Bridge arm module, power conversion circuit and power conversion system

Abstract

The present application relates to the field of power electronics technology, and in particular to a bridge arm module, a power conversion circuit, and a power conversion system. The topological structure of the bridge arm module includes a plurality of power devices; and each power device is respectively packaged in at least two packaging modules; compared with the prior art, it is no longer necessary to divide the topological structure in the bridge arm module into equal parts in parallel according to the circuit structure or power, so the bridge arm module provided by the present application can maximize the use of the power of the packaging module when packaging multiple power devices, and there is no problem of margin design, thereby solving the problem of difficulty in margin design when multiple packaging modules are connected in parallel in the prior art. In addition, since each packaging module adopts at least two different packaging methods, the difficulty of designing the wiring is reduced and the parasitic parameters between each packaging module are reduced.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and in particular to a bridge arm module, a power conversion circuit and a power conversion system. Background Art

[0002] Currently, due to cost and volume considerations of the inverter unit, when designing the inverter unit, a packaged power module, ie, a packaged module, is generally used to construct the inverter unit.

[0003] When the inverter unit to be constructed is a larger power inverter unit, due to the packaging limitations of the packaging modules in the prior art, the inverter unit needs to be composed of multiple packaging modules in parallel, that is, the larger power of the inverter unit is shared by multiple packaging modules.

[0004] However, when designing the inverter unit, it is difficult to achieve a completely equal division of the circuit or power, which results in the parallel packaging modules having either too large a margin, resulting in waste, or insufficient margin, which makes the design difficult. In addition, since the packaging methods of the various packaging modules are consistent in the existing technology, the wiring design is more difficult and the stray inductance of each packaging module is larger. Summary of the Invention

[0005] In view of this, the present invention provides a bridge arm module, a power conversion circuit and a power conversion system to solve the problems in the prior art of difficulty in margin design, difficulty in designing routing and large stray inductance when multiple packaged modules are connected in parallel.

[0006] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0007] A first aspect of the present application provides a bridge arm module, the topology of which includes a plurality of power devices;

[0008] Each power device is packaged in at least two packaging modules;

[0009] Each packaging module adopts at least two different packaging methods.

[0010] Optionally, the topological structure of the bridge arm module includes: a single bridge arm;

[0011] The single bridge arm includes a plurality of power devices, which are respectively packaged in at least two packaging modules with different packaging methods.

[0012] Optionally, the topological structure of the bridge arm module includes: a first bridge arm and a second bridge arm connected in parallel;

[0013] The first bridge arm includes a single power device, and the second bridge arm includes a plurality of power devices;

[0014] The first bridge arm and the second bridge arm are respectively packaged in at least two packaging modules with different packaging methods.

[0015] Optionally, the topology of the bridge arm module is any one of: a full-bridge topology, a half-bridge topology, a three-phase four-bridge-arm inverter topology, a boost topology, a buck topology, and a buck-boost topology.

[0016] Optionally, different packaging methods include: different packaging materials, and / or different packaging structures.

[0017] Optionally, the packaging material includes: a packaging material with an auxiliary heat dissipation portion, and a packaging material without an auxiliary heat dissipation portion.

[0018] Optionally, the auxiliary heat dissipation part is: a copper substrate or an aluminum substrate.

[0019] Optionally, each of the encapsulation modules includes: at least one first encapsulation module and at least one second encapsulation module; wherein:

[0020] The heat generated by the first packaging module is greater than the heat generated by the second packaging module.

[0021] Optionally, the packaging material of the first packaging module is a packaging material with an auxiliary heat dissipation portion; and the packaging material of the second packaging module is a packaging material without an auxiliary heat dissipation portion.

[0022] Optionally, the power devices packaged in the first packaging module are power devices with high-frequency commutation, and the power devices packaged in the second packaging module are power devices without high-frequency commutation.

[0023] Optionally, the power device packaged in the first packaging module is a high-frequency power device, and the power device packaged in the second packaging module is an industrial frequency power device.

[0024] Optionally, the power devices encapsulated in the first encapsulation module are power devices through which active current flows, and the power devices encapsulated in the second encapsulation module are power devices through which reactive current flows.

[0025] Optionally, if the topology of the bridge arm module is an ANPC three-level topology, the power devices packaged in the first package module include: four switching tubes connected to the DC side and their anti-parallel diodes;

[0026] The power devices packaged in the second packaging module include: two switching tubes connected to the AC side and their anti-parallel diodes.

[0027] Optionally, the anti-parallel diode is: a body diode of a corresponding switch tube; or,

[0028] The anti-parallel diode is an external diode connected in anti-parallel with the corresponding switch tube; and the switch tube is a switch tube with a body diode, or a switch tube without a body diode.

[0029] Optionally, if the topology of the bridge arm module is an NPC three-level topology, the power devices packaged in the first package module include: two switching tubes connected to the positive and negative poles of the DC side and their anti-parallel diodes, and two diodes connected to the midpoint of the DC side;

[0030] The power devices packaged in the second packaging module include: two switching tubes connected to the AC side and their anti-parallel diodes.

[0031] Optionally, the anti-parallel diode is: a body diode of a corresponding switch tube; or,

[0032] The anti-parallel diode is an external diode connected in anti-parallel with the corresponding switch tube; and the switch tube is a switch tube with a body diode, or a switch tube without a body diode.

[0033] Optionally, if the topology of the bridge arm module is an ANPC three-level topology, the power devices encapsulated in the first encapsulation module include: two switching tubes connected to the positive and negative poles of the DC side, two switching tubes connected to the AC side, and an anti-parallel diode of the two switching tubes connected to the midpoint of the DC side;

[0034] The power devices packaged in the second packaging module include: anti-parallel diodes of two switching tubes connected to the positive and negative poles of the DC side, anti-parallel diodes of two switching tubes connected to the AC side, and two switching tubes connected to the midpoint of the DC side.

[0035] Optionally, the anti-parallel diode is: an external diode anti-parallel to the corresponding switch tube;

[0036] The switch tube is a switch tube with a body diode, or a switch tube without a body diode.

[0037] A second aspect of the present application further provides a power conversion circuit, comprising: a first bridge arm module and a second bridge arm module connected in series; wherein:

[0038] The heat generated by the first bridge arm module is greater than the heat generated by the second bridge arm module;

[0039] The first bridge arm module and the second bridge arm module are packaged in different ways.

[0040] Optionally, different packaging methods include: different packaging materials, and / or different packaging structures.

[0041] Optionally, the packaging material of the first bridge arm module is a packaging material with an auxiliary heat dissipation part; and the packaging material of the second bridge arm module is a packaging material without an auxiliary heat dissipation part.

[0042] Optionally, the first bridge arm module and the second bridge arm module each include a single power device.

[0043] Optionally, at least one of the first bridge arm module and the second bridge arm module is: a bridge arm module as described in any one of the first aspects of the present application.

[0044] The third aspect of the present application further provides a power conversion system, comprising: a bridge arm module as described in any one of the first aspects of the present application, or a power conversion circuit as described in any one of the second aspects of the present application.

[0045] As can be seen from the above technical solution, the present invention provides a bridge arm module. The topological structure of the bridge arm module includes multiple power devices; and each power device is respectively packaged in at least two packaging modules; compared with the prior art, it is no longer necessary to divide the topological structure in the bridge arm module into equal parts in parallel according to the circuit structure or power. Therefore, when packaging multiple power devices, the bridge arm module provided by the present application can maximize the use of the power of the packaging module, and there is no problem of margin design, thereby solving the problem of difficulty in margin design when multiple packaging modules are connected in parallel in the prior art. In addition, since each packaging module adopts at least two different packaging methods, the difficulty of designing the wiring is reduced and the parasitic parameters between the various packaging modules are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0047] Figure 1a and Figure 1b Schematic diagrams of two packages for each bridge arm in the bridge arm module provided in an embodiment of the present application;

[0048] Figure 2a and Figure 2b Schematic diagram of the packaging method with copper substrate;

[0049] Figure 2c and Figure 2d Schematic diagram of the packaging method without copper substrate;

[0050] Figure 3A schematic diagram of the structure of the ANPC three-level circuit provided in an embodiment of the present application;

[0051] Figure 4a 、 Figure 4b 、 Figure 4c and Figure 4d Schematic diagram of four operating modes of the ANPC three-level circuit provided in an embodiment of the present application when the output voltage on the AC output side is in a positive half-cycle;

[0052] Figure 5a 、 Figure 5b and Figure 6 Schematic diagrams of three packaging solutions for multiple power devices in each bridge arm of the bridge arm module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0053] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0054] In this application, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0055] In order to solve the problems in the prior art of difficulty in margin design, difficulty in designing routing, and large stray inductance when multiple packaged modules are connected in parallel, an embodiment of the present application provides a bridge arm module. The topology structure of the bridge arm module is not limited, such as any one of a full-bridge topology, a half-bridge topology, a three-phase four-bridge arm inverter topology, a boost topology, a buck topology, and a buck-boost topology.

[0056] The topology of the bridge arm module includes multiple power devices. Figure 1a As shown, in the bridge arm module 10 , each power device is packaged in at least two packaging modules 20 , and each packaging module 20 adopts at least two different packaging methods.

[0057] In practical applications, the bridge arm module 10 may include only a single bridge arm, and the single bridge arm may include multiple power devices, which are respectively packaged in at least two packaging modules 20 with different packaging methods. Alternatively, the bridge arm module 10 may include a first bridge arm and a second bridge arm connected in parallel; the first bridge arm may include a single power device, such as a bypass device; the second bridge arm may include multiple power devices, such as a boost topology, a buck topology, or a buck-boost topology; and the first bridge arm and the second bridge arm may be respectively packaged in at least two packaging modules 20 with different packaging methods.

[0058] Furthermore, each packaging module 20 utilizes at least two different packaging methods. Specifically, each packaging module 20 may utilize different packaging materials. For example, some packaging modules 20 utilize packaging materials with auxiliary heat dissipation components, while others utilize packaging materials without such components. The auxiliary heat dissipation components may be a copper substrate or an aluminum substrate, which is not limited to this. Each packaging module 20 may utilize at least two different packaging methods. Alternatively, each packaging module 20 may utilize the same packaging material but a different packaging structure. Alternatively, each packaging module 20 may utilize different packaging materials and different packaging structures. These methods may be determined based on the specific application environment and are all within the scope of protection of this application.

[0059] For example, if the multiple power devices included in the bridge arm module 10 are respectively packaged in two packaging modules 20 in actual application, the two packaging modules 20 can be respectively used as follows: Figure 2a and Figure 2b The package with copper base plate shown, or Figure 2c or Figure 2d The package shown is without a copper base plate.

[0060] However, due to the consideration of reasonable use of the two packaging methods, such as Figure 1b As shown, the packaging module with higher heat generation, i.e., the first packaging module 21, is usually packaged with a copper substrate to enhance its heat dissipation capability so that it can dissipate heat quickly to ensure its normal operation; and the packaging module with lower heat generation, i.e., the second packaging module 22, is usually packaged without a copper substrate to reduce its packaging cost and the packaging volume while ensuring its normal operation.

[0061] In actual applications, in the bridge arm module 10, power devices can be divided into two categories, one is power devices with high-frequency commutation, and the other is power devices without high-frequency commutation. The heat generated by power devices with high-frequency commutation is greater than that of power devices without high-frequency commutation. Therefore, the power devices encapsulated in the first packaging module 21 are power devices with high-frequency commutation, such as high-frequency power devices; the power devices encapsulated in the second packaging module 22 are power devices without high-frequency commutation, such as industrial frequency power devices.

[0062] The above is only one packaging solution for the multiple power devices in the bridge arm module 10. In the packaging process of the bridge arm module 10, another packaging solution for the multiple power devices can actually be adopted, specifically:

[0063] In the bridge arm module 10, power devices are also divided into two categories, but one category is power devices through which active current flows, and the other category is power devices through which reactive current flows. The heat generated by power devices through which active current flows is greater than the heat generated by power devices through which reactive current flows. Therefore, the power devices encapsulated in the first encapsulation module 21 are power devices through which active current flows, and the power devices encapsulated in the second encapsulation module 22 are power devices through which reactive current flows.

[0064] The two aforementioned packaging solutions for multiple power devices are merely preferred among the packaging solutions for multiple power devices. Because they are segmented according to device function, circuit power devices that operate for long periods of time and generate high heat can be placed within a module with a copper substrate, effectively leveraging their heat dissipation advantages. In practical applications, packaging solutions for multiple power devices include, but are not limited to, the two aforementioned packaging solutions. These solutions are not specifically limited here and can be selected based on specific circumstances. Solutions that involve longitudinally segmenting all power devices in the bridge arm module 10 topology, packaging all power devices in the bridge arm module 10 topology into multiple packaged modules, and then connecting each packaged module according to a topological structure so that each packaged module meets the packaging scale limit requirements are all within the scope of protection of this application.

[0065] As can be seen from the above scheme, since the power devices of the bridge arm module 10 provided by the present application are respectively encapsulated in at least two encapsulation modules 20, that is, the longitudinally cut encapsulation modules are connected according to the topological structure, replacing the scheme of parallel connection of the encapsulation modules after parallel cutting in the prior art, the topological structure of the bridge arm module 10 no longer needs to be divided equally according to the circuit structure or power. Therefore, when the present application encapsulates the multiple power devices in the bridge arm module 10, the power of the encapsulation module 20 can be maximized, and there is no problem of margin design, thereby solving the problem of difficulty in margin design when multiple encapsulation modules 20 are connected in parallel in the prior art. In addition, when the present application encapsulates the multiple power devices in each bridge arm module 10, the various encapsulation modules 20 of the bridge arm module 10 can be composed of different types of power devices, and their power can be maximized, the size is optimized, and there is no waste.

[0066] Furthermore, since each packaged module in each bridge arm utilizes at least two different packaging methods, the design and routing complexity is reduced, and parasitic parameters between the various packaged modules are minimized. Furthermore, the different packaging methods facilitate the differentiation of multiple packaged modules 20, further facilitating busbar layout without the limitation of identical pin positions for the same package.

[0067] The above embodiment describes in detail the packaging solution of the multiple power devices included in the topological structure of the bridge arm module 10 . This embodiment further describes the topological structure of the bridge arm module 10 by taking the ANPC three-level topological structure as an example.

[0068] Among them, the ANPC three-level circuit is a relatively mature conversion circuit in the prior art. Its structure is usually as follows: Figure 3 As shown, it specifically includes: a first switch tube Q1, a first anti-parallel diode D1, a second switch tube Q2, a second anti-parallel diode D2, a third switch tube Q3, a third anti-parallel diode D3, a fourth switch tube Q4, a fourth anti-parallel diode D4, a fifth switch tube Q5, a fifth anti-parallel diode D5, a sixth switch tube Q6 and a sixth anti-parallel diode D6.

[0069] In the ANPC three-level circuit, the input end of the first switch Q1 serves as the DC-side positive electrode P+ of the ANPC three-level circuit. The output end of the first switch Q1 is connected to the input end of the second switch Q2, the output end of the second switch Q2 is connected to the input end of the third switch Q3, the output end of the third switch Q3 is connected to the input end of the fourth switch Q4, and the output end of the fourth switch Q4 serves as the DC-side negative electrode N− of the ANPC three-level circuit. The input end of the fifth switch Q5 is connected to the output end of the first switch Q1, the output end of the fifth switch Q5 is connected to the input end of the sixth switch Q6, and the output end of the sixth switch Q6 is connected to the input end of the fourth switch Q4. The connection point between the output end of the second switch Q2 and the input end of the third switch Q3 serves as the DC-side midpoint Ne of the ANPC three-level circuit, and the connection point between the output end of the fifth switch Q5 and the input end of the sixth switch Q6 serves as the AC side AC of the ANPC three-level circuit.

[0070] The first anti-parallel diode D1 is anti-parallel connected to both ends of the first switch tube Q1, the second anti-parallel diode D2 is anti-parallel connected to both ends of the second switch tube Q2, the third anti-parallel diode D3 is anti-parallel connected to both ends of the third switch tube Q3, and the fourth anti-parallel diode D4 is anti-parallel connected to both ends of the fourth switch tube Q4.

[0071] It should be noted that when Figure 3 When each switch tube is a switch tube with a body diode, each reverse diode is the body diode of each switch tube; when Figure 3 When each anti-parallel diode is an external diode, each switching tube can be a switching tube with a body diode (the body diode is not shown in the figure) or a switching tube without a body diode. No specific limitation is made here and it can be determined according to the specific situation. All are within the scope of protection of this application.

[0072] When the voltage outputted by the ANPC three-level circuit on its AC output side is in the positive half cycle, according to the control method of the ANPC three-level circuit, if the voltage outputted by the ANPC three-level circuit on the AC side is positive voltage and current is positive current, then Figure 4a As shown, the first switch tube Q1 and the fifth switch tube Q5 are turned on, and the current flows in from P+, flows through the first switch tube Q1 and the fifth switch tube Q5, and then flows out from AC.

[0073] If the voltage output on the AC side of the ANPC three-level circuit is positive and the current is zero, then Figure 4b As shown, the second anti-parallel diode D2 and the fifth switch tube Q5 are turned on, and the current flows in from Ne, flows through the second anti-parallel diode D2 and the fifth switch tube Q5, and then flows out from AC.

[0074] If the voltage output on the AC side of the ANPC three-level circuit is zero voltage and the current is negative, then Figure 4c As shown, the fifth anti-parallel diode D5 and the first anti-parallel diode D1 are turned on, and the current direction is from AC flowing in, then flowing through the fifth anti-parallel diode D5 and the first anti-parallel diode D1 and then flowing out from P+.

[0075] If the voltage output on the AC side of the ANPC three-level circuit is positive and the current is negative, then Figure 4d As shown, the fifth anti-parallel diode D5 and the second switch tube Q2 are turned on, and the current flows in from AC, flows through the fifth anti-parallel diode D5 and the second switch tube Q2, and then flows out from Ne.

[0076] When the ANPC three-level circuit operates with the voltage outputted at its AC output side in a negative half cycle, the process is similar to the above process, and reference may be made to the above description, which will not be repeated here.

[0077] For the first packaging solution of the multiple power devices in the bridge arm module 10 in the above embodiment, according to the above description, when the output voltage on the AC output side is in the positive half cycle, Figure 5a As shown, the power devices with high-frequency commutation are the first switch tube Q1 and the first anti-parallel diode D1, the second switch tube Q2 and the second anti-parallel diode D2, and the power devices without high-frequency commutation are the fifth switch tube Q5 and the fifth anti-parallel diode D5; when the output voltage on the AC side is in the negative half cycle, as shown in FIG. Figure 5a As shown, the power devices with high-frequency commutation are the third switch tube Q3 and the third anti-parallel diode D3 and the fourth switch tube Q4 and the fourth anti-parallel diode D4, and the power devices without high-frequency commutation are the sixth switch tube Q6 and the sixth anti-parallel diode D6.

[0078] It should be noted that in actual applications Figure 5a The first switch Q1 in the figure cannot accurately refer to the switch at the corresponding position in the ANPC three-level circuit, so Figure 5a The first switch tube Q1 and the first anti-parallel diode D1, the second switch tube Q2 and the second anti-parallel diode D2, the third switch tube Q3 and the third anti-parallel diode D3, and the fourth switch tube Q4 and the fourth anti-parallel diode D4 are described as: four switch tubes and their parallel diodes connected to the DC side; and the fifth switch tube Q5 and the fifth anti-parallel diode D5, and the sixth switch tube Q6 and the sixth anti-parallel diode D6 are described as: two switch tubes and their anti-parallel diodes connected to the AC side.

[0079] In summary, if Figure 5aAs shown in the two dotted boxes in the figure, the power devices packaged in the first packaging module 21 with a larger heat generation include: four switching tubes and their anti-parallel diodes connected to the DC side; the power devices packaged in the second packaging module 22 with a smaller heat generation include: two switching tubes and their anti-parallel diodes connected to the AC side.

[0080] Similarly, if the topological structure of each bridge arm is Figure 5b In the NPC three-level topology shown, the power devices packaged in the first packaging module 21 with a larger heat generation include: two switching tubes (Q1 and Q4) connected to the positive and negative poles of the DC side and their anti-parallel diodes, and two diodes (D2 and D3) connected to the midpoint of the DC side; the power devices packaged in the second packaging module 22 with a smaller heat generation include: two switching tubes (Q2 and Q3) connected to the AC side and their anti-parallel diodes.

[0081] It should be noted that, for the first packaging solution of the multiple power devices in the bridge arm module 10 in the above embodiment, Figure 5a Taking the ANPC three-level topology structure shown as an example, if each anti-parallel diode is the body diode of each switch tube, then each switch tube is a switch tube with a body diode; if each anti-parallel diode is an external diode connected in reverse parallel to the corresponding switch tube, then each switch tube is a switch tube with a body diode or a switch tube without a body diode.

[0082] For the second packaging solution of the multiple power devices in the bridge arm module 10 in the above embodiment, according to the above description, when the output voltage on the AC output side is in the positive half cycle, Figure 6 As shown, the power devices through which the active current flows are the first switch tube Q1, the second anti-parallel diode D2 and the fifth switch tube Q5, and the power devices through which the reactive current flows are the first anti-parallel diode D1, the second switch tube Q2 and the fifth anti-parallel diode D5; when the output voltage on the AC side is in the negative half cycle, as shown in FIG. Figure 6 As shown, the power devices through which active current flows are the third anti-parallel diode D3, the fourth switch tube Q4 and the sixth switch tube Q6, and the power devices through which reactive current flows are the third switch tube Q3, the fourth anti-parallel diode D4 and the sixth anti-parallel diode D6.

[0083] It should be noted that in actual applications Figure 6 The first switch Q1 in the figure cannot accurately refer to the switch at the corresponding position in the ANPC three-level circuit, so Figure 6 The first switch tube Q1 and the fourth switch tube Q4 in the embodiment are described as: two switch tubes connected to the positive and negative electrodes of the DC side; Figure 6The second anti-parallel diode D2 and the third anti-parallel diode D3 in the figure are described as: anti-parallel diodes of two switching tubes connected to the midpoint of the DC side; Figure 6 The fifth switch tube Q5 and the sixth switch tube Q6 in the embodiment are described as: two switch tubes connected to the AC side; Figure 6 The first anti-parallel diode D1 and the fourth anti-parallel diode D4 are described as: anti-parallel diodes of two switching tubes connected to the positive and negative poles of the DC side; Figure 6 The fifth anti-parallel diode D5 and the sixth anti-parallel diode D6 in the figure are described as: anti-parallel diodes of two switching tubes connected to the AC side; Figure 6 The second switch tube Q2 and the third switch tube Q3 are described as: two switch tubes connected to the midpoint of the DC side.

[0084] In summary, if Figure 6 As shown in the two dotted boxes in the figure, the power devices packaged in the first packaging module 21 with a larger heat generation include: two switching tubes connected to the positive and negative poles of the DC side, two switching tubes connected to the AC side, and anti-parallel diodes of the two switching tubes connected to the midpoint of the DC side; the power devices packaged in the second packaging module 22 with a smaller heat generation include: anti-parallel diodes of the two switching tubes connected to the positive and negative poles of the DC side, anti-parallel diodes of the two switching tubes connected to the AC side, and two switching tubes connected to the midpoint of the DC side.

[0085] It should be noted that, for the second packaging solution of the multiple power devices in the bridge arm module 10 in the above embodiment, Figure 6 Each anti-parallel diode in the circuit is an external diode connected in anti-parallel with each switch tube, and each switch tube can be a switch tube with a body diode (such as Figure 6 It can also be a switch tube without a body diode (not shown), and the two types depend on the specific situation and will not be described here one by one.

[0086] Optionally, all of the above-mentioned switching tubes can be MOS transistors or IGBTs, which are not specifically limited here and can be determined according to specific circumstances, and are all within the scope of protection of this application.

[0087] As can be seen from the above, the one-phase bridge arm of the three-phase inverter part given in this embodiment is composed of an inverter unit, each of which contains at least two longitudinally divided power modules. The power modules in each inverter unit are packaged differently, and at least one is a module without a copper substrate. In practical applications, the circuit connected to the positive and negative poles (P+, N-) of the DC bus can be placed in a module with a copper substrate. This part of the circuit also has high-frequency commutation, and the circuit connected to the AC side can be placed in another module. This part of the circuit does not have high-frequency commutation; alternatively, the wafers through which active current flows can be placed in a module with a copper substrate, while the wafers through which reactive current flows can be placed in a module without a copper substrate. The heat generated by the chip in the module with a copper substrate is greater than the heat generated by the chip in the module without a copper substrate, which is beneficial for heat dissipation of power devices with high heat generation.

[0088] For bridge arm modules of other topological structures, they can also be packaged with different packaging materials according to the different heat generation. The specific principles will not be described in detail one by one, and all are within the protection scope of this application.

[0089] Another embodiment of the present invention further provides a power conversion circuit, comprising: a first bridge arm module and a second bridge arm module connected in series; wherein:

[0090] The heat generated by the first bridge arm module is greater than the heat generated by the second bridge arm module; the packaging methods of the first bridge arm module and the second bridge arm module are different, which may be different packaging structures or different packaging materials. For example, the packaging material of the first bridge arm module is a packaging material with an auxiliary heat dissipation part; the packaging material of the second bridge arm module is a packaging material without an auxiliary heat dissipation part.

[0091] The two bridge arm modules are packaged with different packaging materials according to the different heat generation. The specific principles can be found in the above embodiments and will not be described here one by one. All of them are within the protection scope of this application.

[0092] It is worth noting that in the power conversion circuit, the first bridge arm module and the second bridge arm module may both include a single power device, or at least one of the first bridge arm module and the second bridge arm module may be a bridge arm module as described in any of the above embodiments. The specific principles will not be repeated here.

[0093] Another embodiment of the present invention further provides a power conversion system, the main circuit of which includes: the bridge arm module as described in any of the above embodiments, or the power conversion circuit as described in the above embodiments.

[0094] The specific structure and principle of the bridge arm module and the power conversion circuit can be found in the above embodiments and will not be described in detail here.

[0095] Each embodiment in this specification is described in a progressive manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple. For relevant parts, refer to the partial description of the method embodiment. The system and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without expending creative work.

[0096] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0097] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A bridge arm module, characterized in that: Its topology includes multiple power devices; Each power device is encapsulated in at least two encapsulation modules; wherein the power device with high-frequency commutation is encapsulated in the encapsulation module with greater heat generation, and the power device without high-frequency commutation is encapsulated in the encapsulation module with less heat generation; or the power device through which active current flows is encapsulated in the encapsulation module with greater heat generation, and the power device through which reactive current flows is encapsulated in the encapsulation module with less heat generation; Each packaging module adopts at least two different packaging methods; The topological structure of the bridge arm module includes: a first bridge arm and a second bridge arm connected in parallel; The first bridge arm includes a single power device, and the second bridge arm includes a plurality of power devices; The first bridge arm and the second bridge arm are respectively packaged in at least two packaging modules with different packaging methods.

2. The bridge arm module according to claim 1, characterized in that: Different packaging methods include: different packaging materials and / or different packaging structures.

3. The bridge arm module according to claim 2, characterized in that: The packaging material includes: a packaging material with an auxiliary heat dissipation portion, and a packaging material without an auxiliary heat dissipation portion.

4. The bridge arm module according to claim 3, characterized in that: The auxiliary heat dissipation part is: a copper base plate or an aluminum base plate.

5. The bridge arm module according to any one of claims 1 to 4, characterized in that: Each of the encapsulation modules includes: at least one first encapsulation module and at least one second encapsulation module; wherein: The heat generated by the first packaging module is greater than the heat generated by the second packaging module; The power devices encapsulated in the first encapsulation module are power devices with high-frequency commutation, and the power devices encapsulated in the second encapsulation module are power devices without high-frequency commutation; or, the power devices encapsulated in the first encapsulation module are power devices through which active current flows, and the power devices encapsulated in the second encapsulation module are power devices through which reactive current flows.

6. The bridge arm module according to claim 5, characterized in that: The packaging material of the first packaging module is a packaging material with an auxiliary heat dissipation portion; the packaging material of the second packaging module is a packaging material without an auxiliary heat dissipation portion.

7. The bridge arm module according to claim 5, characterized in that: The power devices packaged in the first packaging module are high-frequency power devices, and the power devices packaged in the second packaging module are industrial frequency power devices.

8. A power conversion circuit, characterized in that: include: A first bridge arm module and a second bridge arm module connected in series; wherein: The heat generated by the first bridge arm module is greater than the heat generated by the second bridge arm module; The first bridge arm module and the second bridge arm module are packaged in different ways.

9. The power conversion circuit according to claim 8, characterized in that: Different packaging methods include: different packaging materials and / or different packaging structures.

10. The power conversion circuit according to claim 9, characterized in that: The packaging material of the first bridge arm module is a packaging material with an auxiliary heat dissipation portion; the packaging material of the second bridge arm module is a packaging material without an auxiliary heat dissipation portion.

11. The power conversion circuit according to any one of claims 8 to 10, characterized in that: The first bridge arm module and the second bridge arm module each include a single power device.

12. The power conversion circuit according to any one of claims 8 to 10, characterized in that: At least one of the first bridge arm module and the second bridge arm module is: the bridge arm module according to any one of claims 1-7.

13. A power conversion system, characterized in that: include: The bridge arm module according to any one of claims 1 to 7, or the power conversion circuit according to any one of claims 8 to 12.

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