CN111146925A

CN111146925A - Power unit

Info

Publication number: CN111146925A
Application number: CN201811301959.3A
Authority: CN
Inventors: 黄南; 邵强; 蒋云富; 王世平; 胡长风; 石廷昌; 翟龙
Original assignee: CRRC Zhuzhou Institute Co Ltd
Current assignee: CRRC Zhuzhou Institute Co Ltd
Priority date: 2018-11-02
Filing date: 2018-11-02
Publication date: 2020-05-12

Abstract

The invention discloses a power unit.A bearing plate is fixed on a framework of a cabinet body, and a power module is arranged on the bearing plate. The power module comprises a box body with an upper opening and a lower opening, the bottom of the box body is tightly attached and fixed with the upper part of the bearing plate, and a first air channel is formed. The lower push-in guide rails and the upper push-in guide rails are arranged in parallel and opposite to each other in the vertical direction, and are arranged in pairs in parallel and opposite to each other at the bottom of the bearing plate. The bearing plate is provided with air duct openings which are positioned between the two pairs of lower push-in guide rails and upper push-in guide rails. The fan is pushed in through a fan guide rail arranged at the top of the fan and is fixed between the lower push-in guide rail and the upper push-in guide rail. The power module also comprises a power element and a radiator arranged in the box body, the power element is arranged on the radiator, and the radiator is embedded in a first air duct enclosed by the box body. The invention can solve the technical problem that the existing power module cooling fan is inconvenient to dismantle, maintain and replace.

Description

Power unit

Technical Field

The invention relates to the technical field of electrical equipment, in particular to a fan fast push-in type power unit structure with an air cooling power module.

Background

At present, wind energy and solar energy are renewable energy sources which are widely applied in China. The power modules in the wind power converter and the photovoltaic inverter change the characteristics of input voltage by controlling the on and off of power elements, and play roles in rectification and inversion. The power module is increasingly widely applied to the converter due to the characteristics of light weight, convenience in disassembly, easiness in maintenance and the like. Among them, a power module using an IGBT (Insulated Gate Bipolar Transistor, short for Insulated Gate Bipolar Transistor) as a core component generally integrates devices such as a heat sink, a dc support capacitor, a composite bus bar, and a related driving and control module. The IGBT device is used as a power component of an inverter or a chopper in a converter, has good interchangeability and relatively simple and convenient installation, and can better meet the requirements of high power, high performance and high reliability.

High reliability is generally required for high-power modules, and excellent heat dissipation is an important guarantee for normal operation of the high-power modules. The IGBT is a main heat generating source as a core power component. The forced air cooling heat dissipation structure is widely applied to the field of heat dissipation of power modules because of the advantages of reliable work, easy maintenance, relatively low cost and the like. The centrifugal fan and the like are generally adopted in the air-cooled and heat-dissipating power module to provide cooling air, and the installation and fixing mode of the fan directly determines whether the subsequent maintenance of the power module is convenient and quick.

In the prior art, the closest technical scheme to the application of the invention is as follows:

the power unit is applied by national grid company, China institute of Electrical science, and China grid Anhui province electric power company in 2013, 06 and 21, and is also applied by Chinese invention with publication number CN103401434A, 20 and 11 and 2013. The invention discloses a power unit of a high-power converter, which comprises a power unit integral frame, a laminated busbar, a power element IGBT (insulated gate bipolar transistor) and a driver thereof, a capacitor supporting plate, a supporting capacitor array, a radiator fixing plate, a radiator, a fan mounting plate and a radiating fan, wherein the laminated busbar is positioned in the power unit integral frame. The power unit integral frame comprises a rectangular mounting plate positioned at the back of the power unit integral frame, and the supporting capacitor array is mounted on the mounting plate through a capacitor supporting plate. The heat radiation fan is arranged on the mounting plate through the fan mounting plate. The power element IGBT and the driver thereof are fixed on the mounting plate through the radiator fixing plate. The laminated busbar is parallel to the mounting plates, the main components are mounted on one mounting plate, and all the components are integrated and packaged into one power unit. The power module integrates devices such as an IGBT element, a direct current support capacitor, a composite bus, a driver, a heat dissipation fan and the like, the heat dissipation fan is integrally installed inside the power module and is directly connected with a cabinet body framework by adopting a screw fastener and the like, and the power module has the following defects: under the condition that power module is not completely disassembled, the fan is difficult to be disassembled, and the later maintenance and replacement of the fan are extremely unfavorable.

Disclosure of Invention

In view of this, the present invention provides a power unit to solve the technical problem that the existing power module cooling fan is inconvenient to remove, maintain and replace.

In order to achieve the above object, the present invention specifically provides a technical implementation scheme of a power unit, where the power unit is disposed inside a cabinet, and includes: power module, loading board, fan, lower push-in guide rail and go up push-in guide rail. The bearing plate is fixed on the framework of the cabinet body, and the power module is arranged on the bearing plate. The power module comprises a box body with an upper opening and a lower opening, the bottom of the box body is tightly attached and fixed with the upper part of the bearing plate, and a first air channel is formed. The lower push-in guide rails and the upper push-in guide rails are arranged in parallel and opposite to each other in the vertical direction, and are arranged at the bottom of the bearing plate in pairs in parallel and opposite to each other. The bearing plate is provided with air duct openings, and the air duct openings are located between the two pairs of lower push-in guide rails and the upper push-in guide rails. The fan is pushed in and fixed between the lower push-in guide rail and the upper push-in guide rail through a fan guide rail arranged at the top of the fan. The power module further comprises a power element and a radiator arranged in the box body, the power element is arranged on the radiator, and the radiator is embedded in a first air channel formed by the box body in an enclosing mode. And cooling air enters from the lower part of the cabinet body and passes through the fan, then enters the first air channel of the power module through the air channel opening and is discharged from the upper part of the cabinet body.

Furthermore, the power module further comprises a support capacitor and a composite busbar, the support capacitor is arranged on the upper portion of the power element and is partially located in the first air duct, and a gap is reserved between the support capacitor and the radiator. The composite busbar is arranged on the periphery of the supporting capacitor, and the power element and the supporting capacitor are electrically connected to the composite busbar.

Further, a second air duct is formed between the box body and the composite busbar, a capacitor fixing plate is arranged above the inside of the box body, and a radiator supporting plate is arranged below the capacitor fixing plate. The capacitor fixing plate and the radiator supporting plate are fixed on the inner side of the back of the box body, the fins of the radiator are tightly attached to the radiator supporting plate, and the mounting table board of the radiator is fixed with the box body. And the supporting capacitor penetrates through the box body from the second air duct, then extends into the first air duct and is fixed on the capacitor fixing plate. And cooling air exhausted by the fan blows through the radiator and then passes through the supporting capacitor to dissipate heat of the supporting capacitor.

Preferably, the lower push guide rail is provided with a first protruding part at one end extending into the cabinet body along the push-in direction of the fan. The fan guide rail is arranged along the pushing-in direction of the fan, and a second protruding portion is arranged on the other side, opposite to the first protruding portion, of the fan guide rail.

Preferably, the first protruding portion and the second protruding portion both adopt a Z-shaped secondary bending structure.

Preferably, a sealing ring is arranged at the bottom of the bearing plate along the periphery of the air duct opening, and the sealing ring is simultaneously positioned between the lower push guide rail and the bearing plate. When the fan pushes the cabinet body along the lower push-in guide rail and the upper push-in guide rail, a certain gap is reserved between the fan guide rail and the sealing ring to ensure smooth pushing. When the front end of the fan guide rail contacts the first protruding part of the push-down guide rail, the fan guide rail is lifted deeply into one side of the cabinet body. When the second bulge of the fan guide rail contacts the push-down guide rail, the other side of the fan guide rail is lifted, and the sealing ring between the fan guide rail and the bearing plate is extruded, so that the sealing between the upper part of the fan and the bottom of the first air channel is realized.

Preferably, the lower push guide rail is close to the end part of the side, pushed by the fan, of the lower push guide rail is bent downwards to form a first bending part, the first bending part is provided with a threaded hole, and one end, in the pushing direction of the fan, of the fan guide rail is bent downwards to form a second bending part. When the fan is completely pushed into the cabinet body, the first screw penetrates through the through hole in the second bending part and is fastened in the threaded hole of the lower push-in guide rail to fix the fan.

Furthermore, a current sensor is arranged at the lower part of the power element, the power element forms U, V, W three-phase alternating current in a pairwise parallel connection mode, and the three-phase alternating current is led out and connected through current-sharing drainage. And the current equalizing bar penetrates through the current sensor and then is connected to the alternating current output copper bar.

Further, the row that flow equalizes includes the copper bar body, copper post and branch copper bar, the copper post is connected to the copper bar body through two screws, the copper post is connected to exchange output copper bar. The branch copper bar is connected with the copper bar body, extends to the upper part of the copper bar body in an interdigital shape and is connected to the power element.

Furthermore, a pulse control module is arranged on the back of the power module, the pulse control module is of a drawer type push-pull installation structure, and the pulse control module is fixed on a framework on the back of the cabinet body through an installation frame.

Preferably, the power module adopts a drawer-type push-pull mounting structure, and the pulse control module is arranged close to the back side of the power module.

Through the implementation of the technical scheme of the power unit provided by the invention, the power unit has the following beneficial effects:

(1) the power module is positioned on the upper side of the bearing plate, is aligned and fastened with the air duct opening after being pushed in, ensures the sealing performance of the air duct, and ensures that cold air flows upwards from the lower side because the heat dissipation fan is positioned on the lower side of the framework bearing plate; on the other hand, the sealing between the fan and the air duct opening can be completed, the influence of vibration on the power module in the running process of the fan can be effectively reduced by skillfully using the sealing ring, and meanwhile, the noise caused by resonance and the like is reduced;

(2) the power unit adopts a modular design, has a compact structure, is easy to assemble, disassemble and maintain in each functional area, and power elements in the power module can quickly finish the configuration of the parallel connection quantity of the power elements and the adjustment of an alternating current output structure according to different requirements, thereby ensuring that the power module realizes standardization and simplification to the maximum extent; the peak voltage of the power element during on-off is reduced through the connection of the composite busbar inside the power module, and meanwhile, the capacitor is fixed in the heat dissipation air duct, so that the heat productivity of the capacitor is reduced, the reliability of the power module is improved, and the service life of the power module is prolonged;

(3) the power elements of the invention form U, V, W three-phase alternating current by a pairwise parallel connection mode, and are led out by connecting the current-sharing bar, the current-sharing bar passes through the current sensor and is connected to the alternating current output copper bar, wherein the current-sharing bar is composed of the current-sharing copper bar and the copper column with a fork-shaped symmetrical structure, the consistency of the current flowing path is ensured, and the flowing current can be effectively shared, thereby effectively reducing the non-uniform current property of the power elements during parallel operation, and improving the dynamic and static current sharing performance and stability of the power module.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other embodiments can be obtained from these drawings without inventive effort.

FIG. 1 is a schematic structural layout diagram of a power cell according to an embodiment of the present invention (a part of the skeleton is omitted in the diagram);

FIG. 2 is a schematic diagram of a fan assembly structure according to an embodiment of the power unit of the present invention (a part of the frame is omitted in the drawing);

FIG. 3 is a schematic structural diagram of a fan in an embodiment of a power unit of the present invention;

FIG. 4 is a partial schematic front view of a fan mount according to an embodiment of the power unit of the present invention;

FIG. 5 is a side sectional view of an embodiment of a power unit of the present invention shown installed without a fan fully pushed in;

FIG. 6 is a side sectional view of a power unit according to an embodiment of the present invention with the fan fully pushed in;

FIG. 7 is a schematic structural diagram of a frame in an embodiment of a power cell of the present invention;

FIG. 8 is a schematic diagram of a power module in an embodiment of a power cell of the present invention;

FIG. 9 is a schematic diagram of a power module in another view according to an embodiment of the present invention;

FIG. 10 is a schematic diagram of a pulse control module according to an embodiment of the present invention;

FIG. 11 is a schematic diagram of a current sharing arrangement in an embodiment of a power unit of the present invention;

in the figure: 1-framework, 2-power module, 3-pulse control module, 4-radiator, 5-power element, 6-box, 7-support capacitor, 8-composite bus bar, 9-bearing plate, 10-fan, 11-lower push-in guide rail, 12-upper push-in guide rail, 13-fan guide rail, 14-sealing ring, 15-threaded hole, 16-screw I, 17-current sensor, 18-first air duct, 19-second air duct, 20-capacitor fixing plate, 21-radiator support plate, 22-flow equalizing row, 23-copper bar body, 24-copper column, 25-branch copper bar, 26-screw II, 27-air duct opening, 28-first bulge, 29-second bulge, 30-mounting rack, 31-an alternating current output copper bar, 32-a first bending part, 33-a second bending part and 100-a cabinet body.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 to 11, embodiments of the power unit of the present invention are shown, and the present invention will be further described with reference to the drawings and the embodiments.

As shown in fig. 1 to 3, an embodiment of a power unit, which is disposed inside a cabinet 100 (the cabinet 100 shown in the drawings omits a cover plate), specifically includes: power module 2, loading plate 9, fan 10, lower push-in guide rail 11 and upper push-in guide rail 12. The bearing plate 9 is fixed on the framework 1 of the cabinet 100, and the power module 2 is arranged on the bearing plate 9. As shown in fig. 8 and fig. 9, the power module 2 includes a box body 6 with an upper opening and a lower opening, and the bottom of the box body 6 is closely attached and fixed to the upper portion of the bearing plate 9, and forms a first air duct 18. The lower push-in guide rails 11 and the upper push-in guide rails 12 are arranged opposite to each other in parallel in the vertical direction, and are arranged in pairs parallel to each other and opposite to each other at the bottom of the carrier plate 9. The bearing plate 9 is provided with an air duct opening 27, and the air duct opening 27 is positioned between the two pairs of lower push-in guide rails 11 and upper push-in guide rails 12. The blower 10 is pushed in and fixed between the lower push-in rail 11 and the upper push-in rail 12 by a blower rail 13 provided on the top thereof. The power module 2 further comprises a power element 5 and a radiator 4 arranged in the box body 6, the power element 5 is arranged on the radiator 4, and the power element 5 (for example, an IGBT element can be adopted) can be replaced by IGBT elements with the same package and different models according to the requirements of power grade and rated capacity. The heat sink 4 is embedded in a first air duct 18 surrounded by the case 6. After entering the fan 10 from the lower portion of the cabinet 100, the cooling air enters the first air duct 18 of the power module 2 through the air duct opening 27 formed in the carrier plate 9, and is then discharged from the upper portion of the cabinet 100.

As shown in fig. 4 to 7, the lower push-in guide rail 11 is provided with a first protrusion 28 at one end in the push-in direction of the blower 10 and deep into the cabinet 100. The fan guide 13 is provided with a second boss 29 on the other side opposite to the first boss 28 in the pushing-in direction of the fan 10. The first boss 28 and the second boss 29 are both of a Z-shaped double-bent structure. A sealing ring 14 is arranged at the bottom of the carrier plate 9 along the periphery of the air duct opening 27, the sealing ring 14 being simultaneously located between the push-down guide rail 11 and the carrier plate 9. When the blower 10 is pushed into the cabinet 100 along the lower push-in guide rail 11 and the upper push-in guide rail 12, a certain gap is left between the blower guide rail 13 and the sealing ring 14 to ensure smooth pushing. When the front end of the fan guide 13 contacts the first projection 28 of the lower push-in guide 11, the fan guide 13 is lifted up deep into one side of the cabinet 100. When the second protrusion 29 of the fan guide 13 contacts the lower push-in guide 11, the other side of the fan guide 13 is lifted, and the sealing ring 14 between the fan guide 13 and the bearing plate 9 is pressed, thereby sealing the upper portion of the fan 10 and the bottom of the first air duct 18. The end of the lower push-in guide rail 11 close to the push-in side of the fan 10 is bent downward to form a first bent portion 32, the first bent portion 32 is provided with a threaded hole 15, and one end of the fan guide rail 13 in the push-in direction (as shown by F in fig. 2) of the fan 10 is bent downward to form a second bent portion 33. When the fan 10 is pushed into the cabinet 100 completely, the fan 10 is fixed by the first screw 16 passing through the through hole of the second bent portion 33 and being fastened in the threaded hole 15 of the lower push-in guide rail 11.

As shown in fig. 8 and 9, the power module 2 further includes a support capacitor 7 and a composite busbar 8, the support capacitor 7 is disposed on the upper portion of the power element 5, and is partially located in the first air duct 18, and a gap is left between the support capacitor 7 and the heat sink 4, so that a local flow resistance in the first air duct 18 can be effectively reduced, and sufficient cold air is ensured to dissipate heat of the heat sink 4. The composite busbar 8 is arranged on the periphery of the supporting capacitor 7, the power element 5 and the supporting capacitor 7 are electrically connected to the composite busbar 8, peak voltage when the power element 5(IGBT element) is switched on and switched off is effectively reduced, and stability and reliability of operation of the power element 5 are improved. A second air duct 19 is formed between the box body 6 and the composite busbar 8, a capacitor fixing plate 20 is arranged above the inside of the box body 6, and a radiator supporting plate 21 is arranged below the capacitor fixing plate 20. The capacitor fixing plate 20 and the radiator support plate 21 are both fixed on the inner side of the back of the box body 6, the fins of the radiator 4 are tightly attached to the radiator support plate 21, and the mounting table of the radiator 4 is fixed with the box body 6. The supporting capacitor 7 penetrates the box 6 from the second air duct 19, extends into the first air duct 18, and is fixed on the capacitor fixing plate 20. The cooling air exhausted by the fan 10 blows through the radiator 4 and then passes through the supporting capacitor 7 to dissipate heat of the supporting capacitor 7, and the supporting capacitor 7 is fixed in the heat dissipation air duct (the first air duct 18 and the second air duct 19), so that sufficient air flow of the supporting capacitor 7 is ensured to take away local heat in the use process, and the reliability and the service life of the power module 2 are improved. The lower part of the power element 5 is further provided with a current sensor 17, the power element 5 (comprising three groups of six IGBT elements) forms U, V, W three-phase alternating current in a pairwise parallel connection mode, and the three-phase alternating current is led out and connected through the current equalizing bar 22. The current equalizing bar 22 passes through the current sensor 17 and then is connected to the alternating current output copper bar 31. As shown in fig. 11, the current equalizing bar 22 includes a copper bar body 23, a copper pillar 24 and a branch copper bar 25, the copper pillar 24 is connected to the copper bar body 23 through a second screw 26, and the copper pillar 24 is connected to an ac output copper bar 31. The branch copper bar 25 is connected with the copper bar body 23, extends to the upper part of the copper bar body 23 in an interdigital shape and is connected to the power elements 5, so that the consistency of the paths through which the current flows can be ensured, the non-uniform current during the parallel operation of the two power elements 5 is effectively reduced, and the stability of the power module 2 is improved.

As shown in fig. 1, 7 and 10, the pulse control module 3 is further disposed on the back of the power module 2, the pulse control module 3 adopts a drawer-type push-pull mounting structure, and the pulse control module 3 is fixed on the framework 1 on the back of the cabinet 100 through a mounting frame 30. The power module 2 further adopts a drawer type push-pull mounting structure, and the pulse control module 3 is arranged close to the back side of the power module 2, so that the pulse signals can be fully ensured to reach the power element 5 in a short path, and the interference is reduced to the maximum extent.

By implementing the technical scheme of the power unit described in the specific embodiment of the invention, the following technical effects can be produced:

(1) the power unit described in the specific embodiment of the invention effectively solves the problem of installation and maintenance of the fan used in the power module, on one hand, the push-in type fixing and dismounting of the fan can be quickly completed, the power module is positioned on the upper side of the bearing plate, and is aligned and fastened with the air duct opening after being pushed in, so that the sealing performance of the air duct is ensured, and the heat dissipation fan is positioned on the lower side of the framework bearing plate, so that cold air is ensured to flow upwards from the lower side; on the other hand, the sealing between the fan and the air duct opening can be ensured, the influence of vibration on the power module in the running process of the fan can be effectively reduced by skillfully using the sealing ring, and meanwhile, the noise caused by resonance and the like is reduced;

(2) the power unit described in the specific embodiment of the invention adopts a modular design, has a compact structure, is easy to assemble, disassemble and maintain in each functional area, and can quickly finish the configuration of the parallel number of power elements and the adjustment of an alternating current output structure according to different requirements, thereby ensuring that the power module realizes standardization and simplification to the maximum extent; the peak voltage of the power element during on-off is reduced through the connection of the composite busbar inside the power module, and meanwhile, the capacitor is fixed in the heat dissipation air duct, so that the heat productivity of the capacitor is reduced, the reliability of the power module is improved, and the service life of the power module is prolonged;

(3) in the power unit described in the embodiment of the invention, the power elements form U, V, W three-phase alternating current in a pairwise parallel connection mode, and are connected and led out through the current-sharing bar, and the current-sharing bar passes through the current sensor and is connected to the alternating current output copper bar, wherein the current-sharing bar is composed of the current-sharing copper bar and the copper columns which are of fork-shaped symmetrical structures, so that the consistency of a path through which current flows is ensured, and the flowing current can be effectively shared, thereby effectively reducing the non-uniform current property when the power elements are in parallel connection, and improving the dynamic and static current sharing performance and stability of the power.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The foregoing is merely a preferred embodiment of the invention and is not intended to limit the invention in any manner. Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make many possible variations and modifications to the disclosed embodiments, or equivalent modifications, without departing from the spirit and scope of the invention, using the methods and techniques disclosed above. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A power unit arranged inside a cabinet (100), characterized by comprising: the power module (2), the bearing plate (9), the fan (10), the lower push-in guide rail (11) and the upper push-in guide rail (12); the bearing plate (9) is fixed on the framework (1) of the cabinet body (100), and the power module (2) is arranged on the bearing plate (9); the power module (2) comprises a box body (6) with an upper opening and a lower opening, the bottom of the box body (6) is tightly attached and fixed with the upper part of the bearing plate (9) to form a first air duct (18); the lower push-in guide rails (11) and the upper push-in guide rails (12) are arranged oppositely and parallel to each other in the vertical direction, and are arranged at the bottom of the bearing plate (9) in pairs and are parallel to each other and opposite to each other; the bearing plate (9) is provided with an air duct opening (27), and the air duct opening (27) is positioned between the two pairs of lower push-in guide rails (11) and upper push-in guide rails (12); the fan (10) is pushed in and fixed between the lower push-in guide rail (11) and the upper push-in guide rail (12) through a fan guide rail (13) arranged at the top of the fan; the power module (2) further comprises a power element (5) and a radiator (4) arranged in the box body (6), the power element (5) is mounted on the radiator (4), and the radiator (4) is embedded in a first air duct (18) defined by the box body (6); after entering from the lower part of the cabinet body (100) and passing through the fan (10), cooling air enters the first air channel (18) of the power module (2) through the air channel opening (27) and is exhausted from the upper part of the cabinet body (100).

2. The power cell of claim 1, wherein: the power module (2) further comprises a support capacitor (7) and a composite busbar (8), the support capacitor (7) is arranged at the upper part of the power element (5), part of the support capacitor is positioned in the first air duct (18), and a gap is reserved between the support capacitor (7) and the radiator (4); the composite busbar (8) is arranged on the periphery of the supporting capacitor (7), and the power element (5) and the supporting capacitor (7) are electrically connected to the composite busbar (8).

3. The power cell of claim 2, wherein: a second air duct (19) is formed between the box body (6) and the composite busbar (8), a capacitor fixing plate (20) is arranged above the inner part of the box body (6), and a radiator supporting plate (21) is arranged below the capacitor fixing plate (20); the capacitor fixing plate (20) and the radiator supporting plate (21) are fixed on the inner side of the back of the box body (6), the fins of the radiator (4) are tightly attached to the radiator supporting plate (21), and the mounting table surface of the radiator (4) is fixed with the box body (6); the supporting capacitor (7) penetrates through the box body (6) from the second air duct (19), extends into the first air duct (18), and is fixed on the capacitor fixing plate (20); and cooling air exhausted by the fan (10) blows through the radiator (4) and then passes through the supporting capacitor (7) to dissipate heat of the supporting capacitor (7).

4. A power unit according to any one of claims 1 to 3, characterized in that: a first bulge part (28) is arranged at one end of the lower push guide rail (11) along the push-in direction of the fan (10) and extending into the cabinet body (100); the fan guide rail (13) is arranged along the pushing-in direction of the fan (10), and a second protruding portion (29) is arranged on the other side opposite to the first protruding portion (28).

5. The power cell of claim 4, wherein: the first protruding portion (28) and the second protruding portion (29) both adopt Z-shaped secondary bending structures.

6. The power cell of claim 4, wherein: a sealing ring (14) is arranged at the bottom of the bearing plate (9) along the periphery of the air duct opening (27), and the sealing ring (14) is simultaneously positioned between the lower push-in guide rail (11) and the bearing plate (9); when the fan (10) is pushed into the cabinet body (100) along the lower push-in guide rail (11) and the upper push-in guide rail (12), a certain gap is reserved between the fan guide rail (13) and the sealing ring (14) to ensure smooth pushing; when the front end of the fan guide rail (13) contacts the first bulge part (28) of the lower push-in guide rail (11), the fan guide rail (13) is lifted up deeply at one side of the cabinet body (100); when the second bulge (29) of the fan guide rail (13) contacts the downward pushing guide rail (11), the other side of the fan guide rail (13) is lifted, and the sealing ring (14) between the fan guide rail (13) and the bearing plate (9) is extruded, so that the upper part of the fan (10) and the bottom of the first air duct (18) are sealed.

7. The power cell of claim 6, wherein: the end part, close to the pushing-in side of the fan (10), of the lower pushing-in guide rail (11) is bent downwards to form a first bending part (32), a threaded hole (15) is formed in the first bending part (32), and one end, in the pushing-in direction of the fan (10), of the fan guide rail (13) is bent downwards to form a second bending part (33); when the fan (10) is completely pushed into the cabinet body (100), a first screw (16) penetrates through a through hole in the second bending part (33) and is fastened in a threaded hole (15) of the lower push-in guide rail (11) to fix the fan (10).

8. The power unit of any of claims 1, 2, 3, 5, 6, or 7, wherein: the lower part of the power element (5) is also provided with a current sensor (17), the power element (5) forms U, V, W three-phase alternating current in a pairwise parallel connection mode, and is led out and connected through a current equalizing bar (22); the current equalizing bar (22) penetrates through the current sensor (17) and then is connected to an alternating current output copper bar (31).

9. The power cell of claim 8, wherein: the current equalizing bar (22) comprises a copper bar body (23), a copper column (24) and a branch copper bar (25), the copper column (24) is connected to the copper bar body (23) through a second screw (26), and the copper column (24) is connected to the alternating current output copper bar (31); the branch copper bar (25) is connected with the copper bar body (23) and extends to the upper part of the copper bar body (23) in an interdigital shape and is connected to the power element (5).

10. The power unit of any of claims 1, 2, 3, 5, 6, 7, or 9, wherein: the back of the power module (2) is further provided with a pulse control module (3), the pulse control module (3) adopts a drawer type push-pull mounting structure, and the pulse control module (3) is fixed on a framework (1) at the back of the cabinet body (100) through a mounting frame (30).

11. The power cell of claim 10, wherein: the power module (2) adopts a drawer type push-pull mounting structure, and the pulse control module (3) is arranged close to the back side of the power module (2).