CN113890309A

CN113890309A - Power module and power supply system

Info

Publication number: CN113890309A
Application number: CN202110991195.0A
Authority: CN
Inventors: 肖波; 黄朱勇; 刘汉华; 林臻; 杨江其
Original assignee: Huawei Digital Power Technologies Co Ltd
Current assignee: Huawei Digital Power Technologies Co Ltd
Priority date: 2021-08-26
Filing date: 2021-08-26
Publication date: 2022-01-04

Abstract

The embodiment of the application discloses a power module and a power supply system, wherein the power module comprises a shell, an input end, an output end and a plurality of power units which are connected in series; the input end is used for connecting a power supply and the power unit, and the output end is used for outputting the voltage transformed by the power unit; the plurality of power cells are spatially divided into a first layer and a second layer, each layer including at least one power cell; the housing includes: the first cover plate, the second cover plate and the third cover plate are arranged in a stacked mode, the second cover plate is located between the first cover plate and the third cover plate, the first layer of power units are arranged on one side, close to the second cover plate, of the first cover plate, and the second layer of power units are arranged on one side, close to the second cover plate, of the third cover plate; the first cover plate, the second cover plate and the third cover plate are connected. Therefore, the first cover plate and the third cover plate can adopt a buckled installation mode to encapsulate the power units in the shell, and the installation mode is simple.

Description

Power module and power supply system

Technical Field

The embodiment of the application relates to the technical field of power electronics, in particular to a power module and a power supply system.

Background

At present, with the rapid development of a novel alternating current/direct current power distribution network technology, a transformer needs to convert an input voltage of a kV level into a low voltage of hundreds of volts to supply power for electric equipment.

Fig. 1 is a simplified schematic diagram of a power system architecture. As shown in fig. 1, the power supply system includes: the power supply system comprises a power supply 01, a power frequency transformer 02, an Uninterruptible Power Supply (UPS) system 04 and an electric device 03, wherein the power frequency transformer 02 is used for transforming voltage input by the power supply 01 and outputting the transformed voltage to the UPS system 04, and the UPS system 04 is used for stabilizing voltage of commercial power and supplying the stabilized voltage to the electric device 03 for use.

However, the industrial frequency transformer 02 and the UPS system 04 occupy a large space, which is not favorable for miniaturization of the equipment.

For this reason, the prior art provides a power electronic transformer which can be used in a power supply system, and is more space-saving. Fig. 2 is a schematic structural diagram of a power electronic transformer. As shown in fig. 2, the power electronic transformer 05 has a two-layer structure, i.e., a first layer 0001 and a second layer 0002. Where first tier 100 includes power cell 001, power cell 002, power cell 003, and power cell 004, and second tier 200 includes power cell 005, power cell 006, power cell 007, and power cell 008.

When the voltage difference between adjacent power units is too large, different power units are easy to break down to cause sparking, and as shown in fig. 2, an insulating housing 051 may be arranged outside each power unit.

However, the insulating housing 051 is a single four-sided closed structure, so that each power unit is large in size, low in utilization rate, high in material space occupation rate, low in insulating material utilization rate and low in power density.

Disclosure of Invention

The embodiment of the application provides a power module and a power supply system, and solves the problem that the power supply system occupies a large space.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:

in a first aspect of embodiments of the present application, a power module is provided, including: the power supply comprises a shell, an input end, an output end and a plurality of power units which are connected in series; the input end is used for connecting a power supply and the power unit, and the output end is used for outputting the voltage transformed by the power unit; the plurality of power cells are spatially divided into a first layer and a second layer, each layer including one or more power cells; this casing includes: the first cover plate, the second cover plate and the third cover plate are arranged in a stacked mode, the second cover plate is located between the first cover plate and the third cover plate, the first layer of power units are arranged on one side, close to the second cover plate, of the first cover plate, and the second layer of power units are arranged on one side, close to the second cover plate, of the third cover plate; the first cover plate, the second cover plate and the third cover plate are connected. Therefore, the first cover plate, the second cover plate and the third cover plate are an upper part, a middle part and a lower part, all power units of the first layer can be positioned between the first cover plate and the second cover plate, and all power units of the second layer can be positioned between the second cover plate and the third cover plate. In particular, all power cells of the first layer may be mounted on the first cover plate, and may also be mounted on the second cover plate. All power cells of the second layer may be mounted on the third cover plate, and may also be mounted on the second cover plate. For example, the first cover plate, the second cover plate and the third cover plate can be assembled together in a buckling installation mode, a plurality of power units are packaged in the shell, and the installation mode is simple. Meanwhile, for an application scene that a series connection mode with a small voltage difference is adopted between adjacent power units on the same layer in a plurality of power units, the power module does not need to arrange an insulation structure between the adjacent power units on the same layer, so that the material utilization rate and the power density are improved, and the adjacent power units on the same layer are not easy to break down to cause ignition. .

In an optional implementation manner, each of the first layer and the second layer includes a plurality of the power units, and all the power units in the same layer are sequentially connected in series. And one power unit positioned at the end part in the first layer and one power unit positioned at the end part in the second layer are connected in series, so that the voltage difference between the adjacent power units on the same layer is as small as possible, and the problem of sparking caused by easy breakdown between the adjacent power units on the same layer is further reduced.

In an optional implementation manner, the first cover plate, the second cover plate and the third cover plate are made of insulating materials. Therefore, the insulating cover plate is arranged, so that the adjacent two layers of power units can be prevented from being broken down by higher voltage to strike sparks.

In an alternative implementation, the first cover plate and the third cover plate are provided with conductive layers on the outer sides, and one or more first shielding layers are arranged in the first cover plate. When one first shielding layer is disposed in the first cover plate, the first shielding layer may be opposite to and connected to all the power cells of the first layer. When the first cover plate is provided with a plurality of first shielding layers and the number of the power units of the first layer is one, the power units of the first layer may be opposite to and connected with any one or more first shielding layers. When the first cover plate is provided with a plurality of first shielding layers and the number of the power units of the first layer is multiple, the plurality of first shielding layers are opposite to the plurality of power units of the first layer one by one, and each power unit on the first layer is connected with one or more corresponding first shielding layers. For example, one power cell of the first layer is connected to one first shield layer by a lead. One or more second shielding layers are arranged in the third cover plate. When a second shielding layer is provided in the third cover plate, the second shielding layer may be connected to all power cells of the second layer. When the third cover plate is provided with a plurality of second shielding layers and the number of the power units on the second layer is one, the power units on the second layer may be opposite to and connected with any one or more second shielding layers. When the third cover plate is provided with a plurality of second shielding layers and the number of the power units on the second layer is multiple, the plurality of second shielding layers are opposite to the plurality of power units on the second layer one by one, and each power unit on the second layer is connected with one or more corresponding second shielding layers. For example, one power cell of the second layer is connected to one second shield layer by a lead. Therefore, the conducting layers on the outer sides of the first cover plate and the third cover plate can be used as grounding plates, the shielding layers are arranged in the first cover plate and the third cover plate, the power unit and the shielding layers can be connected through the leads, the leads can conduct the power unit and the shielding layers, the shielding layers and the conducting layers are filled with insulating materials, the insulating property is improved, and the phenomenon that fire is caused due to the fact that air is reserved between the power unit and the grounding plates and is broken down by high voltage is avoided.

In an alternative implementation, one or more third shielding layers are disposed in the second cover plate, and all the third shielding layers may be located below the power cells of the first layer. When a third shielding layer is disposed in the second cover plate, the third shielding layer may be opposite to and connected to all the power cells of the first layer. When the second cover plate is provided with a plurality of third shielding layers and the power unit of the first layer is one, the power unit of the first layer may be opposite to and connected with any one or more third shielding layers. When the second cover plate is provided with a plurality of third shielding layers and the power units of the first layer are multiple, the plurality of third shielding layers are opposite to the plurality of power units of the first layer one by one, and each power unit on the first layer is connected with one or more corresponding third shielding layers. For example, a power cell of the first layer is connected to a third shield layer by a wire. Therefore, the third shielding layer is arranged in the second cover plate, and the power units and the third shielding layer are conducted through the leads, so that the breakdown between the adjacent first layer of power units and the second cover plate due to the existence of air gaps can be prevented, and the insulating property between the first layer of power units and the second layer of power units is improved.

In an optional implementation manner, one or more fourth shielding layers are arranged in the second cover plate, and all the fourth shielding layers may be located above the power cells of the second layer and below the third shielding layer. When a fourth shielding layer is disposed in the second cover plate, the fourth shielding layer may be connected to all power cells of the second layer. When a plurality of fourth shielding layers are disposed in the second cover plate, and one power unit of the second layer is provided, the power unit of the second layer may be opposite to and connected to any one or more fourth shielding layers. When the second cover plate is provided with a plurality of fourth shielding layers and the power units on the second layer are multiple, the plurality of fourth shielding layers are opposite to the plurality of power units on the second layer one by one, and each power unit on the second layer is connected with one or more corresponding fourth shielding layers. For example, one power cell of the second layer is connected to one fourth shield layer by a lead. Therefore, the fourth shielding layer is arranged in the second cover plate, and the power units and the fourth shielding layer are conducted through the leads, so that the breakdown between the adjacent second layer of power units and the second cover plate due to the existence of air gaps can be prevented, and the insulating property between the first layer of power units and the second layer of power units is improved.

In an alternative implementation, the first cover plate includes a top plate and a first connecting plate connected to each other, the third cover plate includes a bottom plate and a third connecting plate connected to each other, the top plate is disposed opposite to the bottom plate, the first connecting plate is disposed between the top plate and the second cover plate, the third connecting plate is disposed between the bottom plate and the second cover plate, the first connecting plate and the third connecting plate are opposite to each other, and a first gap is formed between the first connecting plate and the third connecting plate. Thus, no shielding layer is arranged at the first gap, so that the first gap can be used as an electrical gap, and an electric field can be generated at the position.

In an alternative implementation, a fifth shielding layer is disposed in the first connecting board, and the fifth shielding layer is opposite to one or more power units located in the first layer. Also, the fifth shielding layer may be electrically connected to one or more power cells in the corresponding first layer. For example, the fifth shield layer is connected to one power cell by a lead. Therefore, the fifth shielding layer is arranged in the first connecting plate, and the power units and the fifth shielding layer are conducted through the leads, so that the breakdown between the adjacent first layer of power units and the first connecting plate due to the existence of air gaps can be prevented, and the insulation performance between the first layer of power units and the second layer of power units is further improved.

In an alternative implementation, a sixth shielding layer is disposed in the third connecting board, and the sixth shielding layer is opposite to the one or more power units located in the second layer. And, the sixth shielding layer may be electrically connected to one or more power cells in the corresponding second layer. For example, the sixth shield layer is connected to one power cell by a lead. Therefore, the sixth shielding layer is arranged in the third connecting plate, and the power units and the sixth shielding layer are conducted through the leads, so that the breakdown between the adjacent second-layer power units and the third connecting plate due to the existence of air gaps can be prevented, and the insulation performance between the first-layer power units and the second-layer power units is further improved.

In an alternative implementation, the second cover plate includes: the second connecting plate is positioned on the inner sides of the first connecting plate and the third connecting plate, wherein a second gap is formed between the second connecting plate and the first connecting plate, and a third gap is formed between the second connecting plate and the third connecting plate. Therefore, by arranging the second connecting plate, the second gap and the third gap are formed and are used as electric gaps, the creepage distance between the shielding layer and the conducting layer can be increased, and the electric field intensity is reduced.

In an alternative implementation, one end of the first connecting plate close to the third connecting plate is chamfered. The chamfer angle can be a circular arc chamfer angle or a rectangular chamfer angle. Thereby, the electric gap between the first connecting plate and the third connecting plate can be further increased, and the electric field intensity can be reduced.

In an alternative implementation, one end of the third connecting plate close to the first connecting plate is chamfered. The chamfer angle can be a circular arc chamfer angle or a rectangular chamfer angle. Thereby, the electric gap between the first connecting plate and the third connecting plate can be further increased, and the electric field intensity can be reduced.

In an alternative implementation, a side of the second connecting plate close to the first connecting plate and the third connecting plate is rounded or chamfered in a rectangular shape. Therefore, the electric gaps among the first connecting plate, the second connecting plate and the third connecting plate can be further increased, and the electric field intensity is reduced.

In an optional implementation manner, positioning pillars are disposed on the first cover plate and the third cover plate, positioning holes are disposed on the second cover plate, and the positioning pillars are opposite to the positioning holes one to one. And the positioning column can be inserted in the positioning hole. From this, through setting up reference column and locating hole, reduced the installation degree of difficulty between first apron and the third apron.

In an alternative implementation, the mobile phone further comprises a casing, the casing is arranged around the casing, and the casing is connected with the casing. Thus, the housing can protect the power module.

In an alternative implementation, the casing is made of metal. Therefore, the heat dissipation performance of the shell is better, and the stability is higher.

In an optional implementation manner, heat dissipation holes are formed in the casing. Thus, the heat dissipation performance of the power module can be improved.

In a second aspect of the embodiments of the present application, there is provided a power supply system, which includes a power supply, an electrical device, and the power module as described above, wherein the power supply is connected to an input terminal of the power module, and the electrical device is connected to an output terminal of the power module. Therefore, the power supply system adopts the power module, the size is smaller, and the occupied space can be reduced.

Drawings

FIG. 1 is a simplified schematic diagram of a power system architecture;

FIG. 2 is a schematic diagram of a power electronic transformer;

fig. 3 is a schematic structural diagram of a power module according to an embodiment of the present disclosure;

fig. 4 is a schematic disassembled structure diagram of a power module according to an embodiment of the present disclosure;

fig. 5 is a front view of a power module provided in an embodiment of the present application;

fig. 6 is a schematic structural diagram of a housing of a power module provided in an embodiment of the present application;

fig. 7 is a schematic disassembled structural diagram of a housing of a power module according to an embodiment of the present disclosure;

FIG. 8 is a sectional view taken along line A-A of FIG. 6;

fig. 9 is a schematic diagram of internal routing of a power module according to an embodiment of the present application;

FIG. 10 is a circuit diagram of the power module of FIG. 9;

fig. 11 is an electric field distribution diagram of a power module according to an embodiment of the present disclosure;

fig. 12 is a schematic structural diagram of another power module provided in the embodiment of the present application;

fig. 13 is a disassembled structural diagram of the power module in fig. 12.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more clear, the present application will be further described in detail with reference to the accompanying drawings.

In the following, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.

Further, in the present application, directional terms such as "upper" and "lower" are defined with respect to a schematically-disposed orientation of components in the drawings, and it is to be understood that these directional terms are relative concepts that are used for descriptive and clarity purposes and that will vary accordingly with respect to the orientation in which the components are disposed in the drawings.

In the present application, unless expressly stated or limited otherwise, the term "coupled" is to be construed broadly, e.g., "coupled" may be a fixed connection, a removable connection, or an integral part; may be directly connected or indirectly connected through an intermediate.

In order to make the technical solutions provided by the embodiments of the present application better understood by those skilled in the art, the present invention can be applied to any power unit that needs to be spatially distributed into at least two layers, needs to be connected in series between two adjacent layers, and connects the power units in series to form a certain voltage difference, or connects a power source with a certain voltage difference.

An embodiment of the present application provides a power supply system, which includes: the power supply is connected with the input end of the power module, and the electric equipment is connected with the output end of the power module.

The power module is used for converting input alternating current into direct current. If the power supply system is applied to a data center, the electric equipment can be a server in the data center.

For example, the ac power input to the power module may be ac medium voltage, the dc power output may be dc low voltage, and the data center may use a power supply system to convert the ac medium voltage to the dc low voltage, so as to supply power to the servers in the data center.

For example, when a power grid enters a building (i.e., a building in which a data center is located), three-phase 10kV alternating current (which may be regarded as alternating current input by a power module) is supplied, voltage conversion is performed by a power supply system, and then the three-phase 10kV alternating current is converted into 400V direct current, and the 400V direct current may supply power to terminal Internet Technology (IT) equipment (e.g., a server) in the data center.

The existing power module is large in occupied space, low in power density and high in installation difficulty, and needs to be matched with a UPS system, so that the power module small in occupied space is provided.

Fig. 3 is a schematic structural diagram of a power module according to an embodiment of the present application. Fig. 4 is a schematic disassembly structure diagram of a power module according to an embodiment of the present application. Fig. 5 is a front view of a power module according to an embodiment of the present disclosure. As shown in fig. 3, 4, and 5, the power module 10 includes: the power unit comprises an input end (not shown in the figure), an output end (not shown in the figure), a shell 100 and a plurality of power units (power unit 1-power unit 8) which are connected in series.

The embodiment of the present application does not specifically limit a specific implementation form of the power unit, and the power unit may be, for example, a power conversion unit or a battery cell.

In some embodiments, the power unit is a power conversion unit, the power conversion unit presents two terminals to the outside, and the two terminals may not be positive or negative, as long as the two terminals are connected in series with the terminals of other power conversion units.

In other embodiments, the power unit is an electric core, each electric core serves as a small power source and has an anode and a cathode, and when a plurality of electric cores are connected in series, attention needs to be paid to the connection relationship between the anode and the cathode of each electric core, for example, the anode of a first electric core serves as the anode of the battery power unit, the cathode of the first electric core is connected to the anode of a second electric core, the cathode of the second electric core is connected to the anode of a third electric core, and so on until the cathode of the last electric core serves as the cathode of the battery power unit.

The input end is used for connecting a power supply and the power unit, and the output end is used for outputting the voltage transformed by the power unit; the plurality of power cells are spatially divided into at least two layers, each layer including at least one power cell.

As shown in fig. 3, in the power module 10 provided in this embodiment, the plurality of power units are spatially divided into at least two layers of the following arrangement: a first layer 1001 and a second layer 1002.

The first layer 1001 and the second layer 1002 each include one or more power cells. The number of the plurality of power units may be two or more, and the specific number of the power units in each layer is not particularly limited. Adjacent power cells of the first layer 1001 may be connected in series, adjacent power cells of the second layer 1002 may be connected in series, and one power cell of the first layer 1001 is connected in series with one power cell of the second layer 1002. The sequential series connection of the power cells of the first layer 1001 and the power cells of the second layer 1002 can reduce the voltage difference between some of the power cells of the first layer 1001 and some of the power cells of the second layer 1002.

For example, when the application scenario corresponding to fig. 3 is 10kV high voltage, one power module 10 includes 8 power units, and the 8 power units in fig. 3 are power unit 1-power unit 8, respectively. The power units 1-8 are connected in series in sequence, and the voltage borne by each power unit is 10 kV/8.

For convenience of understanding, the power module 10 includes power cells arranged in two layers as an example. If the voltage class is higher or the voltage stress borne by each power unit is smaller, the number of the power units may also be increased, which is not specifically limited in the embodiment of the present application, and the number of the power units arranged in each layer is only described as 4 in the embodiment, and more or fewer power units may also be provided, specifically considering the size requirement of the power supply cabinet.

In order to effectively utilize the spatial distribution of the power module 10, the number of the power units in each layer may be equal and the power units are symmetrically and uniformly arranged, so that the space may be saved and a larger number of power units may be placed in a limited space.

The series connection of the power cells of the first and second layers is exemplified below.

When both the first layer 1001 and the second layer 1002 include only one power cell, the power cells of the first layer 1001 may be directly connected in series with the power cells of the second layer 1002.

When one of the first layer 1001 and the second layer 1002 includes only one power unit and the other of the first layer 1001 and the second layer 1002 includes two or more power units, taking the example that the first layer 1001 includes two or more power units and the second layer 1002 includes only one power unit, all the power units of the first layer 1001 may be sequentially connected in series and one power unit at a connection end in the first layer 1001 may be connected in series with the power unit of the second layer 1002.

When the first layer 1001 and the second layer 1002 each include a plurality of power cells, some of the power cells in the first layer 1001 may be directly connected in series with some of the power cells in the second layer 1002. When some of the power cells in the first layer 1001 are directly connected in series with some of the power cells in the second layer 1002, the remaining power cells in the first layer 1001 are connected in series within the present layer.

For example, the 1 st to nth power cells are sequentially arranged from the first side of the first layer 1001 to the second side of the first layer 1001. The (n + 1) th to the (2 n) th power units are sequentially arranged from the first side of the second layer 1002 to the second side of the second layer 1002.

The 1 st to the mth power units in the first layer may be connected in series in sequence, wherein 1 < m < n. Then, the mth power cell in the first layer is connected in series with the (n + 1) th power cell in the second layer. Then, the (n + 1) th power unit to the(s) th power unit of the second layer are sequentially connected in series. Wherein n +1 is more than s and less than 2 n. The s-th power cell of the second layer is then connected in series with the m + 1-th power cell of the first layer. Then, the (m + 1) th power unit to the nth power unit of the first layer are connected in series in sequence. Thereafter, the nth power cell of the first layer is connected in series with the (s + 1) th power cell of the second layer. And finally, the (s + 1) th power unit to the (2 n) th power unit of the second layer are sequentially connected in series. The voltage difference between adjacent two power units in the 1 st to the mth power units in the first layer, the n +1 th to the s-th power units in the second layer, the m +1 th to the nth power units in the first layer, and the s +1 th to the 2 nth power units in the second layer is small. As shown in fig. 3, the first layer 1001 includes 4 power units, i.e., power unit 1-power unit 4 from left to right, i.e., from the first side to the second side, respectively, and the second layer 1002 includes 4 power units, i.e., power unit 5-power unit 8 from left to right, i.e., from the first side to the second side, respectively. The above numbering is done for convenience of description only and does not imply any significance, as the numbering may be done in other orders.

That is, in order to make the voltage difference between the power cells in the two layers uniform, the power cells of the first layer 1001 and the power cells of the second layer 1002 may be directly connected in series in sequence, taking the example that the first layer 1001 includes power cell 1-power cell 4, and the second layer 1002 includes power cell 5-power cell 8, as shown in fig. 3, the power cell 1-power cell 4 in the first layer 1001 is connected in series, the power cell 5-power cell 8 in the second layer 1002 is connected in series, and the power cell 4 in the first layer 1001 is directly connected in series with the power cell 5 in the second layer 1002.

It should be noted that the first layer 1001 and the second layer 1002 are for convenience of description, and the positions of the two layers may be interchanged without special representation meaning.

Each power unit comprises two ports, the ports can be input and output independently, the first port of the power unit 1 is connected with a power supply, the second port of the power unit 1 is connected with the first port of the power unit 2, the second port of the power unit 2 is connected with the first port of the power unit 3, the second port of the power unit 3 is connected with the first port of the power unit 4, the second port of the power unit 4 is connected with the first port of the power unit 5, the second port of the power unit 5 is connected with the first port of the power unit 6, the second port of the power unit 6 is connected with the first port of the power unit 7, the second port of the power unit 7 is connected with the first port of the power unit 8, and the second port of the power unit 8 is used as an output end.

Based on the above, since the power units between two adjacent layers of the power units in the power module 10 provided by this embodiment are directly connected in series in sequence, effective voltage equalization around each shielding layer is achieved, that is, the voltage differences between the adjacent power units of each layer are almost equal on average, so that the adjacent power units can be more effectively protected from being broken down by higher voltage differences. For example, when the error is ignored, the voltage difference between the power unit 1 and the power unit 2 is equal to the voltage difference between the power unit 2 and the power unit 3, and is also equal to the voltage difference between the power unit 3 and the power unit 4, and so on, the power units in each layer shown in fig. 3 are directly connected in series, and the voltage-sharing effect can be better achieved. When the power units are connected in series as shown in fig. 3, the adjacent modules on the same layer do not need to be provided with an insulating structure, and insulating materials can be saved.

It should be noted that, some power units in the power module 10 are not used for voltage transformation, for example, a first port of the power unit 1 is used as an input end connected to a power supply, the power units 1 to 7 are sequentially connected in series through the ports, and then a second port of the power unit 7 is used as an output end.

The housing 100 is disposed outside the power unit, for example. The housing 100 includes at least: the cover plate comprises a first cover plate 101, a second cover plate 102 and a third cover plate 103 which are arranged in a stacked mode, wherein the second cover plate 102 is located between the first cover plate 101 and the third cover plate 103.

The power units (power unit 1-power unit 4) of the first layer 1001 are arranged on the side of the first cover plate 101 close to the second cover plate 102, and the power units (power unit 5-power unit 8) of the second layer 1002 are arranged on the side of the third cover plate 103 close to the second cover plate 102. All of the power cells of the first tier 1001 may be mounted on the first cover plate or may be mounted on the second cover plate. All power cells of the second layer may be mounted on the third cover plate 103, and may also be mounted on the second cover plate 102. The following description will be given taking an example in which all the power cells of the first layer 1001 are mounted on the first cover 101 and all the power cells of the second layer 1002 are mounted on the third cover 103.

The first cover plate 101, the second cover plate 102 and the third cover plate 103 are connected. The first cover plate 101, the second cover plate 102 and the third cover plate 103 may be fixedly connected by welding, or may be detachably connected by a connecting member (e.g., a bolt or a screw). Therefore, the first cover plate 101, the second cover plate 102 and the third cover plate 103 are three parts, namely an upper part, a middle part and a lower part, and a plurality of power units can be mounted on the first cover plate 101 and the third cover plate 103.

Meanwhile, because the power units on each layer are directly connected in series in the embodiment of the application, the voltage-sharing effect can be better realized, an insulating structure does not need to be arranged between the adjacent power units on the same layer, the material utilization rate and the power density are improved, and the cover plate material is saved.

However, as shown in fig. 3, the power units 1 to 8 are connected in series in sequence, the first terminal of the power unit 1 is connected to one phase voltage, and the first terminal of the power unit 8 is connected to the other phase voltage, that is, the voltage difference between the power unit 1 and the power unit 8 is the line voltage U between the two phases. Since 8 power units are connected in series, each power unit bears a voltage of U/8, the voltage difference between the power unit 2 and the power unit 7 is 3U/4, and the voltage difference between the power unit 3 and the power unit 6 is U/2. Therefore, the voltage difference between adjacent power units in different layers is large, and breakdown and fire are easily caused.

In the housing provided in the embodiment of the present application, the first cover plate 101, the second cover plate 102, and the third cover plate 103 are made of an insulating material, such as epoxy resin, for example.

The second cover plate 102 is located between the power cells of the first layer 1001 and the power cells of the second layer 1002, so that the voltage difference between the power cells of the upper and lower layers can be reduced, and the power cells can be prevented from being broken down and ignited due to too large voltage difference.

Therefore, in the series connection mode provided by the embodiment of the application, the second cover plate 102 can be arranged between the power unit of the first layer 1001 and the power unit of the second layer 1002, so that the voltage difference between the power units of the upper layer and the lower layer can be reduced, and the situation that the power units break down and fire because of too large voltage difference is prevented.

The embodiment of the present application does not limit the specific structures of the first cover plate 101, the second cover plate 102, and the third cover plate 103.

Fig. 6 is a schematic structural diagram of a housing of a power module according to an embodiment of the present application. Fig. 7 is a schematic disassembled structure diagram of a housing of a power module according to an embodiment of the present application. As shown in fig. 6 and 7, the first cover plate 101 includes: the top plate 1010 and the two first connecting plates 1011 form a concave structure, and the top plate 1010 and the two first connecting plates 1011 can be integrally formed.

The second cover plate 102 includes: the middle plate 1020 and the two second connecting plates 1021 form an H-shaped structure, and the middle plate 1020 and the two second connecting plates 1021 can be integrally formed together.

The third cover plate 103 includes: a base plate 1030, and two third connecting plates 1031, wherein the base plate 1030 and the two third connecting plates 1031 form a concave structure, and the base plate 1030 and the two third connecting plates 1031 can be integrally formed.

In addition, as shown in fig. 7, a first positioning column 10101 is further disposed on the top plate 1010, and the first positioning column 10101 may divide the top plate 1010 into a plurality of regions, each of which may mount a power unit. A plurality of second positioning columns 10301 are further disposed on the bottom board 1030, and the second positioning columns 10301 can divide the bottom board 1030 into a plurality of areas, and each area can mount one power unit.

As shown in fig. 7, the middle plate 1020 is provided with a connecting hole 10201, the first positioning column 10101 on the top plate 1010, the second positioning column 10301 on the bottom plate 1030, and the positioning hole 10201 on the middle plate 1020 are opposite to each other, so that the first positioning column 10101 on the top plate 1010 and the second positioning column 10301 on the bottom plate 1030 can be inserted into the positioning hole 10201 on the middle plate 1020 during positioning, so as to assemble the first cover plate 101, the second cover plate 102, and the third cover plate 103 together.

During assembly, one layer of power units may be mounted on the third cover plate 103, and another layer of power units may be mounted on the first cover plate 101.

Then, the second cover plate 102 can be covered on the third cover plate 103, so that the positioning posts 10101 on the bottom plate 1030 are inserted into the positioning holes 10201 on the middle plate 1020, at this time, the middle plate 1020 is opposite to the bottom plate 1030, and the second connecting plate 1021 is located inside the third connecting plate 1031. Next, the bottom plate 1030 and the middle plate 1020 may be detachably coupled together by a coupling member.

It should be noted that the connecting member may be a bolt, and the connecting hole may be a bolt hole.

Finally, the first cover 101 can be closed to the second cover 102, so that the positioning posts 10101 on the top plate 1010 are inserted into the positioning holes 10201 of the middle plate 1020, at this time, the middle plate 1020 is opposite to the top plate 1010, and the second connecting plate 1021 is located inside the first connecting plate 1011. Similarly, the middle plate 1020 and the top plate 1010 may be detachably connected by a connector.

Therefore, the insulating material consists of an upper part, a middle part and a lower part, and a plurality of power units can be packaged in one set of insulating material by adopting a buckling installation mode.

Wherein, the outer surface of the casing 100 is provided with the conductive layer 104 as shown in fig. 8, one or more shielding layers (a first shielding layer 1012, a second shielding layer 1032, a third shielding layer 1022 and a fourth shielding layer 1023 as shown in fig. 8) are embedded in the casing 100, and the power unit can be connected with the shielding layers through leads.

Fig. 8 is a sectional view a-a in fig. 6. As shown in fig. 8, the housing 100 is provided with a conductive layer 104 on the outer side, and the conductive layer 104 may serve as a ground plate. Wherein the conductive layer 104 comprises: a first conductive layer 1041 disposed on an outer side surface of the first cover plate 101, and a second conductive layer 1042 disposed on an outer side surface of the third cover plate 103.

And a shielding layer is arranged in the cover plate between the power unit and the conductive layer, and the power unit is electrically connected with the shielding layer.

Referring next to fig. 8, a first shielding layer 1012 is disposed in the first cover plate 101, and the number of the first shielding layer 1012 may be one or more. In fig. 8, 4 first shield layers 1012 are shown, 4 first shield layers 1012 being a shield layer 1012a, a shield layer 1012b, a shield layer 1012c and a shield layer 1012d, respectively. The third cover plate 103 is provided with a second shielding layer 1032, and the number of the second shielding layers 1032 is one or more. In fig. 8, 4 second shield layers 1032 are shown, the 4 second shield layers 1032 being respectively a shield layer 1032a, a shield layer 1032b, a shield layer 1032c, and a shield layer 1032 d.

The second cover plate 102 is provided with a third shielding layer 1022 and a fourth shielding layer 1023, the third shielding layer 1022 may be one or more, and the fourth shielding layer 1023 may also be one or more. In fig. 8, 4 third shielding layers 1022 and 4 fourth shielding layers 1023 are shown, the 4 third shielding layers 1022 being a shielding layer 1022a, a shielding layer 1022b, a shielding layer 1022c, and a shielding layer 1022d, respectively, and the 4 fourth shielding layers 1023 being a shielding layer 1023a, a shielding layer 1023b, a shielding layer 1023c, and a shielding layer 1023d, respectively.

The plurality of first shielding layers 1012 are opposite to the plurality of power cells of the first layer 1001 one by one, and each power cell in the first layer 1001 may be connected to a corresponding one of the first shielding layers 1012 through a wire.

As shown in fig. 8, the shielding layer 1012a, the shielding layer 1012b, the shielding layer 1012c, and the shielding layer 1012d are disposed in the top plate 1010 of the first cover plate and are spaced apart in the arrangement direction of the power units 1 to 4. The power unit 1 is opposed to the shield layer 1012a and connected by a lead, the power unit 2 is opposed to the shield layer 1012b and connected by a lead, the power unit 3 is opposed to the shield layer 1012c and connected by a lead, and the power unit 4 is opposed to the shield layer 1012d and connected by a lead.

Note that, the above description has been given taking as an example that the number of the first shield layers 1012 and the number of the power cells of the first layer 1001 are both plural and equal to each other. When there is one power cell for both the first shield layer 1012 and the first layer 1001 in the first cover plate 101, the first shield layer 1012 may directly face and be connected to the power cell for the first layer 1001. When there is one first shielding layer 1012 in the first cover 101 and there are a plurality of power cells in the first layer 1001, the first shielding layer 1012 may be connected to any one of the power cells in the first layer 1001, may be connected to any two or more of the power cells in the first layer 1001, or may be connected to all the power cells in the first layer 1001. For example, the length of the first shielding layer 1012 may be equal to the total length of all power cells of the first layer 1001 along the arrangement direction, so that the first shielding layer 1012 may be opposite to and connected to all power cells of the first layer 1001, thereby ensuring that the first shielding layer 1012 can shield all power cells of the first layer 1001. When there are a plurality of first shielding layers 1012 in the first cover plate 101 and one power cell of the first layer 1001, the power cell of the first layer 1001 may be opposite to and connected to any one or more first shielding layers 1012. When the power cells of the first shielding layer 1012 and the first layer 1001 in the first cover plate 101 are both multiple and the number of the multiple first shielding layers 1012 is not equal to that of the multiple power cells of the first layer 1001, if the number of the multiple first shielding layers 1012 is greater than that of the multiple power cells of the first layer 1001, in some power cells of the first layer 1001, each power cell may be opposite to and connected to one first shielding layer 1012; in another portion of the power cells in the first layer 1001, each power cell may be opposite and connected to two or more first shield layers 1012. If the number of power cells of the first layer 1001 is greater than the number of first shielding layers 1012, each first shielding layer 1012 may be opposite to and connected to one power cell in a portion of the first shielding layers 1012; in another portion of the first shielding layers 1012, each of the first shielding layers 1012 may be opposite to and connected to two or more power cells. A plurality of second shielding layers 1032 may be disposed in the third cover plate 103, the plurality of second shielding layers 1032 are opposite to the plurality of power cells of the second layer 1002 one by one, and each power cell located in the second layer 1002 is connected to one of the second shielding layers 1032 by a lead.

Referring next to fig. 8, a shield layer 1032a, a shield layer 1032b, a shield layer 1032c, and a shield layer 1032d are disposed in the bottom plate 1030 of the third cover plate and are spaced apart in the arrangement direction of the power cells 8 to 5. The power cell 5 is opposed to and connected to the shield layer 1032d by a lead, the power cell 6 is opposed to and connected to the shield layer 1032c by a lead, the power cell 7 is opposed to and connected to the shield layer 1032b by a lead, and the power cell 8 is opposed to and connected to the shield layer 1032a by a lead.

Similarly, the above description has been given by taking an example in which the number of the second shield layers 1032 is equal to the number of the power cells of the second layer 1002. When there is one power unit in both the second shielding layer 1032 and the second layer 1002 in the third cover plate 103, the second shielding layer 1032 may directly face and be connected to the power unit of the second layer 1002. When there is one second shielding layer 1032 in the third cover plate 103 and there are a plurality of power cells in the second layer 1002, the second shielding layer 1032 may be opposite to and connected to any one power cell in the second layer 1002, may be opposite to and connected to any two or more power cells in the second layer 1002, or the second shielding layer 1032 may be opposite to and connected to all the power cells in the second layer 1002. For example, the length of the second shielding layer 1032 may be equal to the total length of all power cells of the second layer 1002 in the arrangement direction, so that the 1012 of the first shielding layer may be opposite to and connected to all power cells of the second layer 1002, thereby ensuring that the 1012 of the first shielding layer can have a shielding effect on all power cells of the second layer 1002. When there are a plurality of second shielding layers 1032 in the third cover plate 103 and one power cell of the second layer 1002, the power cell of the second layer 1002 may be opposite to and connected to any one or more second shielding layers 1032. When the power units of the second shielding layer 1032 and the second layer 1002 in the third cover plate 103 are both multiple and the number of the multiple second shielding layers 1032 is not equal to the number of the multiple power units of the second layer 1002, if the number of the multiple second shielding layers 1032 is greater than the number of the multiple power units of the second layer 1002, in some power units in the second layer 1002, each power unit may be opposite to and connected to one second shielding layer 1032; in another portion of the power cells in the second layer 1002, each power cell may be opposite and connected to two or more second shielding layers 1032. If the number of power cells of the second layer 1002 is greater than the number of second shielding layers 1032, each second shielding layer 1032 may be opposite to and connected to one power cell in a portion of the second shielding layers 1032; in another portion of the second shield layers 1032, each second shield layer 1032 may be opposite and connected to two or more power cells.

Therefore, the conducting layers on the outer sides of the first cover plate and the third cover plate can be used as grounding plates, the shielding layers are arranged in the first cover plate and the third cover plate, and the power unit and the shielding layers are connected through the leads, wherein the leads can conduct the power unit and the shielding layers, and the shielding layers and the conducting layers are filled with insulating materials, so that the insulating property is improved, and the phenomenon that fire is caused by the fact that air is reserved between the power unit and the grounding plates and is broken down by high voltage is avoided.

A plurality of third shielding layers 1022 may be disposed in the second cover plate 102, as shown in fig. 8, wherein the third shielding layers 1022 are located below the power cells of the first layer 1001. It will be appreciated that after turning the power module of fig. 8 upside down, the third shielding layer 1022 is located above the power cells of the first layer 1001. The plurality of power cells in the first layer are opposite to the plurality of third shielding layers 1022, and each power cell in the first layer is connected to one third shielding layer 1022 through a lead.

As shown in fig. 8, the shielding

layers

1022a, 1022b, 1022c, and 1022d are disposed in the middle plate 1020 of the second cover plate and are spaced apart in the arrangement direction of the power units 1 to 4. The power unit 1 is connected to the shield layer 1022a by a lead, the power unit 2 is connected to the shield layer 1022b by a lead, the power unit 3 is connected to the shield layer 1022c by a lead, and the power unit 4 is connected to the shield layer 1022d by a lead.

Similarly, the above description is given by taking as an example that the number of the third shielding layers 1022 and the number of the power cells in the first layer 1001 are both plural and equal to each other. For the scheme that the number of the third shielding layers 1022 is not equal to the number of the power cells of the first layer 1001, or the number of any one of the third shielding layers 1022 and the power cells of the first layer 1001 is one, the connection scheme of the third shielding layers 1022 and the power cells of the first layer 1001 is similar to the connection scheme of the first shielding layers 1012 and the power cells of the first layer 1001, and details thereof are not repeated here.

Therefore, by arranging the third shielding layer 1022 in the second cover plate 102 and conducting the power cells and the third shielding layer 1022 through the leads, the breakdown between the adjacent first-layer power cells and the second cover plate 102 due to the existence of the air gap can be prevented, and the insulation performance between the power cells of the first layer and the power cells of the second layer is improved.

A plurality of fourth shielding layers 1023 may be further disposed in the second cover plate, as shown in fig. 8, the fourth shielding layers 1023 are located above the power units of the second layer and below the third shielding layers 1022. It is understood that, after the power module in fig. 8 is turned upside down, the fourth shielding layer 1023 is located below the power units of the second layer and above the third shielding layer. The power cells on the second layer are opposite to the fourth shielding layers 1023 one by one, and each power cell on the second layer is connected to one fourth shielding layer 1023 through a lead wire.

Referring next to fig. 8, the shielding

layers

1023a, 1023b, 1023c and 1023d are disposed in the middle plate 1020 of the second cover plate 102 and are spaced apart in the arrangement direction of the power units 8 to 5. The power unit 5 is opposed to the shield layer 1023d and connected by a lead wire, the power unit 6 is opposed to the shield layer 1023c and connected by a lead wire, the power unit 7 is opposed to the shield layer 1023b and connected by a lead wire, and the power unit 8 is opposed to the shield layer 1023a and connected by a lead wire.

Similarly, the above description is given by taking as an example that the number of the fourth shielding layers 1023 and the number of the power cells of the second layer 1002 are both plural and equal to each other. For the scheme that the number of the fourth shielding layer 1023 is not equal to the number of the power units of the second layer 1002, or the number of any one of the fourth shielding layer 1023 and the power units of the second layer 1002 is one, the connection scheme of the fourth shielding layer 1023 and the power units of the second layer 1002 is similar to the connection scheme of the second shielding layer 1032 and the power units of the second layer 1002, and is not described again here.

Therefore, by providing the fourth shielding layer 1023 in the second cover plate 102 and conducting the power cells and the fourth shielding layer 1023 through the leads, the breakdown between the adjacent second layer power cells and the second cover plate due to the existence of the air gap can be prevented, and the insulation performance between the first layer power cells and the second layer power cells is improved.

As shown in fig. 9, taking the power cell n and the power cell n +1 as an example, the O point of the power cell n is connected to the first shield layer 1012 and the third shield layer 1022 through a lead wire, respectively, and the O point of the power cell n +1 is connected to the fourth shield layer 1023 and the second shield layer 1032 through a lead wire, respectively.

Fig. 10 is an equivalent circuit diagram of the power unit n and the power unit n +1 in fig. 9, where point O is a capacitance midpoint or a bus midpoint of the power unit n and the power unit n +1, respectively. The potential at the O point is equal to the potentials at the fourth and

third shield layers

1023 and 1022.

Therefore, the shielding layer is arranged in the cover plate, the power unit and the shielding layer are connected through the lead, the power unit can be directly conducted with the shielding layer, the potential on the shielding layer is equal to that of the power unit, the shielding layer and the grounding plate are filled with the insulating material, and the phenomenon that an air gap is generated between the power unit and the conducting layer to cause discharge is avoided.

As shown in fig. 8 and 11, the first connecting plate 1011 is located between the top plate 1010 and the middle plate 1020 of the second cover plate 102. Similarly, the first connecting board 1011 has a fifth shielding layer 10110 disposed therein, and the fifth shielding layer 10110 is opposite to and connected to one or more power cells in the first layer 1001. The fifth shielding layer 10110 may be one or more. Fig. 8 shows two fifth shielding layers 10110, two fifth shielding layers 10110 are respectively disposed in the two first connecting plates 1011, one fifth shielding layer 10110 is opposite to and connected to the power unit 1, and the other fifth shielding layer 10110 is opposite to and connected to the power unit 4.

Therefore, by providing the fifth shielding layer 10110 in the first connecting plate 1011 and conducting the power cells and the fifth shielding layer 10110 through the wires, the breakdown between the adjacent first layer power cells and the first connecting plate 1011 due to the existence of the air gap can be prevented, and the insulation performance between the first layer power cells and the second layer power cells is further improved.

As shown in fig. 8 and 11, the third connecting plate 1031 is located between the bottom plate 1030 and the middle plate 1020 of the second cover plate 102. Similarly, a sixth shielding layer 10310 is disposed in the third connecting plate 1031, and the sixth shielding layer 10310 is opposite to and connected to one or more power cells located in the second layer 1002. The sixth shielding layer 10310 may also be one or more. Fig. 8 shows two sixth shielding layers 10310, two sixth shielding layers 10310 are respectively located in the two third connecting plates 1031, one sixth shielding layer 10310 is opposite to and connected to the power unit 8, and the other sixth shielding layer 10310 is opposite to and connected to the power unit 5.

Thus, by providing the sixth shield layer 10310 in the third connecting plate 1031 and making the power cells and the sixth shield layer 10310 conductive by the leads, it is possible to prevent the breakdown between the adjacent second-layer power cells and the third connecting plate 1031 due to the presence of the air gap, and further improve the insulating performance between the first-layer power cells and the second-layer power cells.

The structure of the fifth shielding layer 10110 and the sixth shielding layer 10310 is not limited in this embodiment, and the fifth shielding layer 10110 may be integrally formed with the first shielding layer 1012. The sixth shield layer 10310 may be integrally formed with the fifth shield layer 10110.

Based on the above, in the embodiment of the present application, the first connecting plate 1011 and the third connecting plate 1031 are opposite to each other, and a first gap 106 is formed between the first connecting plate 1011 and the third connecting plate 1031. Thus, no shielding layer is disposed at the first slot 106, so that the first slot 106 can be used as an electrical gap, and an electric field can be generated at the position.

The second connecting plate 1021 is located inside the first connecting plate 1011 and the third connecting plate 1031, a second gap 107 is formed between the second connecting plate 1021 and the first connecting plate 1011, a third gap 108 is formed between the second connecting plate 1021 and the third connecting plate 1031, and the first gap 106, the second gap 107 and the third gap 108 are communicated. Further, a gap is also provided between the second connecting plate 1021 and the top plate 1010 and the bottom plate 1030.

The creepage paths (electrical gaps) of the first, second, and

third slots

106, 107, and 108 are, as shown by arrows in fig. 11, started by the third and fourth shield layers 1022 and 1024, respectively, and surround the surface of the second connection plate 1021, and then led to the first slot 106 from the second and

third slots

107 and 108, respectively.

Therefore, the second connecting plate 1021, the first connecting plate 1011 and the third connecting plate 1031 form a folded structure, a first gap 106 is reserved at the upper and lower buckling positions of the insulating material, a second gap 107 and a third gap 108 are arranged among the second connecting plate 1021, the first connecting plate 1011 and the third connecting plate 1031, and the first gap 106, the second gap 107 and the third gap 108 are used as electric gaps, so that the creepage distance between the shielding layer and the conducting layer can be increased, and the electric field intensity is reduced.

It should be noted that the electrical gap is the shortest spatial distance measured between two conductive components or between a conductive component and the equipment protection interface. Creepage distance refers to the shortest path between two conductive parts or between a conductive part and an equipment protection interface measured along an insulating surface.

As shown in fig. 11, an end of the first connecting plate 1011 near the third connecting plate 1031 is chamfered (at the junction of the first gap 106 and the second gap 107). The chamfer angle can be a circular arc chamfer angle or a rectangular chamfer angle. Thereby, the width of the first gap 106 between the first connection plate 1011 and the third connection plate 1031 can be increased, the electrical gap can be increased, and the electric field strength can be reduced.

The third connecting plate 1031 is chamfered (at the junction of the first gap 106 and the third gap 108) at the end close to the first connecting plate 1011. The chamfer angle can be a circular arc chamfer angle or a rectangular chamfer angle. Thereby, the width of the first gap 106 between the first connection plate 1011 and the third connection plate 1031 can be increased, the electrical gap can be increased, and the electric field intensity can be reduced.

The second connecting plate 1021 is chamfered at a side thereof close to the first connecting plate 1011 and the third connecting plate 1031. That is, the chamfers are formed at the intersection of the top surface of the second connection plate 1021 and the side surface near the first connection plate 1011, and the intersection of the bottom surface of the second connection plate 1021 and the side surface near the first connection plate 1011. The chamfer angle can be a circular arc chamfer angle or a rectangular chamfer angle. This makes it possible to increase the widths of the second gap 107 and the third gap 108, increase the electrical gap, and reduce the electric field intensity. For example, the top surface and the bottom surface of the second connecting plate 1021 can also directly adopt circular arc surfaces, which is convenient for manufacturing.

Referring to fig. 11, the connection plates enclosing the first gap 106, the second gap 107 and the third gap 108 are all processed by arc angles, so that the gap width is increased, and the air electric field intensity of the gaps at the buckling positions can be reduced.

As shown in fig. 12 and 13, the power module 10 further includes: a housing 105, the housing 105 being disposed and connected outside the housing 100, the housing 105 being used to protect the power module 10.

Wherein, this casing 105 includes at least: an upper case 1051 and a lower case 1052, wherein the upper case 1051 is disposed outside the first cover 101 and detachably coupled to the first cover 101, the lower case 1052 is disposed outside the third cover 103 and detachably coupled to the third cover 103, and the upper case 1051 and the lower case 1052 are detachably coupled.

The material of the housing 105 is not limited in the embodiments of the present application, and in some embodiments, the housing is made of a metal material, for example. The heat dissipation performance is better, and the stability is higher.

The housing 105 further comprises: the power module comprises a front shell 1053 and a rear shell 1054, wherein a heat dissipation structure is arranged on the front shell 1053, so that the heat dissipation performance of the power module can be improved. A single plate is provided on the rear housing 1054.

The above description is only an embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions within the technical scope of the present disclosure should be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A power module, comprising: the power supply comprises a shell, an input end, an output end and a plurality of power units which are connected in series;

the input end is used for connecting a power supply and the power unit, and the output end is used for outputting the voltage transformed by the power unit; the plurality of power cells are spatially divided into a first layer and a second layer, each layer including at least one of the power cells;

the housing includes: the power module comprises a first cover plate, a second cover plate and a third cover plate which are arranged in a stacked mode, wherein the second cover plate is located between the first cover plate and the third cover plate, a first layer of power units are arranged on one side, close to the second cover plate, of the first cover plate, and a second layer of power units are arranged on one side, close to the second cover plate, of the third cover plate;

the first cover plate, the second cover plate and the third cover plate are connected.

2. The power module of claim 1, wherein the first and second layers each include a plurality of the power cells, all of the power cells of a layer are sequentially connected in series, and one of the power cells of an end portion in the first layer and one of the power cells of an end portion in the second layer are connected in series.

3. The power module of claim 1 or 2, wherein the first cover plate, the second cover plate and the third cover plate are all made of insulating materials.

4. The power module according to claim 3, wherein the first cover plate and the third cover plate are provided with conductive layers on the outer sides, at least one first shielding layer is arranged in the first cover plate, the at least one first shielding layer is opposite to the at least one power unit on the first layer in a one-to-one manner, and each power unit on the first layer is electrically connected with the corresponding at least one first shielding layer;

at least one second shielding layer is arranged in the third cover plate, the at least one second shielding layer is opposite to the at least one power unit on the second layer one by one, and each power unit on the second layer is electrically connected with the corresponding at least one second shielding layer.

5. The power module according to claim 3 or 4, wherein at least one third shielding layer is disposed in the second cover plate, the at least one third shielding layer is located below the power cells in the first layer, the at least one third shielding layer is opposite to the at least one power cell in the first layer one by one, and each power cell in the first layer is electrically connected to the corresponding at least one third shielding layer.

6. The power module according to any one of claims 3-5, wherein at least one fourth shielding layer is disposed in the second cover plate, the at least one fourth shielding layer is located above the power cells of the second layer and below the third shielding layer, the at least one fourth shielding layer is one-to-one opposite to the at least one power cell of the second layer, and each power cell of the second layer is electrically connected to the corresponding at least one fourth shielding layer.

7. The power module of any of claims 1-6, wherein the first cover plate comprises: the top plate and the bottom plate are arranged oppositely, the first connecting plate is located between the top plate and the second cover plate, the third connecting plate is located between the bottom plate and the second cover plate, the first connecting plate and the third connecting plate are opposite, and a first gap is formed between the first connecting plate and the third connecting plate.

8. The power module of claim 7, wherein a fifth shielding layer is disposed in the first connection board, the fifth shielding layer being opposite to at least one of the power cells in the first layer and electrically connected to each other.

9. The power module of claim 7, wherein a sixth shield layer is disposed in the third connecting board, the sixth shield layer being opposite to and electrically connected to at least one of the power cells in the second layer.

10. The power module of claim 7, wherein the second cover plate comprises: the second connecting plate is located on the inner side of the first connecting plate and the inner side of the third connecting plate, a second gap is formed between the second connecting plate and the first connecting plate, and a third gap is formed between the second connecting plate and the third connecting plate.

11. The power module according to claim 7 or 10, wherein an end of the first connection plate near the third connection plate is chamfered.

12. The power module of any of claims 7-11, wherein an end of the second connection plate proximate to the first connection plate and the third connection plate is chamfered.

13. A power module according to any one of claims 7-12, characterised in that the third connection plate is chamfered on the side adjacent to the first connection plate.

14. The power module as claimed in any one of claims 1 to 12, wherein the first cover plate and the third cover plate are provided with positioning posts, the second cover plate is provided with positioning holes, the positioning posts are opposite to the positioning holes one by one, and the positioning posts are inserted into the positioning holes.

15. The power module of any of claims 1-13, further comprising a chassis disposed around the housing, the chassis coupled to the housing.

16. The power module of claim 15, wherein the housing is made of metal.

17. The power module as claimed in claim 15 or 16, wherein the housing is provided with heat dissipation holes.

18. A power supply system comprising a power supply, a consumer, and a power module as claimed in any one of claims 1 to 17, the power supply being connected to an input of the power module and the consumer being connected to an output of the power module.