Three-level power module, centralized energy storage apparatus, and centralized energy storage circuit
By introducing equipotential parallel connectors and optimizing terminal layout in the three-level power module, the problem of uneven current flow in the parallel current path of the three-level power module is solved, thereby improving operational stability and safety.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- CONTEMPORARY AMPEREX FUTURE ENERGY RES INST (SHANGHAI) LTD
- Filing Date
- 2025-12-01
- Publication Date
- 2026-07-30
AI Technical Summary
In centralized energy storage PCS, when three-level power modules are connected in parallel, there is a problem of uneven current flow in the current path, which affects the stability and safety of operation.
In the three-level power module, equipotential parallel connectors are introduced to connect the equipotential parallel nodes of multiple modules to maintain potential consistency, and the uneven current path is reduced by optimizing the layout of terminals and baffles.
It effectively reduces the uneven current distribution in the current path when three-level power modules are connected in parallel, thus improving operational stability and safety.
Smart Images
Figure CN2025138881_30072026_PF_FP_ABST
Abstract
Description
Three-level power modules, centralized energy storage devices, and centralized energy storage circuits
[0001] Cross-references to related applications
[0002] This application claims priority to Chinese Patent Application No. 2025101252578, filed on January 26, 2025, entitled “Three-level power module, centralized energy storage device and centralized energy storage circuit”, the entire contents of which are incorporated herein by reference. Technical Field
[0003] This application relates to the field of power electronics, and specifically discloses a three-level power module, a centralized energy storage device, and a centralized energy storage circuit. Background Technology
[0004] Three-level power modules have been widely used in power conversion fields such as rail transit, new energy storage, and steel rolling due to their unique advantages, such as low harmonic content, no need for large reactors, and ability to improve equipment voltage levels. A three-level power module is an electronic device formed by packaging internal electronic chips connected in a three-level topology. Among related technologies, the NPC (Neutral Point Clamped) three-level topology is the most widely used multilevel topology. There are two most common structures for the NPC topology. Additionally, ANPC (Active Neutral Point Clamped) is an improved version of the NPC topology. With the development of devices in recent years, ANPC has also begun to find suitable applications, such as in centralized energy storage PCS (Power Conversion Systems).
[0005] In centralized energy storage PCS, due to the large power of a single system, a single power module cannot meet the power demand, requiring multiple power modules to be used in parallel. However, when power modules are used in parallel with other power modules, there is often uneven current distribution in the current paths between different power modules. This results in the weaker current path among the multiple power modules connected in parallel bearing greater electrical stress. Greater electrical stress makes it easier for current path failure to occur, affecting the stability and safety of the power module operation. Summary of the Invention
[0006] The purpose of this application is to provide a three-level power module, a centralized energy storage device, and a centralized energy storage circuit, which can reduce the uneven current distribution between different three-level power modules when the three-level power module is connected in parallel with other three-level power modules, and improve the operational stability and safety of the three-level power module.
[0007] In a first aspect, embodiments of this application provide a three-level power module, comprising: a three-level power circuit, the three-level power circuit including a plurality of switching devices, a DC node, an AC output node, and an equipotential parallel node, the equipotential parallel node being located between the DC node and the AC output node, and the equipotential parallel node being spaced apart from both the DC node and the AC output node by at least one of the switching devices; and an equipotential parallel connector, the equipotential parallel connector being configured such that one end is connected to the equipotential parallel node, and the other end is connected to the equipotential parallel connectors of other three-level power modules.
[0008] Compared with related technologies, the three-level power module provided in this application embodiment additionally provides an equipotential parallel connector. This equipotential parallel connector is configured such that one end is connected to the equipotential parallel node of the three-level power circuit, and the other end is connected to the equipotential parallel connector of other three-level power modules. When the three-level power module is connected in parallel with other three-level power modules, the corresponding equipotential parallel connectors on each three-level power module can be connected, thereby connecting the equipotential parallel nodes in multiple three-level power modules. This ensures that the potential at the equipotential parallel nodes in the multiple parallel three-level power modules remains consistent. Since the equipotential parallel node is located between the DC node and the AC output node, and the equipotential parallel node is connected to the DC node and the AC output node... With at least one switching device between them, the potential formed at the equipotential parallel node when current flows between the DC node and the AC output node is affected by the switching device. Since there may be differences between the switching devices in different three-level power modules, the potential of the equipotential parallel node at the same circuit position in different three-level power modules will also be different. This difference leads to uneven current flow in the current path of multiple three-level power modules connected in parallel. By connecting the equipotential parallel nodes in multiple three-level power modules to keep the potential at the equipotential parallel nodes of multiple three-level power modules consistent, the degree of uneven current flow between the current paths in multiple three-level power modules connected in parallel can be reduced, thereby improving the operational stability and safety of the three-level power modules.
[0009] In an optional embodiment, the three-level power module further includes: a DC connector, an AC connector, and a package encapsulating the three-level power circuit, the equipotential parallel connector, the DC connector, and the AC connector. One end of the DC connector is connected to the DC node, and the other end forms a DC connection terminal on the outer surface of the package. One end of the AC connector is connected to the AC output node, and the other end forms an AC connection terminal on the outer surface of the package. The DC connection terminal and the AC connection terminal are respectively disposed on opposite sides of the package. Distributing all DC connection terminals uniformly on the same side of the outer surface of the package facilitates parallel connection of multiple three-level power modules. Simultaneously, distributing the AC connection terminal on the opposite side from the DC connection terminal allows for a greater distance between the DC and AC connection terminals, reducing mutual interference between them.
[0010] In an optional embodiment, one end of the equipotential parallel connector is connected to the equipotential parallel node, and the other end forms an equipotential parallel terminal on the outer surface of the package. The AC connection terminal and the equipotential parallel terminal are respectively disposed on two adjacent different outer wall surfaces within the package. Disposing the equipotential parallel terminal on the outer surface adjacent to the AC connection terminal not only optimizes the arrangement of the equipotential parallel connector, reduces the internal space occupied by the equipotential parallel connector, and decreases the volume of the three-level power module, but also allows the equipotential parallel terminal and the AC connection terminal to be on different planes, reducing the mutual influence between the AC connection terminal and the equipotential parallel terminal.
[0011] In an optional embodiment, the DC connection terminal, the AC connection terminal, and the equipotential parallel terminal are disposed on the same outer wall surface of the package, with the equipotential parallel terminal located between the DC connection terminal and the AC connection terminal. Distributing the DC connection terminal, AC connection terminal, and equipotential parallel terminal on the same outer wall surface of the housing facilitates connection of each terminal when multiple three-level power modules are connected in parallel. Furthermore, since the current at the DC connection terminal and the AC connection terminal is relatively large, the mutual influence between them is also greater. Positioning the equipotential parallel terminal between the DC connection terminal and the AC connection terminal allows for a greater distance between them, which better reduces the mutual influence between them.
[0012] In an optional embodiment, the three-level power module further includes a baffle wall disposed on the outer surface of the package, the baffle wall being disposed between the DC connection terminal, the AC connection terminal, and the equipotential parallel terminal. The baffle wall between the DC connection terminal, the AC connection terminal, and the equipotential parallel terminal can separate these terminals, increasing the electrical clearance and creepage distance between them, and reducing the mutual interference between the AC connection terminal, the DC connection terminal, and the equipotential parallel terminal.
[0013] In an optional embodiment, the DC connector also forms a capacitor connection terminal on the outer surface of the package. The capacitor connection terminal is configured to connect to a DC-side absorption capacitor. The DC connection terminal and the capacitor connection terminal are respectively disposed on two adjacent outer wall surfaces within the package. By providing the capacitor connection terminal on the outer surface adjacent to the DC connection terminal, the distance between the DC-side absorption capacitor connected to the capacitor connection terminal and the three-level power module can be reduced. This reduction in distance allows for a reduction in the distance between the DC-side absorption capacitor and the switching devices in the three-level power module, achieving better voltage spike absorption.
[0014] In an optional embodiment, the three-level power module further includes a temperature control component, which and the capacitor connection terminal are respectively disposed on two adjacent outer wall surfaces of the package. By placing the temperature control component on the outer surface adjacent to the capacitor connection terminal, the distance between the DC-side absorption capacitor and the temperature control component can be reduced. The temperature control component can then assist the DC-side absorption capacitor in temperature control, improving the reliability and lifespan of the DC-side absorption capacitor.
[0015] In an optional embodiment, the DC node includes a DC positive node, a DC negative node, and a bus midpoint node; the DC connector includes a DC positive connector connected to the DC positive node, a DC negative connector connected to the DC negative node, and a bus midpoint connector connected to the bus midpoint node. The DC positive connector includes a DC positive busbar, the DC negative connector includes a DC negative busbar, and the bus midpoint connector includes a bus midpoint busbar. The DC positive busbar and the bus midpoint busbar are arranged opposite to each other, and the DC negative busbar and the bus midpoint busbar are arranged opposite to each other. Since the currents in the DC positive busbar and the midpoint busbar are in opposite directions after the three-level power module is powered on, the magnetic flux generated by the currents in the two buses is also in opposite directions. Setting the DC positive busbar and the midpoint busbar opposite to each other can cancel out the magnetic flux generated by the currents in the DC positive busbar and the midpoint busbar, thus reducing the stray inductance in the three-level power module. Similarly, since the currents in the DC negative busbar and the midpoint busbar are in opposite directions after the three-level power module is powered on, the magnetic flux generated by the currents in the two buses is also in opposite directions. Setting the DC negative busbar and the midpoint busbar opposite to each other can cancel out the magnetic flux generated by the currents in the DC negative busbar and the midpoint busbar, thus reducing the stray inductance in the three-level power module.
[0016] In an optional embodiment, the DC positive busbar and the DC negative busbar are located in the same plane. Placing the DC positive and DC negative buses in the same plane increases their area within that plane. The area of the busbar at the midpoint opposite to the DC positive and DC negative buses is also larger. This larger busbar area allows for greater magnetic flux cancellation, further reducing stray inductance in the three-level power module.
[0017] In an optional embodiment, the three-level power circuit includes a DC branch and an AC branch connected to the DC branch. The DC node is located on the DC branch, the AC output node is located on the AC branch, and the equipotential parallel node is located at the connection point of the DC branch and the AC branch. Since the potential at the connection point of the DC branch and the AC branch is simultaneously affected by the switching devices on both the DC and AC branches, placing the equipotential parallel node at the connection point can simultaneously reduce the influence of the switching devices on both the DC and AC branches on the potential at that connection point, thereby achieving a better effect in reducing circuit current unevenness.
[0018] In an optional embodiment, the three-level power circuit includes two symmetrically arranged half-bridge modules. For any half-bridge module, the DC branch includes two first switching devices located within the half-bridge module, and the equipotential parallel node is the connection node between the two first switching devices. The AC branch includes a second switching device located within the half-bridge module, with one end of the second switching device connected to the AC output node and the other end connected to the equipotential parallel node. Each half-bridge module in the three-level power circuit is a complete commutation loop. An equipotential parallel node is provided in each half-bridge module, allowing for potential adjustment of the commutation loop in each half-bridge module and reducing the uneven current distribution within each half-bridge module.
[0019] In an optional embodiment, the three-level power module further includes a substrate, with each half-bridge module disposed on the same substrate. Having each half-bridge module of the three-level power circuit on the same substrate can shorten the circuit length and area occupied by each half-bridge module, and reduce the distance between the switching devices within the half-bridge module. This reduced distance between the switching devices can decrease the induced electromotive force and stray inductance generated by the magnetic field.
[0020] In an optional embodiment, the first switching device includes a silicon carbide MOS transistor, and the second switching device includes an IGBT transistor. Since silicon carbide MOS transistors have high high-frequency reliability, including a silicon carbide MOS transistor as the first switching device (requiring high-frequency switching on the DC branch) can improve the high-frequency reliability of the three-level power module. Since IGBT transistors have lower cost and lower conduction losses, including an IGBT transistor as the second switching device (requiring only low-frequency switching on the AC branch) can reduce the manufacturing cost and conduction losses of the three-level power module.
[0021] Secondly, embodiments of this application provide a centralized energy storage device, including at least two three-level power modules as described above, wherein the equipotential parallel nodes at the same positions in the at least two three-level power modules are interconnected.
[0022] Compared with related technologies, the centralized energy storage device provided in this application embodiment connects at least two equipotential parallel nodes at the same position in the aforementioned three-level power modules to each other, thereby connecting at least two equipotential parallel nodes at the same position in the three-level power modules. This ensures that the potential at the equipotential parallel nodes at the same position in the at least two three-level power modules remains consistent, thereby reducing the uneven current distribution between the current paths in the at least two parallel three-level power modules and improving operational stability and safety.
[0023] Thirdly, embodiments of this application provide a centralized energy storage circuit, including multiple three-level power circuits. Each three-level power circuit includes multiple switching devices. Equipotential parallel nodes located at the same position in the multiple three-level power circuits are interconnected. The equipotential parallel nodes are located between the DC node and the AC output node, and are spaced apart from the DC node and the AC output node by at least one of the switching devices.
[0024] Compared with related technologies, the centralized energy storage circuit provided in this application includes at least two three-level power circuits, and connects the equipotential parallel nodes at the same position in the at least two three-level power circuits to each other, so that the potential at the equipotential parallel nodes at the same position in the at least two three-level power circuits is kept consistent. This reduces the uneven current between the current paths in the at least two parallel three-level power circuits and improves the operational stability and safety of the centralized energy storage circuit. Attached Figure Description
[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings.
[0026] Figure 1 is a schematic diagram of the structure of a three-level power module provided in an embodiment of this application;
[0027] Figure 2 is a schematic diagram of the circuit structure of the NPC topology circuit and the ANPC topology circuit provided in different embodiments of this application;
[0028] Figure 3 is a schematic diagram of a circuit structure in which multiple three-level power circuits are connected in parallel according to an embodiment of this application;
[0029] Figure 4 is a schematic diagram of a three-level power module structure provided in an embodiment of this application;
[0030] Figure 5 is a structural schematic diagram of the three-level power module shown in Figure 1 from different perspectives;
[0031] Figure 6 is a schematic diagram of the structure of a centralized energy storage device provided in an embodiment of this application. Embodiments of the present invention
[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0033] Therefore, the following detailed description of embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the present application.
[0034] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0035] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.
[0036] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.
[0037] The technical solutions provided in this application are applicable to any power electronic device comprising multiple parallel three-level power modules, such as high-frequency transformers, photovoltaic inverters, wind power converters, and centralized energy storage devices. All of these can utilize the three-level power modules, centralized energy storage devices, and centralized energy storage circuits provided in this application. Figure 1 shows a schematic diagram of a three-level power module provided in one embodiment of this application, including a three-level power circuit composed of multiple switching transistors (G1, G2, G3, G4, G5, G6) and diodes, and multiple connectors (21, 22, 23) connected to the three-level power circuit. In different embodiments of this application, the three-level power circuit is specifically a circuit structure formed by connecting switching transistors and diodes in a three-level topology, such as the ANPC topology or NPC topology shown in Figure 2.
[0038] In practical applications, taking the ANPC topology three-level power module as an example, the ANPC topology three-level power module includes at least one ANPC topology three-level power circuit 10 as shown in Figure 2, including multiple switching devices (switching transistors G1, G2, G3, G4, G5, G6, diodes T1, T2, T3, T4, T5, T6), DC nodes (DC positive node DC+, DC negative node DC-), and busbars. The system includes a DC node (N), an AC output node (AC), and equipotential parallel nodes (K1, K2), wherein the equipotential parallel nodes (K1, K2) are located between any of the DC nodes (DC positive node DC+, DC negative node DC-, and bus midpoint node N) and the AC output node (AC), and each of the equipotential parallel nodes (K1, K2) is spaced apart from any of the DC nodes (DC positive node DC+, DC negative node DC-, and bus midpoint node N) and the AC output node (AC) by at least one of the switching devices.
[0039] In this configuration, diode T1 is connected in anti-parallel to switch G1, diode T2 is connected in anti-parallel to switch G2, diode T3 is connected in anti-parallel to switch G3, diode T4 is connected in anti-parallel to switch G4, diode T5 is connected in anti-parallel to switch G5, and diode T6 is connected in anti-parallel to switch G6. Switches G1, G2, G3, and G4 are connected in series, and switches G5 and G6 are connected in series. Switches G5 and G6 are connected in parallel with switches G2 and G4. The input terminal of switch G1 is connected to a three-level power supply. The DC positive port (DC+) of the power circuit is connected. The output of switch G1 is connected to the input of switch G5 and the input of switch G2, respectively. The outputs of switch G6 and switch G3 are both connected to the input of switch G4. The output of switch G4 is connected to the DC negative port (DC-) of the three-level power circuit. The outputs of switch G5 and the input of switch G6 are connected to the bus midpoint port (N) of the three-level power circuit, respectively. The outputs of switch G2 and the input of switch G3 are connected to the AC output node (AC) of the three-level power circuit, respectively.
[0040] Referring to Figure 3, when multiple three-level power modules with ANPC topology are connected in parallel, the DC positive node DC+, DC negative node DC-, and bus midpoint node N of the multiple three-level power modules can be connected to each other, the AC output nodes AC of the multiple three-level power modules can be connected to each other, and the equipotential parallel nodes K1 and K2 of the multiple three-level power modules can be connected to each other to realize the parallel connection of multiple three-level power modules.
[0041] Because the related technologies only connect the DC positive port DC+, DC negative port DC-, bus midpoint port N, and AC output node of the three-level power module, and do not connect the equipotential parallel nodes K1 and K2 to each other, in each three-level topology circuit of the related technologies, at point K1, which is located between the DC positive port DC+ and the AC output node AC and is separated from the DC positive port DC+ and the AC output node AC by a switch, when switch G5 is off, the current path is DC positive port DC+, switch G1, point K1, switch G2, and AC output node AC. When switch G1 is off, the current path is bus midpoint port N, switch G5, point K1, switch G2, and AC output node AC. Therefore, regardless of the current path, the potential at point K1 will be affected by switch G1 or switch G5 and switch G2. Due to the possible differences in the physical performance of the switches in the three-level topology, the potential at point K1 will be different for each three-level topology under the influence of switches with different physical performance. Similarly, at point K2, which is located between the DC negative port DC- and the AC output node AC, and is separated from the DC negative port DC- and the AC output node AC by one switch, the potential at point K2 will be affected by switch G4 or switch G6 and switch G3. Under the influence of switches with different physical performance, the potential at point K2 will also be different for each three-level topology. Due to the potential difference between points K1 and K2, after multiple three-level topologies are connected in parallel, uneven current flow will occur in the different current paths of the different three-level topologies. As a result, the weaker current path in the multiple three-level topologies connected in parallel will bear greater electrical stress. Greater electrical stress makes it easier to cause current path failure, affecting the stability and safety of the power module operation.
[0042] This invention addresses the technical problem in related technologies where, when a three-level power module is used in parallel with other three-level power modules, uneven current flow occurs in the parallel current paths, affecting the stability and safety of operation. Referring to Figure 1, an embodiment of this application provides a three-level power module, including a three-level power circuit 10 and an equipotential parallel connector 21. The three-level power circuit 10 includes multiple switching devices, a DC node, an AC output node, and an equipotential parallel node. The equipotential parallel node is located between the DC node and the AC output node, and at least one of the switching devices is spaced between each equipotential parallel node and either the DC node or the AC output node. The equipotential parallel connector 21 is configured such that one end is connected to the equipotential parallel node, and the other end is connected to the equipotential parallel connectors of other three-level power modules.
[0043] Specifically, referring to Figures 2 and 3, the equipotential parallel node is the port connected to the middle point of the three-level power circuit 10. It is positioned between the DC node and the AC output node, allowing current to flow through it. Because it is positioned with at least one switching device between the DC node and the AC output node, the potential formed at the equipotential parallel node is affected by this switching device, resulting in different potentials at the same circuit location for different three-level power circuits 10. It can be understood that all points in the three-level power circuit 10 that satisfy these characteristics can be configured to form equipotential parallel nodes, and the number of equipotential parallel nodes in each three-level topology can be two or more. For example, the three-level power circuit 10 shown in Figures 2 and 3 can include two different equipotential parallel nodes, K1 and K2.
[0044] Among them, the equipotential parallel connector 21 is a conductor structure. The other end of the equipotential parallel connector 21 is configured to be connected to the equipotential parallel connector of other three-level power modules. That is, when the three-level power module is connected in parallel with other three-level power modules, the equipotential parallel connectors of different three-level power modules are connected to each other, thereby realizing the connection between equipotential parallel nodes at the same position in different three-level power modules through the equipotential parallel connector.
[0045] In addition, referring to Figure 1, the three-level power module may also include a drive control terminal 40 connected to a switching device. The drive control terminal 40 is used to control the closing and opening of the switching device connected thereto.
[0046] Compared with related technologies, the three-level power module provided in this application embodiment is additionally provided with an equipotential parallel connector 21. The equipotential parallel connector 21 is configured such that one end is connected to the equipotential parallel node (K1 or K2) of the three-level power circuit, and the other end is connected to the equipotential parallel connector of other three-level power modules. When the three-level power module is connected in parallel with other three-level power modules, the corresponding equipotential parallel connectors 21 on each three-level power module can be connected, thereby connecting the equipotential parallel nodes (K1, K2) in multiple three-level power modules. After the potential at the equipotential parallel nodes (K1, K2) in the multiple three-level power modules connected in parallel is kept consistent, the degree of uneven current between the current paths in the multiple three-level power modules connected in parallel can be reduced, and the operational stability and safety of the three-level power module can be improved.
[0047] In some embodiments of this application, referring to Figures 1 and 4, the three-level power module may further include a DC connector 22, an AC connector 23, and a package 30 encapsulating the three-level power circuit, the equipotential parallel connector 21, the DC connector 22, and the AC connector 23. One end of the DC connector 22 is connected to the DC node of the three-level power circuit 10, and the other end forms a DC connection terminal 221 on the outer surface of the package 30. One end of the AC connector 23 is connected to the AC output node of the three-level power circuit 10, and the other end forms an AC connection terminal 231 on the outer surface of the package 30. The DC connection terminal 221 and the AC connection terminal 231 are respectively disposed on opposite sides of the package 30.
[0048] In some embodiments of this application, the number of DC connectors 22 can be multiple, and the multiple different DC connectors 22 are respectively connected to different DC nodes. For example, in FIG1, the DC connectors 22 may include a DC positive connector 223 connected to the DC positive node DC+, a DC negative connector 224 connected to the DC negative node DC-, and a bus midpoint connector 225 connected to the bus midpoint node N. Among them, the DC positive connector 223 forms the terminal DC+, the DC negative connector 224 forms the terminal DC-, and the bus midpoint connector 225 forms the terminal N. The terminals DC+, DC-, and N are all DC connection terminals 221.
[0049] Referring to Figures 1 and 4, the DC connection terminal 221 and the AC connection terminal 231 are respectively located on opposite sides of the package 30. That is, the DC connection terminal 221 is concentrated on one side of the package 30, while the AC connection terminal 231 is located on the other side of the package 30, with the two spaced apart from each other.
[0050] It is understandable that, based on the overall shape of the package 30, its entire outer surface can be divided into multiple different outer wall surfaces. For example, the cubic package 30 shown in Figure 4 can include a top surface 31, a side surface 32, and a bottom surface 33 (not shown in Figure 4, see Figure 5). After penetrating the package 30, one end of the connector will be positioned on the outer surface of one of the outer wall surfaces to form a connection terminal. When connecting a three-level power module, the connection can be directly made to the connection terminal on the outer surface of the outer wall surface. The package 30 is specifically made of insulating material, such as injection molded material or rubber, thereby achieving mutual insulation between different connectors.
[0051] In different embodiments of this application, the DC connection terminal 221 and the AC connection terminal 231 can be specifically disposed on the same outer wall surface of the package 30 as shown in FIG. 5, such as the DC connection terminal 221 and the AC connection terminal 231 being disposed on the top surface 31. Alternatively, the DC connection terminal 221 and the AC connection terminal 231 can be disposed on different outer wall surfaces, such as the DC connection terminal 221 being disposed on the top surface 31 and the AC connection terminal 231 being disposed on the side surface 32; or the AC connection terminal 231 being disposed on the top surface 31 and the DC connection terminal 221 being disposed on the side surface 32, or other structures, as long as the DC connection terminal 221 and the AC connection terminal 231 are respectively disposed on opposite sides of the package 30.
[0052] Setting all the DC connection terminals 221 on the same side of the package 30 makes it easier to connect multiple three-level power modules in parallel. At the same time, setting the AC connection terminal 231 on the opposite side of the DC connection terminal 221 allows for a greater distance between the DC connection terminal 221 and the AC connection terminal 231, which reduces the mutual influence between them.
[0053] In some embodiments of this application, please continue to refer to Figures 1 and 4. One end of the equipotential parallel connector 21 is connected to the equipotential parallel nodes (K1, K2), and the other end forms an equipotential parallel terminal 211 on the outer surface of the package 30. The AC connection terminal 231 and the equipotential parallel terminal 211 are respectively disposed on two adjacent different outer wall surfaces in the package 30.
[0054] In this context, two adjacent different outer wall surfaces are two interconnected outer wall surfaces that share the same edge, such as the top surface 31 and side surface 32, the bottom surface 33 and side surface 32, and two adjacent parts within side surface 32, etc., are all adjacent different outer wall surfaces. Specifically, the AC connection terminal 231 and the equipotential parallel terminal 211 can be respectively disposed on two adjacent different outer wall surfaces within the package 30. For example, as shown in Figure 4, the AC connection terminal 231 can be disposed on the top surface 31, and the equipotential parallel terminal 211 on the adjacent side surface 32; or the AC connection terminal 231 can be disposed on the side surface 32, and the equipotential parallel terminal 211 on the top surface 31; or other structures can be used, such as distributing the AC connection terminal 231 and the equipotential parallel terminal 211 on two adjacent different side surfaces 32.
[0055] By placing the AC connection terminal 231 and the equipotential parallel terminal 211 on two adjacent and different outer wall surfaces within the package 30, the arrangement of the equipotential parallel connector 21 can be optimized, reducing the internal space occupied by the equipotential parallel connector 21 and decreasing the volume of the three-level power module. Furthermore, by placing the AC connection terminal 231 and the equipotential parallel terminal 211 on different planes, the mutual influence between the AC connection terminal 231 and the equipotential parallel terminal 211 can be reduced.
[0056] In some embodiments of this application, the DC connection terminal 221, the AC connection terminal 231, and the equipotential parallel terminal 211 may be disposed on the same outer wall surface of the package 30, with the equipotential parallel terminal 211 located between the DC connection terminal 221 and the AC connection terminal 231.
[0057] Specifically, for example, the DC connection terminal 221, the AC connection terminal 231, and the equipotential parallel terminal 211 can be jointly disposed on the top surface 31, or the DC connection terminal 221, the AC connection terminal 231, and the equipotential parallel terminal 211 can be jointly disposed on the side surface 32, etc.
[0058] Furthermore, the equipotential parallel terminal 211 located between the DC connection terminal 221 and the AC connection terminal 231 can specifically be located at the midpoint between the DC connection terminal 221 and the AC connection terminal 231. Alternatively, in some other embodiments of this application, the equipotential parallel terminal 211 can be located in the region between the DC connection terminal 221 and the AC connection terminal 231, near the DC connection terminal 221 or near the AC connection terminal 231, etc.
[0059] By placing the DC connection terminal 221, the AC connection terminal 231, and the equipotential parallel terminal 211 on the same outer wall surface of the package 30, i.e., on the same plane, it is easier to connect each terminal when multiple three-level power modules are connected in parallel. In addition, since the current at the DC connection terminal 221 and the AC connection terminal 231 is relatively large, the mutual influence between them is also greater. By placing the equipotential parallel terminal 211 between the DC connection terminal 221 and the AC connection terminal 231, the distance between the DC connection terminal 221 and the AC connection terminal 231 can be increased. The greater distance can better reduce the mutual influence between the DC connection terminal 221 and the AC connection terminal 231.
[0060] In some embodiments of this application, please continue to refer to FIG4. The three-level power module further includes a baffle 50 disposed on the package 30. The baffle 50 is disposed between the DC connection terminal 221, the AC connection terminal 231 and the equipotential parallel terminal 211.
[0061] The barrier 50 is an insulating material disposed on the outer surface of the encapsulation body 30, such as injection molding or rubber. Depending on the material, the barrier 50 can be manufactured using different methods. For example, it can be integrally molded with the encapsulation body 30 by injection molding, or it can be disposed on the outer surface of the encapsulation body 30 using insulating adhesive, screws, or other structures.
[0062] The length of the retaining wall 50 in its extending direction is greater than the lengths of the DC connection terminal 221, the AC connection terminal 231, and the equipotential parallel terminal 211 in the same direction. That is, for any point on the DC connection terminal 221, a straight line connecting it to any point on the AC connection terminal 231 or the equipotential parallel terminal 211 must pass through the retaining wall 50. Similarly, for any point on the AC connection terminal 231, a straight line connecting it to any point on the DC connection terminal 221 or the equipotential parallel terminal 211 must pass through the retaining wall 50. And for any point on the equipotential parallel terminal 211, a straight line connecting it to any point on the DC connection terminal 221 or the AC connection terminal 231 must pass through the retaining wall 50. In this way, the retaining wall 50 can more completely block the connection between the DC connection terminal 221, the AC connection terminal 231, and the equipotential parallel terminal 211, improving the blocking effect of the retaining wall 50.
[0063] Similarly, in the height direction relative to the outer surface of the package 30, the height of the barrier 50 is greater than the height of the DC connection terminal 221, the AC connection terminal 231, and the equipotential parallel terminal 211. This allows for more complete obstruction between the DC connection terminal 221, the AC connection terminal 231, and the equipotential parallel terminal 211 in the height direction, improving the blocking effect of the barrier 50.
[0064] A barrier 50 is provided between the DC connection terminal 221, the AC connection terminal 231, and the equipotential parallel terminal 211. The barrier 50 can separate the DC connection terminal 221, the AC connection terminal 231, and the equipotential parallel terminal 211, increasing the electrical clearance and creepage distance between them, and reducing the mutual influence between them.
[0065] In some embodiments of this application, please continue to refer to FIG1. The DC connector 22 also forms a capacitor connection terminal 222 on the outer surface of the package 30. The capacitor connection terminal 222 is used to connect the DC end absorption capacitor. The DC connection terminal 221 and the capacitor connection terminal 222 are respectively disposed on two adjacent different outer wall surfaces of the package 30.
[0066] In this context, two adjacent different outer wall surfaces are two interconnected outer wall surfaces that share the same edge. Examples include the top surface 31 and the side surface 32, the bottom surface 33 and the side surface 32, and two adjacent portions of the side surface 32. Specifically, the DC connection terminal 221 and the capacitor connection terminal 222 can be respectively disposed on two adjacent different outer wall surfaces within the package 30. For example, as shown in Figure 1, the DC connection terminal 221 can be disposed on the top surface 31 and the capacitor connection terminal 222 on the adjacent side surface 32; or the DC connection terminal 221 can be disposed on the side surface 32 and the capacitor connection terminal 222 on the top surface 31; or the DC connection terminal 221 and the capacitor connection terminal 222 can be respectively disposed on two adjacent different side surfaces 32, or other structures.
[0067] Further, referring to FIG1, in the embodiments of this application, for each of the multiple independent DC connectors 22 connected to different DC nodes (DC+, DC-, N), each DC connector 22 may have a DC connection terminal 221 and a capacitor connection terminal 222 formed on the outer surface of the package 30, that is, each DC connector 22 includes at least one DC connection terminal 221 and at least one capacitor connection terminal 222.
[0068] By providing a capacitor connection terminal 222 on the side 32 adjacent to the DC connection terminal 221, the distance between the DC end absorption capacitor connected to the capacitor connection terminal 222 and the three-level power module can be reduced. The reduction in the distance between the DC end absorption capacitor and the three-level power module can reduce the distance between the DC end absorption capacitor and the switching devices in the three-level power module, thereby achieving a better voltage spike absorption effect.
[0069] In some embodiments of this application, please refer to FIG5. The three-level power module further includes a temperature control component 60, and the temperature control component 60 and the capacitor connection terminal 222 are respectively disposed on two adjacent outer wall surfaces of the package 30.
[0070] The temperature control component 60 is a structure for regulating the temperature of the three-level power module. In practical applications, since the three-level power module generates heat after being powered on, temperature control of the three-level power module usually involves heat dissipation. Based on this, referring to Figure 5, the temperature control component 60 can be, for example, a grid-like heat dissipation structure. Alternatively, in some other embodiments of this application, the temperature control component 60 can also be a liquid cooling device such as a water-cooled substrate. It is understood that the temperature control component 60 typically being a heat dissipation structure is merely an example for some common application scenarios in this application. In some special application scenarios with extremely low temperatures, the self-heating of the three-level power module is insufficient to maintain normal operating temperature; in this case, the temperature control component 60 can also include a heat-generating component.
[0071] By placing the temperature control component 60 on the outer wall surface adjacent to the capacitor connection terminal 222, the distance between the DC end absorption capacitor and the temperature control component 60 can be reduced. The temperature control component 60 can also assist the DC end in temperature control, thereby improving the reliability and service life of the DC end absorption capacitor.
[0072] In some embodiments of this application, please continue to refer to FIG1. The DC connector 22 includes a DC positive connector 223 connected to the DC positive port DC+ of the three-level power circuit 10, a DC negative connector 224 connected to the DC negative port DC- of the three-level power circuit 10, and a bus midpoint connector 225 connected to the bus midpoint port N of the three-level power circuit 10. The DC positive connector 223 includes a DC positive busbar 2231, the DC negative connector 224 includes a DC negative busbar 2241, and the bus midpoint connector 225 includes a bus midpoint busbar 2251. The DC positive busbar 2231 and the bus midpoint busbar 2251 are arranged opposite to each other, and the DC negative busbar 2241 and the bus midpoint busbar 2251 are arranged opposite to each other.
[0073] As shown in Figure 1, the busbar is a large sheet-like area within the DC connector 22. Each DC connector 22 may specifically include a strip structure for connecting to a DC node, a strip structure for setting DC terminals, and a plate-like busbar disposed between these two strip structures. Specifically, the busbar disposed in the DC positive connector 223 is the DC positive busbar 2231, the busbar disposed in the DC negative connector 224 is the DC negative busbar 2241, and the busbar disposed in the bus midpoint connector 225 is the bus midpoint busbar 2251.
[0074] Furthermore, the DC positive busbar 2231 and the bus midpoint busbar 2251 are arranged opposite each other specifically such that the extension surfaces of the DC positive busbar 2231 and the bus midpoint busbar 2251 are the same and face each other in the vertical direction of their extension surfaces. One of the orthographic projections of the DC positive busbar 2231 on its extension surface and the orthographic projections of the bus midpoint busbar 2251 on its extension surface completely cover the other. For example, the orthographic projection of the DC positive busbar 2231 on its extension surface can completely cover the orthographic projection of the bus midpoint busbar 2251 on its extension surface, or the orthographic projection of the bus midpoint busbar 2251 on its extension surface can completely cover the orthographic projection of the DC positive busbar 2231 on its extension surface.
[0075] Similarly, the DC negative busbar 2241 and the bus midpoint busbar 2251 are arranged opposite each other, specifically, the extension surfaces of the DC negative busbar 2241 and the bus midpoint busbar 2251 are the same and face each other in the vertical direction of their extension surfaces. One of the orthographic projections of the DC negative busbar 2241 on its extension surface and the orthographic projections of the bus midpoint busbar 2251 on its extension surface completely cover the other. For example, the orthographic projection of the DC negative busbar 2241 on its extension surface can completely cover the orthographic projection of the bus midpoint busbar 2251 on its extension surface, or the orthographic projection of the bus midpoint busbar 2251 on its extension surface can completely cover the orthographic projection of the DC negative busbar 2241 on its extension surface.
[0076] Furthermore, the DC negative busbar 2241, DC positive busbar 2231, and busbar midpoint busbar 2251 can be positioned arbitrarily in the vertical direction of their extension surfaces. They can be stacked on top of each other or staggered.
[0077] Since the currents in the DC positive busbar 2231 and the bus midpoint busbar 2251 are in opposite directions after the three-level power module is powered on, the magnetic flux generated by the currents in the two busbars is also in opposite directions. Setting the DC positive busbar 2231 and the bus midpoint busbar 2251 opposite to each other can cancel out the magnetic flux generated by the currents in the DC positive busbar 2231 and the bus midpoint busbar 2251, thus reducing the stray inductance in the three-level power module. Similarly, since the currents in the DC negative busbar 2241 and the bus midpoint busbar 2251 are in opposite directions after the three-level power module is powered on, the magnetic flux generated by the currents in the DC negative busbar 2241 and the bus midpoint busbar 2251 is also in opposite directions. Setting the DC negative busbar 2241 and the bus midpoint busbar 2251 opposite to each other can cancel out the magnetic flux generated by the currents in the DC negative busbar 2241 and the bus midpoint busbar 2251, thus reducing the stray inductance in the three-level power module.
[0078] In some embodiments of this application, as shown in FIG1, the DC positive busbar 2231 and the DC negative busbar 2241 are located in the same plane.
[0079] In this configuration, the DC positive busbar 2231 and the DC negative busbar 2241 are located in the same plane, meaning that the extension surfaces of the DC positive busbar 2231 and the DC negative busbar 2241 are on the same plane. Furthermore, when the DC positive busbar 2231 is positioned opposite the bus midpoint busbar 2251, and the DC negative busbar 2241 is positioned opposite the bus midpoint busbar 2251, meaning the bus midpoint busbar 2251 needs to be simultaneously aligned with both the DC positive busbar 2231 and the DC negative busbar 2241 on the same plane, the orthographic projection of the bus midpoint busbar 2251 on its extension surface can completely encompass the orthographic projections of both the DC positive busbar 2231 and the DC negative busbar 2241 on their respective extension surfaces.
[0080] By placing the DC positive busbar 2231 and the DC negative busbar 2241 in the same plane, their areas are larger. The area of the busbar midpoint busbar 2251, which is opposite to the DC positive busbar 2231 and the DC negative busbar 2241, is also larger. The larger busbar area allows more magnetic flux to cancel each other out, further reducing stray inductance in the three-level power module.
[0081] In some embodiments of this application, as shown in FIG2, the three-level power circuit 10 of the ANPC topology may specifically include a DC branch 11 and an AC branch 12 connected to the DC branch 11. The DC nodes (DC+, DC-, N) are set on the DC branch 11, the AC output node AC is set on the AC branch 12, and the equipotential parallel nodes (K1, K2) are set at the connection point of the DC branch 11 and the AC branch 12.
[0082] The DC branch 11 is the part of the circuit connected to the DC nodes (DC+, DC-, N), and the current in it is direct current. Regardless of the state of each switching device, as long as there is current, its direction remains constant. The AC branch 12 is the part of the circuit connected to the AC output node AC, and the current in it is alternating current. The direction of the current in the AC branch 12 changes as the state of the switching devices changes.
[0083] Since the potential at the connection point of DC branch 11 and AC branch 12 is affected by the switching devices on both DC branch 11 and AC branch 12, setting the equipotential parallel nodes (K1, K2) at the connection point of DC branch 11 and AC branch 12 can simultaneously reduce the influence of the switching devices on DC branch 11 and AC branch 12 on the potential at this connection point, thus achieving a better effect of reducing the uneven current distribution in the circuit.
[0084] In some embodiments of this application, please continue to refer to Figure 2. The three-level power circuit 10 may also include two symmetrically arranged half-bridge modules 13. For any half-bridge module 13, the DC branch 11 includes two first switching devices (switching transistors G1 and G5, or switching transistors G4 and G6) within the half-bridge module 13. The equipotential parallel node (K1 or K2) is the connection node of the two first switching devices (switching transistors G1 and G5, or switching transistors G4 and G6). The AC branch 12 includes a second switching device (switching transistor G2 or G3) within the half-bridge module 13. One end of the second switching device (switching transistor G2 or G3) is connected to the AC output node (K1 or K2), and the other end is connected to the equipotential parallel node AC.
[0085] Each half-bridge module 13 in the three-level power circuit is a complete commutation circuit. Each half-bridge module 13 is equipped with an equipotential parallel node (K1 or K2), which can adjust the potential of the commutation circuit of each half-bridge module 13 and reduce the uneven current of each half-bridge module 13.
[0086] In some embodiments of this application, please refer to FIG1. The three-level power module further includes a liner 70, and each of the half-bridge modules 13 is disposed on the same liner 70.
[0087] Specifically, the backing plate 70 can be a copper-clad ceramic backing plate. The switching devices can be connected to the copper-clad area of the copper-clad ceramic backing plate by means of sintering, welding or other methods. When the connector is connected to each switching device in the three-level power circuit 20, the connector can be first encapsulated to form an encapsulated assembly. Then, the encapsulated assembly is connected to the copper-clad area of the copper-clad ceramic backing plate by means of ultrasonic welding or other methods. The connection between the connector and the three-level power circuit 10 is realized through the copper-clad area of the copper-clad ceramic backing plate.
[0088] Specifically, one half-bridge module 13 is a current loop in the three-level power circuit 10. In the three-level power circuit 10 with the ANPC topology shown in Figure 3, half-bridge modules 13 including switches G1, G2, and G5 together form a current loop, and half-bridge modules 13 including switches G3, G4, and G6 together form a current loop.
[0089] The switching devices on each half-bridge module 13 of the three-level power circuit 10 are arranged on the same substrate 70. For example, switching transistors G1, G2, and G5 can be arranged on one substrate 70, while switching transistors G3, G4, and G6 can be arranged on another substrate 70.
[0090] Furthermore, for copper-clad ceramic backing plates, the same backing plate 70 refers to the backing plate 70 that connects the copper-clad areas, and is not limited to the same complete backing plate 70. Two copper-clad ceramic backing plates that connect the copper-clad areas via a bridge structure are also the same backing plate 70.
[0091] Each half-bridge module 13 of the three-level power circuit is on the same substrate 70, which can shorten the circuit length and area occupied by the half-bridge module 13, and bring the distance between each switching device in the half-bridge module 13 closer. The reduced distance between each switching device can reduce the induced electromotive force and stray inductance generated by magnetic field induction.
[0092] In some embodiments of this application, please continue to refer to Figures 1 and 3. The first switching device includes a silicon carbide MOS transistor, and the second switching device includes an IGBT transistor.
[0093] Specifically, switching transistors G1, G4, G5, and G6 are silicon carbide MOS transistors, switching transistors G2 and G3 are IGBT transistors, and diodes T1, T2, T3, T4, T5, and T6 are FRDs (Fast recovery diodes).
[0094] Because silicon carbide MOS transistors have high high-frequency reliability, using silicon carbide MOS transistors for the high-frequency switching transistors G1, G4, G5, and G6 on the DC branch 11 can improve the high-frequency reliability of the three-level power module. Because IGBT transistors have low cost and low conduction loss, using IGBT transistors for the low-frequency switching transistors G2 and G3 on the AC branch 12 can reduce the manufacturing cost and conduction loss of the three-level power module. Because FRDs have low cost, using diodes T1, T2, T3, T4, T5, and T6 as FRDs can also reduce the manufacturing cost of the three-level power module.
[0095] This application also provides a centralized energy storage device, as shown in FIG6, which includes at least two three-level power modules as provided in the foregoing embodiments, wherein equipotential parallel nodes at the same position in the at least two three-level power modules are interconnected.
[0096] In this context, the equipotential parallel terminals at the same location are the equipotential parallel nodes connected to the equipotential parallel nodes at the same circuit location (i.e., the same connection method as other switching devices) in each three-level power module when the three-level power module includes multiple equipotential parallel nodes. For example, the equipotential parallel nodes K1 of each three-level power module in multiple three-level power modules are interconnected, and the equipotential parallel nodes K2 of each three-level power module in multiple three-level power modules are interconnected, etc.
[0097] In addition, as shown in Figure 6, the same DC connection terminals of at least two three-level power modules can be connected to each other (DC+ connects to DC+, DC- connects to DC-, N connects to N), and the AC connection terminals of at least two three-level power modules can be connected to each other to realize the parallel connection of at least two three-level power modules.
[0098] Compared with related technologies, the centralized energy storage device provided in this application embodiment connects at least two equipotential parallel nodes at the same position in the aforementioned three-level power modules to each other, thereby connecting at least two equipotential parallel nodes at the same position in the three-level power modules. This ensures that the potential at the equipotential parallel nodes at the same position in the at least two three-level power modules remains consistent, thereby reducing the uneven current distribution between the current paths in the at least two parallel three-level power modules and improving the stability and safety of the centralized energy storage device operation.
[0099] This application embodiment also provides a centralized energy storage circuit, as shown in FIG3, including at least two three-level power circuits 101 and 102. Each three-level power circuit includes multiple switching devices (switching transistors G1, G2, G3, G4, G5, G6, diodes T1, T2, T3, T4, T5, T6). Equipotential parallel nodes K1 and K2 located at the same position in the multiple three-level power circuits are interconnected. The equipotential parallel node K1 is located between the DC positive port DC+ and the AC output node AC of the three-level power circuit, and is separated from the DC positive port DC+ and the AC output node AC by at least one switching device. And / or the equipotential parallel node K2 is located between the DC negative port DC- and the AC output node AC of the three-level power circuit, and is separated from the DC negative port DC- and the AC output node AC by at least one switching device.
[0100] In this embodiment, the equipotential parallel nodes located at the same position in multiple three-level power circuits are connected to each other. Specifically, the equipotential parallel node K1 in the three-level power circuit 101 is connected to the equipotential parallel node K1 in the three-level power circuit 102, and the equipotential parallel node K2 in the three-level power circuit 101 is connected to the equipotential parallel node K2 in the three-level power circuit 102.
[0101] Compared with related technologies, the centralized energy storage circuit provided in this application includes at least two three-level power circuits. By connecting the equipotential parallel nodes at the same location in the at least two three-level power circuits to each other, the potential at the equipotential parallel nodes at the same location in the at least two three-level power circuits is kept consistent. This reduces the uneven current distribution between the current paths in the at least two parallel three-level power circuits and improves the operational stability and safety of the centralized energy storage circuit.
[0102] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A three-level power module, characterized in that, include: The three-level power circuit includes multiple switching devices, a DC node, an AC output node, and an equipotential parallel node. The equipotential parallel node is located between the DC node and the AC output node, and at least one of the switching devices is spaced between the equipotential parallel node and both the DC node and the AC output node. An equipotential parallel connector is configured such that one end is connected to the equipotential parallel node and the other end is connected to the equipotential parallel connector of other three-level power modules.
2. The three-level power module according to claim 1, characterized in that, The three-level power module also includes: DC connector, AC connector, and a package that encapsulates the three-level power circuit, the equipotential parallel connector, the DC connector, and the AC connector; One end of the DC connector is connected to the DC node, and the other end forms a DC connection terminal on the outer surface of the package. One end of the AC connector is connected to the AC output node, and the other end forms an AC connection terminal on the outer surface of the package. The DC connection terminal and the AC connection terminal are respectively disposed on opposite sides of the package.
3. The three-level power module according to claim 2, characterized in that, One end of the equipotential parallel connector is connected to the equipotential parallel node, and the other end forms an equipotential parallel terminal on the outer surface of the package. The AC connection terminal and the equipotential parallel terminal are respectively disposed on two adjacent and different outer wall surfaces in the package.
4. The three-level power module according to claim 2, characterized in that, The DC connection terminal, the AC connection terminal, and the equipotential parallel terminal are disposed on the same outer wall surface of the package, and the equipotential parallel terminal is located between the DC connection terminal and the AC connection terminal.
5. The three-level power module according to claim 4, characterized in that, The DC connection terminal, the AC connection terminal, and the equipotential parallel terminal are all disposed on the top surface, or the DC connection terminal, the AC connection terminal, and the equipotential parallel terminal are all disposed on the side surface.
6. The three-level power module according to claim 3 or 4, characterized in that, The three-level power module also includes a baffle wall disposed on the outer surface of the package, the baffle wall being disposed between the DC connection terminal, the AC connection terminal, and the equipotential parallel terminal.
7. The three-level power module according to claim 6, characterized in that, The length of the retaining wall in its extending direction is greater than the length of the DC connection terminal, the AC connection terminal, and the equipotential parallel terminal in the same direction.
8. The three-level power module of claim 6, wherein, In the height direction relative to the outer surface of the package body, the height of the barrier is greater than the height of the DC connection terminal, the AC connection terminal, and the equipotential parallel terminal.
9. The three-level power module of claim 2, wherein, The DC connector also forms a capacitor connection terminal on the outer surface of the package, the capacitor connection terminal being configured to connect to a DC end absorption capacitor, and the DC connection terminal and the capacitor connection terminal being respectively disposed on two adjacent different outer wall surfaces in the package.
10. The three-level power module according to claim 9, characterized in that, The three-level power module also includes a temperature control component, and the temperature control component and the capacitor connection terminal are respectively disposed on two adjacent outer wall surfaces in the package.
11. The three-level power module according to claim 2, characterized in that, The DC node includes a DC positive node, a DC negative node, and a bus midpoint node; The DC connector includes a DC positive connector connected to the DC positive node, a DC negative connector connected to the DC negative node, and a bus midpoint connector connected to the bus midpoint node. The DC positive connector includes a DC positive busbar, the DC negative connector includes a DC negative busbar, and the bus midpoint connector includes a bus midpoint busbar. The DC positive busbar and the bus midpoint busbar are arranged opposite to each other, and the DC negative busbar and the bus midpoint busbar are arranged opposite to each other.
12. The three-level power module according to claim 11, characterized in that, The DC positive busbar and the DC negative busbar are located in the same plane.
13. The three-level power module according to claim 2, characterized in that, All DC connection terminals are uniformly located on the same side of the package, while AC connection terminals are located on the opposite side of the DC connection terminals.
14. The three-level power module according to claim 2, characterized in that, The encapsulation body is made of insulating material.
15. The three-level power module according to claim 1, characterized in that, The three-level power circuit includes a DC branch and an AC branch connected to the DC branch. The DC node is located on the DC branch, the AC output node is located on the AC branch, and the equipotential parallel node is located at the connection point of the DC branch and the AC branch.
16. The three-level power module according to claim 15, characterized in that, The three-level power circuit includes two symmetrically arranged half-bridge modules; For any of the half-bridge modules, the DC branch includes two first switching devices located within the half-bridge module, and the equipotential parallel node is the connection node of the two first switching devices. The AC branch includes a second switching device located within the half-bridge module, with one end of the second switching device connected to the AC output node and the other end connected to the equipotential parallel node.
17. The three-level power module of claim 16, wherein, The three-level power module also includes a substrate, with each half-bridge module mounted on the same substrate.
18. The three-level power module according to claim 16, characterized in that, The first switching device includes a silicon carbide MOS transistor, and the second switching device includes an IGBT transistor.
19. A centralized energy storage device, characterized in that, It includes at least two three-level power modules as described in any one of claims 1 to 18, wherein the equipotential parallel nodes at the same position in the at least two three-level power modules are interconnected.
20. A centralized energy storage circuit, characterized in that, The device includes multiple three-level power circuits, each of which includes multiple switching devices. Equipotential parallel nodes located at the same position in the multiple three-level power circuits are interconnected. The equipotential parallel nodes are located between the DC node and the AC output node, and are spaced apart from the DC node and the AC output node by at least one of the switching devices.