A method, system, device and storage medium for high-frequency harmonic protection of a flexible direct-flow valve group

Abstract

The present invention discloses a method, system, device and storage medium for high-frequency harmonic protection of a flexible direct current valve group. The method for high-frequency harmonic protection of a flexible direct current valve group calculates the harmonic components obtained in real time in a first frequency range, thereby avoiding the influence of transformer saturation and background harmonics when calculating the 2-7 harmonic components, and reducing the false triggering phenomenon of protection action output tripping; by prohibiting the gear adjustment of the commutator tap changer when the comprehensive value of the harmonic components is greater than the first threshold value and the first duration reaches the first delay, the harmonic protection performance is improved; by controlling the non-master control valve group to lock when the flexible direct current valve group is a flexible direct current dual-valve group and the second duration reaches the preset second delay, the equivalent impedance of the flexible direct current dual-valve group as a whole is changed, the resonance condition between the flexible direct current dual-valve group and the high-frequency harmonic system of the flexible direct current valve group is destroyed, the high-frequency resonance between the master control valve group and the system is exited, and the problem of simultaneous locking of the dual-valve group is avoided.

Description

Technical Field

[0001] The present application relates to the field of flexible direct current transmission technology, and in particular to a method, system, device and storage medium for high-frequency harmonic protection of a flexible direct current valve group. Background Art

[0002] When the flexible direct current (FDC) impedance does not match the AC system impedance, the risk of high-frequency resonance is prone to occur. In order to reduce the losses caused by high-frequency resonance, existing projects are equipped with high-frequency harmonic protection devices. The high-frequency harmonic protection method adopted detects the harmonic current components flowing into the converter station and calculates the sum of the 2-50th harmonic components. When the sum of the harmonic components is greater than the preset action threshold and lasts for a period of delay, the protection action outlet trips to protect the safety of the equipment. Among them, the selection of the action threshold and delay needs to consider the harmonic tolerance of the flexible direct current valve group converter tap, converter transformer (converter transformer), flexible direct current valve and primary equipment. The action threshold and delay are selected according to the equipment with the weakest harmonic tolerance.

[0003] However, existing high-frequency harmonic protection methods do not consider harmonic protection coordination in the context of flexible DC dual-valve systems. When applied to flexible DC dual-valve systems, this leads to the problem of both valves locking simultaneously in the presence of high-frequency harmonics. Furthermore, the calculation of the sum of harmonic components by existing high-frequency harmonic protection methods is affected by transformer saturation and background harmonics, resulting in tripping of the protection output in the absence of high-frequency harmonics. Consequently, existing high-frequency harmonic protection methods suffer from poor harmonic protection performance and reliability. Summary of the Invention

[0004] The purpose of the present invention is to solve one of the technical problems existing in the prior art to at least a certain extent.

[0005] To this end, embodiments of the present invention provide a method, system, device, and storage medium for high-frequency harmonic protection of a flexible direct-current valve group, thereby improving harmonic protection performance and reliability.

[0006] In order to achieve the above technical objectives, the technical solutions adopted by the embodiments of the present invention include:

[0007] In one aspect, an embodiment of the present invention provides a method for high-frequency harmonic protection of a flexible direct current valve group, comprising the following steps:

[0008] According to the acquired real-time harmonic current components, a sum of harmonic components is calculated within a first frequency range, where the first frequency range is 8-50;

[0009] confirming that the sum of the harmonic components is greater than a preset first threshold value and a first duration reaches a preset first delay, prohibiting the gear adjustment of the commutation tap changer in the flexible direct current valve group, where the first duration is the time during which the sum of the harmonic components is greater than the first threshold value;

[0010] When it is confirmed that the sum of the harmonic components is greater than a preset second threshold value, determining whether the flexible direct current valve group is a flexible direct current dual valve group, the flexible direct current dual valve group including a main control valve group and a non-main control valve group, and the second threshold value is greater than the first threshold value;

[0011] If yes, when the second duration reaches a preset second delay, the non-master valve group is controlled to be locked, the second duration being the time during which the sum of the harmonic components is greater than the second threshold value, and the second delay is greater than the first delay;

[0012] If not, when the second duration reaches a preset third delay, the flexible straight valve group is controlled to be locked, and the third delay is greater than the second delay.

[0013] In addition, the high-frequency harmonic protection method for a flexible direct-flow valve group according to the above embodiment of the present invention may also have the following additional technical features:

[0014] Furthermore, in a high-frequency harmonic protection method for a flexible direct current valve group according to an embodiment of the present invention, the acquisition of the real-time harmonic current component includes:

[0015] The harmonic current component flowing into the converter station valve side of the flexible direct current valve group is detected in real time to obtain the real-time harmonic current component.

[0016] Furthermore, in one embodiment of the present invention, the preset first threshold value and the first delay include:

[0017] A first constant value is determined according to the harmonic tolerance capability of the converter tap changer, where the first constant value includes the first threshold value and the first delay.

[0018] Furthermore, in one embodiment of the present invention, the preset second threshold value and the third delay include:

[0019] The second constant is determined according to the harmonic tolerance capability of the first device, the second constant includes the second threshold value and the third delay, and the first device is the device with the weakest harmonic tolerance capability in the flexible direct current valve group except the converter tap changer.

[0020] Furthermore, in one embodiment of the present invention, the preset of the second delay includes:

[0021] The third delay is shortened to obtain the second delay.

[0022] Furthermore, in one embodiment of the present invention, prohibiting the gear adjustment of the commutation tap changer in the flexible direct valve group includes:

[0023] A target port at a protection outlet of the commutation variable tap section in the flexible direct valve group is enabled, wherein the target port is used to lock the gear adjustment of the commutation variable tap after being enabled.

[0024] On the other hand, an embodiment of the present invention provides a high-frequency harmonic protection system for a flexible direct current valve group, comprising:

[0025] The first module is configured to calculate the sum of the harmonic components in a first frequency range according to the acquired real-time harmonic current components, where the first frequency range is 8-50;

[0026] a second module, configured to prohibit the gear adjustment of the commutation tap changer in the flexible direct current valve group when confirming that the sum of the harmonic components is greater than a preset first threshold value and a first duration reaches a preset first delay value, wherein the first duration is the time during which the sum of the harmonic components is greater than the first threshold value;

[0027] A third module is configured to determine whether the flexible direct current valve group is a flexible direct current dual valve group when confirming that the sum of the harmonic components is greater than a preset second threshold value, the flexible direct current dual valve group including a main control valve group and a non-main control valve group, and the second threshold value is greater than the first threshold value;

[0028] A fourth module is configured to control the non-master valve group to be locked when a second duration reaches a preset second delay, wherein the second duration is the time during which the sum of the harmonic components is greater than the second threshold value, and the second delay is greater than the first delay;

[0029] The fifth module is used to control the flexible straight valve group to be locked if the second duration reaches a preset third delay, and the third delay is greater than the second delay.

[0030] Furthermore, in one embodiment of the present invention, the system further includes a sixth module, which is configured to detect in real time the harmonic current component flowing into the converter station valve side of the flexible direct current valve group to obtain the real-time harmonic current component.

[0031] On the other hand, an embodiment of the present invention provides a high-frequency harmonic protection device for a flexible direct current valve group, comprising:

[0032] at least one processor;

[0033] at least one memory for storing at least one program;

[0034] When the at least one program is executed by the at least one processor, the at least one processor implements the high-frequency harmonic protection method for a flexible direct current valve group.

[0035] On the other hand, an embodiment of the present invention provides a storage medium storing a program executable by a processor. When the program is executed by the processor, it is used to implement the high-frequency harmonic protection method for a flexible direct current valve group.

[0036] Advantages and beneficial effects of the present invention:

[0037] The embodiment of the present invention calculates the harmonic components obtained in real time within the first frequency range, thereby avoiding the influence of the second harmonics and background harmonics caused by transformer saturation when calculating the 2nd to 7th harmonic components, and reducing the phenomenon of protection action output tripping when no high-frequency harmonics occur; by prohibiting the gear adjustment of the converter tap changer when the sum of the harmonic components is greater than the first threshold value and the first duration reaches the first delay, the converter tap changer is protected, and the determination of the second threshold value, the second delay and the third delay does not need to consider the harmonic tolerance capability of the converter tap changer, thereby improving the harmonic protection performance; by controlling the non-master control valve group of the flexible DC valve group to be locked when the flexible DC valve group is a flexible DC dual-valve group and the second duration reaches the preset second delay, the overall equivalent impedance of the flexible DC dual-valve group is changed, the resonance condition between the flexible DC dual-valve group and the high-frequency harmonic system of the flexible DC valve group is destroyed, so that the master control valve group of the flexible DC valve group and the system exit the high-frequency resonance, thereby avoiding the problem of simultaneous locking of the dual valve groups. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following introduction is made to the drawings of the embodiments of the present application or the related technical solutions in the prior art. It should be understood that the drawings introduced below are only for the convenience of clearly describing some embodiments of the technical solutions of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without any creative work.

[0039] Figure 1 This is a flow chart of a specific embodiment of a method for high-frequency harmonic protection of a flexible direct current valve group according to the present invention;

[0040] Figure 2 This is a schematic diagram of the electrical wiring structure of a flexible DC double valve group according to a specific embodiment of a high-frequency harmonic protection method for a flexible DC valve group of the present invention;

[0041] Figure 3 This is a structural diagram of a specific embodiment of a high-frequency harmonic protection system for a flexible direct-flow valve group according to the present invention;

[0042] Figure 4This is a structural schematic diagram of a specific embodiment of a high-frequency harmonic protection device for a flexible direct-flow valve group of the present invention. DETAILED DESCRIPTION

[0043] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application. The step numbers in the following embodiments are provided only for the convenience of explanation and do not limit the order of the steps. The order of execution of the steps in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0044] The terms "first," "second," "third," and "fourth," etc., in the specification, claims, and accompanying drawings of the present invention are used to distinguish between different items, not to describe a specific order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0045] References to "embodiments" in this disclosure mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the disclosure. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0046] Existing high-frequency harmonic protection methods do not consider harmonic protection coordination in the context of flexible DC dual-valve systems. When applied to flexible DC dual-valve systems, this leads to the problem of both valves locking simultaneously in the presence of high-frequency harmonics. Furthermore, the calculation of the sum of harmonic components by existing high-frequency harmonic protection methods is affected by transformer saturation and background harmonics, resulting in tripping of the protection output in the absence of high-frequency harmonics. Consequently, existing high-frequency harmonic protection methods suffer from poor harmonic protection performance and reliability. To this end, the present invention proposes a method, system, device and storage medium for high-frequency harmonic protection of a flexible DC valve group, which calculates the harmonic components obtained in real time within a first frequency range, avoiding the influence of secondary harmonics and background harmonics caused by transformer saturation when calculating the 2-7 harmonic components, and reducing the phenomenon of protection action output tripping when no high-frequency harmonics occur; by prohibiting the gear adjustment of the converter tap changer when the sum of the harmonic components is greater than the first threshold value and the first duration reaches the first delay, the converter tap changer is protected, and the determination of the second threshold value, the second delay and the third delay does not need to consider the harmonic tolerance capability of the converter tap changer, thereby improving the harmonic protection performance; by controlling the non-master control valve group of the flexible DC valve group to be locked when the flexible DC valve group is a flexible DC dual-valve group and the second duration reaches the preset second delay, the overall equivalent impedance of the flexible DC dual-valve group is changed, the resonance condition between the flexible DC dual-valve group and the high-frequency harmonic system of the flexible DC valve group is destroyed, so that the master control valve group of the flexible DC valve group and the system exit the high-frequency resonance, avoiding the problem of simultaneous locking of the dual valve groups.

[0047] The following describes in detail a high-frequency harmonic protection method, system, device and storage medium for a flexible direct current valve group proposed according to an embodiment of the present invention with reference to the accompanying drawings. First, a high-frequency harmonic protection method for a flexible direct current valve group proposed according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0048] Reference Figure 1 In an embodiment of the present invention, a method for high-frequency harmonic protection of a flexible direct current valve group is provided. The method for high-frequency harmonic protection of a flexible direct current valve group in an embodiment of the present invention can be applied to a terminal, a server, or software running in a terminal or a server. The terminal can be a tablet computer, a laptop computer, a desktop computer, etc., but is not limited thereto. The server can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, content distribution networks (CDNs), and big data and artificial intelligence platforms.

[0049] A high-frequency harmonic protection method for a flexible direct current valve group in an embodiment of the present invention mainly includes the following steps S101-S105:

[0050] S101, calculating a sum of harmonic components within a first frequency range based on the acquired real-time harmonic current components;

[0051] Among them, the first frequency range is 8-50 times.

[0052] According to prior knowledge, the existing high-frequency harmonic protection method calculates the sum of the harmonic components in the frequency range of 2-50 based on the harmonic current components obtained by detection. Among them, the harmonic components in the frequency range of 2-7 are affected by the secondary harmonics and background harmonics caused by transformer saturation, especially in the frequency range of 5-7, the influence of the secondary harmonics and background harmonics on the harmonic components is even greater. If the sum of the harmonic components calculated in the frequency range of 2-50 is used for harmonic protection, it may cause the protection action outlet to trip in the absence of high-frequency harmonics. Therefore, the high-frequency harmonic protection method for the flexible direct current valve group in the embodiment of the present invention only calculates the harmonic components in the frequency range of 8-50 (within the first frequency range), avoiding the influence of the secondary harmonics and background harmonics caused by transformer saturation when calculating the 2-7 harmonic components, and reducing the false operation of the protection action outlet.

[0053] It can be understood that when only the harmonic components within the frequency range of 8-50 (within the first frequency range) are calculated to obtain the total value of the harmonic components, it is necessary to prevent the frequency of high-frequency resonance from occurring within the frequency range of 2-7 to prevent the omission of high-frequency resonance occurring within the frequency range of 2-7.

[0054] Optionally, in some embodiments, parameters of the flexible DC valve group are selected based on flexible DC engineering control to prevent high-frequency resonance from occurring within the frequency range of 2-7. Specifically, by optimizing the PI parameters of the flexible DC valve group's inner control loop and the feedforward filter, the flexible DC exhibits positive damping within the frequency range of 2-7, thereby preventing resonance (including high-frequency resonance) within the frequency range of 2-7.

[0055] Optionally, in some embodiments, the real-time harmonic current component is obtained by detecting the harmonic current component flowing into the flexible direct current valve group on the valve side of the converter station in real time.

[0056] S102: confirming that the sum of the harmonic components is greater than a preset first threshold value and the first duration reaches a preset first delay, prohibiting the gear adjustment of the converter tap changer in the flexible direct current valve group;

[0057] The first duration is the duration during which the sum of the harmonic components is greater than the first threshold.

[0058] In high-frequency harmonic protection methods for flexible DC valve systems, the selection of the action threshold and delay must consider the harmonic tolerance of the converter tap changer, converter transformer (CT), flexible DC valve, and primary equipment within the flexible DC valve system. The action threshold and delay are determined based on the device with the weakest harmonic tolerance. The converter tap changer is the device with the weakest harmonic tolerance within the flexible DC valve system. Therefore, existing harmonic protection methods determine the action threshold and delay based on the harmonic tolerance of the converter tap changer. When the sum of the harmonic components exceeds the action threshold and lasts for the delay, the protection action output trips (harmonic current tripping stage). Based on prior knowledge, during the process of adjusting the converter tap changer position, the converter tap changer is more sensitive to harmonics, meaning its harmonic tolerance is weak. However, when the converter tap changer position is fixed, its harmonic tolerance is stronger. Therefore, the embodiment of the present invention adds a commutation transformer tap section before the harmonic current tripping section, and prohibits the gear adjustment of the commutation transformer tap when the sum of the harmonic components is greater than the first threshold value and the first duration reaches the first delay. As a result, the threshold value and delay corresponding to the harmonic current tripping section are determined without considering the harmonic tolerance capability of the commutation transformer tap, thereby protecting the commutation transformer tap and improving the harmonic protection performance.

[0059] Optionally, in some embodiments, the gear adjustment of the commutation tap changer in the flexible direct current valve group is disabled by enabling a target port at a protection outlet of the commutation tap changer section in the flexible direct current valve group. The target port is used to block the gear adjustment of the commutation tap changer after being enabled.

[0060] Optionally, in some embodiments, the first constant value is determined according to the harmonic tolerance capability of the converter tap changer, wherein the first constant value includes a first threshold value and a first delay.

[0061] According to prior knowledge, prohibiting the gear adjustment of the commutator tap changer has little impact on the active operating range and reactive operating range of the flexible DC power supply. Therefore, in the embodiment of the present invention, prohibiting the gear adjustment of the commutator tap changer when the sum of the harmonic components is greater than the first threshold value and the first duration and the first delay are maintained will not affect the normal operation of the flexible DC power supply.

[0062] S103: When it is confirmed that the sum of the harmonic components is greater than a preset second threshold value, determining whether the flexible direct current valve group is a flexible direct current dual valve group;

[0063] Among them, the flexible direct current dual valve group includes a main control valve group and a non-main control valve group, and the second threshold value is greater than the first threshold value.

[0064] Specifically, in this embodiment of the present invention, according to step S102, when the sum of the harmonic components exceeds the first threshold and the first duration reaches the first delay, the commutation tap changer is prohibited from adjusting its gear position. Since the commutation tap changer has a strong harmonic tolerance when it is fixed (when gear adjustment is prohibited), the second threshold is set based on the other devices in the flexible DC valve group other than the commutation tap changer without considering its harmonic tolerance. Therefore, it can be understood that the second threshold is greater than the first threshold.

[0065] Figure 2 The electrical wiring structure of the flexible direct current double valve group is shown. Figure 2 The main control valve group and non-main control valve group of the flexible direct current dual valve group are connected to the same AC bus, presenting a dual valve group series or dual valve group parallel structure.

[0066] S104: If yes, when the second duration reaches the preset second delay, the non-master control valve group is controlled to be locked;

[0067] The second duration is the time during which the sum of the harmonic components is greater than the second threshold value, and the second delay is greater than the first delay.

[0068] Specifically, in this embodiment of the present invention, according to step S102, when the sum of the harmonic components exceeds the first threshold and the first duration reaches the first delay, the commutation tap changer is prohibited from adjusting its gear position. Since the commutation tap changer has a strong harmonic tolerance when fixed, the second delay is set based on the harmonic tolerance of the commutation tap changer and is instead adjusted based on other devices in the flexible DC valve group other than the commutation tap changer. Therefore, it can be understood that the second delay is greater than the first threshold.

[0069] In an embodiment of the present invention, when the sum of the harmonic components is determined to be greater than a second threshold, if the flexible DC valve group is a flexible dual-valve group, and when the second duration reaches a second delay, the non-master valve group is controlled to close, while the master valve group is not closed (the delay required for the master valve group to close is greater than the second delay). At this point, the non-master valve group changes the equivalent impedance of the flexible dual-valve group as a whole, disrupting the resonance condition between the flexible dual-valve group and the high-frequency harmonic system of the flexible DC valve group, causing the master valve group and the system to exit high-frequency resonance. As a result, after the non-master valve group closes, the master valve group will not close, thus avoiding the problem of simultaneous closing of both valve groups.

[0070] S105: If not, when the second duration reaches the preset third delay, the flexible straight valve group is controlled to be locked.

[0071] The third delay is greater than the second delay.

[0072] Specifically, in the embodiment of the present invention, according to step S102, when the sum of the harmonic components is greater than the first threshold value and the first duration reaches the first delay, the gear adjustment of the converter tap changer is prohibited, and the converter tap changer has a strong harmonic tolerance capability when it is fixed. Therefore, the third delay is preset without considering the harmonic tolerance capability of the converter tap changer, but is adjusted based on other equipment in the flexible DC valve group except the converter tap changer.

[0073] Optionally, in some embodiments, the preset second threshold value and the third delay specifically include:

[0074] The second set value is determined according to the harmonic tolerance capability of the first device.

[0075] The second constant includes a second threshold value and a third delay, and the first device is the device with the weakest harmonic tolerance in the flexible direct current valve group except for the converter tap changer.

[0076] Optionally, in some embodiments, the preset second delay specifically includes:

[0077] Shorten the third delay to get the second delay.

[0078] It can be understood that when the flexible direct current valve group is a flexible direct current double valve group, the delay corresponding to the harmonic current tripping section controlling the locking of the main control valve group is the third delay, and the third delay is greater than the second delay.

[0079] In combination with the high-frequency harmonic protection method for a flexible DC valve group described in steps S101-S105, it can be seen that the present invention calculates the harmonic components obtained in real time within the first frequency range, avoiding the influence of the second harmonics and background harmonics caused by transformer saturation when calculating the 2-7 harmonic components, and reducing the phenomenon of protection action output tripping when no high-frequency harmonics appear; by prohibiting the gear adjustment of the converter tap changer when the sum of the harmonic components is greater than the first threshold value and the first duration reaches the first delay, the converter tap changer is protected, and the determination of the second threshold value, the second delay and the third delay does not need to consider the harmonic tolerance capability of the converter tap changer, thereby improving the harmonic protection performance; by controlling the non-master control valve group of the flexible DC valve group to be locked when the flexible DC valve group is a flexible DC dual-valve group and the second duration reaches the preset second delay, the equivalent impedance of the entire flexible DC dual-valve group is changed, the resonance condition between the flexible DC dual-valve group and the high-frequency harmonic system of the flexible DC valve group is destroyed, so that the master control valve group of the flexible DC valve group and the system exit the high-frequency resonance, avoiding the problem of simultaneous locking of the dual valve groups.

[0080] Next, a high-frequency harmonic protection system for a flexible direct-flow valve group according to an embodiment of the present application will be described with reference to the accompanying drawings.

[0081] Figure 3This is a structural diagram of a high-frequency harmonic protection system for a flexible direct-current valve group according to an embodiment of the present application.

[0082] The system specifically includes:

[0083] The first module 301 is configured to calculate the sum of the harmonic components in a first frequency range according to the acquired real-time harmonic current components, where the first frequency range is 8-50;

[0084] The second module 302 is configured to prohibit the gear adjustment of the commutation tap changer in the flexible direct current valve group when confirming that the sum of the harmonic components is greater than a preset first threshold value and a first duration reaches a preset first delay value, wherein the first duration is the duration during which the sum of the harmonic components is greater than the first threshold value.

[0085] The third module 303 is configured to determine whether the flexible direct current valve group is a flexible direct current dual valve group when confirming that the sum of the harmonic components is greater than a preset second threshold value, the flexible direct current dual valve group including a main control valve group and a non-main control valve group, and the second threshold value is greater than the first threshold value;

[0086] A fourth module 304 is configured to control the non-master control valve group to be locked when a second duration reaches a preset second delay, wherein the second duration is the duration during which the sum of the harmonic components is greater than the second threshold value, and the second delay is greater than the first delay;

[0087] The fifth module 305 is used to control the flexible straight valve group to be locked if the second duration reaches a preset third delay, and the third delay is greater than the second delay.

[0088] Furthermore, in one embodiment of the present invention, the system further includes a sixth module, which is configured to detect in real time the harmonic current component flowing into the converter station valve side of the flexible direct current valve group to obtain the real-time harmonic current component.

[0089] It can be seen that the contents of the above method embodiments are all applicable to the present system embodiments. The functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0090] Reference Figure 4 The embodiment of the present application provides a high-frequency harmonic protection device for a flexible direct-current valve group, comprising:

[0091] at least one processor 401;

[0092] at least one memory 402, configured to store at least one program;

[0093] When the at least one program is executed by the at least one processor 401, the at least one processor 401 implements the high-frequency harmonic protection method for a flexible direct current valve group described in steps S101-S105.

[0094] Similarly, the contents of the above method embodiments are applicable to the present device embodiments. The functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0095] In some optional embodiments, the function / operation mentioned in the block diagram may not occur in the order mentioned in the operation diagram. For example, depending on the function / operation involved, the two boxes shown in succession can actually be executed substantially simultaneously or the boxes can sometimes be executed in reverse order. In addition, the embodiments presented and described in the flow chart of the present application are provided in an exemplary manner for the purpose of providing a more comprehensive understanding of the technology. The disclosed method is not limited to the operations and logical flows presented herein. Optional embodiments are contemplated in which the order of the various operations is changed and the sub-operations described as a part of a larger operation are performed independently.

[0096] In addition, although the present application is described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in separate physical devices or software modules. It is also understood that a detailed discussion of the actual implementation of each module is not necessary for understanding the present application. More specifically, given the properties, functions, and internal relationships of the various functional modules in the devices disclosed herein, the actual implementation of the module will be understood within the routine skills of an engineer. Therefore, a person skilled in the art can implement the present application as set forth in the claims using ordinary techniques without undue experimentation. It is also understood that the specific concepts disclosed are merely illustrative and are not intended to limit the scope of the present application, which is determined by the full scope of the appended claims and their equivalents.

[0097] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several programs for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0098] The logic and / or steps represented in a flowchart or otherwise described herein, for example, may be considered as an ordered list of executable programs for implementing the logical functions, and may be embodied in any computer-readable medium for use by, or in conjunction with, a program execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can retrieve and execute a program from a program execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" may be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, a program execution system, apparatus, or device.

[0099] More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk cartridge (magnetic devices), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering, or processing in another suitable manner as necessary, and then stored in a computer memory.

[0100] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable program execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0101] In the above description of this specification, reference to the terms "one embodiment / example," "another embodiment / example," or "certain embodiments / examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples.

[0102] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

[0103] The above is a specific description of the preferred implementation of the present application, but the present application is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present application. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. A high-frequency harmonic protection method for a flexible direct current valve group, characterized in that: The following steps are involved: According to the acquired real-time harmonic current components, a sum of harmonic components is calculated within a first frequency range, where the first frequency range is 8-50; confirming that the sum of the harmonic components is greater than a preset first threshold value and a first duration reaches a preset first delay, prohibiting the gear adjustment of the commutation tap changer in the flexible direct current valve group, where the first duration is the time during which the sum of the harmonic components is greater than the first threshold value; When it is confirmed that the sum of the harmonic components is greater than a preset second threshold value, determining whether the flexible direct current valve group is a flexible direct current dual valve group, the flexible direct current dual valve group including a main control valve group and a non-main control valve group, and the second threshold value is greater than the first threshold value; If yes, when the second duration reaches a preset second delay, the non-master valve group is controlled to be locked, the second duration being the time during which the sum of the harmonic components is greater than the second threshold value, and the second delay is greater than the first delay; If not, when the second duration reaches a preset third delay, the flexible straight valve group is controlled to be locked, and the third delay is greater than the second delay.

2. A high-frequency harmonic protection method for a flexible direct current valve group according to claim 1, characterized in that: The acquisition of the real-time harmonic current component includes: The harmonic current component flowing into the converter station valve side of the flexible direct current valve group is detected in real time to obtain the real-time harmonic current component.

3. A high-frequency harmonic protection method for a flexible direct current valve group according to claim 1, characterized in that: The presets of the first threshold value and the first delay include: A first constant value is determined according to the harmonic tolerance capability of the converter tap changer, where the first constant value includes the first threshold value and the first delay.

4. A high-frequency harmonic protection method for a flexible direct current valve group according to claim 1, characterized in that: The presets of the second threshold value and the third delay include: The second constant is determined according to the harmonic tolerance capability of the first device, the second constant includes the second threshold value and the third delay, and the first device is the device with the weakest harmonic tolerance capability in the flexible direct current valve group except the converter tap changer.

5. A high-frequency harmonic protection method for a flexible direct current valve group according to claim 4, characterized in that: The presets of the second delay include: The third delay is shortened to obtain the second delay.

6. A high-frequency harmonic protection method for a flexible direct current valve group according to claim 1, characterized in that: The prohibiting the gear adjustment of the commutation tap changer in the flexible direct valve group includes: A target port at a protection outlet of the commutation variable tap section in the flexible direct valve group is enabled, wherein the target port is used to lock the gear adjustment of the commutation variable tap after being enabled.

7. A high-frequency harmonic protection system for a flexible direct-flow valve group, characterized in that: include: The first module is configured to calculate the sum of the harmonic components in a first frequency range according to the acquired real-time harmonic current components, where the first frequency range is 8-50; a second module, configured to prohibit the gear adjustment of the commutation tap changer in the flexible direct current valve group when confirming that the sum of the harmonic components is greater than a preset first threshold value and a first duration reaches a preset first delay value, wherein the first duration is the time during which the sum of the harmonic components is greater than the first threshold value; A third module is configured to determine whether the flexible direct current valve group is a flexible direct current dual valve group when confirming that the sum of the harmonic components is greater than a preset second threshold value, the flexible direct current dual valve group including a main control valve group and a non-main control valve group, and the second threshold value is greater than the first threshold value; A fourth module is configured to control the non-master valve group to be locked when a second duration reaches a preset second delay, wherein the second duration is the time during which the sum of the harmonic components is greater than the second threshold value, and the second delay is greater than the first delay; The fifth module is used to control the flexible straight valve group to be locked if the second duration reaches a preset third delay, and the third delay is greater than the second delay.

8. The high-frequency harmonic protection system for a flexible direct-flow valve group according to claim 7 is characterized in that: The system further includes a sixth module, which is used to detect the harmonic current components flowing into the converter station valve side of the flexible direct current valve group in real time to obtain the real-time harmonic current components.

9. A high-frequency harmonic protection device for a flexible direct current valve group, characterized in that: include: at least one processor; at least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements a high-frequency harmonic protection method for a flexible direct current valve group as described in any one of claims 1-6.

10. A storage medium storing a program executable by a processor, characterized in that: The program executable by the processor is used to implement a high-frequency harmonic protection method for a flexible direct current valve group as described in any one of claims 1 to 6 when executed by the processor.

Images