A valve control device, control method, determination method and system thereof, and storage medium

Abstract

The application relates to a valve control device and a control method, a judgment method and a system thereof and a storage medium, and belongs to the technical field of flexible direct-current power transmission. The valve control device generates control instructions of a plurality of power modules in each set control period, and counts switching frequencies of the control instructions of each power module within a set detection time. In the detection period, if the switching frequency is greater than a set frequency, the number of abnormal power modules is increased by 1. At any moment in the detection period, if the number of abnormal power modules is greater than a set value, it is considered that the valve control device is abnormal; otherwise, it is considered that the valve control device is normal. In the detection period, the valve control device judges the abnormality of each power module in the set detection time, realizes the self-monitoring function of the switching frequency of the control instructions, discovers the abnormality of the valve control device in time, avoids the valve control device from working in an abnormal state to generate incorrect control instructions, and can effectively improve the reliability of the valve control device.

Description

Technical Field

[0001] This invention relates to a valve control device, its control method, judgment method, system, and storage medium, belonging to the field of flexible DC transmission technology. Background Technology

[0002] With the development of power electronics technology, flexible DC transmission based on modular multilevel converters (MMCs) has received more attention. The basic idea of ​​MMCs is to reduce the voltage stress on each submodule by cascading multiple submodules. Due to their modularity, cascading capability, and easy expansion, they have been widely used.

[0003] MMC converter valves are core equipment in flexible DC transmission systems. They are typically constructed using multiple half-bridge power modules connected in series. Each half-bridge power module consists of two IGBT devices: an upper IGBT1 and a lower IGBT2. When the power module receives an activation command, it turns on the upper IGBT1 and turns off the lower IGBT2; when it receives a deactivation command, it turns off the upper IGBT1 and turns on the lower IGBT2. The existing topology of a half-bridge power module is shown in the attached diagram in the manual. Figure 1 As shown.

[0004] The valve control unit (VCU) that controls the MMC converter valve is the "brain" of the converter valve. The VCU generates control commands for all power modules through calculation, controlling the power modules to switch on or off. Under normal operating conditions, the switching frequency of the power modules is typically controlled below 200Hz. If the VCU operates under abnormal conditions and generates incorrect control commands, it can cause malfunctions in the MMC converter valve, and in severe cases, damage to the power modules.

[0005] Therefore, an effective means is needed to detect and address abnormal conditions in valve control equipment in advance, so as to avoid power module failures and affect the availability of flexible DC transmission systems. Summary of the Invention

[0006] The purpose of this invention is to provide a valve control device and its control method, judgment method and system, and storage medium to solve the problem of failing to detect erroneous control commands generated when the valve control device is operating under abnormal conditions.

[0007] To achieve the above objectives, the present invention includes:

[0008] The present invention provides a method for determining the abnormal state of a valve-controlled device, comprising the following steps:

[0009] The valve control device generates control commands for several power modules in each set control cycle and counts the switching frequency of the control commands for each power module within a set detection time.

[0010] If the switching frequency is greater than the set frequency during the detection period, the number of abnormal power modules is incremented by 1.

[0011] At any point during the detection cycle, if the number of abnormal power modules exceeds the set value, the valve control device is considered to be in an abnormal state; otherwise, the valve control device is considered to be in a normal state. The detection cycle consists of multiple set detection times, and the set detection time consists of multiple control cycles.

[0012] This invention determines whether the switching frequency of the control command is abnormal based on the switching frequency and a set frequency. If the switching frequency of the control command is abnormal, the number of abnormal power modules is incremented by 1. At any moment in the detection cycle, if the number of abnormal power modules is greater than the set value, the valve control device is considered to be in an abnormal state; otherwise, the valve control device is considered to be in a normal state. The valve control device of this invention generates several control commands for controlling the corresponding power modules to be put on or taken off in each control cycle. This invention provides a method for judging the abnormal state of a valve control device. Within the detection cycle, each power module is judged for abnormality at a set detection time. This achieves a self-monitoring function of the switching frequency of the control command, promptly detecting abnormalities in the valve control device and preventing the valve control device from generating incorrect control commands under abnormal conditions, which could lead to abnormalities in the MMC converter valve and damage to the power modules. This effectively improves the reliability of the valve control device. This invention performs detection on each power module within a set detection time within the detection cycle, eliminating the need for real-time monitoring of each power module. Compared to real-time monitoring of each power module, this invention has lower application costs and is more suitable for application.

[0013] Furthermore, within the detection cycle, the set detection time is used as a sliding time window to obtain several switching frequencies. If any switching frequency is greater than the set frequency, the power module is abnormal.

[0014] Furthermore, within the sliding time window, the switching frequency within the sliding time window is calculated based on the number of adjacent control cycles in which the control command changes.

[0015] The switching frequency within the sliding time window of this invention depends on the number of adjacent control cycles that change according to the control command. If the control command of the next control cycle changes compared to the control command of the previous control cycle, the switching frequency within the sliding time window increases.

[0016] Furthermore, the control commands for each power module are calculated and generated during the converter valve unlocking operation based on the AC voltage and current collected by the valve control equipment during the control cycle, as well as the reference modulation wave issued by the upper control system.

[0017] Furthermore, the value is set to 0.

[0018] When the set value of this invention is 0, if the switching frequency is greater than the set frequency within the detection cycle, the valve control device is considered to be in an abnormal state.

[0019] Furthermore, if the current power module is fault-bypassed, the switching frequency of the control command of that power module within the set detection time will not be counted.

[0020] This invention addresses power modules with fault bypass, eliminating the need to calculate the switching frequency of these power modules.

[0021] The present invention provides a computer-readable storage medium storing a computer program that, when run on a computer, causes the computer to execute the method for determining the abnormal state of a valve control device as described above.

[0022] This invention, within a detection cycle, judges the abnormality of each power module at a set detection time, realizing a self-monitoring function for the switching frequency of control commands. This timely detection of anomalies in valve-controlled equipment prevents the equipment from generating erroneous control commands under abnormal conditions, thus avoiding malfunctions in the MMC converter valve and damage to the power module, effectively improving the reliability of the valve-controlled equipment. This invention performs detection on each power module within a set detection time during the detection cycle, eliminating the need for real-time monitoring of each module. Compared to real-time monitoring, this invention has lower application costs and is more suitable for practical applications. The valve-controlled equipment abnormality judgment system of this invention includes a processor, which executes instructions to implement the valve-controlled equipment abnormality judgment method described above.

[0023] This invention performs power module anomaly detection for each power module within a set detection time during the detection cycle. It achieves self-monitoring of the control command switching frequency, promptly detecting anomalies in valve control equipment. This prevents the valve control equipment from generating erroneous control commands under abnormal conditions, which could lead to malfunctions in the MMC converter valve and damage to the power module, effectively improving the reliability of the valve control equipment. Since this invention performs detection on each power module within a set detection time during the detection cycle, it eliminates the need for real-time monitoring of each individual power module. Compared to real-time monitoring, this invention has lower application costs and is more suitable for practical applications.

[0024] The present invention provides a control method for a valve-controlled device, wherein the state of the valve-controlled device is determined according to the above-described method for judging abnormal states of the valve-controlled device; if the state of the valve-controlled device is abnormal, the valve-controlled device is controlled to be off duty; if the state of the valve-controlled device is normal, the valve-controlled device is controlled to be on duty.

[0025] This invention performs power module anomaly detection for each power module within a set detection time during the detection cycle. It achieves self-monitoring of the control command switching frequency, promptly detecting anomalies in valve control equipment. This prevents valve control equipment from generating erroneous control commands under abnormal conditions, which could lead to malfunctions in the MMC converter valve and damage to the power module. The invention can determine whether a valve control equipment can be on duty based on its status, and control its on-duty status accordingly, effectively improving the reliability of the valve control equipment. This invention performs detection on each power module within a set detection time during the detection cycle, eliminating the need for real-time monitoring of each individual power module. Compared to real-time monitoring of each power module, this invention has lower application costs and is more suitable for practical applications.

[0026] The present invention provides a valve control device, comprising a valve control host for connecting to an AC power source and an optical transceiver module for controlling a connected power module. The valve control host and the optical transceiver module are connected, and the valve control host is used to execute instructions to implement the control method of the valve control device as described above.

[0027] This invention performs power module anomaly detection for each power module within a set detection time during the detection cycle. It achieves self-monitoring of the control command switching frequency, promptly detecting anomalies in the valve control equipment. This prevents the valve control equipment from generating erroneous control commands under abnormal conditions, which could lead to malfunctions in the MMC converter valve and damage to the power module, effectively improving the reliability of the valve control equipment. The optical transceiver module of this invention is used to quickly and without delay send control commands from the valve control host to the power module, enabling the power module to execute the control commands. This invention performs detection on each power module within a set detection time during the detection cycle, eliminating the need for real-time monitoring of each power module. Compared to real-time monitoring of each power module, this invention has lower application costs and is more suitable for practical applications. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of an existing half-bridge power module;

[0029] Figure 2 This is a structural diagram of the valve control device control system of the present invention;

[0030] Figure 3 This is a flowchart of the valve control device control command anomaly detection process of the present invention;

[0031] Figure 4 This is a schematic diagram of the sliding time window detection of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0033] An embodiment of a method for determining abnormal states of valve-controlled equipment:

[0034] A method for determining abnormal states of valve-controlled equipment, such as... Figure 2 As shown, it consists of a valve control host, an optical transceiver module, and a power module. The valve control host sends control commands to each power module through the optical transceiver module, and the power module executes the commands.

[0035] After the valve control device is powered on, it calculates the control commands for all power modules according to a certain control cycle (usually 50 microseconds) based on the collected AC voltage, current and reference modulation wave sent by the upper control system, and controls the power modules to be put on or cut off. The control commands are updated once every control cycle.

[0036] Each round of testing starts with the first power module and continues until the last power module is detected. The flowchart is as follows: Figure 3 As shown.

[0037] Before a new round of testing begins, the number of power modules with abnormal control command switching frequencies is first reset to zero.

[0038] The detection time for each power module is 10 seconds. Within 10 seconds, if the switching frequency of the power module is greater than 100 (corresponding to a switching frequency of 1KHz) within any 100ms sliding time window, the control command will count the number of modules with abnormal switching frequency as 1, and the detection of that power module will end. Otherwise, the detection will continue until the 10-second countdown ends.

[0039] Method for detecting the switching frequency of power modules within a 100ms sliding time window:

[0040] The first step is to cache the control instructions for 100ms starting from the first control cycle of the 10-second detection window, and count the changes in the control instructions within this time window. If the control instructions change compared to the instructions in the previous cycle, the switching quantity is incremented by 1. The switching frequency within this 100ms time window is obtained based on the switching quantity.

[0041] The second step is to remove the first control instruction from the buffer after the 100ms buffer time ends, add the new control instruction to the buffer in the next new control cycle, and count the switching frequency in the new 100ms time window.

[0042] The third step is to repeat the second step as the control cycle is updated, until the 10-second timer ends or the switching frequency exceeds the limit.

[0043] 100ms sliding time window frequency as Figure 4 As shown.

[0044] After the first power module test is completed, the switching frequency test of the second power module control command begins. Similarly, within 10 seconds, the switching frequency of the power module is checked within a 100ms sliding time window to see if it exceeds the limit. Exceeding the limit means that the switching frequency is greater than the set frequency.

[0045] During the testing process, if the power module being tested has been fault-bypassed, the switching command frequency test will no longer be performed, and the test will automatically be performed on the next power module.

[0046] During the detection process, if the number of sub-modules with abnormal control command switching frequency reaches the set threshold (the set threshold is 0), the valve control equipment's control command switching frequency is determined to be abnormal and cannot be switched to the duty state.

[0047] After all power modules have been tested in this round, if the number of modules with abnormal control command switching frequencies is 0, then the switching frequency of the valve control equipment is determined to be normal, and it can be switched to the duty mode.

[0048] After the previous round of testing is completed, the number of modules with abnormal switching frequencies is reset to zero, and the next round of cyclic testing continues starting from the first power module.

[0049] An embodiment of a computer-readable storage medium:

[0050] The present invention provides a computer-readable storage medium, comprising a computer program stored thereon. When the computer program is executed on a computer, it causes the computer to perform the above-described method for determining the abnormal state of a valve-controlled device. The method for determining the abnormal state of a valve-controlled device has been described in detail in an embodiment of such a method, and will not be repeated here.

[0051] An embodiment of a system for determining abnormal states of valve-controlled equipment:

[0052] The present invention provides a system for determining the abnormal state of a valve-controlled device, comprising a processor. The processor is configured to execute instructions to implement the method for determining the abnormal state of the valve-controlled device as described above. The method for determining the abnormal state of the valve-controlled device has been described in detail in an embodiment of such a method, and will not be repeated here.

[0053] An embodiment of a control method for a valve-controlled device:

[0054] This invention discloses a control method for a valve-controlled device. The method determines the state of the valve-controlled device according to the aforementioned method for judging abnormal states. If the valve-controlled device is in an abnormal state, it is considered unable to operate, and the device is controlled to be off-duty. If the valve-controlled device is in a normal state, it is considered capable of operating, and the device is controlled to operate. The method for judging abnormal states of the valve-controlled device has been described in detail in an embodiment of such a method, and will not be repeated here.

[0055] An embodiment of a valve-controlled device:

[0056] The present invention discloses a valve control device, comprising a valve control host for connecting to an AC power supply and an optical transceiver module for controlling a connected power module. The valve control host and the optical transceiver module are connected, and the valve control host is used to execute instructions to implement the control method of the valve control device as described above. The method for determining the abnormal state of the valve control device has been described in detail in an embodiment of the control method for the valve control device, and will not be repeated here.

Claims

1. A method of determining an abnormal state of a valve control apparatus, characterized by, Includes the following steps: The valve control device generates control commands for several power modules in each set control cycle and counts the switching frequency of the control commands for each power module within a set detection time. Within the detection period, the set detection time is used as a sliding time window to obtain several switching frequencies. If any switching frequency is greater than the set frequency, the number of abnormal power modules is incremented by 1. At any moment during the detection cycle, if the number of abnormal power modules is greater than a set value, the valve control device is considered to be in an abnormal state; otherwise, the valve control device is considered to be in a normal state. The detection cycle consists of multiple set detection times, and the set detection times consist of multiple control cycles. Within the sliding time window, the switching frequency within the sliding time window is calculated based on the number of two adjacent control cycles in which the control command changes.

2. The method of judging an abnormal state of a valve control apparatus according to claim 1, characterized by, Each round of testing begins with the first power module and continues until the last power module is detected.

3. The method of judging an abnormal state of a valve control apparatus according to claim 2, characterized by, Before a new round of testing begins, the number of power modules with abnormal control command switching frequencies is first reset to zero.

4. The method of judging an abnormal state of a valve control apparatus according to claim 1, characterized by The control command for each power module is calculated and generated during the converter valve unlocking operation based on the AC voltage and current collected by the valve control equipment during the control cycle, as well as the reference modulation wave issued by the upper control system.

5. The method of judging an abnormal state of a valve control apparatus according to any one of claims 1 to 4, characterized by, The set value is 0.

6. The method of judging an abnormal state of a valve control apparatus according to claim 1, characterized by If the power module is currently fault-bypassed, the switching frequency of the control commands for that power module within the set detection time will not be counted.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when run on a computer, causes the computer to execute the method for determining the abnormal state of the valve control device as described in claim 1.

8. The computer-readable storage medium of claim 7, wherein, Each round of testing begins with the first power module and continues until the last power module is detected.

9. The computer-readable storage medium of claim 8, wherein, Before a new round of testing begins, the number of power modules with abnormal control command switching frequencies is first reset to zero.

10. The computer-readable storage medium of claim 7, wherein, The control command for each power module is calculated and generated during the converter valve unlocking operation based on the AC voltage and current collected by the valve control equipment during the control cycle, as well as the reference modulation wave issued by the upper control system.

11. The computer-readable storage medium of any of claims 7 to 10, wherein, The set value is 0.

12. The computer-readable storage medium of claim 7, wherein, If the power module is currently fault-bypassed, the switching frequency of the control commands for that power module within the set detection time will not be counted.

13. A system for determining the abnormal state of a valve-controlled device, characterized in that, Includes a processor, which executes instructions to implement the method for determining the abnormal state of the valve-controlled device as described in claim 1.

14. The abnormal state judgment system for valve-controlled equipment according to claim 13, characterized in that, Each round of testing begins with the first power module and continues until the last power module is detected.

15. The abnormal state judgment system for valve-controlled equipment according to claim 14, characterized in that, Before a new round of testing begins, the number of power modules with abnormal control command switching frequencies is first reset to zero.

16. The abnormal state judgment system for valve-controlled equipment according to claim 13, characterized in that, The control command for each power module is calculated and generated during the converter valve unlocking operation based on the AC voltage and current collected by the valve control equipment during the control cycle, as well as the reference modulation wave issued by the upper control system.

17. The system for determining the abnormal state of a valve-controlled device according to any one of claims 13 to 16, characterized in that, The set value is 0.

18. The abnormal state judgment system for valve-controlled equipment according to claim 13, characterized in that, If the power module is currently fault-bypassed, the switching frequency of the control commands for that power module within the set detection time will not be counted.

19. A control method for a valve-controlled device, characterized in that, The abnormal state of the valve control equipment is determined according to the method for judging the abnormal state of the valve control equipment as described in claim 1. If the valve control equipment is in an abnormal state, the valve control equipment is controlled to be off duty; if the valve control equipment is in a normal state, the valve control equipment is controlled to be on duty.

20. The control method for the valve-controlled device according to claim 19, characterized in that, Each round of testing begins with the first power module and continues until the last power module is detected.

21. The control method for the valve-controlled device according to claim 20, characterized in that, Before a new round of testing begins, the number of power modules with abnormal control command switching frequencies is first reset to zero.

22. The control method for the valve-controlled device according to claim 19, characterized in that, The control command for each power module is calculated and generated during the converter valve unlocking operation based on the AC voltage and current collected by the valve control equipment during the control cycle, as well as the reference modulation wave issued by the upper control system.

23. The control method for the valve-controlled device according to any one of claims 19 to 22, characterized in that, The set value is 0.

24. The control method for the valve-controlled device according to claim 19, characterized in that, If the power module is currently fault-bypassed, the switching frequency of the control commands for that power module within the set detection time will not be counted.

25. A valve-controlled device, comprising a valve-controlled host for connecting to an AC power supply and an optical transceiver module for controlling a connected power module, wherein the valve-controlled host and the optical transceiver module are connected, characterized in that, The valve control host is used to execute instructions to implement the control method of the valve control device as described in claim 19.

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