Converter valve commutation failure monitoring method and device
By monitoring the zero-crossing moment and minimum turn-off angle of the converter valve bridge arm voltage, the problem of low accuracy in monitoring converter valve commutation failure is solved, achieving fast and accurate fault identification and control, and ensuring the stability of the AC system.
Patent Information
- Application Number
- CN202510714637.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-30
- Publication Date
- 2025-09-16
AI Technical Summary
The accuracy of the existing method for monitoring commutation failure of converter valves is low, and it is impossible to adopt a suppression control strategy in time, resulting in aggravation of AC system failure.
By monitoring the bridge arm voltage of the converter valve to determine the first and second zero-crossing moments, the minimum turn-off angle is calculated, and the bridge arm voltage signal is processed using a monostable trigger and logic AND operation to achieve rapid monitoring of commutation failure.
The sensitivity and accuracy of commutation failure monitoring of converter valves have been improved, enabling timely adoption of suppression control strategies to prevent AC system faults from expanding and ensure stable operation.
Smart Images
Figure CN120652181A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of power systems, and in particular to a method and device for monitoring commutation failure of a converter valve. Background Art
[0002] Both AC and DC system faults can easily lead to commutation failures in the converter valves. AC system faults primarily arise from a drop in the commutation bus voltage, which leads to insufficient commutation energy. This inability to fully extract the current carriers from the thyristors during the commutation process leads to commutation failure. DC system faults primarily include trigger pulse loss, delay, false triggering, and thyristor device damage.
[0003] Related art methods for monitoring converter valve commutation failure typically first calculate the zero-sequence voltage from a single-phase AC voltage. If the zero-sequence voltage exceeds a preset voltage threshold, the converter valve is considered to have experienced a single-phase commutation failure. Related art detection methods also perform a Park transform on the three-phase AC voltage to obtain voltage components in a two-phase rotating coordinate system. Based on these voltage components, the converter valve's AC system is determined to have experienced a three-phase fault. If a three-phase fault occurs in the AC system, a three-phase commutation failure is considered to have occurred if the voltage component is less than a preset voltage component threshold.
[0004] When the voltage drop of the AC system is not serious, the obtained zero-sequence voltage will not exceed the preset voltage threshold, or the voltage component is still higher than the voltage component threshold under steady-state conditions, resulting in insensitive and low-accuracy commutation failure monitoring, and the inability to adopt a control strategy to suppress commutation failure in time, which in turn leads to aggravated AC system faults and affects the stable operation of the AC system. Summary of the Invention
[0005] In order to solve the problem of low monitoring accuracy in the prior art, the present application provides a method and device for monitoring commutation failure of a converter valve.
[0006] In a first aspect, the present application provides a method for monitoring commutation failure of a converter valve, which may include:
[0007] The first zero-crossing moment and the second zero-crossing moment of the bridge arm voltage of the converter valve are determined based on the bridge arm voltage of the converter valve. The minimum shut-off angle of the converter valve is calculated based on the first zero-crossing moment and the second zero-crossing moment. The converter valve is monitored for commutation failure based on the minimum shut-off angle.
[0008] In some possible implementations, determining the first zero-crossing time instant and the second zero-crossing time instant of the bridge arm voltage according to the bridge arm voltage of the converter valve includes:
[0009] A first identification pulse signal and a second identification pulse signal are determined based on the bridge arm voltage. The first identification pulse signal and the second identification pulse signal are input into a bistable trigger to obtain a third identification pulse signal. The moment corresponding to the rising edge of the third identification pulse signal is selected as the first zero-crossing moment, and the moment corresponding to the falling edge of the third identification pulse signal is selected as the second zero-crossing moment.
[0010] Furthermore, determining the first identification pulse signal and the second identification pulse signal according to the bridge arm voltage includes:
[0011] The bridge arm voltage and the preset voltage zero crossing threshold are input into the comparator to obtain a first positive zero crossing identification signal. The first positive zero crossing identification signal is input into the first monostable trigger to obtain a second positive zero crossing identification signal. The second positive zero crossing identification signal is input into the second monostable trigger to obtain a first identification pulse signal. Wherein, when the bridge arm voltage is less than the preset voltage zero crossing threshold, the first positive zero crossing identification signal is a high level signal. When the bridge arm voltage is greater than or equal to the preset voltage zero crossing threshold, the first positive zero crossing identification signal is a low level signal.
[0012] A plurality of zero-crossing identification signals are extracted from the bridge arm voltage. A logical AND operation is performed on the plurality of zero-crossing identification signals and the high-level signal to obtain a first negative zero-crossing identification signal. The first negative zero-crossing identification signal is input into a third monostable trigger to obtain a second negative zero-crossing identification signal. The second negative zero-crossing identification signal is input into a fourth monostable trigger to obtain a second identification pulse signal.
[0013] In some other possible implementations, calculating the minimum shut-off angle of the converter valve according to the first zero-crossing moment and the second zero-crossing moment includes:
[0014] The time difference between the first zero-crossing point and the second zero-crossing point is used as the actual shutoff angle of the bridge arm in the converter valve. The minimum value of the actual shutoff angles of all bridge arms in the converter valve is selected as the minimum shutoff angle of the converter valve.
[0015] In some further possible implementations, monitoring the commutation failure of the converter valve according to the minimum shut-off angle includes:
[0016] If the minimum shutoff angle is greater than or equal to the limit shutoff angle of the converter valve, it is determined that the converter valve has not experienced a commutation failure. If the minimum shutoff angle is less than the limit shutoff angle of the converter valve, it is determined that the converter valve has experienced a commutation failure.
[0017] In a second aspect, the present application provides a device for monitoring commutation failure of a converter valve, which may include:
[0018] The determination module is used to determine the first zero-crossing moment and the second zero-crossing moment of the bridge arm voltage according to the bridge arm voltage of the converter valve.
[0019] The calculation module is used to calculate the minimum shut-off angle of the converter valve according to the first zero-crossing point moment and the second zero-crossing point moment.
[0020] The monitoring module is used to monitor the commutation failure of the converter valve according to the minimum shut-off angle.
[0021] In some possible implementations, the determination module is specifically configured to:
[0022] The first identification pulse signal and the second identification pulse signal are determined according to the bridge arm voltage.
[0023] The first identification pulse signal and the second identification pulse signal are input into a bistable trigger to obtain a third identification pulse signal.
[0024] The moment corresponding to the rising edge of the third identification pulse signal is selected as the first zero-crossing moment, and the moment corresponding to the falling edge of the third identification pulse signal is selected as the second zero-crossing moment.
[0025] Furthermore, the module is specifically used to:
[0026] The bridge arm voltage and the preset voltage zero crossing threshold are input into the comparator to obtain a first positive zero crossing identification signal. The first positive zero crossing identification signal is input into the first monostable trigger to obtain a second positive zero crossing identification signal. The second positive zero crossing identification signal is input into the second monostable trigger to obtain a first identification pulse signal. Wherein, when the bridge arm voltage is less than the preset voltage zero crossing threshold, the first positive zero crossing identification signal is a high level signal. When the bridge arm voltage is greater than or equal to the preset voltage zero crossing threshold, the first positive zero crossing identification signal is a low level signal. It can be seen that the determination module can obtain the first identification pulse signal according to the above process.
[0027] Extract multiple zero-crossing identification signals from the bridge arm voltage. Perform a logical AND operation on the multiple zero-crossing identification signals and the high-level signal to obtain a first negative zero-crossing identification signal. Input the first negative zero-crossing identification signal into a third monostable trigger to obtain a second negative zero-crossing identification signal. Input the second negative zero-crossing identification signal into a fourth monostable trigger to obtain a second identification pulse signal. It can be seen that the determination module can obtain the second identification pulse signal according to the above process.
[0028] In some other possible implementations, the computing module is specifically configured to:
[0029] The time difference between the first zero-crossing point and the second zero-crossing point is used as the actual shutoff angle of the bridge arm in the converter valve. The minimum value of the actual shutoff angles of all bridge arms in the converter valve is selected as the minimum shutoff angle of the converter valve.
[0030] In some further possible implementations, the monitoring module is specifically configured to:
[0031] If the minimum shutoff angle is greater than or equal to the limit shutoff angle of the converter valve, it is determined that the converter valve has not experienced a commutation failure. If the minimum shutoff angle is less than the limit shutoff angle of the converter valve, it is determined that the converter valve has experienced a commutation failure.
[0032] On the other hand, the present application also provides a computer device, including: one or more processors.
[0033] A processor is used to execute one or more programs.
[0034] When one or more programs are executed by one or more processors, the monitoring method described above is implemented.
[0035] In another aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the monitoring method described above.
[0036] Compared with the prior art, the present invention has the following advantages:
[0037] In the method for monitoring commutation failure of a converter valve provided in the present application, a first zero-crossing moment and a second zero-crossing moment of the bridge arm voltage are determined based on the bridge arm voltage of the converter valve. The minimum shut-off angle of the converter valve is calculated based on the first zero-crossing moment and the second zero-crossing moment. The converter valve is monitored for commutation failure based on the minimum shut-off angle. By obtaining the first zero-crossing moment and the second zero-crossing moment only from the bridge arm voltage, and then using the minimum shut-off angle, rapid monitoring of commutation failure of the converter valve can be achieved. This not only improves monitoring sensitivity and detection accuracy, but also facilitates the timely implementation of a control strategy to suppress commutation failure, thereby preventing further expansion of the AC system fault range as much as possible and ensuring stable operation of the AC system.
[0038] This application only needs to collect the bridge arm voltage to monitor the commutation failure, without the need for other electrical parameters. The logic is simple and clear, and can be directly applied to engineering, which is beneficial to increasing the probability of the converter valve resisting commutation failure.
[0039] The present application calculates the minimum shut-off angle of the converter valve according to the first zero-crossing moment and the second zero-crossing moment, which can quickly respond to and accurately position the bridge arm at the early stage of commutation failure, further accelerating the monitoring speed of commutation failure. BRIEF DESCRIPTION OF THE DRAWINGS
[0040] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.
[0041] Figure 1 This is a schematic flow chart of a method for monitoring commutation failure of a converter valve in an embodiment of the present application.
[0042] Figure 2 This is a schematic flowchart of determining the first zero-crossing moment and the second zero-crossing moment of the bridge arm voltage in an embodiment of the present application.
[0043] Figure 3 In the embodiment of the present application, the first identification pulse signal Sg is determined T1VN A schematic flow chart of .
[0044] Figure 4 In the embodiment of the present application, the second identification pulse signal Sg is determined T2VN A schematic flow chart of .
[0045] Figure 5 This is a schematic structural diagram of a converter valve commutation failure monitoring device in an embodiment of the present application. DETAILED DESCRIPTION
[0046] The technical solution in this application will be described below with reference to the accompanying drawings.
[0047] The terms "first," "second," and the like in the description, embodiments, claims, and drawings of this application are used solely for descriptive purposes and are not to be construed as indicating or implying relative importance or order. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions, such as, for example, inclusion of a series of steps or units. A method, system, product, or apparatus is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0048] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.
[0049] Example 1:
[0050] The embodiment of the present application provides a method for monitoring commutation failure of a converter valve. The converter valve may be a twelve-pulsation converter valve, etc. Figure 1 As shown, the monitoring method 100 includes the following steps:
[0051] Step S1: According to the bridge arm voltage U of the converter valve VN Determine the first zero-crossing moment of the bridge arm voltage T 1VN and the second zero-crossing time T 2VN .
[0052] Step S2: According to the first zero-crossing time T 1VN and the second zero-crossing time T 2VN Calculate the minimum closing angle γ of the converter valve vmin .
[0053] Step S3: According to the minimum cut-off angle γ vmin Monitor the commutation failure of the commutation valve.
[0054] In some possible implementations, in step S1, the bridge arm voltage U VN Determine the first zero-crossing moment of the bridge arm voltage T 1VN and the second zero-crossing time T 2VN ,like Figure 2 As shown, the following steps are included:
[0055] Step S11: According to the bridge arm voltage U VN Determine the first identification pulse signal Sg T1VN and the second identification pulse signal Sg T2VN .
[0056] Step S12: The first identification pulse signal Sg T1VN and the second identification pulse signal Sg T2VN Input a bistable trigger (which can be an SR trigger, etc.) to obtain the third identification pulse signal Sg γVN .
[0057] Step S13: Select the third identification pulse signal Sg γVN The moment corresponding to the rising edge of is taken as the first zero crossing moment T 1VN and the falling edge Sg of the third identification pulse signal γVN The corresponding moment is the second zero-crossing moment T 2VN .
[0058] Since the bridge arm voltage U VN There are zero drift and burrs near the zero crossing point, which leads to inaccurate judgment of the zero crossing moment. zero-ref And the bridge arm voltage UVN and the voltage zero-crossing threshold U zero-ref Compare and make the judgment of zero crossing point as accurate as possible. Voltage zero crossing threshold U zero-ref The value of cannot be too large, which may cause the zero-crossing judgment to be advanced. The voltage zero-crossing threshold U zero-ref The value should not be too small, which may cause inaccurate zero-crossing point determination. Generally, it can be set to 0.5kV.
[0059] When the zero drift and burrs are large, or the converter valve is in an operating state with a large trigger angle, the bridge arm voltage will jump violently, causing the bridge arm voltage to cross zero, and will also cause a large error in the identification of the zero-crossing point of the turn-off angle. Therefore, it is necessary to set a monostable trigger to hold the zero-crossing point identification signal. Generally, the holding time does not exceed half of the converter valve operation cycle, which can be 0.008s. Finally, the identified zero-crossing point identification signal is cut off as a pulse width modulation signal, and the pulse width can generally be 100μs.
[0060] Therefore, further, in the above step S11, according to the bridge arm voltage U VN Determine the first identification pulse signal Sg T1VN and the second identification pulse signal Sg T2VN ,include:
[0061] like Figure 3 As shown, the bridge arm voltage U VN and the preset voltage zero-crossing threshold U zero-ref Input the comparator COMP to obtain the first positive zero-crossing point identification signal S I1+ The first positive zero-crossing identification signal S I1+ Input the first monostable trigger T1 to obtain the second positive zero-crossing point identification signal S I2+ The second positive zero-crossing point identification signal S I2+ Input the second monostable trigger T2 to obtain the first identification pulse signal Sg T1VN Among them, the bridge arm voltage U VN Less than the preset voltage zero-crossing threshold U zero-ref In the case of the first positive zero-crossing identification signal S I1+ It is a high level signal. Bridge arm voltage U VN Greater than or equal to the preset voltage zero-crossing threshold U zero-ref In the case of the first positive zero-crossing identification signal S I1+ It is a low level signal.
[0062] like Figure 4 As shown, the bridge arm voltage U VN Extract multiple zero-crossing point identification signals S IPerform a logical AND operation on multiple zero-crossing point identification signals and the high-level signal to obtain a first negative zero-crossing point identification signal S I1- The first negative zero-crossing identification signal S I1- Input the third monostable trigger T3 to obtain the second negative zero-crossing point identification signal S I2- The second negative zero-crossing identification signal S I2- Input the fourth monostable trigger T4 to obtain the second identification pulse signal Sg T2VN .
[0063] Optionally, in the above step S12, the input signal of the SR trigger is the first identification pulse signal Sg T1VN and the second identification pulse signal Sg T2VN , when the trigger signal Clik=1, the following Table 1 can be obtained:
[0064] Table 1
[0065] <![CDATA[Sg T1VN ]]> <![CDATA[Sg T2VN ]]> <![CDATA[Sg γVN ]]> illustrate 0 0 0 <![CDATA[Sg T1VN =0, Sg T2VN =0, Sg γVN Keep status unchanged]]> 1 0 1 <![CDATA[Sg T1VN =1, Sg T2VN =0, Sg γVN Status is set to 1]]> 0 1 0 <![CDATA[Sg T1VN =0, Sg T2VN =1, Sg γVN Status is set to 0]]>
[0066] The period of the trigger signal Clik will affect Sg γVN The response speed of the state, the frequency of Clik is too low, Sg γVN Slow status response will cause Sg γVN Inaccurate. A Clik frequency that is too high will affect the calculation speed. Clik can generally be set to 1000 times the operating frequency of the AC system.
[0067] In some other possible implementations, in step S2, the first zero-crossing time T 1VN and the second zero-crossing time T 2VN Calculate the minimum closing angle γ of the converter valve vmin ,include:
[0068] The first zero-crossing time T 1VN and the second zero-crossing time T 2VN The time difference is taken as the actual closing angle γ of the bridge arm in the converter valve vN Select the actual cut-off angle γ of all bridge arms in the converter valve vN The minimum value is taken as the minimum shut-off angle γ of the converter valve vmin .
[0069] In some other possible implementations, in step S3, the minimum cut-off angle γ vmin Monitor commutation failure of the converter valve, including:
[0070] If the minimum cut-off angle γ vmin Greater than or equal to the limit shut-off angle γ of the converter valve min, it is determined that no commutation failure occurs in the converter valve, and the commutation failure signal CF can be kept as a low level signal.
[0071] If the minimum cut-off angle γ vmin Less than the limit shut-off angle γ of the converter valve min , it is determined that the commutation failure occurs in the converter valve, and the commutation failure signal CF can be set to a high level signal.
[0072] Example 2:
[0073] Based on the same inventive concept, the embodiment of the present application also provides a device for monitoring commutation failure of a converter valve. Figure 5 As shown, the monitoring device 200 may include:
[0074] Determining module 201, for determining the bridge arm voltage U of the converter valve according to VN Determine the first zero-crossing moment of the bridge arm voltage T 1VN and the second zero-crossing time T 2VN .
[0075] Calculation module 202, for the first zero-crossing time T 1VN and the second zero-crossing time T 2VN Calculate the minimum closing angle γ of the converter valve vmin .
[0076] Monitoring module 203, based on the minimum cut-off angle γ vmin Monitor the commutation failure of the commutation valve.
[0077] In some possible implementations, the determining module 201 is specifically configured to:
[0078] According to the bridge arm voltage U VN Determine the first identification pulse signal Sg T1VN and the second identification pulse signal Sg T2VN The first identification pulse signal Sg T1VN and the second identification pulse signal Sg T2VN Input a bistable trigger (which can be an SR trigger, etc.) to obtain the third identification pulse signal Sg γVN . Select the third identification pulse signal Sg γVN The moment corresponding to the rising edge of is taken as the first zero crossing moment T 1VN and the falling edge Sg of the third identification pulse signal γVN The corresponding moment is the second zero-crossing moment T 2VN .
[0079] Furthermore, the determination module 201 is specifically configured to:
[0080] like Figure 3 As shown, the bridge arm voltage U VNand the preset voltage zero-crossing threshold U zero-ref Input the comparator COMP to obtain the first positive zero-crossing point identification signal S I1+ The first positive zero-crossing identification signal S I1+ Input the first monostable trigger T1 to obtain the second positive zero-crossing point identification signal S I2+ The second positive zero-crossing point identification signal S I2+ Input the second monostable trigger T2 to obtain the first identification pulse signal Sg T1VN Among them, the bridge arm voltage U VN Less than the preset voltage zero-crossing threshold U zero-ref In the case of the first positive zero-crossing identification signal S I1+ It is a high level signal. Bridge arm voltage U VN Greater than or equal to the preset voltage zero-crossing threshold U zero-ref In the case of the first positive zero-crossing identification signal S I1+ It can be seen that the determination module 201 can obtain the first identification pulse signal Sg according to the above process. T1VN .
[0081] like Figure 4 As shown, the bridge arm voltage U VN Extract multiple zero-crossing point identification signals S I Perform a logical AND operation on multiple zero-crossing point identification signals and the high-level signal to obtain a first negative zero-crossing point identification signal S I1- The first negative zero-crossing identification signal S I1- Input the third monostable trigger T3 to obtain the second negative zero-crossing point identification signal S I2- The second negative zero-crossing identification signal S I2- Input the fourth monostable trigger T4 to obtain the second identification pulse signal Sg T2VN It can be seen that the determination module 201 can obtain the second identification pulse signal Sg according to the above process. T2VN .
[0082] In some other possible implementations, the calculation module 202 is specifically configured to:
[0083] The first zero-crossing time T 1VN and the second zero-crossing time T 2VN The time difference is taken as the actual closing angle γ of the bridge arm in the converter valve vN Select the actual cut-off angle γ of all bridge arms in the converter valve vN The minimum value is taken as the minimum shut-off angle γ of the converter valve vmin .
[0084] In some further possible implementations, the monitoring module 203 is specifically configured to:
[0085] If the minimum cut-off angle γ vmin Greater than or equal to the limit shut-off angle γ of the converter valve min , confirm that the converter valve has not experienced commutation failure. If the minimum shut-off angle γ vmin Less than the limit shut-off angle γ of the converter valve min , it is determined that the commutation failure of the converter valve occurs.
[0086] Example 3:
[0087] Based on the same inventive concept, an embodiment of the present application further provides a computer device, comprising a processor and a memory, the memory being used to store a computer program, the computer program comprising program instructions, and the processor being used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc., which are the computing core and control core of the terminal, and are suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in a computer storage medium to implement a corresponding method flow or corresponding function, so as to implement the steps of the monitoring method provided in the above embodiment.
[0088] Example 4:
[0089] Based on the same inventive concept, an embodiment of the present application further provides a computer-readable storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium herein may include both a built-in storage medium in a computer device and, of course, an extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space that stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space. These instructions may be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium herein may be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor may load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the monitoring method provided in the above embodiment.
[0090] Those skilled in the art will appreciate that embodiments of the application may be provided as methods, systems, or computer program products. Thus, the application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0091] The application is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as a combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.
[0092] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1The function specified in one or more boxes.
[0093] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.
[0094] The above are merely embodiments of the application and are not intended to limit the application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the application are included in the scope of the claims of the pending application.
Claims
1. A method for monitoring commutation failure of a converter valve, characterized in that: include: Determining a first zero-crossing moment and a second zero-crossing moment of the bridge arm voltage according to the bridge arm voltage of the converter valve; Calculating a minimum shut-off angle of the converter valve according to the first zero-crossing time and the second zero-crossing time; The commutation failure of the converter valve is monitored according to the minimum shut-off angle.
2. The monitoring method according to claim 1, characterized in that The step of determining the first zero-crossing moment and the second zero-crossing moment of the bridge arm voltage according to the bridge arm voltage of the converter valve includes: determining a first identification pulse signal and a second identification pulse signal according to the bridge arm voltage; Inputting the first identification pulse signal and the second identification pulse signal into a bistable trigger to obtain a third identification pulse signal; The moment corresponding to the rising edge of the third identification pulse signal is selected as the first zero-crossing moment, and the moment corresponding to the falling edge of the third identification pulse signal is selected as the second zero-crossing moment.
3. The monitoring method according to claim 2, characterized in that: The determining of the first identification pulse signal and the second identification pulse signal according to the bridge arm voltage includes: The bridge arm voltage and a preset voltage zero-crossing threshold are input into a comparator to obtain a first positive zero-crossing identification signal; the first positive zero-crossing identification signal is input into a first monostable trigger to obtain a second positive zero-crossing identification signal; the second positive zero-crossing identification signal is input into a second monostable trigger to obtain the first identification pulse signal; wherein, when the bridge arm voltage is less than the preset voltage zero-crossing threshold, the first positive zero-crossing identification signal is a high-level signal; when the bridge arm voltage is greater than or equal to the preset voltage zero-crossing threshold, the first positive zero-crossing identification signal is a low-level signal; Extract multiple zero-crossing point identification signals from the bridge arm voltage; perform a logical AND operation on the multiple zero-crossing point identification signals and a high-level signal to obtain a first negative zero-crossing point identification signal; input the first negative zero-crossing point identification signal into a third monostable trigger to obtain a second negative zero-crossing point identification signal; input the second negative zero-crossing point identification signal into a fourth monostable trigger to obtain the second identification pulse signal.
4. The monitoring method according to claim 1, characterized in that: Calculating the minimum shut-off angle of the converter valve according to the first zero-crossing time and the second zero-crossing time includes: Using the time difference between the first zero-crossing point and the second zero-crossing point as the actual shut-off angle of the bridge arm in the converter valve; The minimum value of the actual shut-off angles of all bridge arms in the converter valve is selected as the minimum shut-off angle of the converter valve.
5. The monitoring method according to claim 1, characterized in that: The monitoring of commutation failure of the converter valve according to the minimum shut-off angle includes: If the minimum shut-off angle is greater than or equal to the limit shut-off angle of the converter valve, it is determined that no commutation failure occurs in the converter valve; If the minimum shut-off angle is less than the limit shut-off angle of the converter valve, it is determined that a commutation failure occurs in the converter valve.
6. A device for monitoring commutation failure of a converter valve, characterized in that: include: A determination module, configured to determine a first zero-crossing moment and a second zero-crossing moment of the bridge arm voltage according to the bridge arm voltage of the converter valve; a calculation module, configured to calculate a minimum shut-off angle of the converter valve according to the first zero-crossing time and the second zero-crossing time; A monitoring module is used to monitor the commutation failure of the converter valve according to the minimum shut-off angle.
7. The monitoring device according to claim 6, characterized in that The determining module is specifically configured to: determining a first identification pulse signal and a second identification pulse signal according to the bridge arm voltage; Inputting the first identification pulse signal and the second identification pulse signal into a bistable trigger to obtain a third identification pulse signal; The moment corresponding to the rising edge of the third identification pulse signal is selected as the first zero-crossing moment, and the moment corresponding to the falling edge of the third identification pulse signal is selected as the second zero-crossing moment.
8. The monitoring device according to claim 7, characterized in that The determining module is specifically configured to: The bridge arm voltage and a preset voltage zero-crossing threshold are input into a comparator to obtain a first positive zero-crossing identification signal; the first positive zero-crossing identification signal is input into a first monostable trigger to obtain a second positive zero-crossing identification signal; the second positive zero-crossing identification signal is input into a second monostable trigger to obtain the first identification pulse signal; wherein, when the bridge arm voltage is less than the preset voltage zero-crossing threshold, the first positive zero-crossing identification signal is a high-level signal; when the bridge arm voltage is greater than or equal to the preset voltage zero-crossing threshold, the first positive zero-crossing identification signal is a low-level signal; Extract multiple zero-crossing point identification signals from the bridge arm voltage; perform a logical AND operation on the multiple zero-crossing point identification signals and a high-level signal to obtain a first negative zero-crossing point identification signal; input the first negative zero-crossing point identification signal into a third monostable trigger to obtain a second negative zero-crossing point identification signal; input the second negative zero-crossing point identification signal into a fourth monostable trigger to obtain the second identification pulse signal.
9. The monitoring device according to claim 6, characterized in that The calculation module is specifically used for: Using the time difference between the first zero-crossing point and the second zero-crossing point as the actual shut-off angle of the bridge arm in the converter valve; The minimum value of the actual shut-off angles of all bridge arms in the converter valve is selected as the minimum shut-off angle of the converter valve.
10. The monitoring device according to claim 6, characterized in that: The monitoring module is specifically used for: If the minimum shut-off angle is greater than or equal to the limit shut-off angle of the converter valve, it is determined that no commutation failure occurs in the converter valve; If the minimum shut-off angle is less than the limit shut-off angle of the converter valve, it is determined that a commutation failure occurs in the converter valve.
11. A computer device, characterized in that: include: one or more processors; The processor is configured to store one or more programs; When the one or more programs are executed by the one or more processors, the monitoring method according to any one of claims 1 to 5 is implemented.
12. A computer-readable storage medium, characterized in that A computer program is stored thereon, and when the computer program is executed, the monitoring method according to any one of claims 1 to 5 is implemented.