Method and system for positioning open-circuit fault of full-bridge sub-module of bipolar modular converter

Abstract

The invention discloses a method and a system for positioning open-circuit faults of full-bridge sub-modules of a bipolar modular converter. The method comprises the following steps: acquiring capacitor voltage data of each full-bridge sub-module on each bridge arm of the bipolar modular converter; calculating a capacitor voltage average value of each sub-module at each sampling moment; calculating a capacitance voltage absolute error of each sub-module at each sampling moment according to the capacitance voltage data and the average value; calculating the capacitance voltage standard deviation of each sub-module at each sampling moment; and according to the capacitor voltage average value and the standard value, constructing a corresponding confidence threshold interval, and performing fault diagnosis and positioning: when the capacitor voltage value of a certain sub-module at the sampling moment exceeds the confidence threshold interval and the time reaches preset decision time, determining that a fault occurs, and outputting a positioning result. According to the method, an accurate mathematical model and additional hardware equipment are not needed, the algorithm is simple and efficient, the fault sub-module can be effectively positioned and removed, and the operation stability of the bipolar modular converter can be improved.

Description

Technical Field

[0001] This invention relates to a method and system for locating open-circuit faults in a full-bridge submodule of a bipolar modular converter, belonging to the field of fault location for power electronic equipment. Background Technology

[0002] With the continuous increase in the utilization of renewable energy, low-frequency AC transmission has become a strong candidate for high-voltage, long-distance power transmission. Bipolar modular AC-AC converters, with their simple structure and independent control of active and reactive power, are widely used in such systems. However, the converter contains a large number of full-bridge submodules, and the switching devices within are prone to open-circuit faults, leading to output waveform distortion and a continuous rise in capacitor voltage.

[0003] Therefore, there is an urgent need for an efficient localization method specifically designed for this problem. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for locating open-circuit faults in full-bridge submodules of a bipolar modular converter. By synchronously collecting capacitor voltage data of each submodule within the same bridge arm, calculating the average value, absolute error, and standard deviation of the capacitor voltage of each submodule, constructing a confidence threshold range for the capacitor voltage of the submodule, and determining and accurately locating the submodule fault based on whether the voltage value exceeds the range and reaches a preset time.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution.

[0006] In a first aspect, the present invention provides a method for locating open-circuit faults in a full-bridge submodule of a bipolar modular converter, comprising:

[0007] Collect capacitor voltage data for each full-bridge submodule on each arm of the bipolar modular converter;

[0008] Based on the capacitor voltage data of each full-bridge submodule on each bridge arm, calculate the average capacitor voltage of each full-bridge submodule at each sampling time.

[0009] Based on the capacitor voltage data and the average capacitor voltage, calculate the absolute error of the capacitor voltage of each full-bridge submodule at each sampling time;

[0010] Based on the absolute error of the capacitor voltage, calculate the standard deviation of the capacitor voltage of each full-bridge submodule at each sampling time;

[0011] Based on the average capacitor voltage and the standard capacitor voltage, a corresponding confidence threshold range is constructed, and fault diagnosis and location are performed on the full-bridge submodule:

[0012] When the capacitor voltage value of a certain full-bridge submodule exceeds the confidence threshold range at the sampling time and the time reaches the preset decision time, the full-bridge submodule is determined to have failed, and the corresponding location result is output.

[0013] Furthermore, the bipolar modular converter includes a bipolar transformer and modular circuitry, wherein the bipolar transformer includes a primary winding. Secondary winding 1 and secondary winding two The primary winding and secondary winding use Connection, the secondary winding two use Connection: Secondary winding one The same-named terminal connects to the upper arm of the three-phase bridge, and the secondary winding two Non-identical terminals connect to the lower arm of the three-phase bridge, primary winding The corresponding terminal is connected to the low-frequency AC system;

[0014] The modular circuit adopts a three-phase six-bridge-arm structure, with each phase including an upper bridge arm and a lower bridge arm, and each bridge arm consisting of... The bridge is composed of cascaded full-bridge sub-modules, and the connection point of the upper and lower bridge arms is connected to the network side.

[0015] Furthermore, the full-bridge submodule includes capacitors. Anti-parallel diode Anti-parallel diode 2 Anti-parallel diodes and anti-parallel diodes The anti-parallel diode emitter and anti-parallel diode two The collector connection is used as the positive output of the full-bridge submodule; the anti-parallel diode three The transmitter and anti-parallel diodes The collector is connected to the terminal of the bridge submodule and is used as the negative output terminal of the full-bridge submodule.

[0016] The anti-parallel diode emitter and anti-parallel diode three collector and capacitor The positive terminal is connected, and the anti-parallel diode is connected. and anti-parallel diodes emitter and capacitor The negative ends are connected.

[0017] Furthermore, the secondary winding one and secondary winding two The output voltage is equal in amplitude and inverse in phase.

[0018] Furthermore, fault location for a full-bridge submodule refers to the open-circuit fault of one to four anti-parallel diodes in a full-bridge submodule.

[0019] In the method of this invention, fault location is performed on the full-bridge submodule. When an open-circuit fault occurs in a certain anti-parallel diode (T1, T2, T3 or T4) on the same bridge arm at the time of data acquisition, it can accurately determine which anti-parallel diode has failed.

[0020] Furthermore, at the acquisition time, the capacitor voltage data of all full-bridge submodules on the same bridge arm of the bipolar modular converter are acquired, and the capacitor voltage data is... The expression for calculating the average capacitor voltage is as follows:

[0021] ;

[0022] in, This represents the average capacitor voltage at the sampling time. The number of submodules within a bridge arm. ;

[0023] The absolute error of the capacitor voltage The expression is calculated using capacitor voltage data and the average capacitor voltage:

[0024] .

[0025] Furthermore, the standard deviation of the capacitor voltage The expression is:

[0026] ;

[0027] in, The number of submodules within a bridge arm. ; This represents the absolute error of the capacitor voltage.

[0028] Furthermore, a bipolar modular converter based on the Laida criterion is adopted. The confidence threshold interval is constructed based on the average value and standard deviation of the capacitor voltage, and the expression is:

[0029] ;

[0030] in, This represents the average capacitor voltage of the submodule at the sampling time. The standard deviation of the capacitor voltage corresponding to the submodule at the sampling time is denoted as .

[0031] Furthermore, the submodule fault location determination includes: when the real-time sampled value of a certain submodule continuously exceeds the confidence threshold range, and the duration reaches the preset decision time. If the fault is found, the submodule is determined to be faulty, and fault location and isolation are performed; otherwise, the submodule is determined to be operating normally.

[0032] The full-bridge submodule fault location method proposed in this invention uses the Lay criterion to construct a dynamic confidence threshold interval, thereby achieving accurate identification and location of open-circuit faults. Compared with traditional submodule fault judgment methods, this invention method does not require an accurate mathematical model or additional hardware equipment, significantly reducing system cost and complexity.

[0033] Secondly, the present invention provides a system for locating open-circuit faults in a full-bridge submodule of a bipolar modular converter, comprising:

[0034] The data acquisition module is used to collect the capacitor voltage data of each full-bridge submodule on each arm of the bipolar modular converter.

[0035] The average value calculation module is used to calculate the average value of the capacitor voltage of each full-bridge submodule at each sampling time based on the capacitor voltage data of each full-bridge submodule on each bridge arm.

[0036] The absolute error calculation module is used to calculate the absolute error of the capacitor voltage of each full-bridge submodule at each sampling time based on the capacitor voltage data and the average capacitor voltage.

[0037] The standard deviation calculation module is used to calculate the standard deviation of the capacitor voltage of each full-bridge submodule at each sampling time based on the absolute error of the capacitor voltage.

[0038] The submodule fault location module is used to construct a corresponding confidence threshold range based on the average capacitor voltage and the standard capacitor voltage, and to perform fault diagnosis and location for the full-bridge submodule.

[0039] When the capacitor voltage value of a certain full-bridge submodule exceeds the confidence threshold range at the sampling time and the time reaches the preset decision time, the full-bridge submodule is determined to have failed, and the corresponding location result is output.

[0040] Thirdly, the present invention provides a computer-readable storage medium having a computer program / instruction stored thereon, wherein when the computer program / instruction is executed by a processor, the steps of the bipolar modular converter full-bridge submodule open-circuit fault location method described in any of the first aspects are implemented.

[0041] Fourthly, the present invention provides a computer device, comprising:

[0042] Memory, used to store computer programs / instructions;

[0043] A processor is configured to execute the computer program / instructions to implement the steps of the bipolar modular converter full-bridge submodule open-circuit fault location method as described in any one of the first aspects.

[0044] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0045] 1. The present invention provides a method for locating open-circuit faults in full-bridge submodules of a bipolar modular converter. The bipolar modular converter consists of a bipolar transformer and modular circuits. By calculating the mean, absolute deviation, and standard deviation of the capacitor voltages of all full-bridge submodules in the same bridge arm within the acquisition time, a confidence threshold range for capacitor voltage is obtained. Abnormal modules whose voltages continuously exceed the confidence threshold range are effectively identified and accurately located. The method of the present invention provides a reliable basis for subsequent fault-tolerant control and system protection.

[0046] 2. The open-circuit fault diagnosis method for full-bridge submodules of bipolar modular converters based on the Laida criterion provided by this invention does not require precise mathematical models or additional hardware devices. The algorithm is simple and efficient, and can effectively locate and remove faulty submodules, thereby effectively improving the operational stability of bipolar modular converters.

[0047] 3. The computer-readable storage medium and computer device provided by the present invention can execute the steps of the open-circuit fault location method for the full-bridge submodule of the bipolar modular converter provided by the present invention. Attached Figure Description

[0048] Figure 1 A schematic diagram of the topology of the open-circuit fault location method for a full-bridge submodule of a bipolar modular converter provided in an embodiment of the present invention;

[0049] Figure 2 A flowchart illustrating the fault diagnosis process of the open-circuit fault location method for a full-bridge submodule of a bipolar modular converter according to an embodiment of the present invention. Detailed Implementation

[0050] It should be noted that:

[0051] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0052] The term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0053] Example 1

[0054] like Figure 1 As shown in the figure, this embodiment introduces a method for locating open-circuit faults in a full-bridge submodule of a bipolar modular converter, including:

[0055] Collect capacitor voltage data for each full-bridge submodule on each arm of the bipolar modular converter;

[0056] Based on the capacitor voltage data of each full-bridge submodule on each bridge arm, calculate the average capacitor voltage of each full-bridge submodule at each sampling time.

[0057] Based on the capacitor voltage data and the average capacitor voltage, calculate the absolute error of the capacitor voltage of each full-bridge submodule at each sampling time;

[0058] Based on the absolute error of the capacitor voltage, calculate the standard deviation of the capacitor voltage of each full-bridge submodule at each sampling time;

[0059] Based on the average capacitor voltage and the standard capacitor voltage, a corresponding confidence threshold range is constructed, and fault diagnosis and location are performed on the full-bridge submodule:

[0060] When the capacitor voltage value of a certain full-bridge submodule exceeds the confidence threshold range at the sampling time and the time reaches the preset decision time, the full-bridge submodule is determined to have failed, and the corresponding location result is output.

[0061] Furthermore, the bipolar modular converter includes a bipolar transformer and modular circuitry, wherein the bipolar transformer includes a primary winding. Secondary winding 1 and secondary winding two The primary winding and secondary winding use Connection, the secondary winding two use Connection: Secondary winding one The same-named terminal connects to the upper arm of the three-phase bridge, and the secondary winding two Non-identical terminals connect to the lower arm of the three-phase bridge, primary winding The corresponding terminal is connected to the low-frequency AC system;

[0062] In this embodiment, the primary winding Non-same-name end connection Point, secondary winding one Non-same-name end connection Point, secondary winding two The same-named end connects to Points, among which , as well as All grounded;

[0063] The modular circuit adopts a three-phase six-bridge-arm structure, with each phase including an upper bridge arm and a lower bridge arm, and each bridge arm consisting of... The bridge is composed of cascaded full-bridge sub-modules, and the connection point of the upper and lower bridge arms is connected to the network side.

[0064] In this embodiment, the three phases are configured as follows: Each corresponding upper arm and lower arm are respectively , and Each bridge arm is made of The system is composed of cascaded full-bridge submodules FB-SM, and the connection points of the upper and lower bridge arms of each phase are connected to the grid side. With the net side Connected With the net side Connected With the net side Connected.

[0065] Furthermore, the secondary winding one and secondary winding two The output voltage is equal in amplitude and inverse in phase.

[0066] Furthermore, the full-bridge submodule FB-SM includes capacitors. Anti-parallel diode Anti-parallel diode 2 Anti-parallel diodes and anti-parallel diodes The anti-parallel diode emitter and anti-parallel diode two The collector connection is used as the positive output of the full-bridge submodule; the anti-parallel diode three The transmitter and anti-parallel diodes The collector is connected to the terminal of the bridge submodule and is used as the negative output terminal of the full-bridge submodule.

[0067] The anti-parallel diode emitter and anti-parallel diode three collector and capacitor The positive terminal is connected, and the anti-parallel diode is connected. and anti-parallel diodes emitter and capacitor The negative ends are connected.

[0068] Furthermore, in this embodiment, fault location of the full-bridge submodule refers to performing open-circuit fault detection on a certain anti-parallel diode one to four of a certain full-bridge submodule FB-SM, wherein the anti-parallel diode one of the submodule... The capacitor voltage changes when a fault occurs at the time of data acquisition are shown in Table 1 below:

[0069] Table 1 Anti-parallel diodes Operating status of the full-bridge submodule during open-circuit fault

[0070]

[0071] Anti-parallel diode of submodule The capacitor voltage changes when a fault occurs at the time of data acquisition are shown in Table 2 below:

[0072] Table 2 Anti-parallel diodes II Operating status of the full-bridge submodule during open-circuit fault

[0073]

[0074] The anti-parallel diodes of the submodule The capacitor voltage changes when a fault occurs at the time of data acquisition are shown in Table 3 below:

[0075] Table 3 Anti-parallel diodes Operating status of the full-bridge submodule during open-circuit fault

[0076]

[0077] Submodule anti-parallel diodes four The capacitor voltage changes when a fault occurs at the time of data acquisition are shown in Table 4 below:

[0078] Table 4 Anti-parallel diodes Operating status of the full-bridge submodule during open-circuit fault

[0079]

[0080] As can be seen from Tables 1 to 4, the capacitor voltage of the faulty submodule is always higher than that of the normal submodule.

[0081] Furthermore, such as Figure 2 As shown, the method for locating open-circuit faults in the full-bridge submodules of a bipolar modular converter is to collect capacitor voltage data of all full-bridge submodules on the same bridge arm of the bipolar modular converter at the acquisition time. The capacitor voltage data is... The expression for calculating the average capacitor voltage is as follows:

[0082] ;

[0083] in, This represents the average capacitor voltage at the sampling time. The number of submodules within a bridge arm. ;

[0084] The absolute error of the capacitor voltage The expression is calculated using capacitor voltage data and the average capacitor voltage:

[0085] .

[0086] Furthermore, the standard deviation of the capacitor voltage The expression is:

[0087] ;

[0088] in, The number of submodules within a bridge arm. ; This represents the absolute error of the capacitor voltage.

[0089] Furthermore, a bipolar modular converter based on the Laida criterion is adopted. The confidence threshold interval is constructed based on the average value and standard deviation of the capacitor voltage, and the expression is:

[0090] ;

[0091] in, The number of submodules within a bridge arm. ; This represents the absolute error of the capacitor voltage.

[0092] In this embodiment, the average value and standard deviation are used. The constructed confidence threshold interval is .

[0093] Furthermore, the submodule fault determination and localization includes: when the real-time sampled value of a certain submodule continuously exceeds the confidence threshold range, and the duration reaches the preset decision time. If the fault is found, the submodule is determined to be faulty, and fault location and isolation are performed; otherwise, the submodule is determined to be operating normally.

[0094] Example 2

[0095] Based on the open-circuit fault location method for a bipolar modular converter full-bridge submodule described in Embodiment 1, this embodiment introduces an open-circuit fault location system for a bipolar modular converter full-bridge submodule, including:

[0096] The data acquisition module is used to collect the capacitor voltage data of each full-bridge submodule on each arm of the bipolar modular converter.

[0097] The average value calculation module is used to calculate the average value of the capacitor voltage of each full-bridge submodule at each sampling time based on the capacitor voltage data of each full-bridge submodule on each bridge arm.

[0098] The absolute error calculation module is used to calculate the absolute error of the capacitor voltage of each full-bridge submodule at each sampling time based on the capacitor voltage data and the average capacitor voltage.

[0099] The standard deviation calculation module is used to calculate the standard deviation of the capacitor voltage of each full-bridge submodule at each sampling time based on the absolute error of the capacitor voltage.

[0100] The submodule fault location module is used to construct a corresponding confidence threshold range based on the average capacitor voltage and the standard capacitor voltage, and to perform fault diagnosis and location for the full-bridge submodule.

[0101] When the capacitor voltage value of a certain full-bridge submodule exceeds the confidence threshold range at the sampling time and the time reaches the preset decision time, the full-bridge submodule is determined to have failed, and the corresponding location result is output.

[0102] Example 3

[0103] Based on the bipolar modular converter full-bridge submodule open-circuit fault location method described in Embodiment 1, this embodiment introduces a computer-readable storage medium storing a computer program / instruction thereon. When the computer program / instruction is executed by a processor, it implements the steps of the bipolar modular converter full-bridge submodule open-circuit fault location method as described in any of Embodiment 1.

[0104] Example 4

[0105] Based on the open-circuit fault location method for a full-bridge submodule of a bipolar modular converter described in Embodiment 1, this embodiment provides a computer device, including:

[0106] Memory, used to store computer programs / instructions;

[0107] A processor is used to execute the computer program / instructions to implement the steps of the bipolar modular converter full-bridge submodule open-circuit fault location method as described in any one of Embodiment 1.

[0108] 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.

[0109] 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.

[0110] 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 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0111] 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.

[0112] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A method for locating open-circuit faults in a full-bridge submodule of a bipolar modular converter, characterized in that, include: Collect capacitor voltage data for each full-bridge submodule on each arm of the bipolar modular converter; Based on the capacitor voltage data of each full-bridge submodule on each bridge arm, calculate the average capacitor voltage of each full-bridge submodule at each sampling time. Based on the capacitor voltage data and the average capacitor voltage, calculate the absolute error of the capacitor voltage of each full-bridge submodule at each sampling time; Based on the absolute error of the capacitor voltage, calculate the standard deviation of the capacitor voltage of each full-bridge submodule at each sampling time; Based on the average capacitor voltage and the standard capacitor voltage, a corresponding confidence threshold range is constructed, and fault diagnosis and location are performed on the full-bridge submodule: When the capacitor voltage value of a certain full-bridge submodule exceeds the confidence threshold range at the sampling time and the time reaches the preset decision time, the full-bridge submodule is determined to have failed, and the corresponding location result is output.

2. The method for locating open-circuit faults in a full-bridge submodule of a bipolar modular converter according to claim 1, characterized in that, The bipolar modular converter includes a bipolar transformer and modular circuitry, the bipolar transformer including a primary winding. Secondary winding one and secondary winding two The primary winding and secondary winding use Connection, the secondary winding two use Connection: Secondary winding one The same-named terminal connects to the upper arm of the three-phase bridge, and the secondary winding two Non-identical terminals connect to the lower arm of the three-phase bridge, primary winding The corresponding terminal is connected to the low-frequency AC system; The modular circuit adopts a three-phase six-bridge-arm structure, with each phase including an upper bridge arm and a lower bridge arm, and each bridge arm consisting of... The bridge is composed of cascaded full-bridge sub-modules, and the connection point of the upper and lower bridge arms is connected to the network side.

3. The method for locating open-circuit faults in a full-bridge submodule of a bipolar modular converter according to claim 2, characterized in that, The full-bridge submodule includes capacitors. Anti-parallel diode Anti-parallel diode 2 Anti-parallel diodes and anti-parallel diodes The anti-parallel diode emitter and anti-parallel diode two The collector connection is used as the positive output of the full-bridge submodule; the anti-parallel diode three The transmitter and anti-parallel diodes The collector is connected to the terminal of the bridge submodule and is used as the negative output terminal of the full-bridge submodule. The anti-parallel diode emitter and anti-parallel diode three collector and capacitor The positive terminal is connected, and the anti-parallel diode is connected. and anti-parallel diodes emitter and capacitor The negative ends are connected.

4. The method for locating open-circuit faults in a full-bridge submodule of a bipolar modular converter according to claim 2, characterized in that, The secondary winding one and secondary winding two The output voltage is equal in amplitude and inverse in phase.

5. The method for locating open-circuit faults in a full-bridge submodule of a bipolar modular converter according to claim 1, characterized in that, The capacitor voltage data is The expression for calculating the average capacitor voltage is as follows: ； in, This represents the average capacitor voltage at the sampling time. The number of submodules within a bridge arm. ; The absolute error of the capacitor voltage is calculated using the capacitor voltage data and the average capacitor voltage, and the expression is: 。 6. The method for locating open-circuit faults in a full-bridge submodule of a bipolar modular converter according to claim 1, characterized in that, The standard deviation of the capacitor voltage The expression is: ； in, The number of submodules within a bridge arm. ; This represents the absolute error of the capacitor voltage.

7. The method for locating open-circuit faults in a full-bridge submodule of a bipolar modular converter according to claim 1, characterized in that, The confidence threshold interval is constructed based on the average value and standard deviation of the capacitor voltage, and is expressed as follows: ； in, This represents the average capacitor voltage at the sampling time. This represents the standard deviation of the capacitor voltage.

8. A system for locating open-circuit faults in a full-bridge submodule of a bipolar modular converter, characterized in that, include: The data acquisition module is used to collect the capacitor voltage data of each full-bridge submodule on each arm of the bipolar modular converter. The average value calculation module is used to calculate the average value of the capacitor voltage of each full-bridge submodule at each sampling time based on the capacitor voltage data of each full-bridge submodule on each bridge arm. The absolute error calculation module is used to calculate the absolute error of the capacitor voltage of each full-bridge submodule at each sampling time based on the capacitor voltage data and the average capacitor voltage. The standard deviation calculation module is used to calculate the standard deviation of the capacitor voltage of each full-bridge submodule at each sampling time based on the absolute error of the capacitor voltage. The submodule fault location module is used to construct a corresponding confidence threshold range based on the average capacitor voltage and the standard capacitor voltage, and to perform fault diagnosis and location for the full-bridge submodule. When the capacitor voltage value of a certain full-bridge submodule exceeds the confidence threshold range at the sampling time and the time reaches the preset decision time, the full-bridge submodule is determined to have failed, and the corresponding location result is output.

9. A computer-readable storage medium having a computer program / instructions stored thereon, characterized in that, When the computer program / instruction is executed by the processor, it implements the steps of the bipolar modular converter full-bridge submodule open-circuit fault location method as described in any one of claims 1 to 7.

10. A computer device / equipment / system, characterized in that, include: Memory, used to store computer programs / instructions; A processor for executing the computer program / instructions to implement the steps of the bipolar modular converter full-bridge submodule open-circuit fault location method according to any one of claims 1 to 7.

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