Dual-slave judgment method and system for valve control system of flexible direct-current converter valve

Abstract

The invention relates to the field of flexible direct-current power transmission, in particular to a dual-slave judgment method and system for a valve control system of a flexible direct-current converter valve. The first valve control unit and the second valve control unit determine own main and standby states respectively; the first valve control unit and the second valve control unit interact respective main and standby states through a first communication path; the first valve control unit and the second valve control unit send respective main and standby states to the judgment module through the second communication path port; performing dual-slave fault judgment based on the master-slave state; according to the invention, an independent judgment module is introduced as a backup judgment unit, and the judgment module directly receives the main and standby states of the first valve control unit and the second valve control unit through an independent second communication path, so that the main and standby states of the first valve control unit and the second valve control unit are ensured under the condition that any single communication path fails; and the system still has complete and independent state sensing and fault judgment capabilities, so that redundant fault tolerance of a judgment function is realized, and system mis-tripping caused by a single-point fault of a communication link is thoroughly avoided.

Description

Technical Field

[0001] This invention relates to the field of flexible DC power transmission, and specifically to a dual-slave judgment method and system for a flexible DC converter valve control system. Background Technology

[0002] The flexible DC transmission converter valve control system, or valve control for short, is the core control system of the flexible DC converter equipment. It also serves as the interface between the flexible DC transmission control and protection system and the converter valve. Its main function is to receive control and protection signals and perform control, monitoring, and protection functions for the converter valve. It is a crucial component of the flexible DC transmission system. Figure 1 As shown, the valve control system generally adopts a redundant configuration of A and B sets, mainly consisting of two layers: the VCMI (valve control master) chassis and the VGC (pulse distribution) chassis. The valve control system (including the VCMI chassis and the VGC chassis) uses a fully redundant A / B configuration, achieving high reliability through a master system output control commands and a slave system standby mode. Specifically, the CPU board (within the VCMI) sends master / slave duty signals to the pulse switching board (VGCB board within the VGC). The pulse switching board then selects whether to send master system data to the pulse distribution board, which only sends the master system's trigger pulses and control commands to the converter valves.

[0003] The VCMI chassis receives duty signals (divided into master system signals and slave system signals) and modulated wave signals from the CCP (Converter Control and Protection System), converts them into trigger pulses and control commands for the converter valve submodules, and then sends them to the pulse switching boards (VGCB boards) A and B of each VGC chassis. Each pulse switching board simultaneously receives control commands from both A and B sets of valve control. After recognizing the master system identifier, it executes the master system's control commands and sends the master system data to the pulse distribution board. The pulse distribution board then sends the trigger pulses of each module to the converter valves. When the pulse switching board cannot recognize the master system identifier, i.e., both sets of valve control are slave systems, it will block the pulses on the pulse distribution board's optical port and report a dual-slave fault on the pulse switching board. Currently, the valve control system mainly determines dual-slave faults on the CPU board of the VCMI chassis. There are redundant optical fibers between the CPU boards of valve control system A and valve control system B for mutual communication, which are used to transmit duty signals and other backup data. When either valve control CPU board detects the presence of a duty signal, it will not output a dual-slave fault signal.

[0004] The drawbacks of existing technologies are that, in terms of judgment logic, the long data link for transmitting duty signals leads to slow response in dual-slave fault detection; and the large number of pulse distribution boards results in occasional misjudgments. Secondly, in terms of the system, since the same pulse switching board only receives master-slave signals from its own valve control system, a backplane bus needs to be added between the dual pulse switching boards to transmit master-slave signals between the two valve control systems, thus increasing the propagation path of master-slave signals. Summary of the Invention

[0005] To address the problems mentioned in the prior art, this invention proposes a dual-slave judgment method and system for a flexible DC converter valve control system, in order to solve the problems of slow response in dual-slave fault detection and occasional misjudgment due to the large number of pulse distribution boards in the background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: This invention discloses a dual-slave judgment method for a flexible DC converter valve control system, comprising the following steps: S1. The first valve control unit and the second valve control unit respectively determine their own master / standby status; S2, the first valve control unit and the second valve control unit exchange their respective master / standby status through the first communication path; S3. The first valve control unit and the second valve control unit send their respective primary / standby status to the judgment module through the second communication path port; S4. Dual-slave fault determination based on master / standby status, including: When the first communication path is normal, the first valve control unit or the second valve control unit executes the first judgment logic. The first judgment logic includes determining that a dual slave failure has occurred if both the master and backup states of the first valve control unit and the second valve control unit are in backup state. When the first communication path fails, the judgment module executes the second judgment logic, which includes determining that a dual slave failure has occurred if both the master and backup states of the first valve control unit and the second valve control unit are in backup state.

[0007] As a further improvement of the present invention, when performing dual-slave fault determination in S4, it is also necessary to satisfy that both the master and backup states are in the backup state, and the backup state continues for more than a preset time threshold.

[0008] As a further improvement of the present invention, the preset time threshold is 1ms.

[0009] As a further improvement of the present invention, in S1, the first valve control unit and the second valve control unit determine their own master / standby status based on receiving the master / slave signals from their respective converter control and protection systems.

[0010] As a further improvement of the present invention, the first communication path is a hot-backup optical fiber.

[0011] As a further improvement of the present invention, the second communication path is a high-speed optical fiber.

[0012] As a further improvement of the present invention, the judgment module is a pulse switching board in the pulse distribution chassis.

[0013] This invention proposes a fault detection system for dual-slave faults in flexible DC transmission systems, applied to the aforementioned dual-slave fault detection method for flexible DC converter valve control systems, comprising: The first and second valve control units are redundantly configured and are used to determine their own primary / standby status, respectively. The first communication path is used to exchange the master / standby status between the first valve control unit and the second valve control unit; The second communication path is used to send the master / standby status of the first valve control unit and the second valve control unit to a judgment module; The system is configured to perform dual-slave fault determination, specifically including: When the first communication path is normal, the first judgment unit executes the first judgment logic by the first valve control unit or the second valve control unit. The first judgment logic includes determining that a dual-slave failure has occurred if both the master and backup states of the first valve control unit and the second valve control unit are in backup state. The second judgment unit, when the first communication path fails, executes the second judgment logic by the judgment module. The second judgment logic includes determining that a dual slave failure has occurred if both the master and backup states of the first valve control unit and the second valve control unit are in backup state.

[0014] As a further improvement of the present invention, the judgment module is a pulse switching board in the pulse distribution chassis.

[0015] As a further improvement of the present invention, the first communication path is a hot backup optical fiber between the first valve control unit and the second valve control unit; The second communication path is a high-speed optical fiber between the first valve control unit, the second valve control unit, and the judgment module.

[0016] Compared with the prior art, the present invention achieves the following technical effects: This invention introduces an independent judgment module as a backup judgment unit. The judgment module directly receives the master / backup status of the first and second valve control units through an independent second communication path, thus forming a judgment channel that runs parallel to and is independent of the valve control unit communication path. When the first communication path between valve control units is normal, the system prioritizes any one of the valve control master control units to execute the first judgment logic. Once the first communication path fails, the system switches to the judgment module, which executes the second judgment logic. This ensures that even if any single communication path fails, the system still has complete and independent status awareness and fault judgment capabilities, achieving redundancy and fault tolerance of the judgment function. It completely avoids system false tripping caused by single-point failure of the communication link, fundamentally solving the problems of slow detection response and false alarms caused by excessively long signal transmission paths and reliance on a single judgment node in the prior art, and realizing accurate and rapid detection of dual-slave faults in the valve control system. Attached Figure Description

[0017] Figure 1 Here is a block diagram of the existing flexible DC transmission valve control system. Figure 2 This is a schematic diagram of the method flow of the present invention; Figure 3 This is a schematic diagram of the system structure of the present invention; Figure 4 This is a schematic diagram of the method of the present invention. Detailed Implementation

[0018] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0019] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0023] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0024] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0025] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0026] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0027] See Figure 2 This embodiment proposes a dual-slave judgment method for a flexible DC converter valve control system, including the following steps: S1. The first valve control unit and the second valve control unit respectively determine their own master / standby status; S2, the first valve control unit and the second valve control unit exchange their respective master / standby status through the first communication path; S3. The first valve control unit and the second valve control unit send their respective primary / standby status to the judgment module through the second communication path port; S4. Dual-slave fault determination based on master / standby status, including: When the first communication path is normal, the first valve control unit or the second valve control unit executes the first judgment logic. The first judgment logic includes determining that a dual slave failure has occurred if both the master and backup states of the first valve control unit and the second valve control unit are in backup state. When the first communication path fails, the judgment module executes the second judgment logic, which includes determining that a dual slave failure has occurred if both the master and backup states of the first valve control unit and the second valve control unit are in backup state.

[0028] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0029] join Figure 3 The system in this embodiment includes a first valve control unit (which may correspond to system A) and a second valve control unit (which may correspond to system B) that are redundantly configured with each other, as well as a pulse distribution chassis. Specifically, the core of the first valve control unit and the second valve control unit is the main control CPU board, which is responsible for communicating with the upper-level converter control and protection system (CCP), receiving the duty signal (i.e. master-slave signal) sent by it, and determining whether it is in the primary or standby state.

[0030] In this embodiment, the pulse distribution chassis contains two pulse switching boards (preferably VGCB boards) and a subsequent pulse distribution board (LB board). The structural improvement in this embodiment lies in the connection relationship and information flow. The first valve control unit and the second valve control unit are connected through a first communication path. The first communication path is usually preferably implemented by a hot-backup optical fiber. Its function is to realize real-time and efficient data synchronization and status interaction between the CPU boards of the first valve control unit and the second valve control unit.

[0031] Meanwhile, this embodiment introduces a second communication path. Specifically, the first and second valve control units do not only communicate with their own pulse distribution chassis, but also cross-send their master / standby status information to the judgment module in the pulse distribution chassis through the second communication path. The second communication path preferably uses high-speed optical fiber, and the judgment module is preferably a pulse switching board in the pulse distribution chassis, so that each pulse switching board can receive status information from the two valve control master control units A and B through high-speed optical fiber. Each pulse switching board receives status information from both valve control main control units A and B simultaneously via an independent high-speed optical fiber. In addition, the pulse distribution board is equipped with dual FPGAs, which are connected to the pulse switching board via an independent communication bus. There is no physical communication between the two pulse switching boards, which further reduces complexity.

[0032] See Figure 4 The specific process of this embodiment is as follows: 1. The main control CPU boards of the first and second valve control units will continuously receive duty signals from the CCP system. Once the CCP designates the master system and slave system, for example, designating set A as the master and set B as the backup, the two valve control units will determine their master / backup status accordingly.

[0033] Subsequently, the first and second valve control units will perform two parallel actions: First, they will inform each other of their status through the first communication path. For example, under normal communication conditions, valve control unit A will know that valve control unit B is on standby, and valve control unit B will know that valve control unit A is in primary use. Second, they will transmit their respective status information to the pulse switching board in the pulse distribution chassis through the second communication path. The registers of pulse switching board A and pulse switching board B will simultaneously record the information "Status of valve control unit A: Primary use" and "Status of valve control unit B: Standby use".

[0034] When the first communication path, i.e., the hot backup fiber connecting the two valve control main control units, is functioning normally, the system prioritizes the first judgment logic. At this time, the judgment is executed by the main control CPU board of either the first or second valve control unit. Because the hot backup fiber is unobstructed, either main control CPU board can monitor the global status of both systems in real time. If the status flags of both the first and second valve control units are found to be "both in standby," and this abnormal state persists for more than a preset time threshold (1ms in this embodiment), a dual-slave fault will be immediately determined, and a corresponding fault signal will be generated. Using the preset time threshold effectively filters out transient state inconsistencies caused by instantaneous signal jitter, electromagnetic interference, or system switching, thereby preventing false protection activation and greatly improving the accuracy of the judgment.

[0035] When the primary communication path fails, such as due to a loose fiber optic interface, damage to the fiber optic cable itself, or a fault in the related drive circuit, the hot backup fiber optic cable connecting the two valve-controlled master control units is completely interrupted. In the traditional solution, although the primary system (Set A) is still operating normally, the backup system (Set B) cannot detect the status of Set A due to the communication interruption. The CPU board of Set B will assume that both systems are in "standby" mode, thus misjudging a dual-slave failure and causing unnecessary system downtime.

[0036] However, in this invention, a second judgment logic is used for the determination. In this case, the judgment is made by the pulse switching board in the pulse distribution chassis.

[0037] Since the second communication path is independent of the first communication path, the interruption of the hot backup fiber does not affect the normal operation of the high-speed fiber. Therefore, the pulse switching board receives status information from the valve control units of sets A and B. At this time, the second judgment logic executed by the pulse switching board continuously monitors the global status of the two systems. When it is found that the status flags of the first valve control unit and the second valve control unit are both "standby", and this abnormal state persists for more than a preset time threshold (1ms in this embodiment), a dual-slave failure is determined to have occurred.

[0038] Once a fault is confirmed, the pulse switching board immediately reports the dual-slave fault status signal to the valve control master unit via the communication bus between itself and the master control CPU board. Upon receiving this confirmation signal from the pulse switching board, the valve control master unit generates a system-level dual-slave fault trip command.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0040] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A dual-slave judgment method for a flexible DC converter valve control system, characterized in that, Includes the following steps: S1. The first valve control unit and the second valve control unit respectively determine their own master / standby status; S2, the first valve control unit and the second valve control unit exchange their respective master / standby status through the first communication path; S3. The first valve control unit and the second valve control unit send their respective primary / standby status to the judgment module through the second communication path port; S4. Dual-slave fault determination based on master / standby status, including: When the first communication path is normal, the first valve control unit or the second valve control unit executes the first judgment logic. The first judgment logic includes determining that a dual slave failure has occurred if both the master and backup states of the first valve control unit and the second valve control unit are in backup state. When the first communication path fails, the judgment module executes the second judgment logic, which includes determining that a dual slave failure has occurred if both the master and backup states of the first valve control unit and the second valve control unit are in backup state.

2. The dual-slave judgment method for a flexible DC converter valve control system according to claim 1, characterized in that, When performing dual-slave fault determination in S4, it is also necessary to ensure that both the master and backup states are in backup state, and the backup device continues to exceed a preset time threshold.

3. The dual-slave judgment method for a flexible DC converter valve control system according to claim 2, characterized in that, The preset time threshold is 1ms.

4. The dual-slave judgment method for a flexible DC converter valve control system according to claim 1, characterized in that, In S1, the first valve control unit and the second valve control unit determine their own master / standby status based on the master / slave signals received from their respective converter control and protection systems.

5. The dual-slave judgment method for a flexible DC converter valve control system according to claim 1, characterized in that, The first communication path is a hot-backup optical fiber.

6. The dual-slave judgment method for a flexible DC converter valve control system according to claim 1, characterized in that, The second communication path is a high-speed optical fiber.

7. The dual-slave judgment method for a flexible DC converter valve control system according to claim 1, characterized in that, The judgment module is a pulse switching board in the pulse distribution chassis.

8. A fault detection system for dual slaves in a flexible DC transmission system, characterized in that, The dual-slave determination method applied to the flexible DC converter valve control system according to any one of claims 1 to 7 includes: The first and second valve control units are redundantly configured and are used to determine their own primary / standby status, respectively. The first communication path is used to exchange the master / standby status between the first valve control unit and the second valve control unit; The second communication path is used to send the master / standby status of the first valve control unit and the second valve control unit to a judgment module; The system is configured to perform dual-slave fault determination, specifically including: When the first communication path is normal, the first judgment unit executes the first judgment logic by the first valve control unit or the second valve control unit. The first judgment logic includes determining that a dual-slave failure has occurred if both the master and backup states of the first valve control unit and the second valve control unit are in backup state. The second judgment unit, when the first communication path fails, executes the second judgment logic by the judgment module. The second judgment logic includes determining that a dual slave failure has occurred if both the master and backup states of the first valve control unit and the second valve control unit are in backup state.

9. The system for determining dual-slave faults in a flexible DC transmission system according to claim 8, characterized in that, The judgment module is a pulse switching board in the pulse distribution chassis.

10. A fault detection system for a flexible DC transmission system with dual slaves according to claim 8, characterized in that, The first communication path is a hot-backup optical fiber between the first valve control unit and the second valve control unit; The second communication path is a high-speed optical fiber between the first valve control unit, the second valve control unit, and the judgment module.

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