A direct current recording wave channel positioning method and system based on fault content

Abstract

The application discloses a DC recording wave channel positioning method and system based on fault content, which is characterized in that: based on the DC protection area division, the protection area and protection function mapping model, and the correlation model of the protection function and the recording wave file, the multi-level search based on the fault content is carried out to locate the recording wave channel corresponding to the DC fault; the correlation coefficient of the recording wave channel corresponding to the DC fault is calculated according to the close degree coefficient of the protection function and the recording wave channel and the protection function action result, and the final DC fault recording wave channel is located according to the correlation coefficient. The method can realize the fast and accurate positioning of the DC fault recording wave channel, meet the demand of professional personnel for fast checking of the DC fault recording wave channel, and thus quickly locate the fault problem, thereby providing a new auxiliary method for the DC fault diagnosis.

Description

Technical Field

[0001] This invention belongs to the field of DC waveform recording channel positioning technology, and relates to a DC waveform recording channel positioning method and system based on fault content. Background Technology

[0002] When a power outage occurs, users can analyze waveform recordings via mobile applications to quickly determine the nature of the fault and propose solutions. While waveform recordings can currently be obtained from the substation using automated methods, quickly extracting and locating the faulty equipment and the waveform recording channel at the moment of the fault from a large volume of recordings remains a practical challenge.

[0003] Traditional AC fault location recording channels are located by configuring the association between the recorder and the primary equipment, and based on the mapping relationship between the primary equipment and the recording channel in the uploaded DMF file.

[0004] However, DC fault recording channels are numerous, sampling times are long, and data volumes are large. Furthermore, the recording channels correspond to protection functions, meaning a single DC fault generates multiple recording files. Therefore, traditional AC fault location recording channel methods are unsuitable for DC fault situations. Additionally, viewing recordings on mobile devices is limited by screen size and network bandwidth. Consequently, there is currently a lack of solutions for rapid and accurate recording channel location and display for DC faults. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method and system for locating DC waveform recording channels based on fault content.

[0006] The present invention adopts the following technical solution.

[0007] A method for locating DC recording channels based on fault content is proposed. This method uses a multi-level retrieval based on fault content, which is based on the division of DC protection areas, the mapping model between protection areas and protection functions, and the association model between protection functions and recording files, to locate the corresponding recording channels for DC faults.

[0008] The correlation coefficient of the DC fault recording channel is calculated based on the tightness coefficient of the protection function and the recording channel and the action result of the protection function. The final DC fault recording channel is located based on the correlation coefficient.

[0009] Preferably, the method specifically includes the following steps:

[0010] Step 1: Divide the DC protection zone and establish a mapping model between the protection zone and the protection function, as well as a correlation model between the protection function and the waveform file;

[0011] Step 2: Configure the tightness coefficient of protection function and recording channel according to the protection function criteria and the requirements of recording channel;

[0012] Step 3: Determine the corresponding protection area of ​​the DC fault by analyzing the DC fault content, determine the corresponding protection function of the DC fault by combining the protection area and the protection function mapping model, and identify the corresponding protection function action results.

[0013] Step 4: Based on the protection function corresponding to the DC fault, locate the corresponding waveform file of the DC fault according to the correlation model between the protection function and the waveform file, and then determine the corresponding waveform channel of the DC fault.

[0014] Step 5: Based on the tightness coefficient of the protection function and the recording channel and the action result of the protection function, calculate the correlation coefficient of the corresponding recording channel for the DC fault, and locate the final DC fault recording channel based on the correlation coefficient.

[0015] Preferably, in step 1, the DC protection zone is divided according to the installation location of the current transformer.

[0016] Preferably, in step 1, an association model between the protection function and the waveform recording file is established by using identifiable feature strings in the waveform recording file name. After determining the protection function, the corresponding waveform recording file can be located based on the feature strings.

[0017] Preferably, in step 2, the configuration method of the tightness coefficient between the protection function and the recording channel is as follows:

[0018] For the waveform recording channel, if the protection function criterion involves the waveform recording channel, then the tightness coefficient between the protection function and the waveform recording channel is set to 1.

[0019] If the protection function criterion does not involve the recording channel, but the actual situation on site requires attention to the recording channel, set the tightness coefficient between the protection function and the recording channel to between (0,1).

[0020] If the protection function criteria do not involve the waveform recording channel and the user operation and maintenance manual does not require the user to pay attention to the waveform recording channel, set the tightness coefficient between the protection function and the waveform recording channel to 0.

[0021] Preferably, in step 3, the protection function actions and output signals at the time of the fault are identified by analyzing the DC SER event.

[0022] Preferably, in step 5, the formula for calculating the correlation coefficient of the corresponding recording channel for a DC fault, based on the tightness coefficient of the protection function and the recording channel and the action result of the protection function, is as follows:

[0023]

[0024] In the formula, S m This represents the correlation coefficient of the m-th recording channel;

[0025] tmn This represents the tightness coefficient between the nth protection function and the mth recording channel;

[0026] p n This indicates whether the nth protection function has been activated. Its value is 0 or 1, which respectively represent the protection function being activated or not activated.

[0027] Preferably, in step 5, the recording channels are sorted in descending order according to their correlation coefficients, and the top N recording channels are selected as the final DC fault recording channels, where the value of N is user-defined.

[0028] Preferably, step 5 also includes sending the final DC fault recording channel to the user terminal, and the user can also manually select the recording channel of interest for viewing.

[0029] A DC waveform recording channel location system based on fault content includes:

[0030] The multi-level retrieval module is used to perform multi-level retrieval based on fault content, based on the DC protection area division, the protection area and protection function mapping model and the association model between protection function and recording file, to locate the corresponding recording channel of DC fault.

[0031] The positioning module is used to calculate the correlation coefficient of the recording channel based on the tightness coefficient of the protection function and the recording channel and the action result of the protection function, and to locate the final DC fault recording channel based on the correlation coefficient.

[0032] The beneficial effects of this invention are compared with those of the prior art:

[0033] This invention performs multi-level retrieval based on fault content, using a DC protection zone division, a protection zone and protection function mapping model, and a correlation model between protection function and waveform recording file. By locating the DC fault protection zone, it finds the corresponding waveform recording file and locates the corresponding waveform recording channel for the DC fault. Based on the tightness coefficient between the protection function and the waveform recording channel and the protection function action result, it calculates the correlation coefficient of each waveform recording channel at the moment of the DC fault, and locates the final DC fault waveform recording channel based on the correlation coefficient, thus achieving rapid and accurate location of the DC fault waveform recording channel.

[0034] This invention is suitable for background service programs to run, quickly and accurately locates DC fault recording channels and displays them precisely on mobile devices, meeting the needs of professionals to quickly view DC fault recording channels, thereby quickly locating fault problems and providing a new auxiliary method for DC fault diagnosis.

[0035] This invention configures the tightness coefficient between protection functions and recording channels based on protection function criteria and recording channel attention requirements. It allows for dynamic expansion or trimming of configuration content, flexibly expanding fault-related recording channels to support protection configuration requirements and user needs across different application scenarios, thus meeting personalized application needs. Based on the tightness coefficient between protection functions and recording channels and the protection function's action results, it calculates the correlation coefficient of the corresponding recording channels for DC faults. This is applicable to DC fault application scenarios, enabling rapid acquisition of DC fault-related recording channel data, reducing mobile data transmission resource consumption, and improving fault location efficiency. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the DC waveform recording channel positioning process based on fault content in this invention.

[0037] Figure 2 This is a schematic diagram of the data flow of the waveform recording channel in this invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, other embodiments obtained by those skilled in the art without creative effort are all within the protection scope of this invention.

[0039] Embodiment 1 of the present invention provides a DC waveform recording channel location method based on fault content. Based on the DC protection area division, the protection area and protection function mapping model and the association model between protection function and waveform recording file, a multi-level retrieval based on fault content is performed to locate the corresponding waveform recording channel of DC fault. The association coefficient of the corresponding waveform recording channel of DC fault is calculated according to the tightness coefficient between protection function and waveform recording channel and the action result of protection function. The final DC fault waveform recording channel is located according to the association coefficient.

[0040] In a preferred but non-limiting embodiment of the present invention, the method includes the following steps:

[0041] Step 1: Divide the DC protection zone and establish a mapping model between the protection zone and the protection function, as well as a correlation model between the protection function and the waveform file;

[0042] More preferably, the DC protection zone is divided according to the installation location of the current transformer (CT).

[0043] This involves constructing a DC protection zone model, dividing the DC plant model into multiple protection zones based on the installation location of the current transformers (CTs), and performing fault analysis on a per-protection-zone basis.

[0044] By establishing a correlation model between protection functions and waveform recording files through identifiable characteristic strings in the waveform recording file names, the waveform recording files of fault signals can be located based on the characteristic strings after the protection function is determined.

[0045] Step 2: Configure the tightness coefficient of protection function and recording channel according to the protection function criteria and the requirements of recording channel;

[0046] More preferably, the relationship between the protection function and the recording channel is configured mainly based on the protection function criteria and the degree of user concern;

[0047] For the waveform recording channel, according to the protection function criteria, if the protection function criteria involve the waveform recording channel, the tightness coefficient between the protection function and the waveform recording channel is set to 1.

[0048] If the protection function criteria do not involve the waveform recording channel, but the actual site conditions require attention to the waveform recording channel according to the user's operation and maintenance manual, set the tightness coefficient between the protection function and the waveform recording channel to between (0,1); the default value can be set to 0.5, and the user can adjust the coefficient according to the actual site conditions. For example, DC faults are generally line faults, and the tightness coefficient between the line protection function and these waveform recording channels can be adjusted to facilitate quick fault location.

[0049] The user operation and maintenance guide is a document prepared in advance by operation and maintenance personnel based on actual operation and maintenance situations, which facilitates the standardization of operation and maintenance processes;

[0050] If the protection function criteria do not involve the waveform recording channel and the user operation and maintenance manual does not require the user to pay attention to the waveform recording channel, set the tightness coefficient between the protection function and the waveform recording channel to 0.

[0051] Step 3: Determine the corresponding protection area of ​​the DC fault by analyzing the DC fault content, determine the corresponding protection function of the DC fault by combining the protection area and the protection function mapping model, and identify the corresponding protection function action results.

[0052] More preferably, by analyzing DC SER events, the protection function actions and output signals at the time of the fault are identified.

[0053] Step 4: Based on the protection function corresponding to the DC fault, locate the corresponding waveform file of the DC fault according to the correlation model between the protection function and the waveform file, and then determine the corresponding waveform channel of the DC fault.

[0054] Step 5: Based on the tightness coefficient of the protection function and the recording channel and the action result of the protection function, calculate the correlation coefficient of the corresponding recording channel for the DC fault, and locate the final DC fault recording channel based on the correlation coefficient.

[0055] Further preferably, the formula for calculating the correlation coefficient of the recording channel corresponding to the DC fault based on the tightness coefficient between the protection function and the recording channel and the operation result of the protection function is:

[0056]

[0057] where S m represents the correlation coefficient of the m-th recording channel;

[0058] t mn represents the tightness coefficient between the n-th protection function and the m-th recording channel;

[0059] p n indicates whether the n-th protection function has operated and exited, and its value is 0 or 1, which respectively represent that the protection function has operated and exited, and the protection function has not operated and exited.

[0060] Further preferably, the recording channels are sorted in descending order according to their correlation coefficients, and the first N recording channels are selected as the final DC fault recording channels, wherein the N value is user-defined.

[0061] Step 5 further includes sending the final DC fault recording channel to the user end, and the user can also manually select the recording channels of interest for viewing.

[0062] In specific implementation, an example of the multi-level search mapping of protection functions and coefficient configuration information is as follows:

[0063] 1) Configure the protection function of the protection zone, such as configuration file 1:

[0064] <ProtArea name=”C11”cn_name=”Pole 1 High Valve Group Protection Zone”>

[0065] <Relay name=”VSCP”cn_name=”Valve Short Circuit Protection” / >

[0066] <Relay name=”VOCP”cn_name=”Converter Overcurrent Protection” / >

[0067]

[0068] where C11 is the English abbreviation of Pole 1 High Valve Group Protection Zone, C is the abbreviation of converter, 11 / 12 corresponds to Pole 1 high valve / low valve, 21 / 22 corresponds to Pole 2 high valve / low valve; VSCP is the English abbreviation of valve shortcut protection, which represents that the valve short circuit protection is configured in the Pole 1 High Valve Group Protection Zone;

[0069] 2) Configure the association relationship between the protection function and the recording:

[0070] For multiple recorded waveforms of a faulty DC control and protection system, the recorded waveform file names have identifiable characteristic strings,

[0071] Configure the correspondence between protection functions and characteristic strings, such as in configuration file 2:

[0072] <Relay name="VSCP"ied_code="CPR"spec_code="Child4" / >

[0073] <Relay name="VOCP"ied_code="CPR"spec_code="Child1" / >

[0074] where name represents the English abbreviation of the protection function, corresponding to the protection function in configuration file 1; the ied_code attribute indicates the type of protection device corresponding to the protection function, and CPR is the English abbreviation for converter protection relay; spec_code is the characteristic string of the recorded waveform file for this protection function;

[0075] Configuration file 2 contains identifiers for the correspondence between protection functions and characteristic strings, and the recorded waveform file corresponding to the protection function can be obtained by matching the recorded waveform file name with the characteristic string.

[0076] 3) Configure the tightness coefficient between protection functions and recorded waveform channels, such as in configuration file 3:

[0077] <Channel type="Analog"cfg_index="1"name="IVDH"cn_name="Three-phase current on the valve side of the high-end converter transformer">

[0078] <Relay name="VSCP"coef="1" / >

[0079] <Relay name="VOCP"coef="1" / >

[0080]

[0081] <Channel type="Analog"cfg_index="2"name="UVDH"cn_name="Three-phase voltage on the valve side of the high-end converter transformer">

[0082] <Relay name="VSCP"coef="0.6" / >

[0083] <Relay name="VOCP"coef="0.6" / >

[0084]

[0085] wherein <Channel type="Analog" cfg_index="1" name="IVDH" cn_name="高端换流变阀角侧三相电流">, type denotes the channel type, including Analog or Digit; cfg_index denotes the sequence number of the channel in the wave recording CFG file; name denotes the English abbreviated name of the channel, refer to the standard <q gdw11355>;cn_name represents the Chinese name of the recorded waveform, see the standard <Q / GDW 11355>;< / q>

[0086] <Relay name=”VSCP”coef=”1” / > The name represents the English abbreviation of the protection function, corresponding to the protection function in configuration file 2. The coef represents the tightness coefficient between the recording channel and the protection function; other lines are similar.

[0087] Based on the above correlation coefficient calculation method and configuration information, the correlation coefficient of the relevant waveform recording channels for this DC fault can be calculated. The data of the first N (e.g., 10) are sent to the mobile terminal to complete the waveform recording channel push.

[0088] This embodiment 1 matches waveform files by dividing DC protection zones, mapping protection zones to protection functions, associating protection functions with waveform files, and using a tightness coefficient between protection functions and waveform channels. It also calculates the correlation coefficient of waveform channels and ultimately pushes the waveform channel data that the user wants to view to the mobile device to meet the user's need for rapid fault analysis. Users can also manually select the waveform channels they are interested in to view. It features simplicity, effectiveness, and suitability for mobile devices.

[0089] Embodiment 2 of the present invention provides a DC waveform recording channel location system based on fault content, comprising:

[0090] The multi-level retrieval module is used to perform multi-level retrieval based on fault content, based on the DC protection area division, the protection area and protection function mapping model and the association model between protection function and recording file, to locate the corresponding recording channel of DC fault.

[0091] The positioning module is used to calculate the correlation coefficient of the recording channel based on the tightness coefficient of the protection function and the recording channel and the action result of the protection function, and to locate the final DC fault recording channel based on the correlation coefficient.

[0092] A terminal includes a processor and a storage medium; the storage medium is used to store instructions.

[0093] The processor is configured to operate according to the instructions to execute the steps of the method.

[0094] A computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of the method.

[0095] The beneficial effects of this invention are compared with those of the prior art:

[0096] ​This invention performs multi-level retrieval based on fault content, using a DC protection zone division, a protection zone and protection function mapping model, and a correlation model between protection function and waveform recording file. By locating the DC fault protection zone, it finds the corresponding waveform recording file and locates the corresponding waveform recording channel for the DC fault. Based on the tightness coefficient between the protection function and the waveform recording channel and the protection function action result, it calculates the correlation coefficient of each waveform recording channel at the moment of the DC fault, and locates the final DC fault waveform recording channel based on the correlation coefficient, thus achieving rapid and accurate location of the DC fault waveform recording channel.

[0097] This invention is suitable for background service programs to run, quickly and accurately locates DC fault recording channels and displays them precisely on mobile devices, meeting the needs of professionals to quickly view DC fault recording channels, thereby quickly locating fault problems and providing a new auxiliary method for DC fault diagnosis.

[0098] This invention configures the tightness coefficient between protection functions and recording channels based on protection function criteria and recording channel attention requirements. It allows for dynamic expansion or trimming of configuration content, flexibly expanding fault-related recording channels to support protection configuration requirements and user needs across different application scenarios, thus meeting personalized application needs. Based on the tightness coefficient between protection functions and recording channels and the protection function's action results, it calculates the correlation coefficient of the corresponding recording channels for DC faults. This is applicable to DC fault application scenarios, enabling rapid acquisition of DC fault-related recording channel data, reducing mobile data transmission resource consumption, and improving fault location efficiency.

[0099] This disclosure can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this disclosure.

[0100] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example—but not limited to—electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination of the foregoing. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0101] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0102] Computer program instructions used to perform the operations of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as "C" or similar languages. The computer-readable program instructions may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing state information from the computer-readable program instructions to implement various aspects of this disclosure.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.< / q>

Claims

1. A method for locating a DC waveform recording channel based on fault content, characterized in that: The method specifically includes the following steps: Step 1: Divide the DC protection zone and establish a mapping model between the protection zone and the protection function, as well as a correlation model between the protection function and the waveform file; Step 2: Configure the tightness coefficient of protection function and recording channel according to the protection function criteria and the requirements of recording channel; Step 3: Determine the corresponding protection area of ​​the DC fault by analyzing the DC fault content, determine the corresponding protection function of the DC fault by combining the protection area and the protection function mapping model, and identify the corresponding protection function action results. Step 4: Based on the protection function corresponding to the DC fault, locate the corresponding waveform file of the DC fault according to the correlation model between the protection function and the waveform file, and then determine the corresponding waveform channel of the DC fault. Step 5: Based on the tightness coefficient of the protection function and the recording channel, and the protection function operation results, calculate the correlation coefficient of the corresponding recording channel for the DC fault, and locate the final DC fault recording channel based on the correlation coefficient; wherein, the formula for calculating the correlation coefficient of the corresponding recording channel for the DC fault based on the tightness coefficient of the protection function and the recording channel, and the protection function operation results, is as follows: （1） In the formula, This represents the correlation coefficient of the m-th recording channel; This represents the tightness coefficient between the nth protection function and the mth recording channel; This indicates whether the nth protection function has been activated. Its value is 0 or 1, which respectively represent the protection function being activated or not activated.

2. The DC waveform recording channel location method based on fault content according to claim 1, characterized in that: In step 1, the DC protection zone is divided according to the installation location of the current transformer.

3. The DC waveform recording channel location method based on fault content according to claim 1, characterized in that: In step 1, a correlation model between the protection function and the waveform recording file is established by using the identifiable feature strings in the waveform recording file name. After determining the protection function, the corresponding waveform recording file can be located based on the feature strings.

4. The DC waveform recording channel location method based on fault content according to claim 1, characterized in that: In step 2, the configuration method for the tightness coefficient of the protection function and the recording channel is as follows: For the waveform recording channel, if the protection function criterion involves the waveform recording channel, then the tightness coefficient between the protection function and the waveform recording channel is set to 1. If the protection function criterion does not involve the recording channel, but the actual situation on site requires attention to the recording channel, set the tightness coefficient between the protection function and the recording channel to between (0,1). If the protection function criteria do not involve the waveform recording channel and the user operation and maintenance manual does not require the user to pay attention to the waveform recording channel, set the tightness coefficient between the protection function and the waveform recording channel to 0.

5. The DC waveform recording channel location method based on fault content according to claim 1, characterized in that: In step 3, the protection function actions and output signals at the time of the fault are identified by analyzing the DC SER events.

6. The DC waveform recording channel location method based on fault content according to claim 1, characterized in that: In step 5, the recording channels are sorted in descending order according to their correlation coefficients, and the top N recording channels are selected as the final DC fault recording channels, where the value of N is user-defined.

7. The DC waveform recording channel location method based on fault content according to claim 1, characterized in that: Step 5 also includes sending the final DC fault recording channel to the user terminal, where the user can manually select the recording channel of interest for viewing.

8. A DC waveform recording channel positioning system based on fault content, implemented according to the method described in any one of claims 1-7, characterized in that: The system includes: A multi-level retrieval module is used to divide DC protection zones and establish a mapping model between protection zones and protection functions, as well as a correlation model between protection functions and waveform recording files. Based on protection function criteria and waveform recording channel attention requirements, the module configures the tightness coefficients between protection functions and waveform recording channels. By analyzing the DC fault content, the module determines the corresponding protection zone for the DC fault, and combines the mapping model between the protection zone and protection function to determine the corresponding protection function for the DC fault, identifying the corresponding protection function action results. Based on the corresponding protection function for the DC fault, and according to the correlation model between the protection function and waveform recording files, the module locates the corresponding waveform recording file for the DC fault, and then determines the corresponding waveform recording channel for the DC fault. The positioning module is used to calculate the correlation coefficient of the corresponding DC fault recording channel based on the tightness coefficient of the protection function and the recording channel and the action result of the protection function, and to locate the final DC fault recording channel based on the correlation coefficient.

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