Power module of power electronic transformer and power electronic transformer

Abstract

The invention discloses a power module of a power electronic transformer and the power electronic transformer, relates to the technical field of power electronic transformers, and aims to increase the output capacity. The power module of the power electronic transformer comprises a rectification unit and at least one direct current conversion unit group. The rectifying unit comprises a first input end, a second input end, a first output end and a second output end. The direct current conversion unit group comprises a plurality of direct current conversion units, each direct current conversion unit comprises a third input end, a fourth input end, a third output end and a fourth output end, and the third input ends of the plurality of direct current conversion units are connected in parallel and are connected with the first output end of one rectification unit. The fourth input ends of the plurality of DC conversion units are connected in parallel and are connected with the second output end of one rectification unit. The third output ends of the plurality of DC conversion units are connected in parallel. The fourth output ends of the plurality of DC conversion units are connected in parallel. The power module of the power electronic transformer is used for the power electronic transformer.

Description

Technical Field

[0001] The present application relates to the technical field of power electronic transformers, and in particular to a power electronic transformer power module and a power electronic transformer. Background Art

[0002] Power Electronic Transformer (PET) is a new type of intelligent transformer that combines power electronic conversion technology with electric energy conversion technology based on the principle of electromagnetic induction to convert electric energy of one power characteristic into electric energy of another power characteristic. Compared with traditional distribution transformers, power electronic transformers have higher power conversion efficiency and output controllability, and are conducive to miniaturization of the device and cost savings.

[0003] At present, the topological structure of power electronic transformer mainly adopts the form of one-to-one correspondence between rectifier unit and DC conversion unit, and the input side is connected in series with voltage division and the output side is connected in parallel on the same bus. However, in the face of loads of various capacities, this kind of power electronic transformer cannot achieve the expansion of output capacity, resulting in poor system flexibility. Summary of the invention

[0004] The present application provides a power electronic transformer power module and a power electronic transformer, which are used to solve the problem in the related art that the power electronic transformer cannot achieve expanded output capacity.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions:

[0006] In a first aspect, the present application provides a power electronic transformer power module, comprising a rectifier unit and at least one DC conversion unit group. The rectifier unit comprises a first input terminal, a second input terminal, a first output terminal and a second output terminal, wherein the first input terminal and the second input terminal are configured to connect to alternating current. The DC conversion unit group comprises a plurality of DC conversion units, wherein the DC conversion unit comprises a third input terminal, a fourth input terminal, a third output terminal and a fourth output terminal, wherein the third input terminals of the plurality of DC conversion units are connected in parallel and connected to the first output terminal of one of the rectifier units. The fourth input terminals of the plurality of DC conversion units are connected in parallel and connected to the second output terminal of one of the rectifier units. The third output terminals of the plurality of DC conversion units are connected in parallel and configured to be connected to a first output interface. The fourth output terminals of the plurality of DC conversion units are connected in parallel and configured to be connected to a second output interface.

[0007] In this case, a rectifier unit is connected to at least one DC conversion unit group, and the DC conversion unit group includes multiple DC conversion units arranged in parallel. In this way, the output capacity of the first output interface and the second output interface can be increased simply by increasing the number of DC conversion units, thereby enhancing system flexibility.

[0008] In some embodiments, the power electronic transformer power module includes a plurality of the DC conversion unit groups, and the third output terminals of the DC conversion units belonging to different DC conversion unit groups are configured to be connected to different first output interfaces. The fourth output terminals of the DC conversion units belonging to different DC conversion unit groups are configured to be connected to different second output interfaces. In this case, multiple DC conversion unit groups are connected to multiple output interface groups, so that multiple loads can be connected, further improving system flexibility.

[0009] In some embodiments, the third input terminals of the DC conversion units belonging to different DC conversion unit groups are connected in parallel and connected to the first output terminal of one of the rectifier units. The fourth input terminals of the DC conversion units belonging to different DC conversion unit groups are connected in parallel and connected to the second output terminal of one of the rectifier units. In this case, multiple DC conversion unit groups are connected in parallel with one rectifier unit, which reduces the number of rectifier units in the power module, helps improve system integration, and reduces production costs.

[0010] In some embodiments, the rectifier unit includes two three-level topology circuits, the three-level topology circuits include a first topology input terminal, a first topology output terminal and a second topology output terminal, the first input terminal and the second input terminal are respectively connected to the first topology input terminals of the two three-level topology circuits. The first topology output terminals of the two three-level topology circuits are connected in parallel and connected to the first output terminal. The second topology output terminals of the two three-level topology circuits are connected in parallel and connected to the second output terminal. At this time, the three-level topology circuit can reduce the voltage stress borne by the power devices in the circuit during the switching process, thereby reducing the risk of damage to the power devices due to overvoltage, extending the service life of the power devices, and improving the reliability and stability of the entire power module. At the same time, the three-level topology circuit enables a single power module to handle higher voltage and power. In this way, when the same power output requirements are achieved, the number of power modules required will be reduced accordingly, thereby reducing the hardware cost of the system and improving the cost performance of the system.

[0011] In some embodiments, the DC conversion unit includes a three-level topology circuit, two diodes in series, a conversion circuit and a full-bridge topology circuit, and the three-level topology circuit includes a first topology input terminal, a first topology output terminal and a second topology output terminal. One end of the two diodes in series is connected to the first topology output terminal, and the other end is connected to the second topology output terminal, and the connection point of the two diodes in series is a first node. The conversion circuit includes a first conversion input terminal, a second conversion input terminal, a first conversion output terminal and a second conversion output terminal, the first conversion input terminal is connected to the first topology input terminal, and the second conversion input terminal is connected to the first node. The full-bridge topology circuit includes a second topology input terminal, a third topology input terminal, a third topology output terminal and a fourth topology output terminal, the second topology input terminal is connected to the first conversion output terminal, the third topology input terminal is connected to the second conversion output terminal, the third topology output terminal is connected to the third output terminal, and the fourth topology output terminal is connected to the fourth output terminal.

[0012] In this case, the three-level topology circuit can reduce the voltage stress that the power devices in the circuit are subjected to during the switching process, thereby reducing the risk of damage to the power devices due to overvoltage, extending the service life of the power devices, and improving the reliability and stability of the entire power module. The two diodes in series can act as voltage clamps. When a voltage spike or overvoltage occurs, the diode can limit the voltage rise and protect the power devices in the subsequent circuit from damage by excessive voltage. The conversion circuit can realize the conversion between different voltage levels or current forms. The full-bridge topology circuit can flexibly realize the size adjustment of DC or voltage.

[0013] In some embodiments, the DC conversion unit group also includes multiple current sensors, one end of one of the current sensors is connected to the third output end of one of the DC conversion units, and the other end is configured to be connected to one of the first output interfaces to achieve overcurrent protection for the DC conversion unit and power balancing control of different DC conversion units, thereby improving the reliability and flexibility of the system.

[0014] On the other hand, a power electronic transformer is provided, comprising the power electronic transformer power module provided in the first aspect. The power electronic transformer further comprises an input interface group and an output interface group, the input interface group comprises a first input interface and a second input interface, the first input interface is connected to the first input end of the rectifier unit, and the second input interface is connected to the second input end of the rectifier unit. The output interface group comprises a first output interface and a second output interface, the first output interface is connected to the third output end of the DC conversion unit, and the second output interface is connected to the fourth output end of the DC conversion unit.

[0015] In some embodiments, the power electronic transformer includes a first connecting line, a plurality of power electronic transformer power modules, a first bus, a second bus, and a first switch circuit. The rectifier units of the plurality of power electronic transformer power modules are cascaded through the first connecting line. Moreover, in two adjacent power electronic transformer power modules, one end of the first connecting line is connected to the first input end of the rectifier unit of the power electronic transformer power module of the previous level, and the other end is connected to the second input end of the rectifier unit of the power electronic transformer power module of the next level. The first input interface is connected to the first input end of the rectifier unit of the power electronic transformer power module of the first level through the first bus. The second input interface is connected to the second input end of the rectifier unit of the power electronic transformer power module of the last level through the second bus. The first switch circuit is connected to the first input end and the second input end of the rectifier unit of each power electronic transformer power module.

[0016] In some embodiments, the power electronic transformer further comprises a plurality of circuit boards, and a plurality of power modules of the power electronic transformer are integrated on the circuit boards. The plurality of circuit boards are arranged in sequence along a first direction. The first direction is perpendicular to the plane where the circuit boards are located.

[0017] In some embodiments, the power electronic transformer also includes a shell, the shell includes a first sub-shell and a second sub-shell, the first sub-shell is arranged in the second sub-shell, and the power module of the power electronic transformer is arranged in the second sub-shell. The material of the first sub-shell includes a conductive material, and the material of the second sub-shell includes an insulating material. At this time, the power module of the power electronic transformer is protected and the risk of being damaged by external forces is reduced. At the same time, it can ensure that the internal circuit of the power module can operate in a stable electrical environment, thereby improving the reliability and stability of the power electronic transformer. In addition, the current leaked from the power module due to insulation aging, component damage, etc. can flow into the ground, avoiding the risk of electric shock for maintenance personnel, and preventing the current from affecting other components that are working normally.

[0018] The above-mentioned power electronic transformer has the same structure and beneficial technical effects as the power electronic transformer power module provided in the first aspect, which will not be repeated here.

[0019] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application, and do not constitute an improper limitation on the present application.

[0021] Figure 1 A structural block diagram of a power electronic transformer provided in an embodiment of the present application;

[0022] Figure 2 A structural block diagram of a power electronic transformer power module provided in an embodiment of the present application;

[0023] Figure 3 A circuit diagram of a rectifier unit and a DC conversion power supply provided in an embodiment of the present application;

[0024] Figure 4 A circuit diagram of a three-level topology circuit provided in an embodiment of the present application;

[0025] Figure 5 A circuit diagram of a conversion circuit provided in an embodiment of the present application;

[0026] Figure 6 A circuit diagram of a full-bridge topology circuit provided in an embodiment of the present application;

[0027] Figure 7 A structural block diagram of another power electronic transformer provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0029] In the description of the present application, it is to be understood that, unless the context otherwise requires, throughout the specification and claims, the term "including" is to be interpreted as an open, inclusive meaning, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "examples" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics described may be included in any one or more embodiments or examples in any appropriate manner.

[0030] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0031] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] “At least one of A, B, and C” has the same meaning as “at least one of A, B, or C” and both include the following combinations of A, B, and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B, and C.

[0033] The use of "configured to" herein is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0034] In the circuit provided by the embodiment of the present disclosure, the first node, the second node and the third node do not represent actually existing components, but represent the junction points of related electrical connections in the circuit diagram, that is, these nodes are nodes formed by the junction points of related electrical connections in the circuit diagram being equivalent.

[0035] like Figure 1 , Figure 2 and Figure 3 As shown, the embodiment of the present application provides a power electronic transformer 1000, including a power electronic transformer power module 100, an input interface group 200 and an output interface group 300. The power electronic transformer power module 100 includes a rectifier unit 10 and a DC conversion unit group 20.

[0036] in,

[0037] The rectifier unit 10 includes a first input terminal 11, a second input terminal 12, a first output terminal 13, and a second output terminal 14, and the DC conversion unit 20 includes a third input terminal 21, a fourth input terminal 22, a third output terminal 23, and a fourth output terminal 24. The first output terminal 13 of the rectifier unit 10 is connected to the third input terminal 21 of the DC conversion unit 20, and the second output terminal 14 of the rectifier unit 10 is connected to the fourth input terminal 22 of the DC conversion unit 20.

[0038] The input interface group 200 includes a first input interface 210 and a second input interface 220 . The first input interface 210 is connected to the first input end 11 of the rectifier unit 10 , and the second input interface 220 is connected to the second input end 12 of the rectifier unit 10 .

[0039] The output interface group 300 includes a first output interface 310 and a second output interface 320 . The first output interface 310 is connected to the third output terminal 23 of the DC conversion unit 20 , and the second output interface 320 is connected to the fourth output terminal 24 of the DC conversion unit 20 .

[0040] It should be noted that the input interface group 200 is configured to connect to AC power, and the output interface group 300 is configured to connect to a load. Exemplarily, the input interface group 200 is configured to connect to a power grid, which can output three-phase power. The output interface group 300 is configured to connect to an industrial load, a commercial load, or a civilian load.

[0041] In some embodiments, Figure 1 , Figure 2 and Figure 3 As shown, the power electronic transformer 1000 includes a plurality of power electronic transformer power modules 100 and a first connecting line 400. The rectifier units 10 of the plurality of power electronic transformer power modules 100 are cascaded through the first connecting line 400. Moreover, in two adjacent power electronic transformer power modules 100, one end of the first connecting line 400 is connected to the first input end 11 of the rectifier unit 10 of the previous power electronic transformer power module 100, and the other end is connected to the second input end 12 of the rectifier unit 10 of the next power electronic transformer power module 100.

[0042] In some embodiments, Figure 1 As shown, the power electronic transformer 1000 further includes a first busbar 500, a second busbar 600 and a first switch circuit 700. The first input interface 210 is connected to the first input terminal 11 of the rectifier unit 10 of the first-stage power electronic transformer power module 100 through the first busbar 500. The second input interface 220 is connected to the second input terminal 12 of the rectifier unit 10 of the last-stage power electronic transformer power module 100 through the second busbar 600. The first switch circuit 700 is connected to the first input terminal 11 and the second input terminal 12 of the rectifier unit 10 of each power electronic transformer power module 100. At this time, the first switch circuit 700 can control the working state of the power electronic transformer power module 100 connected thereto according to demand.

[0043] In some examples, such as Figure 1 As shown, one end of the first switch circuit 700 is connected to the first busbar 500 , and the other end is connected to the first connecting line 400 .

[0044] In other examples, such as Figure 1 As shown, two ends of the first switch circuit 700 are connected to two different first connection lines 400 .

[0045] In some other examples, such as Figure 1As shown, one end of the first switch circuit 700 is connected to the first connecting line 400 , and the other end is connected to the second busbar 600 .

[0046] In some embodiments, Figure 1 As shown, the power electronic transformer 1000 further includes a plurality of circuit boards 800, and a plurality of power electronic transformer power modules 100 are integrated on the circuit boards 800. The plurality of circuit boards 800 are arranged in sequence along a first direction X. The first direction X is perpendicular to the plane where the circuit boards 800 are located.

[0047] In some examples, such as Figure 1 As shown, along the first direction X, the projections of the plurality of circuit boards 800 on the plane where one of the circuit boards 800 is located overlap. On each circuit board 800, a plurality of power electronic transformer power modules 100 are arranged in sequence along the second direction Z. The second direction Z is perpendicular to the first direction X. For example, the second direction Z is as follows: Figure 1 In this case, the wiring on the circuit board 800 can be more regular and the layout can be more compact, which is convenient for improving the integration of the power electronic transformer 1000.

[0048] like Figure 1 , Figure 2 and Figure 3 As shown, the embodiment of the present application also provides a power electronic transformer power module 100, including the power electronic transformer power module 100 as described in the above embodiment. The power electronic transformer power module 100 includes a rectifier unit 10 and at least one DC conversion unit group 110. The rectifier unit 10 includes a first input terminal 11, a second input terminal 12, a first output terminal 13 and a second output terminal 14. Among them, the first input terminal 11 and the second input terminal 12 are configured to connect to alternating current. The DC conversion unit group 110 includes a plurality of DC conversion units 20, and the DC conversion unit 20 includes a third input terminal 21, a fourth input terminal 22, a third output terminal 23 and a fourth output terminal 24. The third input terminals 21 of the plurality of DC conversion units 20 are connected in parallel and connected to the first output terminal 13 of a rectifier unit 10. The fourth input terminals 22 of the plurality of DC conversion units 20 are connected in parallel and connected to the second output terminal 14 of a rectifier unit 10. The third output terminals 23 of the plurality of DC conversion units 20 are connected in parallel and configured to be connected to a first output interface 310. The fourth output terminals 24 of the plurality of DC conversion units 20 are connected in parallel and are configured to be connected to a second output interface 320 .

[0049] In this case, a rectifier unit 10 is connected to at least one DC conversion unit group 110, and the DC conversion unit group 110 includes a plurality of DC conversion units 20 arranged in parallel. In this way, the output capacity of the first output interface 310 and the second output interface 320 can be increased by simply increasing the number of DC conversion units 20, thereby enhancing the system flexibility.

[0050] In addition, when the load of the power electronic transformer 1000 is lower than the design capacity of a power electronic transformer power module 100, the operating efficiency of the power electronic transformer 1000 can be improved and the loss can be reduced by adjusting the working number of multiple DC conversion units 20 in the DC conversion unit group 110 in the power electronic transformer power module 100. In addition, the multiple DC conversion units 20 in the DC conversion unit group 110 can be alternately dormant, which is conducive to extending the service life.

[0051] In some examples, the power electronic transformer power module 100 includes a DC conversion unit group 110, and the DC conversion unit group 110 includes two DC conversion units 20. At this time, the output capacity of the first output interface 310 and the second output interface 320 is expanded, and the power electronic transformer 1000 can control the two DC conversion units 20 to alternately sleep according to the load condition to improve the low load efficiency.

[0052] In some embodiments, Figure 1 , Figure 2 and Figure 3 As shown, the power electronic transformer power module 100 includes a plurality of DC conversion unit groups 110, and the third output terminals 23 of the DC conversion units 20 belonging to different DC conversion unit groups 110 are configured to be connected to different first output interfaces 310. The fourth output terminals 24 of the DC conversion units 20 belonging to different DC conversion unit groups 110 are configured to be connected to different second output interfaces 320. At this time, the plurality of DC conversion unit groups 110 are connected to the plurality of output interface groups 300, so that the plurality of loads can be connected, thereby further improving the flexibility of the system.

[0053] In some embodiments, Figure 2 and Figure 3 As shown, the third input terminals 21 of the DC conversion units 20 belonging to different DC conversion unit groups 110 are connected in parallel and connected to the first output terminal 13 of a rectifier unit 10. The fourth input terminals 22 of the DC conversion units 20 belonging to different DC conversion unit groups 110 are connected in parallel and connected to the second output terminal 14 of a rectifier unit 10. At this time, multiple DC conversion unit groups 110 are connected in parallel to one rectifier unit 10, which reduces the number of rectifier units 10 in the power module, is conducive to improving system integration, and reduces production costs.

[0054] In some examples, such as Figure 2 As shown, the power electronic transformer power module 100 includes two DC conversion unit groups 110, and each DC conversion unit group 110 includes two DC conversion units 20. In this case, two loads can be connected, and in the case of low load, the two DC conversion units 20 can be alternately dormant to improve low load efficiency.

[0055] In some embodiments, Figure 3 As shown, the rectifier unit 10 includes two three-level topology circuits 10a, and the three-level topology circuit 10a includes a first topology input terminal 101, a first topology output terminal 102, and a second topology output terminal 103. The first input terminal 11 and the second input terminal 12 are respectively connected to the first topology input terminals 101 of the two three-level topology circuits 10a. The first topology output terminals 102 of the two three-level topology circuits 10a are connected in parallel and connected to the first output terminal 13, and the second topology output terminals 103 of the two three-level topology circuits 10a are connected in parallel and connected to the second output terminal 14.

[0056] At this time, the three-level topology circuit 10a can reduce the voltage stress borne by the power devices in the circuit during the switching process, thereby reducing the risk of damage to the power devices due to overvoltage, extending the service life of the power devices, and improving the reliability and stability of the entire power module. At the same time, the three-level topology circuit 10a enables a single power module to handle higher voltage and power. In this way, when the same power output requirement is achieved, the number of power modules required will be reduced accordingly, thereby reducing the hardware cost of the system and improving the cost performance of the system.

[0057] In some examples, such as Figure 3 and Figure 4 As shown, the three-level topology circuit 10a includes a first power device Q1, a second power device Q2, a third power device Q3, and a fourth power device Q4 connected in series, and a first diode D1 and a second diode D2 connected in series. The connection point between the first power device Q1 and the second power device Q2 is the second node N1, and the connection point between the third power device Q3 and the fourth power device Q4 is the third node N2. One end of the first diode D1 and the second diode D2 connected in series is connected to the second node N1, and the other end is connected to the third node N2. The connection point between the first diode D1 and the second diode D2 is the fourth node N3, and the fourth nodes N3 of the two three-level topology circuits 10a are connected in parallel.

[0058] Exemplarily, the first power device Q1, the second power device Q2, the third power device Q3 and the fourth power device Q4 may include insulated gate bipolar transistors (IGBTs), or other types of power devices, which are not listed here one by one.

[0059] It should be noted that the first topology input terminal 101 is the connection point between the second power device Q2 and the third power device Q3, the first topology output terminal 102 is the connection point of the two first power devices Q1 in the two three-level topology circuits 10a, and the second topology output terminal 103 is the connection point of the two fourth power devices Q4 in the two three-level topology circuits 10a.

[0060] In some embodiments, Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the DC conversion unit 20 includes a three-level topology circuit 20a, two diodes 20b connected in series, a conversion circuit 20c and a full-bridge topology circuit 20d. The three-level topology circuit 20a includes a first topology input terminal 201a, a first topology output terminal 202a and a second topology output terminal 203a. One end of the two diodes 20b connected in series is connected to the first topology output terminal 202a, and the other end is connected to the second topology output terminal 203a. The connection point of the two diodes 20b connected in series is a first node 201b. The conversion circuit 20c includes a first conversion input terminal 201c, a second conversion input terminal 202c, a first conversion output terminal 203c and a second conversion output terminal 204c. The first conversion input terminal 201c is connected to the first topology input terminal 201a, and the second conversion input terminal 202c is connected to the first node 201b. The full-bridge topology circuit 20d includes a second topology input terminal 201d, a third topology input terminal 202d, a third topology output terminal 203d and a fourth topology output terminal 204d. The second topology input terminal 201d is connected to the first conversion output terminal 203c, the third topology input terminal 202d is connected to the second conversion output terminal 204c, the third topology output terminal 203d is connected to the third output terminal 23, and the fourth topology output terminal 204d is connected to the fourth output terminal 24.

[0061] In this case, the three-level topology circuit 20a can reduce the voltage stress borne by the power devices in the circuit during the switching process, thereby reducing the risk of damage to the power devices due to overvoltage, extending the service life of the power devices, and improving the reliability and stability of the entire power module. The two diodes 20b connected in series can play the role of voltage clamping. When a voltage spike or overvoltage occurs, the diode can limit the rise of the voltage and protect the power devices in the subsequent circuit from damage by excessive voltage. The conversion circuit 20c can realize the conversion between different voltage levels or current forms. The full-bridge topology circuit 20d can flexibly realize the size adjustment of direct current or voltage.

[0062] In some examples, such as Figure 3 and Figure 4 As shown, the three-level topology circuit 20a includes a first power device Q1, a second power device Q2, a third power device Q3, and a fourth power device Q4, and a first diode D1 and a second diode D2 connected in series. The connection point between the first power device Q1 and the second power device Q2 is the second node N1, and the connection point between the third power device Q3 and the fourth power device Q4 is the third node N2. One end of the first diode D1 and the second diode D2 connected in series is connected to the second node N1, and the other end is connected to the third node N2. The connection point between the first diode D1 and the second diode D2 is the fourth node N3, and the fourth node N3 of the DC conversion unit 20 is connected to the fourth node N3 of the rectifier unit 10.

[0063] It should be noted that the first topology input terminal 201 a is a connection point between the second power device Q2 and the third power device Q3 .

[0064] In some examples, such as Figure 3 As shown, the DC conversion unit 20 further includes a first capacitor C1 and a second capacitor C2, and the two diodes 20b connected in series include a third diode D3 and a fourth diode D4. The first capacitor C1 is connected in parallel with the third diode D3, and the second capacitor C2 is connected in parallel with the fourth diode D4.

[0065] In some examples, such as Figure 3 , Figure 4 and Figure 5 As shown, the conversion circuit 20c includes a first inductor L1, a second inductor L2 and a transformer M1. One end of the second inductor L2 is connected to the input end of the transformer M1 and to the first node 201b, the other end of the second inductor L2 is connected to the input end of the transformer M1 and to one end of the first inductor L1, and the other end of the first inductor L1 is connected to the first topology input end 201a of the three-level topology circuit 20a.

[0066] In some examples, such as Figure 3 and Figure 6 As shown, the full-bridge topology circuit 20d includes an upper half bridge arm and a lower half bridge arm, and the upper half bridge arm and the lower half bridge arm are connected in parallel. The upper half bridge arm includes a fifth power device Q5 and a sixth power device Q6, and the lower half bridge arm includes a seventh power device Q7 and an eighth power device Q8. The connection points of the upper half bridge arm and the lower half bridge arm are the fifth node N4 and the sixth node N5, respectively, the fifth node N4 is connected to the first conversion output terminal 203c, and the sixth node N5 is connected to the second conversion output terminal 204c. The connection point between the fifth power device Q5 and the sixth power device Q6 is the seventh node N6, the connection point between the seventh power device Q7 and the eighth power device Q8 is the eighth node N7, the seventh node N6 is connected to the third output terminal 23, and the eighth node N7 is connected to the fourth output terminal 24.

[0067] Exemplarily, the fifth power device Q5, the sixth power device Q6, the seventh power device Q7 and the eighth power device Q8 may include silicon carbide-based semiconductor field effect transistors (Metal Oxide Semiconductor Field Effect Transistor, referred to as MOSFET), and may also include other types of power devices, which are not listed here one by one.

[0068] In some embodiments, Figure 1 and Figure 2 As shown, the DC conversion unit group 110 also includes a plurality of current sensors 30, one end of a current sensor 30 is connected to the third output end 23 of a DC conversion unit 20, and the other end is configured to be connected to a first output interface 310, so as to realize overcurrent protection of the DC conversion unit 20 and power balancing control of different DC conversion units 20, thereby improving the reliability and flexibility of the system.

[0069] In some embodiments, Figure 7 As shown, the power electronic transformer 1000 further includes a housing 900, the housing 900 includes a first sub-housing 910 and a second sub-housing 920, and the first sub-housing 910 is disposed in the second sub-housing 920. The power electronic transformer power module 100 is disposed in the second sub-housing 920 to protect the power electronic transformer power module 100 and reduce the risk of being damaged by external forces.

[0070] In some embodiments, the material of the second sub-shell 920 includes an insulating material to ensure that the internal circuit of the power module can work in a stable electrical environment, thereby improving the reliability and stability of the power electronic transformer 1000. The material of the first sub-shell 910 includes a conductive material. When the first sub-shell 910 is grounded, the current leaked from the power module due to insulation aging, component damage, etc. can flow into the ground, thereby avoiding the risk of electric shock to maintenance personnel. At the same time, the current can be prevented from affecting other components that are working normally.

[0071] In some examples, the insulating material includes epoxy resin, and the conductive material includes any one of iron, copper, aluminum, or a combination thereof.

[0072] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0073] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A power electronic transformer power module, characterized in that: include: A rectifying unit, comprising a first input terminal, a second input terminal, a first output terminal, and a second output terminal; The first input terminal and the second input terminal are configured to connect to an alternating current; At least one DC conversion unit group, including: A plurality of DC conversion units, including a third input terminal, a fourth input terminal, a third output terminal and a fourth output terminal; the third input terminals of the plurality of DC conversion units are connected in parallel and connected to the first output terminal of one of the rectifier units; the fourth input terminals of the plurality of DC conversion units are connected in parallel and connected to the second output terminal of one of the rectifier units; the third output terminals of the plurality of DC conversion units are connected in parallel and configured to be connected to a first output interface; the fourth output terminals of the plurality of DC conversion units are connected in parallel and configured to be connected to a second output interface.

2. The power electronic transformer power module according to claim 1, characterized in that: It includes a plurality of the DC conversion unit groups, wherein the third output ends of the DC conversion units belonging to different DC conversion unit groups are configured to be connected to different first output interfaces; and the fourth output ends of the DC conversion units belonging to different DC conversion unit groups are configured to be connected to different second output interfaces.

3. The power electronic transformer power module according to claim 2, characterized in that: The third input terminals of the DC conversion units belonging to different DC conversion unit groups are connected in parallel and connected to the first output terminal of one of the rectifier units; the fourth input terminals of the DC conversion units belonging to different DC conversion unit groups are connected in parallel and connected to the second output terminal of one of the rectifier units.

4. The power electronic transformer power module according to claim 1, characterized in that: The rectifier unit includes two three-level topology circuits, and the three-level topology circuit includes a first topology input terminal, a first topology output terminal, and a second topology output terminal; The first input terminal and the second input terminal are respectively connected to the first topology input terminals of the two three-level topology circuits; the first topology output terminals of the two three-level topology circuits are connected in parallel and connected to the first output terminal; the second topology output terminals of the two three-level topology circuits are connected in parallel and connected to the second output terminal.

5. The power electronic transformer power module according to claim 1, characterized in that: The DC conversion unit includes a three-level topology circuit, two diodes in series, a conversion circuit and a full-bridge topology circuit; The three-level topology circuit comprises a first topology input terminal, a first topology output terminal and a second topology output terminal; one end of the two diodes in series are connected to the first topology output terminal, and the other end is connected to the second topology output terminal; the connection point of the two diodes in series is a first node; The conversion circuit comprises a first conversion input terminal, a second conversion input terminal, a first conversion output terminal and a second conversion output terminal; the first conversion input terminal is connected to the first topology input terminal; the second conversion input terminal is connected to the first node; The full-bridge topology circuit includes a second topology input terminal, a third topology input terminal, a third topology output terminal and a fourth topology output terminal; the second topology input terminal is connected to the first conversion output terminal; the third topology input terminal is connected to the second conversion output terminal; the third topology output terminal is connected to the third output terminal; and the fourth topology output terminal is connected to the fourth output terminal.

6. The power electronic transformer power module according to claim 1, characterized in that: The DC conversion unit group also includes: A plurality of current sensors, one end of each current sensor is connected to the third output end of each DC conversion unit, and the other end of each current sensor is configured to be connected to one of the first output interfaces.

7. A power electronic transformer, characterized in that: include: A power electronic transformer power module, wherein the power electronic transformer power module is the power electronic transformer power module according to any one of claims 1 to 6; An input interface group, comprising a first input interface and a second input interface; the first input interface is connected to the first input end of the rectifier unit; the second input interface is connected to the second input end of the rectifier unit; The output interface group includes a first output interface and a second output interface; the first output interface is connected to the third output end of the DC conversion unit; and the second output interface is connected to the fourth output end of the DC conversion unit.

8. The power electronic transformer according to claim 7, characterized in that: include: First connecting line; A plurality of the power electronic transformer power modules, wherein the rectifier units of the plurality of the power electronic transformer power modules are cascaded through the first connecting line; Furthermore, in two adjacent power electronic transformer power modules, one end of the first connecting line is connected to the first input end of the rectifier unit of the power electronic transformer power module of the previous stage; and the other end is connected to the second input end of the rectifier unit of the power electronic transformer power module of the next stage; The first input interface is connected to the first input end of the rectifier unit of the power module of the first-stage power electronic transformer through the first bus; The second input interface is connected to the second input end of the rectifier unit of the power module of the power electronic transformer of the last stage through the second bus; The first switch circuit is connected to the first input terminal and the second input terminal of the rectifier unit of each power electronic transformer power module.

9. The power electronic transformer according to claim 8, characterized in that: Also includes: A plurality of circuit boards, on which a plurality of power electronic transformer power modules are integrated; Along a first direction, a plurality of circuit boards are arranged in sequence; The first direction is perpendicular to the plane where the circuit board is located.

10. The power electronic transformer according to claim 8, characterized in that: Also includes: The shell comprises a first subshell and a second subshell, wherein the first subshell is arranged in the second subshell; the power electronic transformer power module is arranged in the second subshell; the material of the first subshell comprises a conductive material; and the material of the second subshell comprises an insulating material.

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