A power unit for a frequency converter and a frequency converter

Abstract

The power unit for a frequency converter and the frequency converter provided by the present disclosure, the power unit comprises a shell, a direct current capacitor module, an input rectification module and an output module; the ventilation direction of the shell is the front-rear direction, wherein the air inlet is in front and the air outlet is in back; the direct current capacitor module is located on one side of the shell in the left-right direction perpendicular to the front-rear direction; the input rectification module and the output module are located on the other side of the shell, wherein the output module and the input rectification module are arranged in the up-down direction, and the modules located in the upper part and the modules located in the lower part at least partially overlap in the projection along the up-down direction. The power unit provided by the present disclosure is compact in structure, fully utilizes the space, and has excellent overall heat dissipation effect without higher cost.

Description

Technical Field

[0001] This disclosure belongs to the field of frequency converter technology, and specifically relates to a power unit for a frequency converter and a frequency converter. Background Technology

[0002] The power unit is a crucial component of a frequency converter, playing a vital role in converting external alternating current (AC) into direct current (DC) for output. Existing power units, especially those in medium- and high-voltage frequency converters, typically include capacitor modules and functional modules. The functional modules include input rectification-related component groups and output-related component groups, etc. When designing the structural layout of such power units, there are usually two schemes: front-to-back arrangement of capacitor modules and functional modules, or left-to-right arrangement.

[0003] If the capacitor module and functional module are arranged in front and behind each other, the air duct will be longer and the air resistance will be increased. This requires a higher performance fan, resulting in higher costs. Moreover, the heat dissipation effect of the module located at the rear of the air duct will obviously be affected, and it will not be as effective as the heat dissipation of the module located at the front.

[0004] When arranging capacitor modules and functional modules side-by-side, existing arrangements often involve placing the capacitor modules, input rectification components, and output components in a straight line. In this arrangement, the power unit is significantly wider, and the height of each functional module is often lower than that of the capacitor module. This side-by-side arrangement also results in wasted space in the vertical direction. If the input rectification components and output components located to the left or behind the capacitor module are arranged one in front of the other to address the aforementioned width issue, the problem of wasted space in the vertical direction cannot be solved. At the same time, the heat dissipation effect of components located at the rear of the air duct on this side will also be affected, which may lead to performance degradation and shortened lifespan. Utility Model Content

[0005] The technical problem to be solved by this disclosure is to provide a power unit and a frequency converter for a frequency converter, wherein the power unit has a compact structure, makes full use of space, and has excellent overall heat dissipation effect without higher cost.

[0006] To address the aforementioned technical problems, this disclosure provides a power unit for a frequency converter, comprising a housing, a DC capacitor module, an input rectifier module, and an output module. With the ventilation direction of the housing as the front-to-back direction (air intake at the front and air outlet at the rear), the DC capacitor module is located on one side of the housing in the left-to-right direction perpendicular to the front-to-back direction. The input rectifier module and the output module are located on the other side of the housing, wherein the output module and the input rectifier module are arranged vertically, and the upper module and the lower module at least partially overlap in their projection along the vertical direction.

[0007] In the power unit provided in this disclosure, the DC capacitor module, input rectifier module, and output module are arranged side-by-side, not front-to-back. This avoids the increased airflow caused by front-to-back arrangement of the capacitor module and these functional modules in the air duct, thus preventing an increase in unit air resistance. This significantly saves costs and reduces the fan footprint. Furthermore, in this side-by-side arrangement of the DC capacitor module and these functional modules, the input rectifier module and output module are arranged vertically, and the upper module and the lower module at least partially overlap in the vertical projection. Compared to arranging the input rectifier module and output module horizontally side-by-side or front-to-back, this arrangement clearly makes full use of the vertical space. Moreover, this disclosure also avoids the higher temperature of the functional module located at the rear end of the air duct caused by the aforementioned front-to-back arrangement, thus avoiding any adverse effects on the performance and lifespan of that functional module.

[0008] Furthermore, the input rectifier module includes a rectifier diode and a diode heat sink; the output module includes a thyristor and a thyristor heat sink; the rectifier diode is mounted flat on the heat dissipation surface of the diode heat sink; the thyristor is mounted flat on the heat dissipation surface of the thyristor heat sink.

[0009] Furthermore, the housing includes a base plate; the output module is located above the input rectifier module, wherein the diode heat sink and the thyristor heat sink are arranged back-to-back adjacently, so that the rectifier diode faces the base plate; a maintenance window is provided on the base plate, the position of the maintenance window corresponds to the position of the rectifier diode, and is covered by a window cover plate.

[0010] Furthermore, the power unit also includes a control module, which includes a control circuit board; the output module is located above the input rectifier module; the control module is located above the output module and the DC capacitor module.

[0011] Furthermore, the power unit also includes a flying capacitor module, which includes a flying capacitor; the flying capacitor module is located on one side of the input rectifier module and the output module inside the housing, and the flying capacitor module is located above the input rectifier module and arranged side by side with the output module; in the vertical projection, the projections of the output module and the flying capacitor module are both located within the projection area of ​​the input rectifier module.

[0012] Furthermore, the input rectifier module also includes a bleed resistor and an input connector; the bleed resistor, rectifier diode, and input connector are arranged sequentially in a front-to-back direction or a back-to-front direction.

[0013] Furthermore, the power unit includes a first enclosed chamber and a second enclosed chamber isolated from the cooling airflow, wherein the upper part of the flying capacitor with terminals, the control module and the thyristor are located in the first enclosed chamber; the bleeder resistor and the rectifier diode are located in the second enclosed chamber.

[0014] Furthermore, the power unit also includes a busbar and a connecting cable. The busbar is connected to the control circuit board and is located within the first enclosed cavity. The busbar is also connected to the rectifier diode via the connecting cable. The connecting cable includes two connecting ends and a main body located between the two connecting ends. One connecting end is located within the second enclosed cavity and connected to the rectifier diode. The main body of the connecting cable extends upward along the partition wall between the DC capacitor module and the input rectifier module, so that the other connecting end enters the first enclosed cavity and connects to the busbar.

[0015] Furthermore, the power unit also includes a DC capacitor module chamber, with at least one front wall air inlet on the front wall and a rear wall air outlet on the rear wall.

[0016] Furthermore, the DC capacitor module chamber has three air inlets on the front wall, arranged vertically along the height direction, wherein the width of the air inlet located in the middle is greater than the width of the air inlets located on both sides.

[0017] Furthermore, the housing has: a front panel, wherein the front panel has a front panel air inlet at a position corresponding to the diode heat sink and the thyristor heat sink; and a rear panel, wherein the rear panel has a rear panel air outlet at a position corresponding to the diode heat sink and the thyristor heat sink.

[0018] Furthermore, the DC capacitor module is a first pre-assembled module including a DC capacitor and a tray; the thyristor and thyristor heat sink form a second pre-assembled module; and the rectifier diode, diode heat sink, bleed resistor and input connector form a third pre-assembled module.

[0019] In addition, this disclosure also provides a frequency converter including the power unit for the frequency converter as described above.

[0020] Other beneficial effects of the present invention will be explained in detail through the introduction of specific technical features and technical solutions in specific embodiments. Those skilled in the art should be able to understand the beneficial technical effects brought about by the technical features and technical solutions through the introduction of these technical features and technical solutions. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of this disclosure and form part of this disclosure, illustrate exemplary embodiments of the present disclosure and are used to explain the disclosure, but do not constitute an undue limitation of the disclosure. In the drawings: Figure 1 This is a three-dimensional structural schematic diagram of one embodiment of the power unit for a frequency converter disclosed herein; Figure 2 This is a three-dimensional exploded view of one embodiment of the power unit for a frequency converter disclosed herein; Figure 3 This is a front view structural schematic diagram of one embodiment of the power unit for a frequency converter disclosed herein; Figure 4 This is a three-dimensional structural diagram of the corresponding panel after removing the outer casing of one embodiment of the power unit for a frequency converter disclosed herein. Figure 5 This is an inverted three-dimensional structural diagram of one embodiment of the input rectifier module disclosed herein; Figure 6 This is an inverted, exploded three-dimensional structural diagram of one embodiment of the input rectifier module disclosed herein; Figure 7 This is a schematic diagram of the structure of one embodiment of the power unit for a frequency converter disclosed herein, after being rotated 90 degrees. Figure 8 This is a rear-view perspective view of one embodiment of the power unit for a frequency converter disclosed herein (control module, busbar and thyristor omitted); Figure 9 This is a schematic diagram of one embodiment of the present disclosure where the connecting cable extends along the partition wall.

[0022] Explanation of icon numbers: Detailed Implementation

[0023] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0024] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise.

[0025] See appendix Figure 1-8 This disclosure provides a power unit for a frequency converter, including a housing 100, a DC capacitor module 200, an input rectifier module 300, and an output module 400; With the ventilation direction of the outer casing as the front-to-back direction, where the air intake is in front and the air outlet is in the back, in the left-to-right direction perpendicular to the front-to-back direction, the DC capacitor module 200 is located on one side of the outer casing 100; the input rectifier module 300 and the output module 400 are located on the other side of the outer casing 100, wherein the output module 400 and the input rectifier module 300 are arranged vertically, and in the projection along the vertical direction, the module located at the upper part and the module located at the lower part at least partially overlap.

[0026] Because, under normal circumstances, the DC capacitor module 200 used in the power unit of the frequency converter is a cube or similar cube, while the functional modules such as the input rectifier module 300 and the output module 400 are cuboids or similar cuboids, and when the vertical direction is determined by the placement direction of each module, the height of the DC capacitor module 200 is significantly higher than that of each functional module. Taking into account the size differences between these modules, this disclosure provides a compact and reasonable module arrangement scheme.

[0027] In this disclosure, the DC capacitor module 200, input rectifier module 300, and output module 400 are arranged side-by-side, not front-to-back. This avoids the increased airflow caused by front-to-back arrangement of the capacitor module and these functional modules in the air duct, thus preventing an increase in unit air resistance. This significantly saves costs and reduces the fan footprint. Increased unit air resistance requires a larger external fan to cool the unit, providing greater airflow, which obviously increases the fan's cost and footprint.

[0028] Furthermore, in the left-right arrangement of the DC capacitor module 200 and these functional modules in this disclosure, the input rectifier module 300 and the output module 400 in the functional modules are arranged vertically, and in the projection along the vertical direction, the upper module and the lower module at least partially overlap. Compared with arranging the input rectifier module and the output module horizontally side by side or front and back, this can obviously make full use of the space in height (see the next paragraph for details). In addition, this disclosure also avoids the higher temperature of the functional module located at the rear end of the air duct caused by the aforementioned front and back arrangement, thereby avoiding adverse effects on the performance and service life of the functional module.

[0029] In the vertical projection, the upper module and the lower module at least partially overlap. This indicates that the present disclosure not only makes full use of the height space on the functional module side, but also makes reasonable use of the space in the front-back direction. If the projections of the upper and lower functional modules do not overlap at all in the vertical projection, it means that the area below the upper functional module and the area above the lower functional module are completely empty, which is obviously not a sufficient use of space. Similarly, the space in the left-right direction is also rationally utilized. If the projections of the upper and lower functional modules do not overlap at all, for example, with the output module on the right and the input rectifier module on the left, then the area to the left of the output module and the area to the right of the input rectifier module are completely empty, which is also obviously not a sufficient use of space.

[0030] Furthermore, see the appendix in particular. Figure 2 , 5 6. The input rectifier module 300 includes a rectifier diode 310 and a diode heat sink 320; the output module 400 includes a thyristor 410 and a thyristor heat sink 420; the rectifier diode 310 is mounted flat on the heat dissipation surface of the diode heat sink 320; the thyristor 410 is mounted flat on the heat dissipation surface of the thyristor heat sink 420.

[0031] This disclosure provides separate heat sinks for the rectifier diode 310 and the thyristor 410, respectively, to meet their different heat dissipation requirements. Different heat sinks can be designed and selected based on the different heat generation of these two components. However, if both components share the same heat sink, the heat dissipation requirements of the thyristor 410 must be considered, as its heat dissipation is significantly greater than that of the rectifier diode 310. If external cooling air cools the thyristor to its allowable temperature, the temperature of the rectifier diode will be significantly lower than its allowable temperature, resulting in unnecessary waste.

[0032] Furthermore, since the heat dissipation requirements of the rectifier diode 310 are relatively low, the size of the diode heat sink 320 used for it can be relatively small and the fins can be relatively sparse. Therefore, the processing difficulty of the heat sink used for the diode will be significantly reduced.

[0033] By mounting the rectifier diode 310 flat on the heat dissipation surface of the diode heat sink 320 and the thyristor 410 flat on the heat dissipation surface of the thyristor heat sink 420, the entire components are located on the heat dissipation surface of their respective heat sinks, thus facilitating sufficient heat dissipation for the components.

[0034] Furthermore, see the appendix in particular. Figure 2 , 4 7. The housing 100 includes a base plate 110; the output module 400 is located above the input rectifier module 300, wherein the diode heat sink 320 and the thyristor heat sink 420 are arranged back to back adjacently, so that the rectifier diode 310 faces the base plate 110; the base plate 110 has a maintenance window 111, the position of the maintenance window 111 corresponds to the position of the rectifier diode 310, and is covered by a window cover plate 112.

[0035] The housing includes a base plate 110. This structural arrangement allows the rectifier diode 310 to be mounted facing the base plate 110 of the power unit housing. The base plate 110 has a maintenance window 111, facilitating maintenance of the rectifier diode 310 in case of a malfunction. During maintenance, the power unit is rotated at an appropriate angle (e.g., 90 degrees or inverted) so that the base plate is no longer pressed against the bottom of the power unit and is exposed. Then, the window cover 112 on the maintenance window 111 can be opened for maintenance. The window cover 112 can be closed during normal use to protect the internal components, including the rectifier diode 310.

[0036] Furthermore, see the appendix in particular. Figure 2 and 4 The power unit also includes a control module 500, which includes a control circuit board; the output module 400 is located above the input rectifier module 300; the control module 500 is located above the output module 400 and the DC capacitor module 200.

[0037] The main functions of the control module 500 include controlling the operation of the output module 400, such as controlling the output module 400 to output / stop the output current, and controlling the magnitude of the output current.

[0038] This disclosure positions the output module 400 above the input rectifier module 300, and the control module further above the output module 400 and the DC capacitor module 200. This allows the control module 500, located at the top, to be closer to the output module 400 (compared to the case where the output module 400 is below the input rectifier module 300). The connection distance between the control module 500 and the output module 400 can be shortened, thereby enhancing the control reliability of the control module 500.

[0039] Furthermore, see the appendix in particular. Figure 2 and 4 The power unit also includes a flying capacitor module 600, which includes a flying capacitor 610. The flying capacitor module 600 is located on the same side of the input rectifier module 300 and the output module 400 inside the housing 100, and is located above the input rectifier module 300 and arranged in parallel with the output module 400. In the vertical projection, the projections of the output module 400 and the flying capacitor module 600 are both located within the projection area of ​​the input rectifier module 300.

[0040] The purpose of further providing a flying capacitor 610 in the power unit is to reduce harmonics. When the thyristor 410 is connected to the flying capacitor 610, the harmonics in the current output by the output module will be reduced.

[0041] Considering that the output module 400 is typically smaller than the input rectifier module 300, even if the output module 400 is located above the input rectifier module 300 and its projection is entirely within the input module in the vertical direction, there will still be remaining space above the input rectifier module 300. Placing the flying capacitor module 600 within this remaining space allows for full utilization of that space. Furthermore, when the flying capacitor module 600 and the output module 400 are arranged side-by-side, either one can be placed in front; that is, their positions can be interchanged.

[0042] Furthermore, see the appendix in particular. Figure 5 and 6 The input rectifier module 300 also includes a bleed resistor 330 and an input connector 340; the bleed resistor 330, the rectifier diode 310 and the input connector 340 are arranged in sequence in a front-to-back direction or a back-to-front direction.

[0043] In the event of a sudden inverter shutdown, residual electricity is usually stored inside the DC capacitor module. This disclosure further discloses that by setting a discharge resistor 330 in the power unit, this residual electricity can be discharged and consumed, thus avoiding the adverse effects of long-term storage of residual electricity on the DC capacitor module.

[0044] The input connector 340 in this disclosure is used to connect an external cable so that external AC power can enter the input rectifier module 300 and be processed into DC power.

[0045] Furthermore, see the appendix in particular. Figure 8 The power unit includes a first enclosed chamber 10 and a second enclosed chamber 20 that are isolated from the cooling airflow. The upper part of the flying capacitor 610 with terminals, the control module 500 and the thyristor 410 are located in the first enclosed chamber 10; the bleeder resistor 330 and the rectifier diode 310 are located in the second enclosed chamber 20.

[0046] Because the power unit needs to be used in a ventilated environment, with cooling airflow provided by an external fan to dissipate heat from the thyristor 410 and rectifier diode 310, and this cooling airflow often carries external dust, if dust accumulates at the terminals of the corresponding modules or on the surface of precision components (such as control circuit boards), it may affect the electrical insulation of these parts, leading to short-circuit failure. Therefore, this disclosure provides a first enclosed chamber 10 isolated from the cooling airflow, so that the upper part of the flying capacitor 610 with terminals is located in the first enclosed chamber, and the control module 500 is also located in the first enclosed chamber (obviously the control module 500 is located in the first enclosed chamber). The circuit board is located in the enclosed chamber, and the thyristor 410 is also located in the first enclosed chamber (the terminals of the thyristor 410 are obviously also located in the enclosed chamber). In this way, these terminals and precision components such as the control circuit board are isolated by the first enclosed chamber 10, preventing the accumulation of dust carried by the cooling airflow from affecting the electrical insulation of the corresponding parts. This disclosure also provides a second enclosed chamber 20, in which the bleeder resistor 330 and the rectifier diode 310 are located. Obviously, the terminals of these two will not easily accumulate dust due to the cooling airflow, thus ensuring the electrical insulation effect of these two.

[0047] See appendix for details Figure 8 In one specific implementation, the flying capacitor module 600 further includes a flying capacitor support plate 620, which is flush with the upper surface 421 of the thyristor heat sink. Figure 4 The image shows a flush connection between the two (the flying capacitor 610 is mounted on the flying capacitor tray 620, and at least the upper part of the flying capacitor 610 with terminals is located on the flying capacitor tray 620); and a DC capacitor module cover plate 230 is provided on the upper part of the DC capacitor module 200. At this time, the first enclosed chamber is formed as follows: The first enclosed chamber comprises a first top wall, a first front wall, a first rear wall, a first left side wall, a first right side wall, and a first bottom wall, wherein the walls are connected to form a closed environment. Specifically, the top plate 120 of the power unit's housing forms the first top wall; the front panel 130 of the housing, adjacent to a corresponding portion of the top plate 120, forms the first front wall; the rear panel 140 of the housing, adjacent to a corresponding portion of the top plate 120, forms the first rear wall; the left side panel 150 of the housing, adjacent to a corresponding portion of the top plate 120, forms the first left side wall; and the right side panel 160 of the housing, adjacent to a corresponding portion of the top plate 120, forms the first bottom wall. The first right side wall; the first bottom wall includes a first sub-bottom wall and a second sub-bottom wall, with the flying capacitor support plate 620 and the upper surface 421 of the thyristor heat sink jointly forming the first sub-bottom wall; the DC capacitor module cover plate 230 forms the second bottom sub-wall, and the first and second sub-bottom walls are adjacent and connected (if the two bottom walls are flush, they are directly connected; if they are not flush but have a height difference, they are indirectly connected through other corresponding components), and the first and second sub-bottom walls each extend to connect with the corresponding junctions of the first front wall, the first rear wall, the first left side wall, and the second rear side wall. Thus, the housing of the power unit and the corresponding components together constitute the first enclosed chamber, and the formation of the chamber is simple and easy.

[0048] See appendix for details Figure 4 and 8 In one specific embodiment, the input rectifier module 300 further includes a bleed resistor bracket 350, which includes a lifting portion 351 and a planar bending portion 352 formed by bending from the lifting portion 351; the input rectifier module 300 is located on the left side inside the housing 100, and the DC capacitor module 200 is located on the right side inside the housing 100. A partition wall 170 is provided between the input rectifier module 300 and the DC capacitor module 200. The bottom edge of the partition wall 170 is connected to the base plate 110, and the partition wall 170 extends upward to connect with the DC capacitor module cover plate 230 (see...). Figure 2 The bleeder resistor 330 is located behind the rectifier diode 310, and the lifting part 351 is located above the bleeder resistor 330 to lift it. The bleeder resistor support 350 is flush with the lower surface 321 of the diode heat sink. Figure 4 The planar bend 352 is located behind the bleeder resistor 330, and the bottom of the planar bend 352 is connected to the base plate 110; the input connector 340 includes an input connector bar 341 and an input connector bar bracket 342. The side of the input connector bar bracket 342 facing the rectifier diode is flat. The input connector bar bracket 342 is mounted on the base plate 110 and extends upward in the height direction (see Figure 110). Figure 6 At this point, the second closed chamber is formed in the following way: The second enclosed chamber has a second top wall, a second front wall, a second rear wall, a second left side wall, a second right side wall, and a second bottom wall, wherein each wall is connected to form a closed environment. The portion of the bottom plate 110 corresponding to the positions of the bleeder resistor 330 and the rectifier diode 310 forms the second bottom wall; the corresponding portion of the left side plate 150 near the bottom plate 110 forms the second left side wall; the corresponding portion of the partition wall 170 near the bottom plate 110 forms the second right side wall; the planar bending portion 352 in the bleeder resistor bracket 350 forms the second rear wall; the plane of the input connection row bracket 342 facing the rectifier diode forms the second front wall; the second top wall includes a first sub-top wall and a second sub-top wall. The lifting portion 351 in the bleeder resistor bracket 350 forms the first sub-top wall, and the lower surface 321 of the diode heat sink forms the second sub-top wall. The first sub-top wall and the second sub-top wall each extend to the corresponding junctions with the second left side wall, the second right side wall, and the second front wall for sealing connection.

[0049] Furthermore, see the appendix in particular. Figure 2 and 9 The power unit also includes a busbar 700 and a connecting cable 800. The busbar 700 is connected to the control circuit board and is located in the first enclosed chamber 10. The busbar 700 is also connected to the rectifier diode 310 through the connecting cable 800. The connecting cable 800 includes two connecting ends and a connecting cable body located between the two connecting ends. One connecting end is located in the second enclosed chamber 20 and is connected to the rectifier diode 310. The connecting cable body extends upward along the partition wall 170 between the DC capacitor module 200 and the input rectifier module 300 so that the other connecting end enters the first enclosed chamber 10 and is connected to the busbar 700.

[0050] Busbar 700 acts as a conductor. The current output after rectification by rectifier diode 310 enters busbar 700 through connecting cable 800, and then flows from busbar 700 to DC capacitor module 200 for storage. This disclosure avoids the need for dedicated extension space for the connecting cable by having the main body extend along the partition wall 170 between DC capacitor module 200 and input rectifier module 300. Furthermore, by placing one connection end of connecting cable 800 within the first enclosed chamber 10 and the other within the second enclosed chamber 20, these two connection ends are isolated by their respective enclosed chambers, preventing dust accumulation at these connection ends due to cooling airflow and thus avoiding insulation failure caused by dust accumulation.

[0051] Because one of the connection terminals of the connecting cable 800 is connected to the rectifier diode 310, and the rectifier diode 310 faces the base plate 110 of the power unit, in this case, the connection terminal of the connecting cable 800 connected to the rectifier diode 310 can be smoothly connected and installed by rotating the power unit at a certain angle and then opening the window cover 112 on the base plate.

[0052] Furthermore, see the appendix in particular. Figure 1 , 2 In addition to 3, the power unit also includes a DC capacitor module chamber 30. At least one front wall air inlet 131 is provided on the front wall of the DC capacitor module chamber 30, and a rear wall air outlet 141 is provided on the rear wall.

[0053] The front wall air inlet 131 and the rear wall air outlet 141 provide air inlet and outlet channels for the DC capacitor module chamber, cool down the DC capacitor module 200, and prevent the DC capacitor from overheating, which would lead to a decrease in DC capacitor performance and a reduction in service life.

[0054] Furthermore, see the appendix in particular. Figure 3 The DC capacitor module chamber 30 has three front wall air inlets 131, which are arranged vertically along the height direction. The width of the front wall air inlet 131 located in the middle is greater than the width of the front wall air inlets 131 located on both sides.

[0055] With the above-described configuration, the width of the front wall air inlet 131 located in the middle is maximized, making it easy to grasp the entire power unit using the front wall air inlet as a grip, which facilitates the rapid assembly and disassembly of the power unit.

[0056] Furthermore, see the appendix in particular. Figure 3 The housing 100 has: a front panel 130, which has a front panel air inlet 132 at a position corresponding to the diode heat sink 320 and the thyristor heat sink 420; and a rear panel 140, which has a rear panel air outlet at a position corresponding to the diode heat sink 320 and the thyristor heat sink 420.

[0057] Combining the air inlet and outlet cooling ducts for the DC capacitor module 200 described above, the power unit naturally forms three independent air ducts (in... Figure 3 (Illustrated by three thick black boxes): the air duct for the DC capacitor module, the air duct for the output module, and the air duct for the input rectifier module. Each air duct is a short duct, which reduces the unit's air resistance and lowers the requirements for the system fan. Furthermore, the separate air ducts provide better cooling for the corresponding components, allowing for more targeted control of the cooling temperature and ensuring the stable operation of the power unit.

[0058] Furthermore, see the appendix in particular. Figure 2 The DC capacitor module 200 is a first pre-assembled module including a DC capacitor 210 and a tray 220; the thyristor 410 and the thyristor heat sink 420 form a second pre-assembled module; and the rectifier diode 310, the diode heat sink 320, the bleeder resistor 330 and the input connector 340 form a third pre-assembled module.

[0059] By pre-assembling the corresponding components into the aforementioned pre-assembled module, the on-site assembly speed of the power unit can be significantly improved compared to assembling the components from their individual, scattered states into a complete power unit. Furthermore, those skilled in the art will understand that the terminals and fuses in the input connectors 340 of components such as the thyristor 410 and rectifier diode 310 are essential for the normal operation of their respective components. Therefore, when forming the corresponding pre-assembled module, these terminals and fuses also need to be installed onto the corresponding components.

[0060] In addition, this disclosure also provides a frequency converter including the power unit for the frequency converter as described above, which has a compact structure, makes full use of space, and has excellent overall heat dissipation performance without increasing costs.

[0061] The above are merely preferred embodiments of this disclosure. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this disclosure, and these improvements and modifications should also be considered within the scope of protection of this disclosure.

Claims

1. A power unit for a frequency converter, characterized in that: It includes a housing (100), a DC capacitor module (200), an input rectifier module (300), and an output module (400). With the ventilation direction of the housing (100) as the front-to-back direction, where the air intake is in front and the air outlet is in the back, in the left-to-right direction perpendicular to the front-to-back direction, the DC capacitor module (200) is located on one side of the housing (100); the input rectifier module (300) and the output module (400) are located on the other side of the housing (100), wherein the output module (400) and the input rectifier module (300) are arranged vertically, and in the projection along the vertical direction, the module located at the upper part and the module located at the lower part at least partially overlap.

2. The power unit according to claim 1, characterized in that, The input rectifier module (300) includes a rectifier diode (310) and a diode heat sink (320). The output module (400) includes a thyristor (410) and a thyristor heat sink (420). The rectifier diode (310) is mounted flat on the heat dissipation surface of the diode heat sink (320); The thyristor (410) is laid flat on the heat dissipation surface of the thyristor heat sink (420).

3. The power unit according to claim 2, characterized in that, The outer casing (100) includes a base plate (110); The output module (400) is located above the input rectifier module (300), wherein the diode heat sink (320) and the thyristor heat sink (420) are arranged back to back adjacent to each other, so that the rectifier diode (310) faces the base plate (110). The base plate (110) has a maintenance window (111) which is located at the position of the rectifier diode (310) and is covered by a window cover plate (112).

4. The power unit according to claim 1, characterized in that, The power unit also includes a control module (500), which includes a control circuit board; The output module (400) is located above the input rectifier module (300); The control module (500) is located above the output module (400) and the DC capacitor module (200).

5. The power unit according to claim 4, characterized in that, The power unit also includes a flying capacitor module (600), which includes a flying capacitor (610). The flying capacitor module (600) is located on the same side of the input rectifier module (300) and the output module (400) inside the housing (100), and the flying capacitor module (600) is located above the input rectifier module (300) and arranged side by side with the output module (400); In the projection along the vertical direction, the projections of the output module (400) and the flying capacitor module (600) are both located within the projection area of ​​the input rectifier module (300).

6. The power unit according to claim 5, characterized in that, The input rectifier module (300) also includes a bleed resistor (330) and an input connector (340). The bleeder resistor (330), rectifier diode (310), and input connector (340) are arranged in sequence in either a front-to-back or back-to-front direction.

7. The power unit according to claim 6, characterized in that, The power unit includes a first enclosed chamber (10) and a second enclosed chamber (20) isolated from the cooling airflow, wherein, The upper part of the flying capacitor (610) with terminals, the control module (500) and the thyristor (410) are located in the first enclosed chamber (10); The bleeder resistor (330) and the rectifier diode (310) are located inside the second enclosed chamber (20).

8. The power unit according to claim 7, characterized in that, The power unit also includes a busbar (700) and a connecting cable (800). The busbar (700) is connected to the control circuit board and is located in the first enclosed chamber (10); The busbar (700) is also connected to the rectifier diode (310) via the connecting cable (800). The connecting cable (800) includes two connecting ends and a connecting cable body located between the two connecting ends. One connecting end is located in the second enclosed chamber (20) and connected to the rectifier diode (310). The connecting cable body extends upward along the partition wall (170) between the DC capacitor module (200) and the input rectifier module (300) so that the other connecting end enters the first enclosed chamber (10) and connects to the busbar (700).

9. The power unit according to claim 1, characterized in that, The power unit also includes a DC capacitor module chamber (30), with at least one front wall air inlet (131) on the front wall and a rear wall air outlet (141) on the rear wall.

10. The power unit according to claim 9, characterized in that, The DC capacitor module chamber (30) has three front wall air inlets (131), which are arranged vertically along the height direction. The width of the front wall air inlet (131) located in the middle is greater than the width of the front wall air inlets (131) located on both sides.

11. The power unit according to claim 2, characterized in that, The outer casing (100) has: The front panel (130) has a front panel air inlet (132) at a position corresponding to the diode heat sink (320) and the thyristor heat sink (420). The rear panel (140) has a rear panel air outlet at a position corresponding to the diode heat sink (320) and the thyristor heat sink (420).

12. The power unit according to claim 7, characterized in that, The DC capacitor module (200) is a first pre-assembled module including a DC capacitor (210) and a tray (220); The thyristor (410) and the thyristor heat sink (420) form a second pre-assembled module; The rectifier diode (310), diode heat sink (320), bleeder resistor (330) and input connector (340) form a third pre-assembled module.

13. A frequency converter, characterized in that, The power unit for a frequency converter includes any one of claims 1-12.

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