth ends 52, 58 may be provided with mounting holes for receiving the second fastener 60. For example, the extension conductor 54 may be made of the same material as the aluminum busbar segments 36. In this way, the aluminum busbar segments 36 can be connected to the extension conductor 54 using a connection method similar to that of the copper busbar segments 34, allowing the busbar 30 to serve as an adapter between the output end 32 and the extension conductor 54. In this configuration, the busbar 30, acting as an adapter, can be shorter, allowing it to be welded using a smaller jig, making it easier to manufacture and reducing manufacturing costs.

[0090] It should be understood that even if the aluminum row segment 36 is provided with the third base portion 50 and the third end portion 52, the extension conductor 54 is not necessarily required. For example, the port of the motor may be provided with a structure for mounting a fastener, so that the third end portion 52 can be mounted to the port of the motor through the fastener and electrically contact the port.

[0091] Reference Figure 7 The third base portion 50 separates the third end portion 52 from the transition portion 38 between the copper busbar segment 34 and the aluminum busbar segment 36. The length of the third base portion 50 is greater than or equal to 3 cm. For example, the length of the third base portion 50 can be 3 cm to 5 cm, for example, 4 cm. This ensures that the fold between the third end portion 52 and the third base portion 50 is at an appropriate distance from the transition portion 38, ensuring that the mechanical strength of the transition portion 38 is not easily or substantially affected by the fold.

[0092] Reference Figure 7 The second fastener 60 may comprise aluminum. For example, the second fastener 60 may be made of the same material as the aluminum segments 36 and / or the extension conductor 54. This prevents electrochemical corrosion between the second fastener 60 and the aluminum segments 36 and the extension conductor 54, thereby further improving the reliability of the inverter 26.

[0093] Reference Figure 7 The third base portion 50 and the fourth base portion 56 extend parallel to each other and are away from each other relative to the third end portion 52 and the fourth end portion 58. The third end portion 52 extends in the third direction ( Figure 7 The fourth end portion 58 is bent relative to the fourth base portion 56 in the fourth direction ( Figure 7The third direction is opposite to the fourth direction. The third end 52 and the third base 50 form a third bending angle, the fourth end 58 and the fourth base 56 form a fourth bending angle, and the third bending angle and the fourth bending angle are equal. As an example, the third bending angle and the fourth bending angle can be 60° to 280°, for example, 90°. In this way, by making the third bending angle equal to the fourth bending angle, the aluminum row segment 36 and the extension conductor 54 can be bent by the same jig, thereby reducing the manufacturing cost of the inverter 26. In addition, when the aluminum row segment 36 and the extension conductor 54 are arranged as shown Figure 7 In the manner shown (i.e., the third end portion 52 and the fourth end portion 58 are bent in opposite directions), even if there is a discrepancy between the third bend angle and the fourth bend angle, the third base portion 50 and the fourth base portion 56 can still extend parallel to each other. It should be understood that in other examples, the third bend angle and the fourth bend angle may be unequal. For example, the third bend angle and the fourth bend angle may be complementary.

[0094] Reference Figure 7 , the first bending angle (the angle formed on the copper busbar segment 34) and the third bending angle are equal. As an example, the first bending angle and the third bending angle can be 60° to 280°, for example, 90°. In this way, by making the first bending angle and the third bending angle equal, the copper busbar segment 34 and the aluminum busbar segment 36 can be bent using the same jig, thereby reducing the manufacturing cost of the inverter 26. It should be understood that in other examples, the first bending angle and the third bending angle can also be unequal. For example, the first bending angle and the third bending angle can be complementary.

[0095] In some examples, the variable frequency speed control system includes a motor and the aforementioned inverter 26. The output terminal 32 is electrically connected to the motor via the busbar 30 and the extension conductor 54 in turn.

[0096] Refer to the following Figure 8 The third embodiment of the present disclosure is introduced. The third embodiment is a modification of the first embodiment. For features that are the same or similar to those of the first embodiment, the same reference numerals are used in this embodiment and detailed description of these features is omitted.

[0097] Figure 8 This is a schematic diagram of the main structure of a part of a frequency converter of a variable frequency speed regulation system according to the third embodiment of the present disclosure.

[0098] Reference Figure 8The copper busbar segment 34 is integrally formed with the output terminal 32. For example, the copper busbar segment 34 and the output terminal 32 can be integrally formed by casting, or they can be integrally formed from a single blank using sheet metal or other methods. This arrangement allows for a more compact arrangement of the output terminal 32 and the copper busbar segment 34, compared to the aforementioned fastener connection method, thereby facilitating miniaturization of the inverter 26. This configuration is particularly advantageous when installation space is limited.

[0099] In other examples, the aluminum row segments 36 may be bent and formed similar to Figure 7 The structure of the third base portion 50 and the third end portion 52 is shown in FIG.

[0100] Refer to the following Figure 9 The fourth embodiment of the present disclosure is introduced. The fourth embodiment is a modification of the first embodiment. For features that are the same or similar to those of the first embodiment, the same reference numerals are used in this embodiment, and detailed descriptions of these features are omitted.

[0101] Figure 9 It is a partial structural diagram of a frequency converter of a variable frequency speed regulation system according to the fourth embodiment of the present disclosure, wherein the busbar and the output end of the power unit are shown in an exploded manner.

[0102] Reference Figure 9 ,and Figure 4 Compared to the first embodiment shown, the copper busbar segment 34 and the end of the output end 32 close to the copper busbar segment 34 both extend in a straight line. In other words, the copper busbar segment 34 no longer has the bent first end 44, and the output end 32 no longer has the bent second end 48. In this way, the output end 32 and the copper busbar segment 34 are aligned in the height direction ( Figure 4 The dimension occupied in the vertical direction (in the vertical direction) is small, which is conducive to the miniaturization of the inverter 26. In addition, since the copper busbar segment 34 does not need to be bent, there is no need to leave a distance between the fold and the transition portion 38, so the length of the copper busbar segment 34 can be shortened.

[0103] The above is only a preferred embodiment of the present disclosure. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present disclosure. These improvements and modifications should also be regarded as within the scope of protection of the present disclosure.

Claims

1. A frequency converter (26), characterized in that: include: A power cell (28), the power cell (28) comprising an output end (32), the output end (32) comprising copper; and A busbar (30) comprising a copper busbar segment (34) and an aluminum busbar segment (36) welded together by a welding structure, wherein The copper busbar segment (34) is in electrical contact with the copper of the output end (32) and separates the output end (32) from the aluminum busbar segment (36).

2. The frequency converter (26) according to claim 1, characterized in that The welding structure between the copper bar segment (34) and the aluminum bar segment (36) is a diffusion welding structure.

3. The frequency converter (26) according to claim 1, characterized in that The length of the transition portion (38) between the copper bar segment (34) and the aluminum bar segment (36) is 3 cm to 5 cm.

4. The frequency converter (26) according to any one of claims 1 to 3, characterized in that The copper busbar segment (34) is detachably connected to the output end (32).

5. The frequency converter (26) according to claim 4, characterized in that The copper busbar segment (34) is connected to the output end (32) via one or more first fasteners (40); The copper busbar segment (34) includes a first base portion (42) and a first end portion (44), wherein the first end portion (44) is bent relative to the first base portion (42); The output end (32) includes a second base portion (46) and a second end portion (48), and the second end portion (48) is bent relative to the second base portion (46); The first end portion (44) is in electrical contact with the second end portion (48), and the first fastener (40) passes through the first end portion (44) and the second end portion (48).

6. The frequency converter (26) according to claim 5, characterized in that The first base (42) separates the first end (44) from the transition portion (38) between the copper bar segment (34) and the aluminum bar segment (36), and the length of the first base (42) is greater than or equal to 3 cm.

7. The frequency converter (26) according to claim 5, characterized in that The first base portion (42) and the second base portion (46) extend parallel to each other and are spaced apart from each other relative to the first end portion (44) and the second end portion (48); the first end portion (44) is bent in a first direction relative to the first base portion (42); and the second end portion (48) is bent in a second direction relative to the second base portion (46); the first direction is opposite to the second direction; The first end portion (44) and the first base portion (42) form a first bending angle, the second end portion (48) and the second base portion (46) form a second bending angle, and the first bending angle and the second bending angle are equal.

8. The frequency converter (26) according to claim 5, characterized in that The first fastener (40) comprises copper.

9. The frequency converter (26) according to any one of claims 1 to 3, characterized in that The aluminum row segment (36) includes a third base (50) and a third end (52), and the third end (52) is bent relative to the third base (50); The frequency converter (26) further includes an extension conductor (54), wherein the extension conductor (54) includes aluminum; The extension conductor (54) includes a fourth base portion (56) and a fourth end portion (58), and the fourth end portion (58) is bent relative to the fourth base portion (56); The aluminum row segment (36) is connected to the extension conductor (54) via one or more second fasteners (60); The third end portion (52) is in electrical contact with the fourth end portion (58), and the second fastener (60) passes through the third end portion (52) and the fourth end portion (58).

10. The frequency converter (26) according to claim 9, characterized in that The third base (50) separates the third end (52) from the transition portion (38) between the copper bar segment (34) and the aluminum bar segment (36), and the length of the third base (50) is greater than or equal to 3 cm.

11. The frequency converter (26) according to claim 9, characterized in that The second fastener (60) comprises aluminum.

12. The frequency converter (26) according to claim 9, characterized in that The third base portion (50) and the fourth base portion (56) extend parallel to each other and are spaced apart from each other relative to the third end portion (52) and the fourth end portion (58); the third end portion (52) is bent in a third direction relative to the third base portion (50); and the fourth end portion (58) is bent in a fourth direction relative to the fourth base portion (56); the third direction is opposite to the fourth direction; The third end portion (52) and the third base portion (50) form a third bending angle, the fourth end portion (58) and the fourth base portion (56) form a fourth bending angle, and the third bending angle and the fourth bending angle are equal.

13. The frequency converter (26) according to any one of claims 1 to 3, characterized in that The copper busbar segment (34) and the output end (32) are integrally formed.

14. A variable frequency speed regulation system, characterized in that: include: Motor; as well as The frequency converter (26) according to any one of claims 1 to 13, wherein The output terminal (32) is electrically connected to the motor via the busbar (30).

15. A variable frequency speed regulation system, characterized in that: include: Motor; as well as The frequency converter (26) according to any one of claims 9 to 12, wherein The output end (32) is electrically connected to the motor via the busbar (30) and the extension conductor (54) in turn.

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