A converter module, protection circuit control method, device and medium

Abstract

The application provides a converter module, a protection circuit control method, equipment and a medium, comprising: a converter submodule, a DC small bus and a protection circuit; the protection circuit comprises a first control module and a second control module; the first control module and the second control module are connected in series and connected with the converter submodule through the DC small bus; the two ends of the first control module and the second control module are a first DC port (1), and the two ends of the second control module are a second DC port (2); one end of the second DC port (2) is connected with one end of a second DC port (2) of another converter module in cascade or connected with a DC bus of an external DC system of the converter module; the converter submodule, the DC small bus, the protection circuit and the DC bus are connected in communication with a control protection system outside the converter module; and the application realizes reliable isolation of the converter submodule in a fault state, bypass, protection of overvoltage of a DC bus or a DC small bus.

Description

Technical Field

[0001] This invention belongs to the field of power electronics, specifically relating to a converter module, a protection circuit control method, equipment, and medium. Background Technology

[0002] DC power grids offer large transmission capacity and high controllability, improving power quality, reducing line losses, isolating AC / DC faults, and supporting flexible and convenient integration of renewable energy. They will play a crucial role in future new power systems dominated by new energy sources. Converters are the core equipment of DC power grids. With technological advancements, cascaded DC converter topologies offer advantages such as low DC voltage in submodules, no need for valves or numerous series-connected switching devices, low electromagnetic interference levels, small converter size and weight, and ease of compact design.

[0003] When a submodule of a DC-side cascaded converter topology fails, reliable fault isolation needs to be achieved by bypassing the submodule on the DC side. Furthermore, rapid overvoltage suppression is required when an overvoltage occurs in the DC system. Existing DC-side cascaded converter topologies lack submodule fault isolation and overvoltage protection capabilities, resulting in the entire converter's protection tripping in the event of a submodule failure or DC-side overvoltage, leading to poor operational reliability. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention proposes a converter module, comprising: Converter submodule, DC busbar and protection circuit; The protection circuit includes a first control module and a second control module; The first control module and the second control module are connected in series and then connected to the converter sub-module via a DC bus. The first control module and the second control module have two ends as a first DC port (1), and the second control module has two ends as a second DC port (2). One end of the second DC port (2) is cascaded to one end of the second DC port (2) of another converter module or connected to the DC bus of the external DC system of the converter module; The converter submodule, DC busbar and DC busbar are monitored for their working status by an external control and protection system. The converter submodule and protection circuit are connected to the control and protection system. By monitoring the operating status of the converter submodule, DC busbar and DC bus, the fault type of the converter submodule in the fault state is determined, and the DC busbar and DC busbar in the overvoltage state are connected and disconnected by receiving the instructions of the control and protection system. In this way, the converter submodule is isolated from the fault and bypass is achieved, and the DC busbar or DC busbar is protected from overvoltage. The second control module includes: Resistor R, second IGBT T2, mechanical switch K, second diode D2 and third diode D3; The second diode D2 is connected in anti-parallel between the collector and emitter of the second IGBT T2, and the third diode D3 is connected in anti-parallel across the resistor R. One end of the resistor R is electrically connected to the collector of the second IGBT T2, and the other end of the resistor R is connected to the first control module and one end of the mechanical switch K, respectively. The emitter of the second IGBT T2 is electrically connected to the other end of the mechanical switch K. The emitter of the second IGBT T2 is the negative terminal of the first DC port (1); One end of the mechanical switch K is the positive terminal of the second DC port (2), and the other end of the mechanical switch K is the negative terminal of the second DC port (2); The second IGBT T2 and the mechanical switch K are communicatively connected to the control and protection system; When the converter submodule is in a fault state, the second IGBT T2 is turned on and the mechanical switch K is closed, thereby enabling the second control module to bypass. When the DC bus or the DC busbar is in an overvoltage state, the mechanical switch K is turned off, the second IGBTT2 is in PWM working state, and the current is discharged through the resistor R to protect the DC bus or the DC busbar from overvoltage.

[0005] Preferably, the first control module includes: First IGBT T1 and first diode D1; The first diode D1 is connected in anti-parallel between the collector and emitter of the first IGBT T1, and the emitter of the first IGBT T1 is electrically connected to the second control module; The first IGBT T1 is connected to the control and protection system. The collector of the first IGBT T1 is the positive terminal of the first DC port (1); When the converter submodule is in a fault state, the first IGBT T1 is locked to isolate the fault in the converter submodule; When the DC bus or the DC busbar is in an overvoltage state, the first IGBT T1 is turned on, thereby causing the second module to operate in a depressurization state.

[0006] Preferably, the DC busbars include two, and the two ends of the first DC port (1) are respectively connected to the converter submodule through a DC busbar.

[0007] Preferably, the resistor R includes at least one or more of the following: linear resistor and nonlinear resistor.

[0008] Based on the same inventive concept, the present invention also provides a protection circuit control method for a converter module, comprising: The DC bus, converter sub-modules in the converter module, and DC busbar of the DC system are monitored for their operating status by a control and protection system. The operating status includes fault status and overvoltage status. When the converter submodule is in a fault state, the fault type is determined according to the direction of current flow in the first DC port (1) and the second DC port (2), and the first control module and the second control module in the protection circuit are opened or closed according to the instructions received from the control and protection system, so as to isolate the fault in the converter submodule and realize bypass. When the DC bus or the DC busbar is in an overvoltage state, the first control module and the second control module are opened or closed according to the instructions received from the control and protection system, thereby providing overvoltage protection for the DC bus or the DC busbar. The converter submodule and protection circuit maintain a communication connection with the control and protection system, and the instructions are generated based on the operating status received by the control and protection system; the converter module is any of the converter modules described above.

[0009] Preferably, when the converter submodule is in a fault state, the fault type is determined according to the current flow direction at the first DC port (1) and the second DC port (2), and the first control module and the second control module in the protection circuit are opened or closed according to the instructions received from the control and protection system, thereby enabling the converter submodule to isolate the fault and achieve bypass, including: When the converter submodule is in a fault state, and the current flows from the first DC port (1) to the second DC port (2), it is determined that the converter submodule is in a rectification fault state. The control and protection system receives the instruction to lock the first IGBT T1 of the first control module in the protection circuit, turn on the second IGBT T2 of the second control module, and close the mechanical switch K, so that the current flows through the second diode D2 and the third diode D3, thereby isolating the converter submodule from the fault and achieving bypass. When the converter submodule is in a fault state and the current flows from the second DC port (2) to the first DC port (1), it is determined that the converter submodule is in an inverter fault state. The control and protection system receives the instruction to lock the first IGBT T1 of the first control module in the protection circuit, turn on the second IGBT T2 of the second control module, and close the mechanical switch K, so that the current flows through the first diode D1, thereby isolating the converter submodule from the fault and achieving bypass.

[0010] Preferably, when the DC bus or the DC busbar is in an overvoltage state, the step of opening or closing the first control module and the second control module according to the instruction received from the control and protection system to perform overvoltage protection for the DC bus or the DC busbar includes: When the DC bus or the DC busbar is in the overvoltage state, according to the instruction received from the control and protection system, the first IGBT T1 of the first control module is turned on, the mechanical switch K of the second control module is turned off, and the second IGBT T2 enters the PWM working state. The current is discharged through the resistor R of the second control module, thereby providing overvoltage protection for the DC bus or the DC sub-bus.

[0011] Preferably, the operating states also include: pre-charge state, steady state, and exit state.

[0012] Preferably, after the control and protection system identifies the operating status of the DC bus, the converter sub-module in the converter module, and the DC busbar, it further includes: When the operating state is pre-charge state, steady state, or exit state, the converter submodule is normally controlled.

[0013] Preferably, when the operating state is the pre-charging state, normal control of the converter submodule is performed, including: When the converter submodule is in the pre-charge state, according to the instruction received from the control and protection system, the first IGBT T1 of the first control module is locked, the second IGBT T2 of the second control module is locked, and the mechanical switch K is opened. The charging current flows in from the positive terminal of the second DC port (2), is injected into the positive terminal of the DC energy storage element of the converter submodule through the first diode D1 of the first control module, and flows out from the negative terminal of the DC energy storage element through the negative terminal of the second DC port (2) to charge the converter submodule.

[0014] Preferably, when the operating state is a steady state, normal control of the converter submodule is performed, including: When the converter submodule is in the steady state, according to the instruction received from the control and protection system, the first IGBT T1 of the first control module is turned on, the second IGBT T2 of the second control module is locked, and the mechanical switch K is turned off, thereby enabling the DC voltage of the converter submodule to be output normally.

[0015] Preferably, when the operating state is the exit state, normal control is performed on the converter submodule, including: When the converter submodule is in the off-run state, according to the instruction received from the control and protection system, the first IGBT T1 of the first control module is turned on, the mechanical switch K of the second control module is turned off, and the second IGBT T2 enters the PWM working state or the on state. Then, energy is discharged through the resistor R to shorten the exit time.

[0016] Based on the same inventive concept, the present invention also provides a computer device, comprising: one or more processors; Memory, used to store one or more programs; When the one or more programs are executed by the one or more processors, a protection circuit control method for a converter module as described above is implemented.

[0017] Based on the same inventive concept, the present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed, it implements a protection circuit control method for a converter module as described above.

[0018] Compared with the closest existing technology, the present invention has the following beneficial effects: 1. This invention provides a converter module, a protection circuit control method, equipment, and medium, comprising: a converter submodule, a DC bus, and a protection circuit; the protection circuit includes a first control module and a second control module; the first control module and the second control module are connected in series and then connected to the converter submodule via the DC bus; the two ends of the first control module and the second control module are first DC ports (1), and the two ends of the second control module are second DC ports (2); one end of the second DC port (2) is cascaded to one end of the second DC port (2) of another converter module or connected to the DC bus of the external DC system of the converter module; the converter submodule, the DC bus, and the DC bus are monitored for their operating status by a control and protection system external to the converter module, and the converter submodule... The invention establishes a communication connection between the protection circuit and the control and protection system. By monitoring the operating status of the converter submodule, DC bus, and DC bus, it determines the fault type of the converter submodule in a faulty state and, through receiving instructions from the control and protection system, opens or closes the first and second control modules of the DC bus and DC bus in an overvoltage state. This isolates the converter submodule from faults and enables bypassing, as well as overvoltage protection for the DC bus or DC bus. The invention achieves reliable isolation of the converter submodule during faults and enables bypassing and overvoltage protection for the DC bus or DC bus by receiving instructions from the control and protection system to open or close the first and second control modules of the protection circuit. This promotes the development of DC-side cascaded converter technology and improves the operational reliability of the converter. Attached Figure Description

[0019] Figure 1 A schematic diagram of a converter module provided by the present invention; Figure 2 A schematic diagram of the protection circuit provided by the present invention; Figure 3 A schematic diagram of the protection circuit for swapping the positions of the second IGBT T2 and the resistor R provided by the present invention; Figure 4 A flowchart of a protection circuit control method for a converter module provided by the present invention. Detailed Implementation

[0020] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0021] Example 1: This invention provides a converter submodule, such as... Figure 1 As shown, it includes: Converter submodule, DC busbar and protection circuit; The protection circuit includes a first control module and a second control module; The first control module and the second control module are connected in series and then connected to the converter sub-module via a DC bus. The first control module and the second control module have a first DC port (1) at both ends, and the second control module has a second DC port (2) at both ends. One end of the second DC port (2) is cascaded to one end of the second DC port (2) of another converter module or connected to the DC bus of the external DC system of the converter module; The DC busbars include two, and the two ends of the first DC port (1) are respectively connected to the converter submodule through a DC busbar; The converter submodule, DC busbar and DC busbar are monitored for their working status by an external control and protection system. The converter submodule and protection circuit are connected to the control and protection system. A converter is formed by cascading multiple converter submodules through their second DC ports (2); like Figure 2 The diagram shows a protection circuit. The first control module in the protection circuit includes: First IGBT T1 and first diode D1; The first diode D1 is connected in anti-parallel between the collector and emitter of the first IGBT T1, and the emitter of the first IGBT T1 is electrically connected to the second control module. The first IGBT T1 is connected to the control and protection system. The collector of the first IGBT T1 is the positive terminal of the first DC port (1); When the converter submodule is in a fault state, the first IGBT T1 is locked, thereby isolating the converter submodule from the fault. When the DC bus or DC busbar is under overvoltage, the first IGBT T1 is turned on, thereby causing the second module to operate in the pressure relief state.

[0022] The second control module in the protection circuit includes: Resistor R, second IGBT T2, mechanical switch K, second diode D2 and third diode D3; The second diode D2 is connected in anti-parallel between the collector and emitter of the second IGBT T2, and the third diode D3 is connected in anti-parallel across the resistor R. One end of the resistor R is electrically connected to the collector of the second IGBT T2, and the other end of the resistor R is connected to the first control module and one end of the mechanical switch K, respectively. The emitter of the second IGBT T2 is electrically connected to the other end of the mechanical switch K. The emitter of the second IGBT T2 is the negative terminal of the first DC port (1); One end of the mechanical switch K is the positive terminal of the second DC port (2), and the other end of the mechanical switch K is the negative terminal of the second DC port (2); The second IGBT T2 and the mechanical switch K are connected in communication with the control and protection system. When the converter submodule is in a fault state, the second IGBT T2 is turned on and the mechanical switch K is closed, thereby enabling the second control module to bypass. When the DC bus or the DC busbar is in an overvoltage state, the mechanical switch K is turned off, the second IGBTT2 is in PWM working state, and the current is discharged through the resistor R to protect the DC bus or the DC busbar from overvoltage.

[0023] Furthermore, the resistor R includes at least one or more of the following: linear resistors and nonlinear resistors.

[0024] like Figure 3 In the protection circuit shown, the second IGBT T2 and the resistor R are swapped. After the swap, the collector of the second IGBT T2 is connected to the first control module and one end of the mechanical switch K, respectively. The emitter of the second IGBT T2 is electrically connected to one end of the resistor R. The other end of the resistor R is the negative terminal of the first DC port (1).

[0025] Example 2: This invention provides a control method for the protection circuit of a DC-side cascaded converter submodule, such as... Figure 4 As shown, it includes: Step 1: The DC bus, converter sub-modules in the converter module, and DC busbar of the DC system are monitored for their operating status by the control and protection system. The operating status includes fault status and overvoltage status. Step 2: When the converter submodule is in a fault state, the fault type is determined according to the current flow direction at the first DC port (1) and the second DC port (2), and the first control module and the second control module in the protection circuit are opened or closed according to the instructions received from the control and protection system, so as to isolate the fault in the converter submodule and realize bypass. Step 3: When the DC bus or the DC busbar is in an overvoltage state, the first control module and the second control module are opened or closed according to the instructions received from the control and protection system, thereby providing overvoltage protection for the DC bus or the DC busbar. The converter submodule and protection circuit maintain a communication connection with the control and protection system, and the instructions are generated based on the operating status received by the control and protection system; the converter module is any of the converter modules described above.

[0026] Specifically, step 1 includes: The converter submodule and protection circuit maintain communication with the control and protection system. The DC bus of the DC system, the converter submodule in the converter module, and the DC minibus are monitored for their operating status by the control and protection system. The operating status includes fault status and overvoltage status, as well as pre-charge status, steady-state status, and shutdown status. When the operating status is pre-charge status, steady-state status, or shutdown status, the converter submodule is normally controlled. The normal control method is as follows: When the converter submodule is in the pre-charging state, according to the instructions of the receiving control and protection system, the first IGBT T1 of the first control module is locked, the second IGBT T2 of the second control module is locked, and the mechanical switch K is opened; the charging current flows in from the positive terminal of the second DC port (2), is injected into the positive terminal of the DC energy storage element of the converter submodule through the first diode D1 of the first control module, and flows out from the negative terminal of the DC energy storage element through the negative terminal of the second DC port (2) to charge the converter submodule. The present invention can charge the DC energy storage element of the converter submodule through the first diode D1 to establish DC voltage and ensure the normal operation of the DC voltage energy harvesting circuit of the converter submodule.

[0027] When the converter submodule is in a steady state, according to the instructions received from the control and protection system, the first IGBT T1 of the first control module is turned on, the second IGBT T2 of the second control module is locked, and the mechanical switch K is turned off, thereby enabling the DC voltage of the converter submodule to be output normally.

[0028] When the converter submodule is out of operation, according to the instructions received from the control and protection system, the first IGBT T1 of the first control module is turned on, the mechanical switch K of the second control module is turned off, and the second IGBT T2 enters the PWM working state or the on state. Then, the energy is discharged through the resistor R, thereby shortening the exit time. The present invention realizes the rapid discharge of DC energy stored in the converter submodule through the resistor R, shortens the device exit time, and facilitates the rapid development of maintenance work.

[0029] Specifically, step 2 includes: When the converter submodule is in a fault state, and the current flows from the first DC port (1) to the second DC port (2), it is determined that the converter submodule is in a rectification fault state. The control and protection system receives the instruction to lock the first IGBT T1 of the first control module in the protection circuit, turn on the second IGBT T2 of the second control module, and close the mechanical switch K, so that the current flows through the second diode D2 and the third diode D3, thereby isolating the converter submodule from the fault and achieving bypass. When the converter submodule is in a fault state, and the current flows from the second DC port (2) to the first DC port (1), it is determined that the converter submodule is in an inverter fault state. The control and protection system receives the instruction to lock the first IGBT T1 of the first control module in the protection circuit, turn on the second IGBT T2 of the second control module, and close the mechanical switch K, so that the current flows through the first diode D1, thereby isolating the converter submodule from the fault and achieving bypass. In this invention, when the converter submodule is in a fault state, the control time is on the order of milliseconds by locking the first IGBT T1, turning on the second IGBT T2, and closing the mechanical switch K. Therefore, a large-capacity heat dissipation system is not required.

[0030] Specifically, step 3 includes: When the DC bus or DC mini-bus is in the overvoltage state, according to the instruction received from the control and protection system, the first IGBT T1 of the first control module is turned on, the mechanical switch K of the second control module is turned off, and the second IGBT T2 enters the PWM working state. The current is discharged through the resistor R of the second control module to provide overvoltage protection for the DC bus or DC mini-bus. This invention achieves DC bus overvoltage protection and DC mini-bus overvoltage protection by intermittently discharging the resistor R until the voltage does not exceed the limit. The process dynamically controls the size of the equivalent discharge resistance, resulting in a smaller impact on the DC bus and making it easy to achieve DC voltage control of the converter sub-module.

[0031] Example 3: Based on the same inventive concept, this invention also provides a computer device, which includes a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in the computer storage medium to implement corresponding method flows or corresponding functions, thereby implementing the steps of the protection circuit control method for a converter module in the above embodiments.

[0032] Example 4: Based on the same inventive concept, this invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the protection circuit control method for a converter module in the above embodiments.

[0033] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0034] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0035] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0036] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit its scope of protection. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading the present invention, they can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the application, but these changes, modifications or equivalent substitutions are all within the scope of protection of the claims pending approval.

Claims

1. A converter module, characterized in that, include: Converter submodule, DC busbar and protection circuit; The protection circuit includes a first control module and a second control module; The first control module and the second control module are connected in series and then connected to the converter sub-module via a DC bus. The first control module and the second control module have two ends as a first DC port (1), and the second control module has two ends as a second DC port (2). One end of the second DC port (2) is cascaded to one end of the second DC port (2) of another converter module or connected to the DC bus of the external DC system of the converter module; The converter submodule, DC busbar and DC busbar are monitored for their working status by an external control and protection system. The converter submodule and protection circuit are connected to the control and protection system. By monitoring the operating status of the converter submodule, DC busbar and DC bus, the fault type of the converter submodule in the fault state is determined, and the DC busbar and DC busbar in the overvoltage state are connected to the first control module and the second control module by receiving the instructions of the control and protection system, thereby isolating the converter submodule from the fault and realizing bypass, and providing overvoltage protection for the DC busbar or DC busbar. The second control module includes: Resistor R, second IGBT T2, mechanical switch K, second diode D2 and third diode D3; The second diode D2 is connected in anti-parallel between the collector and emitter of the second IGBT T2, and the third diode D3 is connected in anti-parallel across the resistor R. One end of the resistor R is electrically connected to the collector of the second IGBT T2, and the other end of the resistor R is connected to the first control module and one end of the mechanical switch K, respectively. The emitter of the second IGBT T2 is electrically connected to the other end of the mechanical switch K. The emitter of the second IGBT T2 is the negative terminal of the first DC port (1); One end of the mechanical switch K is the positive terminal of the second DC port (2), and the other end of the mechanical switch K is the negative terminal of the second DC port (2); The second IGBT T2 and the mechanical switch K are communicatively connected to the control and protection system; When the converter submodule is in a fault state, the second IGBT T2 is turned on and the mechanical switch K is closed, thereby enabling the second control module to bypass. When the DC bus or the DC busbar is in an overvoltage state, the mechanical switch K is turned off, the second IGBT T2 is in PWM operation, and the current is discharged through the resistor R to protect the DC bus or the DC busbar from overvoltage.

2. The converter module as described in claim 1, characterized in that, The first control module includes: First IGBT T1 and first diode D1; The first diode D1 is connected in anti-parallel between the collector and emitter of the first IGBT T1, and the emitter of the first IGBT T1 is electrically connected to the second control module; The first IGBT T1 is connected to the control and protection system. The collector of the first IGBT T1 is the positive terminal of the first DC port (1); When the converter submodule is in a fault state, the first IGBT T1 is locked to isolate the fault in the converter submodule; When the DC bus or the DC busbar is in an overvoltage state, the first IGBT T1 is turned on, thereby causing the second module to operate in a depressurization state.

3. The converter module as described in claim 2, characterized in that, The DC busbars include two, and the two ends of the first DC port (1) are respectively connected to the converter submodule through a DC busbar.

4. The converter module as described in claim 1, characterized in that, The resistor R includes at least one or more of the following: linear resistor and nonlinear resistor.

5. A protection circuit control method for a converter module, characterized in that, include: The DC bus, converter sub-modules in the converter module, and DC busbar of the DC system are monitored for their operating status by a control and protection system. The operating status includes fault status and overvoltage status. When the converter submodule is in a fault state, the fault type is determined according to the direction of current flow in the first DC port (1) and the second DC port (2), and the first control module and the second control module in the protection circuit are opened or closed according to the instructions received from the control and protection system, so as to isolate the fault in the converter submodule and realize bypass. When the DC bus or the DC busbar is in an overvoltage state, the first control module and the second control module are opened or closed according to the instructions received from the control and protection system, thereby providing overvoltage protection for the DC bus or the DC busbar. The converter submodule and protection circuit maintain a communication connection with the control and protection system, and the instructions are generated based on the operating status received by the control and protection system; the converter module is a converter module according to any one of claims 1 to 4.

6. The method as described in claim 5, characterized in that, When the converter submodule is in a fault state, the fault type is determined according to the current flow direction at the first DC port (1) and the second DC port (2), and the first control module and the second control module in the protection circuit are opened or closed according to the instructions received from the control and protection system, thereby isolating the converter submodule from the fault and achieving bypass, including: When the converter submodule is in a fault state, and the current flows from the first DC port (1) to the second DC port (2), it is determined that the converter submodule is in a rectification fault state. The control and protection system receives the instruction to lock the first IGBT T1 of the first control module in the protection circuit, turn on the second IGBT T2 of the second control module, and close the mechanical switch K, so that the current flows through the second diode D2 and the third diode D3, thereby isolating the converter submodule from the fault and achieving bypass. When the converter submodule is in a fault state and the current flows from the second DC port (2) to the first DC port (1), it is determined that the converter submodule is in an inverter fault state. The control and protection system receives the instruction to lock the first IGBT T1 of the first control module in the protection circuit, turn on the second IGBT T2 of the second control module, and close the mechanical switch K, so that the current flows through the first diode D1, thereby isolating the converter submodule from the fault and achieving bypass.

7. The method as described in claim 5, characterized in that, When the DC bus or the DC busbar is in an overvoltage state, the first control module and the second control module are opened or closed according to the instruction received from the control and protection system to provide overvoltage protection for the DC bus or the DC busbar, including: When the DC bus or the DC busbar is in the overvoltage state, according to the instruction received from the control and protection system, the first IGBT T1 of the first control module is turned on, the mechanical switch K of the second control module is turned off, and the second IGBT T2 enters the PWM working state. The current is discharged through the resistor R of the second control module, thereby providing overvoltage protection for the DC bus or the DC sub-bus.

8. The method as described in claim 5, characterized in that, The operating states also include: pre-charge state, steady state, and exit state.

9. The method as described in claim 5, characterized in that, After identifying the operating status of the DC bus, the converter sub-module in the converter module, and the DC busbar, the control and protection system also includes: When the operating state is pre-charge state, steady state, or exit state, the converter submodule is normally controlled.

10. The method as described in claim 9, characterized in that, When the operating state is the pre-charging state, normal control is performed on the converter submodule, including: When the converter submodule is in the pre-charge state, according to the instruction received from the control and protection system, the first IGBT T1 of the first control module is locked, the second IGBT T2 of the second control module is locked, and the mechanical switch K is opened. The charging current flows in from the positive terminal of the second DC port (2), is injected into the positive terminal of the DC energy storage element of the converter submodule through the first diode D1 of the first control module, and flows out from the negative terminal of the DC energy storage element through the negative terminal of the second DC port (2) to charge the converter submodule.

11. The method as described in claim 9, characterized in that, When the operating state is a steady state, the converter submodule is normally controlled, including: When the converter submodule is in the steady state, according to the instruction received from the control and protection system, the first IGBT T1 of the first control module is turned on, the second IGBT T2 of the second control module is locked, and the mechanical switch K is turned off, thereby enabling the DC voltage of the converter submodule to be output normally.

12. The method as described in claim 7, characterized in that, When the operating state is the exit state, normal control is performed on the converter submodule, including: When the converter submodule is in the off-run state, according to the instruction received from the control and protection system, the first IGBT T1 of the first control module is turned on, the mechanical switch K of the second control module is turned off, and the second IGBT T2 enters the PWM working state or the on state. Then, energy is discharged through the resistor R to shorten the exit time.

13. A computer device, characterized in that, include: One or more processors; Memory, used to store one or more programs; When the one or more programs are executed by the one or more processors, a protection circuit control method for a converter module as described in any one of claims 5 to 12 is implemented.

14. A computer-readable storage medium, characterized in that, It contains a computer program, which, when executed, implements a protection circuit control method for a converter module as described in any one of claims 5 to 12.

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