Online state monitoring device of flexible DC converter valve bypass switch energy storage capacitor

Abstract

The invention belongs to the technical field of power electronics, and particularly relates to an on-line state monitoring device for a flexible DC converter valve bypass switch energy storage capacitor, which comprises a DC power supply, a voltage acquisition unit, a control unit, a drive circuit and an energy storage capacitor, the direct-current power supply is used for outputting rated voltage to the energy storage capacitor; the voltage acquisition unit is used for acquiring the voltage of the energy storage capacitor and sending the voltage of the energy storage capacitor to the control unit; and the control unit is used for controlling the energy storage capacitor to discharge by controlling the driving circuit and calculating the capacitance value of the energy storage capacitor when the voltage of the energy storage capacitor reaches a rated voltage value and the bypass switch is not triggered. According to the technical scheme, the requirement for monitoring the energy storage capacitor in real time is met, the testing precision of the capacitor voltage and the capacitance value is high, universality is good, the circuit structure is simple, economical efficiency is good, and engineering application and popularization are facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of power electronics, and particularly relates to an on-line state monitoring device for an energy storage capacitor of a bypass switch of a flexible DC converter valve. Background Art

[0002] With the completion and commissioning of multiple flexible DC transmission system projects, the total converter capacity of the flexible DC transmission system is close to 20GW, and it has become an important part of the regional power grid.

[0003] As a core device, the high-voltage and large-capacity flexible DC converter valve has more diverse topological structures, control principles and operating conditions compared with conventional thyristor converter valves, and its operating characteristics are also more complex. The flexible DC converter valve is subjected to frequent internal and external transient impact effects and environmental influences for a long time, and is extremely prone to aging, cumulative damage and other phenomena, which can easily lead to abnormalities and failures of key components. In severe cases, it will cause system failures and even system damage. However, the current operation and maintenance monitoring methods of flexible DC converter valves are not intuitive, highly dependent on the experience of operation and maintenance personnel, have low fault tracing efficiency, single on-line state monitoring dimension, and low equipment safety warning level. As a result, operation and maintenance personnel lack panoramic evaluation and monitoring means for the health status change trend of the entire life cycle of the converter valve, resulting in poor direction and low efficiency of operation and maintenance and repair, and it is difficult to fundamentally improve the system availability.

[0004] The bypass switch of the sub-module of the flexible DC converter valve is a key protection action execution component. When a fault occurs in the sub-module body, it can quickly act to bypass the faulty sub-module, short-circuit the faulty sub-module from the system operation loop, and completely isolate the influence of the faulty module on the converter. For the flexible DC project, the bypass switch is equivalent to the last fuse for protecting the system operation. When direct current is applied to the bypass switch, a magnetic field is generated in the coil to drive the moving iron core, and the moving iron core pushes the contact of the vacuum interrupter to close through a pull rod. The direct current is realized by a small energy storage capacitor installed inside the bypass switch. When the capacitance value of this capacitor is lost or fails, it will cause the bypass switch to refuse to operate. At present, there is a problem that in the operation stage of flexible DC transmission projects, due to the loss of the capacitance value of the energy storage capacitor of the bypass switch of the converter sub-module, the bypass switch cannot be reliably closed, resulting in the tripping of the entire system. Since the bypass switch is installed inside the sub-module and, according to the different designs of each converter manufacturer, most of the capacitors to the trigger circuit are connected in series with power electronic components such as diodes, it is very difficult to achieve fast and convenient capacitance measurement. Therefore, the state of the energy storage capacitor of the bypass switch cannot be mastered in the current project. Summary of the Invention

[0005] In order to overcome the problems existing in the above related technologies, the invention provides an on-line state monitoring device for an energy storage capacitor of a bypass switch of a flexible DC converter valve.

[0006] According to the first aspect of the embodiments of the present invention, an on-line state monitoring device for the energy storage capacitor of a flexible DC converter valve bypass switch is provided, including: a DC power supply, a voltage acquisition unit, a control unit, a drive circuit and an energy storage capacitor;

[0007] The positive output terminal of the DC power supply is connected to one end of the energy storage capacitor, and the negative output terminal of the DC power supply, the other end of the energy storage capacitor and the control unit are connected in sequence. The control unit is respectively connected to the drive circuit and the voltage acquisition unit, and the voltage acquisition unit is connected to one end of the energy storage capacitor;

[0008] The DC power supply is used to output a rated voltage to the energy storage capacitor;

[0009] The voltage acquisition unit is used to acquire the voltage of the energy storage capacitor and send the voltage of the energy storage capacitor to the control unit;

[0010] The control unit is used to control the energy storage capacitor to discharge by controlling the drive circuit and calculate the capacitance value of the energy storage capacitor when the voltage of the energy storage capacitor reaches the rated voltage value and the bypass switch is not triggered.

[0011] Preferably, the device further includes: a normally closed switch and a resistor;

[0012] One end of the normally closed switch is connected to the positive output terminal of the DC power supply, and the other end is connected to one end of the energy storage capacitor;

[0013] The normally closed switch is connected to the drive circuit;

[0014] One end of the resistor is connected to the connection point between one end of the energy storage capacitor and the normally closed switch;

[0015] The connection point between one end of the energy storage capacitor and the negative output terminal of the DC power supply, the other end of the resistor and the control unit are connected in sequence.

[0016] Preferably, the device further includes: an inductor and a thyristor;

[0017] One end of the inductor is connected to one end of the resistor, and the other end is connected to the anode of the thyristor;

[0018] The cathode of the thyristor is connected to the connection point between the other end of the resistor and the control unit, and the gate of the thyristor is connected to the control unit.

[0019] Preferably, the control unit is specifically used for:

[0020] When the voltage of the energy storage capacitor reaches the rated voltage and the bypass switch is not triggered, the normally closed switch is controlled to open through the driving circuit, so that the energy storage capacitor discharges through the resistor. When the voltage of the energy storage capacitor drops to the voltage threshold, the capacitance value of the energy storage capacitor is calculated.

[0021] Preferably, the calculation formula of the capacitance value of the energy storage capacitor includes:

[0022] C1 = t / (R1 * ln(Ue / Uc))

[0023] In the above formula, C1 is the capacitance value of the energy storage capacitor, t is the time taken for the voltage of the energy storage capacitor to drop from the rated voltage to the voltage threshold, R1 is the resistance value of the resistor, Ue is the rated voltage, and Uc is the voltage threshold.

[0024] Preferably, the control unit is further configured to:

[0025] When it is necessary to trigger the bypass switch, control the thyristor to conduct, so that the energy storage capacitor discharges and supplies power to the inductor to drive the bypass switch to close.

[0026] Preferably, the control unit is a high-potential control board.

[0027] Preferably, the voltage acquisition unit is an AD conversion module or a voltage comparator.

[0028] According to the second aspect of the embodiments of the present invention, an on-line state monitoring method for the energy storage capacitor of the flexible DC converter valve bypass switch is provided, which is applied to the on-line state monitoring device for the energy storage capacitor of the flexible DC converter valve bypass switch described above, and includes:

[0029] Output a rated voltage to the energy storage capacitor using a DC power supply;

[0030] Collect the voltage of the energy storage capacitor using a voltage acquisition unit;

[0031] When the voltage of the energy storage capacitor reaches the rated voltage and the bypass switch is not triggered, use the control unit to control the energy storage capacitor to discharge through the control of the driving circuit, and calculate the capacitance value of the energy storage capacitor.

[0032] Preferably, the use of the control unit to control the energy storage capacitor to discharge through the control of the driving circuit and calculate the capacitance value of the energy storage capacitor includes:

[0033] When the voltage of the energy storage capacitor reaches the rated voltage and the bypass switch is not triggered, use the control unit to control the normally closed switch to open through the driving circuit, so that the energy storage capacitor discharges through the resistor. When the voltage of the energy storage capacitor drops to the voltage threshold, calculate the capacitance value of the energy storage capacitor.

[0034] Preferably, the calculation formula for the capacitance value of the energy storage capacitor includes:

[0035] C1 = t / (R1 * ln(Ue / Uc))

[0036] In the above formula, C1 is the capacitance value of the energy storage capacitor, t is the time taken for the voltage of the energy storage capacitor to drop from the rated voltage to the voltage threshold, R1 is the resistance value of the resistor, Ue is the rated voltage, and Uc is the voltage threshold.

[0037] Preferably, the method further includes:

[0038] When it is necessary to trigger the bypass switch, the control unit is used to control the thyristor to conduct, so that the energy storage capacitor discharges and supplies power to the inductor to drive the bypass switch to close.

[0039] According to the third aspect of the embodiments of the present invention, an electronic device is provided, including: at least one processor and a memory; the memory and the processor are connected by a bus;

[0040] The memory is used to store one or more programs;

[0041] When the one or more programs are executed by the at least one processor, the online state monitoring method for the energy storage capacitor of the flexible DC converter valve bypass switch is implemented.

[0042] According to the fourth aspect of the embodiments of the present invention, a readable storage medium is provided, on which an execution program is stored. When the execution program is executed, the online state monitoring method for the energy storage capacitor of the flexible DC converter valve bypass switch is implemented.

[0043] The technical solution provided by the present invention has the following beneficial effects:

[0044] An online state monitoring device for the energy storage capacitor of a flexible DC converter valve bypass switch provided by the present invention outputs a rated voltage to the energy storage capacitor through a DC power supply. The voltage acquisition unit acquires the voltage of the energy storage capacitor and sends the voltage of the energy storage capacitor to the control unit. When the voltage of the energy storage capacitor reaches the rated voltage and the bypass switch is not triggered, the control unit is used to control the energy storage capacitor to discharge through the control drive circuit and calculate the capacitance value of the energy storage capacitor. It not only meets the real-time monitoring requirements of the energy storage capacitor, has high test accuracy for the capacitor voltage and capacitance value, but also has good universality, simple circuit structure, good economy, and is convenient for engineering application and promotion. Description of the Drawings

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0046] Figure 1 is the structural block diagram of an on-line status monitoring device for the energy storage capacitor of the flexible DC converter valve bypass switch provided by the embodiment of the present invention;

[0047] Figure 2 is the flowchart of an on-line status monitoring method for the energy storage capacitor of the flexible DC converter valve bypass switch provided by the embodiment of the present invention;

[0048] Figure 3 is the structural block diagram of an electronic device provided by the embodiment of the present invention;

[0049] In the figure, NC - normally closed switch, C - energy storage capacitor, R - resistor, L - inductor, Q - thyristor, 1 - DC power supply, 2 - voltage acquisition unit, 3 - control unit, 4 - drive circuit. Detailed Embodiments

[0050] To make the objectives, technical solutions and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the following embodiments are some embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0051] Embodiment 1

[0052] The present invention provides an on-line status monitoring device for the energy storage capacitor of the flexible DC converter valve bypass switch, as Figure 1 shown, including: DC power supply 1, voltage acquisition unit 2, control unit 3, drive circuit 4 and energy storage capacitor C;

[0053] The positive output terminal of the DC power supply 1 is connected to one end of the energy storage capacitor C, and the negative output terminal of the DC power supply 1, the other end of the energy storage capacitor C and the control unit 3 are connected in sequence. The control unit 3 is respectively connected to the drive circuit 4 and the voltage acquisition unit 2, and the voltage acquisition unit 2 is connected to one end of the energy storage capacitor C;

[0054] The DC power supply 1 is used to output a rated voltage to the energy storage capacitor C;

[0055] The voltage acquisition unit 2 is used to acquire the voltage of the energy storage capacitor C and send the voltage of the energy storage capacitor C to the control unit 3;

[0056] A control unit 3, when the voltage of the energy storage capacitor C reaches the rated voltage and the bypass switch is not triggered, controls the energy storage capacitor C to discharge by controlling the drive circuit 4, and calculates the capacitance value of the energy storage capacitor C.

[0057] An on-line state monitoring device for the energy storage capacitor of the flexible DC converter valve bypass switch provided by the present invention meets the complex and demanding monitoring requirements of the energy storage capacitor of the flexible DC converter valve bypass switch at present. Through the obtained monitoring data of the energy storage capacitor C, the state of the energy storage capacitor of the flexible DC converter valve bypass switch can be judged timely and accurately. Furthermore, without disassembling the flexible DC converter valve, the operating state of the flexible DC converter valve bypass switch can be accurately measured and evaluated.

[0058] Furthermore, the device further includes: a normally closed switch NC and a resistor R;

[0059] One end of the normally closed switch NC is connected to the positive output end of the DC power supply 1, and the other end is connected to one end of the energy storage capacitor C;

[0060] The normally closed switch NC is connected to the drive circuit 4;

[0061] One end of the resistor R is connected to the connection point between one end of the energy storage capacitor C and the normally closed switch NC;

[0062] The connection point between one end of the energy storage capacitor C and the negative output end of the DC power supply 1, the other end of the resistor R and the control unit 3 are connected in sequence.

[0063] It should be noted that by connecting the normally closed switch NC in series in the circuit, the DC power supply 1 can be disconnected, and the action time is within 1 ms.

[0064] In some embodiments, the normally closed switch NC can be implemented by, but not limited to, a normally closed relay, a solid-state switch, an optocoupler or a MOSFET.

[0065] Furthermore, the device further includes: an inductor L and a thyristor Q;

[0066] One end of the inductor L is connected to one end of the resistor R, and the other end is connected to the anode A of the thyristor Q;

[0067] The cathode of the thyristor Q is connected to the connection point between the other end of the resistor R and the control unit 3, and the gate G of the thyristor Q is connected to the control unit 3.

[0068] Furthermore, the control unit 3 is specifically used for:

[0069] When the voltage of the energy storage capacitor C reaches the rated voltage and the bypass switch is not triggered, the normally closed switch NC is controlled to open through the drive circuit 4, so that the energy storage capacitor C discharges through the resistor R. When the voltage of the energy storage capacitor C drops to the voltage threshold, the capacitance value of the energy storage capacitor C is calculated.

[0070] It should be noted that the control unit 3 provided by the present invention can periodically calculate the capacitance value and control the discharge time to prevent the capacitor voltage from being too low to trigger the bypass switch.

[0071] Further, the calculation formula for the capacitance value of the energy storage capacitor C includes:

[0072] C1 = t / (R1 * ln(Ue / Uc))

[0073] In the above formula, C1 is the capacitance value of the energy storage capacitor C, t is the time taken for the voltage of the energy storage capacitor C to drop from the rated voltage to the voltage threshold, R1 is the resistance value of the resistor R, Ue is the rated voltage, and Uc is the voltage threshold.

[0074] Further, the control unit 3 is also used for:

[0075] When it is necessary to trigger the bypass switch, the thyristor Q is controlled to conduct, so that the energy storage capacitor C discharges and supplies power to the inductor L to drive the bypass switch to close.

[0076] It can be understood that generally when a fault occurs in the commutation valve sub-module, it is necessary to trigger the bypass switch. The control unit 3 sends a trigger command to the thyristor Q, and the thyristor Q conducts. The energy storage capacitor C instantaneously discharges to generate a very high current pulse to supply power to the inductor L, thereby ensuring the smooth closing of the bypass switch. Therefore, the energy storage capacitor C, as a key component, is a necessary condition to ensure that the commutation valve sub-module can be cut off in a timely and rapid manner during a fault.

[0077] In some embodiments, the control unit 3 can be, but is not limited to, a high-potential control board; the voltage acquisition unit 2 can be, but is not limited to, a high-speed serial or parallel AD conversion module, or a voltage comparator.

[0078] In practical applications, the DC power supply 1 of the present invention outputs a rated voltage value to keep the capacitor at the rated power supply voltage. When it is necessary to trigger the bypass switch, the control unit 3 triggers the thyristor Q to conduct, and the capacitor discharges through the inductor L to drive the bypass switch to close. The working principle of calculating the capacitance value of the capacitor is as follows: when the capacitor voltage is at the rated value Ue and no bypass trigger occurs, the control unit 3 opens the normally closed switch NC through the drive circuit 4, and the capacitor discharges through the resistor R. The discharge time is t, the capacitor voltage drops to Uc, and the capacitance value is calculated.

[0079] This application focuses on the problems of voltage and capacitance value detection of the energy storage capacitor C of the bypass switch, studies the voltage detection method of the energy storage capacitor C based on the AD conversion module, develops a high-potential control board for the flexible DC converter valve with the function of collecting the voltage and capacitance value of the bypass switch energy storage capacitor C, proposes a technical solution for data acquisition of the energy storage capacitor C voltage, and debugs and realizes the voltage acquisition of the bypass switch energy storage capacitor C.

[0080] The on-line state monitoring device of the energy storage capacitor of the bypass switch of the flexible DC converter valve provided by the present invention can meet the conditions of real-time monitoring requirements and high test accuracy; the state on-line monitoring circuit of the energy storage capacitor of the bypass switch of the flexible DC converter valve of the present invention can be directly integrated into the high-potential control board, with simple structure, good economy, good universality, and is convenient for engineering application and promotion; the on-line state monitoring device of the energy storage capacitor of the bypass switch of the flexible DC converter valve provided by the present invention has high reliability and plays a role in isolating faults. When a fault occurs in the converter valve sub-module, it is completely isolated from the main circuit without affecting the normal operation of the rest of the equipment.

[0081] Embodiment 2

[0082] The present invention also provides an on-line state monitoring method for the energy storage capacitor of the bypass switch of the flexible DC converter valve, which is applied to the on-line state monitoring device of the energy storage capacitor of the bypass switch of the flexible DC converter valve in the above embodiment, as Figure 2 shown, including:

[0083] Step 11: Use the DC power supply 1 to output the rated voltage to the energy storage capacitor C;

[0084] Step 12: Use the voltage acquisition unit 2 to acquire the voltage of the energy storage capacitor C;

[0085] Step 13: When the voltage of the energy storage capacitor C reaches the rated voltage value and the bypass switch is not triggered, use the control unit 3 to control the energy storage capacitor C to discharge through the control drive circuit 4, and calculate the capacitance value of the energy storage capacitor C.

[0086] Further, step 13 includes:

[0087] When the voltage of the energy storage capacitor C reaches the rated voltage value and the bypass switch is not triggered, use the control unit 3 to control the normally closed switch NC to open through the drive circuit 4, so that the energy storage capacitor C discharges through the resistor R until the voltage of the energy storage capacitor C drops to the voltage threshold value, and calculate the capacitance value of the energy storage capacitor C.

[0088] Further, the calculation formula for the capacitance value of the energy storage capacitor C includes:

[0089] C1 = t / (R1 * ln(Ue / Uc))

[0090] In the above formula, C1 is the capacitance value of the energy storage capacitor C, t is the time taken for the voltage of the energy storage capacitor C to drop from the rated voltage to the voltage threshold, R1 is the resistance value of the resistor R, Ue is the rated voltage, and Uc is the voltage threshold.

[0091] Further, the method further includes:

[0092] Step 14: When it is necessary to trigger the bypass switch, the control unit 3 is used to control the thyristor Q to conduct, so that the energy storage capacitor C discharges through the inductor L to drive the bypass switch to close.

[0093] It can be understood that the method embodiments provided above correspond to the above device embodiments, and the corresponding specific contents can be referred to each other, which will not be elaborated here.

[0094] It can be understood that the same or similar parts in the above embodiments can be referred to each other, and the content not detailed in some embodiments can be referred to the same or similar content in other embodiments.

[0095] Embodiment III

[0096] As Figure 3 shown, the present invention further provides an electronic device, which may be a computer device, a single-chip microcomputer device, a smart mobile device, etc. The electronic device in this embodiment may include a processor, a memory, a transceiver component, etc. The memory, the processor, and the transceiver component are connected through a bus; the memory can be used to store an execution program, and an exemplary execution program may include instructions; the processor is used to execute the instructions stored in the memory. The memory can also be used to store data, and this data can be called and / or modified when the instructions are executed.

[0097] The processor may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions in the storage medium to implement the corresponding method flow or corresponding function, so as to implement the steps of an online status monitoring method for an energy storage capacitor of a flexible DC converter valve bypass switch in the above embodiments.

[0098] Embodiment IV

[0099] Based on the same inventive concept, the present invention also provides a readable storage medium, specifically an electronic device-readable storage medium (Memory). The electronic device-readable storage medium is a memory device in an electronic device, used to store programs and data. It can be understood that the storage medium here can include both the built-in storage medium in the electronic device and, of course, the extended storage medium supported by the electronic device. The storage medium provides a storage space, and this storage space stores the operating system of the terminal. Moreover, in this storage space, there is also stored one or more instructions suitable for being loaded and executed by the processor. These instructions can be one or more executable programs (including program codes). It should be noted that the storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. By the processor loading and executing one or more instructions stored in the storage medium, the steps of the online status monitoring method for the energy storage capacitor of the flexible DC converter valve bypass switch in the above embodiments can be implemented.

[0100] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. 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. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0101] The present invention is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows 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 the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0102] These computer program instructions can 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, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and this instruction device implements the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1The functions specified in one or more boxes.

[0103] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide for implementing the steps of the functions specified in one Figure 1 one process or more processes and / or boxes Figure 1 or more boxes.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the specific implementation manners of the present invention can still be modified or equivalently replaced, and any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. An online state monitoring device for a bypass switch energy storage capacitor of a flexible direct current converter valve, characterized in that: include: DC power supply, voltage acquisition unit, control unit, drive circuit and energy storage capacitor; The positive output terminal of the DC power supply is connected to one end of the energy storage capacitor, the negative output terminal of the DC power supply, the other end of the energy storage capacitor and the control unit are connected in sequence, the control unit is respectively connected to the drive circuit and the voltage acquisition unit, and the voltage acquisition unit is connected to one end of the energy storage capacitor; The DC power supply is used to output a rated voltage to the energy storage capacitor; The voltage acquisition unit is used to acquire the voltage of the energy storage capacitor and send the voltage of the energy storage capacitor to the control unit; The control unit is used to control the energy storage capacitor to discharge by controlling the drive circuit when the voltage of the energy storage capacitor reaches the rated voltage and the bypass switch is not triggered, and calculate the capacitance value of the energy storage capacitor.

2. The device according to claim 1, characterized in that Also includes: Normally closed switch and resistor; One end of the normally closed switch is connected to the positive output end of the DC power supply, and the other end is connected to one end of the energy storage capacitor; The normally closed switch is connected to the driving circuit; One end of the resistor is connected to a connection point between one end of the energy storage capacitor and the normally closed switch; A connection point between one end of the energy storage capacitor and the negative output end of the DC power supply, the other end of the resistor and the control unit are connected in sequence.

3. The device according to claim 2, characterized in that Also includes: Inductors and thyristors; One end of the inductor is connected to one end of the resistor, and the other end is connected to the anode of the thyristor; The cathode of the thyristor is connected to a connection point between the other end of the resistor and the control unit, and the gate of the thyristor is connected to the control unit.

4. The device according to claim 3, characterized in that The control unit is specifically used for: When the voltage of the energy storage capacitor reaches the rated voltage and the bypass switch is not triggered, the normally closed switch is controlled to open by the drive circuit so that the energy storage capacitor discharges through the resistor until the voltage of the energy storage capacitor drops to the voltage threshold, and the capacitance value of the energy storage capacitor is calculated.

5. The device according to claim 4, characterized in that The calculation formula of the capacitance value of the energy storage capacitor includes: C1=t / (R1*ln(Ue / Uc)) In the above formula, C1 is the capacitance value of the energy storage capacitor, t is the time taken for the voltage of the energy storage capacitor to drop from the rated voltage to the voltage threshold, R1 is the resistance value of the resistor, Ue is the rated voltage, and Uc is the voltage threshold.

6. The device according to claim 3, characterized in that The control unit is further used for: When the bypass switch needs to be triggered, the thyristor is controlled to be turned on, so that the energy storage capacitor is discharged and the inductor is powered to drive the bypass switch to be closed.

7. The device according to claim 1, characterized in that The control unit is a high potential control board.

8. The device according to claim 1, characterized in that The voltage acquisition unit is an AD conversion module or a voltage comparator.

9. An online state monitoring method for a bypass switch energy storage capacitor of a flexible direct current converter valve, applied to an online state monitoring device for a bypass switch energy storage capacitor of a flexible direct current converter valve according to any one of claims 1 to 8, characterized in that: include: Utilize a DC power supply to output a rated voltage to the energy storage capacitor; Using a voltage collection unit to collect the voltage of the energy storage capacitor; When the voltage of the energy storage capacitor reaches the rated voltage and the bypass switch is not triggered, the control unit is used to control the drive circuit to control the energy storage capacitor to discharge, and the capacitance value of the energy storage capacitor is calculated.

10. The method according to claim 9, characterized in that The control unit controls the energy storage capacitor to discharge by controlling the driving circuit, and calculates the capacitance value of the energy storage capacitor, including: When the voltage of the energy storage capacitor reaches the rated voltage and the bypass switch is not triggered, the control unit controls the normally closed switch to open through the drive circuit to discharge the energy storage capacitor through the resistor until the voltage of the energy storage capacitor drops to the voltage threshold, and the capacitance value of the energy storage capacitor is calculated.

11. The method according to claim 10, characterized in that The calculation formula of the capacitance value of the energy storage capacitor includes: C1=t / (R1*ln(Ue / Uc)) In the above formula, C1 is the capacitance value of the energy storage capacitor, t is the time taken for the voltage of the energy storage capacitor to drop from the rated voltage to the voltage threshold, R1 is the resistance value of the resistor, Ue is the rated voltage, and Uc is the voltage threshold.

12. The method according to claim 9, characterized in that Also includes: When the bypass switch needs to be triggered, the control unit is used to control the thyristor to be turned on, so that the energy storage capacitor is discharged and the inductor is powered to drive the bypass switch to be closed.

13. An electronic device, characterized in that: include: at least one processor and memory; The memory and the processor are connected via a bus; The memory is used to store one or more programs; When the one or more programs are executed by the at least one processor, the online status monitoring method of the bypass switch energy storage capacitor of the flexible direct current converter valve according to any one of claims 1 to 8 is implemented.

14. A readable storage medium, characterized in that: An execution program is stored thereon, and when the execution program is executed, an online state monitoring method for a bypass switch energy storage capacitor of a flexible direct current converter valve as described in any one of claims 1 to 8 is implemented.

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