CN111463754A - Converter valve overcurrent protection method and system - Google Patents

Abstract

The invention discloses a converter valve overcurrent protection method and system. The method includes: detecting the overcurrent fault of the submodule through the IGBT driver in the IGBT submodule of each bridge arm of the converter valve; The number of submodules with overcurrent faults; judge whether the number of submodules with overcurrent faults is greater than the overcurrent protection threshold; when the number of submodules with overcurrent faults is greater than the overcurrent protection threshold, determine the overall overcurrent of the converter valve, and convert the The valve is completely closed. The invention detects the overcurrent fault of the sub-module through the IGBT driver, and directly detects the over-current fault of the sub-module without adding other devices, so as to improve the detection efficiency; It avoids the problem that the number of bypass sub-modules is too large, which threatens the reliability and stability of the converter valve operation; and the overcurrent detection speed of the IGBT driver in the sub-module is very fast, which improves the reliability and stability of the converter valve operation. .

Description

A kind of converter valve overcurrent protection method and system

technical field

The invention relates to the field of flexible direct current power transmission, in particular to a converter valve overcurrent protection method and system.

Background technique

The converter valve is responsible for the DC-AC conversion and the AC-DC conversion in the DC transmission project, and is the core equipment of the DC transmission project. When the modular multi-level converter valve technology (MMC) is applied in the field of HVDC power transmission, hundreds or even thousands of sub-modules are required to be connected in series, and each sub-module must be controlled, protected and monitored individually. The failure of a single sub-module, if not handled properly, will affect the operation of the entire converter valve and even the entire DC transmission system.

The overcurrent fault of the converter valve sub-module is a serious fault. When the sub-module withstands the current exceeding the maximum withstand threshold of the component, the sub-module will be broken down, and even explode in severe cases. At present, the overcurrent protection strategy of the converter valve is generally to detect the bridge arm current of the converter valve through the CT equipment arranged at the bridge arm reactance position. When the valve base controller detects that the instantaneous value of a certain bridge arm current exceeds the threshold and reaches the judgment time After that, it is determined that the bridge arm of the converter valve is over-current. If the CT equipment or the electronic merging unit equipment responsible for the current data transmission of the bridge arm fails, there is a risk of failure of the bridge arm current overcurrent protection function. In the sub-module unit, there are multiple current paths, and the instantaneous value of the bridge arm current cannot It completely represents the current flowing through the IGBT devices of the upper and lower tubes of the sub-module. The inventor found that when the converter valve has a valve tower flashover and other faults, the sub-module capacitance of the faulty valve section is rapidly discharged through the fault point, and the fault current rises rapidly, while the optical CT The overcurrent cannot be detected in a very short time, so that the overcurrent protection of the VBC bridge arm cannot act in time and cannot quickly detect the overcurrent and actively block the converter valve for protection.

SUMMARY OF THE INVENTION

In view of this, the embodiments of the present invention provide a converter valve overcurrent protection method and system, which solves the problem in the prior art that the bridge arm overcurrent protection cannot act in time and cannot quickly detect overcurrent and actively lock the converter valve to implement protection. question.

To achieve the above object, the present invention provides the following technical solutions:

In a first aspect, an embodiment of the present invention provides an overcurrent protection method for a converter valve. The method includes the following steps: detecting the overcurrent fault of the submodule through the IGBT driver in the IGBT submodule of each bridge arm of the converter valve, and counting the The number of submodules with overcurrent faults in each of the bridge arms; judging whether the number of submodules in the overcurrent fault is greater than the overcurrent protection threshold; when the number of submodules in the overcurrent fault is greater than the overcurrent protection threshold, It is determined that the overall flow of the converter valve is over-current, and the entire converter valve is blocked.

In one embodiment, the detection of the overcurrent fault of the sub-module by the IGBT driver in the IGBT sub-module of each bridge arm of the converter valve includes the following steps: acquiring state information of all sub-modules in each bridge arm of the converter valve, The state information includes overcurrent fault information; the submodule in which the overcurrent fault occurs is determined by using the overcurrent fault information.

In one embodiment, the acquiring state information of all sub-modules in each bridge arm of the converter valve includes: acquiring state information of all sub-modules in each bridge arm of the converter valve through a valve base controller for each control cycle, and the The valve base controller connection station controls the protection system and the converter valve sub-module.

In an embodiment, acquiring the status information of all sub-modules in each bridge arm of the converter valve includes: detecting the current of each sub-module through the IGBT driver; The sub-module of the current fault includes: judging whether the current exceeds a preset current value; when the current exceeds the preset current value, determining that the corresponding sub-module has an overcurrent fault.

In an embodiment, the converter valve overcurrent protection method further includes the following steps: when the number of submodules in the overcurrent fault is not greater than the overcurrent protection threshold, controlling the occurrence of Submodules for overcurrent faults perform blocking.

In an embodiment, the state information further includes: switching state and capacitor voltage value of the sub-module.

In a second aspect, an embodiment of the present invention provides an overcurrent protection system for a converter valve, including an overcurrent detection module, a valve base controller interface device, and a bridge arm current control chassis: the overcurrent detection module is used to detect each bridge status information of all sub-modules in the arm, and send the status information of each sub-module to the valve-base controller interface device in each control cycle; the valve-base controller interface device is used to update the sub-module status information Carry out statistics, and send the number of sub-modules that have overcurrent faults in each of the bridge arms in the current cycle to the bridge arm current control chassis; the bridge arm current control chassis is used to send control protection commands to the valve base controller interface device ; The valve base controller interface device is also used for decoding the control and protection command and sending it to each of the sub-modules.

In an embodiment, the bridge arm current control chassis further includes: a judgment unit, the judgment unit is configured to judge whether the number of sub-modules in the overcurrent fault is greater than an overcurrent protection threshold, and obtain a judgment result.

In a third aspect, an embodiment of the present invention provides an electronic device, including: at least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by at least one processor. One processor executes, so that at least one processor executes the converter valve overcurrent protection method of the first aspect of the embodiment of the present invention.

In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, where the computer-readable storage medium stores computer instructions, and the computer instructions are used to cause a computer to execute the converter valve overcurrent protection method of the first aspect of the embodiment of the present invention.

The technical scheme of the present invention has the following advantages:

1. In the converter valve overcurrent protection method and system provided by the present invention, the overcurrent fault of the submodule is detected by the IGBT driver in the IGBT submodule of each bridge arm of the converter valve, and the occurrence of overcurrent faults in each bridge arm is counted. If the number of sub-modules is larger than the over-current protection threshold, it is not necessary to add other devices to directly detect the over-current fault of the sub-module to improve the detection efficiency. The overall blocking of the converter valve avoids the problem that the number of bypass sub-modules is too large, which threatens the reliability and stability of the converter valve operation; and the over-current detection speed of the IGBT driver in the sub-module is very fast, and the blocking action is completed in advance. , which solves the problem that the bridge arm overcurrent protection cannot act in time and cannot quickly detect overcurrent and actively block the converter valve for protection, thereby improving the reliability and stability of the converter valve operation.

2. The converter valve overcurrent protection method and system provided by the present invention utilizes the overcurrent detection module to detect the status information of all sub-modules in each bridge arm, and judges whether the converter valve has over-current through the number of sub-module over-currents, which simplifies the process. The over-current fault judgment process has the ability to quickly block. When the converter valve is over-current protected, the valve base controller interface device sends the control and protection commands sent from the bridge arm current control chassis to the sub-module, without the sub-module for command coding, etc. operation, shortens the response time of the bridge arm current control chassis to the bridge arm overcurrent protection; each bridge arm has an independent control sequence, and the bridge arm current control chassis can realize independent protection control for each bridge arm, reducing the need for Disturbances in DC Systems.

Description of drawings

In order to illustrate the specific embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the specific embodiments or the prior art. Obviously, the accompanying drawings in the following description The drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

1 is a flowchart of a specific example of a converter valve overcurrent protection method provided by an embodiment of the present invention;

FIG. 2 is a flowchart of a specific example of detecting an overcurrent fault of a sub-module by an IGBT driver according to an embodiment of the present invention;

3 is a flowchart of another specific example of a converter valve overcurrent protection method provided by an embodiment of the present invention;

4 is a schematic diagram of a converter valve overcurrent protection system provided by an embodiment of the present invention;

FIG. 5 is a composition diagram of a specific example of an electronic device provided by an embodiment of the present invention.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation or a specific orientation. construction and operation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first", "second", and "third" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

In the description of the present invention, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, unless otherwise expressly specified and limited, for example, it may be a fixed connection or a detachable connection connection, or integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal connection of two components, which can be a wireless connection or a wired connection connect. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

Example 1

An embodiment of the present invention provides an overcurrent protection method for a converter valve, as shown in FIG. 1 , including the following steps:

Step S1: Detect the overcurrent fault of the submodule through the IGBT driver in the IGBT submodule of each bridge arm of the converter valve, and count the number of submodules with an overcurrent fault in each bridge arm.

In the embodiment of the present invention, a single bridge arm in the converter valve includes hundreds of power sub-modules, and the sub-module structures can be divided into three types: half H-bridge type, full H-bridge type and double clamp type. If a sub-module fails, the bypass switch will act to cut off the faulty sub-module, and then put the redundant module into operation instead of the faulty module. In order to facilitate detection and do not need to add other devices, it can directly pass the IGBT sub-modules of each bridge arm of the converter valve. The IGBT driver in the module detects the overcurrent fault of the sub-module, which makes the detection efficiency more efficient and convenient. In practical applications, the faulty module can also be detected by the fault detector. If the sub-module fails, the IGBT driver in the IGBT sub-module of each bridge arm of the converter valve will add 1 to the number of sub-modules with an overcurrent fault, and feed back the statistical result to the control part of the converter valve, which can detect Overcurrent faults of submodules are obtained, and the number of submodules with overcurrent faults in each bridge arm is determined.

It should be noted that when detecting the overcurrent fault of the sub-module, the IGBT driver can be selected for direct detection, or the fault detector can be used for detection. The fault detector can be a chip or an actual detection program. The present invention is not limited to this.

Step S2: judging whether the number of sub-modules in the overcurrent fault is greater than the overcurrent protection threshold.

In the embodiment of the present invention, if the neutron sub-module of the converter valve fails, the sub-module in the bypass state will not be put into operation again if the converter valve is to be repaired without stopping the operation. If the number of faulty sub-modules is Too many sub-modules will cause avalanche bypass, which will threaten the reliability and stability of the converter valve operation. Therefore, it is necessary to judge whether the number of sub-modules with over-current fault is greater than the over-current protection threshold, so as to avoid bypass. Too many sub-modules affect the normal operation of the system, and even cause irreparable losses.

Step S3: when the number of sub-modules in the overcurrent fault is greater than the overcurrent protection threshold, it is determined that the entire converter valve is overcurrent, and the entire converter valve is blocked.

In the embodiment of the present invention, when the number of sub-modules in the overcurrent fault is greater than the overcurrent protection threshold, it is determined that the entire converter valve is overcurrent. Generally, there are 6 bridge arms in the converter valve, corresponding to the bridge arm 1 of the converter valve. To 6, it can be divided into A-phase upper arm, A-phase lower arm, B-phase upper arm, B-phase lower arm, C-phase upper arm and C-phase lower arm. When the number of sub-modules flowing exceeds the overcurrent protection threshold, it is considered that the converter valve is overcurrent as a whole, and the 6 bridge arms are temporarily blocked as a whole. The protection can be implemented by actively blocking the IGBT device, and the blocking information is reported to the station control and protection system. The over-current detection speed of the IGBT driver in the sub-module is very fast, the over-current detection can be completed within 30us, and the corresponding sub-module is blocked in advance, so that the over-current protection of the converter valve can act in time to avoid the rapid rise of the fault current, which may lead to a larger system existence. security risks.

In practical applications, the overall overcurrent protection of the converter valve can obtain the status information of all sub-modules in each bridge arm of the converter valve in each control cycle through the valve base controller. The valve base controller connection station controls the protection system and the converter valve. Module, the valve base controller (VBC) of the converter valve realizes the overall overcurrent protection of the converter valve. The valve base controller of the converter valve is composed of the VBC interface device and the bridge arm current control chassis. The valve base controller has system communication. , modulation, circulating current suppression, sub-module voltage balance, all sub-module control protection and monitoring functions. The delay of VBC overcurrent protection judgment is about 2-3 control cycles. According to the control speed of the existing valve base controller, the delay of overcurrent protection judgment is less than 300us, and the delay of the protection command issuing link is about 150us. Therefore, from the occurrence of the overall overcurrent fault of the converter valve IGBT to the blocking of the converter valve, the entire delay time is less than 500us.

It should be noted that in practical applications, the overcurrent protection threshold in the converter valve judgment process is set in advance, which may be set according to the simulation results or according to actual experience. In the application, it can also be set according to the actual needs of the system, and the overcurrent protection judgment delay is also judged according to actual experience, and the embodiment of the present invention only illustrates that there are 6 bridge arms in the converter valve, in other experiments In the process, the number of other bridge arms may also be selected, and the present invention is not limited to this.

In the converter valve overcurrent protection method provided by the present invention, the IGBT driver in the IGBT submodules of each bridge arm of the converter valve detects the overcurrent fault of the submodule, and counts the number of submodules with an overcurrent fault in each bridge arm. , do not need to add other devices, directly detect the overcurrent fault of the sub-module to improve the detection efficiency; when the number of sub-modules with an overcurrent fault is greater than the overcurrent protection threshold, determine the overall overcurrent of the converter valve, and the overall converter valve Blocking avoids the problem that the number of bypass sub-modules is too large, which threatens the reliability and stability of the converter valve operation; and the over-current detection speed of the IGBT driver in the sub-module is very fast, and the blocking action is completed in advance, solving the problem of The bridge arm overcurrent protection cannot act in time and cannot quickly detect overcurrent and actively block the converter valve for protection, which improves the reliability and stability of the converter valve operation.

In a specific embodiment, as shown in FIG. 2 , the overcurrent fault of the sub-module is detected by the IGBT driver in the IGBT sub-module of each bridge arm of the converter valve, including the following steps:

Step S11: Acquire state information of all sub-modules in each bridge arm of the converter valve, wherein the state information includes overcurrent fault information.

In the embodiment of the present invention, in the process of detecting the overcurrent fault of the sub-module by the IGBT driver in the IGBT sub-module of each bridge arm of the converter valve, the state information of all the sub-modules in each bridge arm of the converter valve is first obtained through the IGBT driver , among which, the selection of IGBT driver and the calculation of output power determine the reliability of the commutation system. Insufficient driver power or wrong selection may directly lead to damage to the IGBT and the driver. In practical applications, there are various forms of driver circuits used for IGBTs. From the perspective of circuit isolation, IGBT drivers can be divided into two categories. One uses optocouplers. The other type uses pulse transformers, both of which can realize signal transmission and circuit isolation.

In practical applications, assuming that a photocoupler is used as the IGBT driver, it is simply stated that the biggest feature of the photocoupler driver is that both sides are active, and the width of the positive pulse and negative blocking pulse provided by it can be unlimited, and It can easily realize overcurrent and short circuit protection under various conditions by detecting the IGBT on-state collector voltage, and send an overcurrent signal to the outside. Both at home and abroad tend to make this kind of driver into the form of thick film circuit, so it has the advantages of more convenient use, better consistency and stability. However, its disadvantage is that it requires more working power supplies. For example, a full-bridge switching power supply generally requires four working power supplies, which increases the complexity of the circuit.

It should be noted that the sub-module status information includes overcurrent fault information, and the sub-module status information detected during the detection process also includes the switching status and capacitor voltage value of the sub-module. In the embodiment of the present invention, only an example is used to illustrate the selection of the optocoupler. As the IGBT driver, other devices or circuits can also be used as the IGBT driver in practical applications, and the present invention is not limited to this.

Step S12: Use the overcurrent fault information to determine the submodule in which the overcurrent fault occurs.

In this embodiment of the present invention, after the overcurrent fault information is obtained, the sub-module in which the overcurrent fault has occurred can be determined according to the overcurrent fault information. First, it is necessary to determine whether the detected current exceeds the preset current value. If the current exceeds the preset current value current value, determine the overcurrent fault of the corresponding sub-module, record the fault information of the sub-module and count the number of sub-module faults. If the current does not exceed the preset current value, it means that the current sub-module is in a normal operation state, no operation is performed in this control cycle, and the next control cycle is waited for the next state information detection. It should be noted that the preset current value in the judgment process is determined in the simulation process, or set according to actual experience, and can also be adjusted according to the actual needs of the system, and the present invention is not limited to this. .

In a specific embodiment, as shown in FIG. 3 , the overcurrent protection method for a converter valve further includes the following steps:

Step S4: when the number of the sub-modules with the over-current fault is not greater than the over-current protection threshold, the IGBT driver of the sub-module with the over-current fault is controlled to perform blocking on the sub-module with the over-current fault.

In practical applications, when the number of sub-modules with over-current fault is not greater than the over-current protection threshold, the IGBT driver of the sub-module with over-current fault will block the faulty sub-module, and consider that the sub-module itself is over-current. Some sub-module overcurrent protection methods deal with the sub-module itself. It should be noted that when over-current protection is performed on the sub-module itself, an existing protection method can be selected. In practical applications, which over-current protection method is selected in the embodiment of the present invention is not limited, and can be selected according to actual needs. to make a selection.

In the converter valve overcurrent protection method provided by the present invention, the IGBT driver in the IGBT submodules of each bridge arm of the converter valve detects the overcurrent fault of the submodule, and counts the number of submodules with an overcurrent fault in each bridge arm. , do not need to add other devices, directly detect the overcurrent fault of the sub-module to improve the detection efficiency; when the number of sub-modules with an overcurrent fault is greater than the overcurrent protection threshold, determine the overall overcurrent of the converter valve, and the overall converter valve Blocking avoids the problem that the number of bypass sub-modules is too large, which threatens the reliability and stability of the converter valve operation; and the over-current detection speed of the IGBT driver in the sub-module is very fast, and the blocking action is completed in advance, solving the problem of The bridge arm overcurrent protection cannot act in time and cannot quickly detect overcurrent and actively block the converter valve for protection, which improves the reliability and stability of the converter valve operation.

Example 2

An embodiment of the present invention provides an overcurrent protection system for a converter valve, as shown in FIG. 4 , including an overcurrent detection module 1, a valve base controller interface device 2, and a bridge arm current control chassis 3:

The overcurrent detection module 1 is used to detect the status information of all submodules in each bridge arm, and sends the status information of each submodule to the valve base controller interface device 2 in each control cycle. The flow valve corresponds to the current information of the bridge arm, and directly sends the collected current information to the valve base controller interface device 2, which can directly detect the current of each sub-module through the IGBT driver, without adding external equipment for detection, which improves the detection efficiency. , which further ensures the stability and security of the power system.

The valve base controller interface device 2 is used to count the status information of the sub-modules, and send the number of sub-modules that have overcurrent faults in each bridge arm in the current cycle to the bridge arm current control chassis 3, and the bridge arm current control chassis 3 passes the valve The base controller interface device 2 receives the current information sent by each current measurement unit, and performs overcurrent protection of the converter valve according to the current information. Specifically, the bridge arm current control chassis 3 uses the received bridge arm current sampling value end flag of the current information as the synchronization flag to synchronize the control sequence of the corresponding converter valve bridge arm and realize the independent control sequence of the bridge arm. In the control sequence of each converter valve bridge arm, the judgment unit 31 in the bridge arm current control cabinet 3 performs overcurrent fault judgment on the received bridge arm current information. Then use the fast channel to issue the control protection command to all the valve base controller interface devices 2 corresponding to the bridge arm of the converter valve, and the valve base controller interface device 2 decodes and processes the control protection command, and sends it to each sub-module. , if it is judged that there is no overall overcurrent fault in the bridge arm of the converter valve, the judgment unit 31 in the bridge arm current control chassis 3 will issue the bypass command of the sub-module to the corresponding sub-module of the corresponding converter valve bridge arm, The overcurrent detection module 1 is connected to the converter valve and the bridge arm current control chassis 3 through an optical fiber. The time for overcurrent fault detection is reduced, so that the overall overcurrent fault of the converter valve IGBT occurs until the converter valve is blocked, and the entire delay only takes microseconds, which greatly improves the safety of the entire system.

It should be noted that in practical applications, other connection methods can also be used to connect the overcurrent detection module, the converter valve and the bridge arm current control chassis, and the number of valve base controller interface devices can also be determined according to actual needs. Optionally, the present invention is not limited to this.

The converter valve overcurrent protection system provided by the present invention utilizes the overcurrent detection module to detect the status information of all sub-modules in each bridge arm, and judges whether the converter valve has overcurrent through the number of submodules overcurrent, which simplifies the overcurrent fault judgment. The process has the ability of fast blocking. When the converter valve is over-current protected, the interface device of the valve base controller sends the control and protection commands sent from the bridge arm current control chassis to the sub-module, without the need for the sub-module to perform command coding and other operations, shortening the time. The response time of the bridge arm current control chassis to the bridge arm overcurrent protection; each bridge arm has an independent control sequence, and the bridge arm current control chassis can realize independent protection control for each bridge arm, reducing the disturbance to the DC system .

Example 3

An embodiment of the present invention provides an electronic device, as shown in FIG. 5 , including: at least one processor 401 , such as a CPU (Central Processing Unit, central processing unit), at least one communication interface 403 , memory 404 , and at least one communication bus 402 . Among them, the communication bus 402 is used to realize the connection and communication between these components. The communication interface 403 may include a display screen (Display) and a keyboard (Keyboard), and the optional communication interface 403 may also include a standard wired interface and a wireless interface. The memory 404 may be a high-speed RAM memory (Ramdom Access Memory, volatile random access memory), or may be a non-volatile memory (non-volatile memory), such as at least one disk memory. The memory 404 can optionally also be at least one storage device located away from the aforementioned processor 401 . The processor 401 may execute the converter valve overcurrent protection method of Embodiment 1. A set of program codes are stored in the memory 404, and the processor 401 calls the program codes stored in the memory 404 for executing the overcurrent protection method of the converter valve of the first embodiment.

The communication bus 402 may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus or the like. The communication bus 402 can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, only one line is shown in FIG. 5, but it does not mean that there is only one bus or one type of bus.

The memory 404 may include volatile memory (English: volatile memory), such as random-access memory (English: random-access memory, abbreviation: RAM); the memory may also include non-volatile memory (English: non-volatile memory) memory), such as flash memory (English: flash memory), hard disk (English: hard diskdrive, abbreviation: HDD) or solid-state drive (English: solid-state drive, abbreviation: SSD); the memory 404 may also include the above types of combination of memory.

The processor 401 may be a central processing unit (English: central processing unit, abbreviation: CPU), a network processor (English: network processor, abbreviation: NP), or a combination of CPU and NP.

The processor 401 may further include a hardware chip. The above-mentioned hardware chip may be an application-specific integrated circuit (English: application-specific integrated circuit, abbreviation: ASIC), a programmable logic device (English: programmable logic device, abbreviation: PLD) or a combination thereof. The above-mentioned PLD may be a complex programmable logic device (English: complex programmable logic device, abbreviation: CPLD), a field programmable gate array (English: field-programmable gate array, abbreviation: FPGA), a general array logic (English: generic arraylogic , abbreviation: GAL) or any combination thereof.

Optionally, memory 404 is also used to store program instructions. The processor 401 may invoke program instructions to implement the overcurrent protection method for the converter valve in Embodiment 1 of the present application.

Embodiments of the present invention further provide a computer-readable storage medium, where computer-executable instructions are stored thereon, and the computer-executable instructions can execute the converter valve overcurrent protection method of Embodiment 1. Wherein, the storage medium may be a magnetic disk, an optical disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a flash memory (Flash Memory), a hard disk (Hard Disk Drive, Abbreviation: HDD) or solid-state drive (Solid-State Drive, SSD), etc.; the storage medium may also include a combination of the above-mentioned types of memory.

Obviously, the above-mentioned embodiments are only examples for clear description, and are not intended to limit the implementation manner. For those of ordinary skill in the art, changes or modifications in other different forms can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. However, the obvious changes or changes derived from this are still within the protection scope of the present invention.

Claims (10)

1. An overcurrent protection method for a converter valve is characterized by comprising the following steps:

detecting the overcurrent faults of the sub-modules through IGBT drivers in IGBT sub-modules of bridge arms of the converter valve, and counting the number of the sub-modules with the overcurrent faults in each bridge arm;

judging whether the number of the sub-modules with the overcurrent faults is larger than an overcurrent protection threshold value or not;

and when the number of the sub-modules with the overcurrent faults is larger than the overcurrent protection threshold value, determining that the whole converter valve is overcurrent, and locking the whole converter valve.

2. The converter valve overcurrent protection method of claim 1, wherein the detecting of the sub-module overcurrent fault by the IGBT driver in the IGBT sub-module of each bridge arm of the converter valve comprises:

acquiring state information of all sub-modules in each bridge arm of the converter valve, wherein the state information comprises overcurrent fault information;

and determining the submodule with the overcurrent fault by using the overcurrent fault information.

3. The converter valve overcurrent protection method according to claim 2, wherein the obtaining of the state information of all the sub-modules in each bridge arm of the converter valve comprises: and acquiring state information of all sub-modules in each bridge arm of the converter valve in each control period through a valve base controller, wherein the valve base controller is connected with a station control protection system and the converter valve sub-modules.

4. The converter valve over-current protection method according to claim 2,

acquiring state information of all sub-modules in each bridge arm of the converter valve, wherein the state information comprises the following steps: detecting, by the IGBT driver, a current of each of the sub-modules;

the sub-module which has the overcurrent fault is determined by using the overcurrent fault information, and the method comprises the following steps: judging whether the current exceeds a preset current value or not; and when the current exceeds the preset current value, determining that the corresponding sub-module has overcurrent fault.

5. The converter valve over-current protection method according to claim 1, further comprising: and when the number of the sub-modules with the overcurrent faults is not greater than the overcurrent protection threshold value, controlling to lock the sub-modules with the overcurrent faults through the IGBT driver of the sub-modules with the overcurrent faults.

6. The converter valve over-current protection method according to claim 2, wherein the status information further comprises: switching state and capacitance voltage value of the sub-modules.

7. The converter valve overcurrent protection system is characterized by comprising an overcurrent detection module, valve base controller interface equipment and a bridge arm current control cabinet:

the over-current detection module is used for detecting state information of all sub-modules in each bridge arm and sending the state information of each sub-module to the valve base controller interface equipment in each control period;

the valve base controller interface equipment is used for counting the state information of the submodules and sending the number of the submodules with overcurrent faults in each bridge arm in the current period to the bridge arm current control case;

the bridge arm current control cabinet is used for sending a control protection command to valve base controller interface equipment;

and the valve base controller interface equipment is also used for decoding the control protection command and sending the control protection command to each submodule.

8. The converter valve overcurrent protection system of claim 7, wherein the bridge arm current control box further comprises:

and the judging unit is used for judging whether the number of the sub-modules with the overcurrent faults is greater than the overcurrent protection threshold value or not to obtain a judging result.

9. A computer-readable storage medium storing computer instructions which, when executed by a processor, implement a converter valve over-current protection method according to any one of claims 1-6.

10. An electronic device, comprising:

a memory and a processor, the memory and the processor being communicatively connected to each other, the memory having stored therein computer instructions, the processor executing the computer instructions to perform the converter valve over-current protection method according to any one of claims 1 to 6.

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