A fault locating method of a power distribution network fault locating device

Abstract

The application discloses a fault positioning method of a power distribution network fault positioning device, and the software of the fault positioning device is composed of an ICD file model based on the IEC61850 standard and software function modules, the ICD configuration file contains more than one logical device, is used for establishing the mapping relationship of various fault positioning function modules and data communication modules, and the software function modules keep one-to-one correspondence with the logical devices of the ICD according to different fault positioning functions; the software function modules work cooperatively according to the internal data sharing mode of the device, and finally realize fault positioning; the method solves the problems that the fault positioning devices in the prior art have different divisions, perform different functions, especially when various switch stations of the power distribution network are deployed, there are more types of fault positioning devices, and the devices lack cooperation, and the multiple types of devices result in high investment cost and large maintenance workload.

Description

Technical Field

[0001] This invention belongs to the field of power system fault location technology, and particularly relates to a fault location method for a power distribution network fault location device. Background Technology

[0002] The voltage level of the distribution network is 3~66kV, and it generally adopts a neutral point non-direct grounding method (including three types: neutral point ungrounded, grounded through arc suppression coil, and grounded through resistor). Due to the large number of branch lines, the fault location technology after a fault occurs in the distribution network is more complex than that of the high-voltage transmission network. The fault location technology of the distribution network is an important task to ensure the safe and reliable operation of the distribution network. In a broad sense, the existing distribution network fault location devices include various protection devices, various distribution network terminals (including station terminals DTU, feeder terminals FTU, fault indicators, etc.), low current grounding line selection devices, fault location devices, etc. Among these, protection devices directly cut off phase-to-phase faults with significant short-circuit currents, thus achieving fault isolation and location. However, when used in distribution network feeders, the difficulty in setting protection settings and delay level differences can easily lead to a loss of selectivity. Various distribution network terminals mainly use feeder automation functions to identify the fault section where the fault point is located, in order to isolate the fault and restore power supply to non-faulty areas. However, they usually rely on communication and have weak location capabilities for single-phase grounding faults with slight fault currents. Small-current grounding fault location devices are used to select faults for single-phase grounding faults on each outgoing line of the same busbar, but cannot achieve more precise section location of single-phase grounding faults. Fault ranging devices calculate the accurate fault distance after identifying a fault on a feeder to facilitate maintenance. Therefore, these fault location devices have different functions and perform different tasks. Especially when deployed in various switching stations of the distribution network, there are problems such as a large number of fault location devices and a lack of coordination between devices. The impacts include: a large number of device types leading to high investment costs and a large maintenance workload; each device working independently without coordination, resulting in multiple location results for the same fault point; and difficulties in upgrading new algorithms and expanding new functions, etc. Summary of the Invention

[0003] The problem this invention aims to solve is to provide a fault location method for a power distribution network fault location device, addressing the issues of existing fault location devices having different functions and performing their own tasks, especially when deployed in various switching stations of the power distribution network. These issues include the large number of fault location devices, the lack of coordination between devices, the high investment cost and maintenance workload due to the large number of device types, the independent operation of each device without coordination resulting in multiple location results for the same fault point, and the difficulty in upgrading new algorithms and expanding new functions.

[0004] The technical solution of this invention is: A fault location method for a power distribution network fault location device, wherein the software of the fault location device consists of an ICD file model based on the IEC61850 standard and software functional modules. The ICD configuration file contains one or more logical devices, which are used to establish the mapping relationship between various fault location functional modules and data communication modules. The software functional modules are designed according to different fault location functions and maintain a one-to-one correspondence with the logical devices of the ICD. The software functional modules work together in a way that shares data within the device to ultimately achieve fault location.

[0005] The hardware of the fault location device is designed according to the functional integration method, and is equipped with corresponding functions including various protection functions, feeder automation functions, low current grounding line selection functions, and fault location functions.

[0006] The modeling method based on the IEC61850 standard ICD file model is as follows: The two logical devices, public and protection, are expanded into more than one module, with each pair of modules corresponding to one function. Each logical device is configured with more than one logical node (LN), and each logical node is configured with more than one data object instance (DOI). Mapped data values, i.e., short addresses, are added to the sAddr node of the data object instance's data attribute. The last byte of this short address represents the module number. Simultaneously, a data constant table is established in the ICD's Private information area to represent the module identifier and module number of each functional module. Using the private information data constant table as a connecting link, an internal mapping between IEC61850 data and the device's real-time database is formed, completing the modeling of the fault location device based on the IEC61850 standard ICD file.

[0007] The software functional modules are designed based on a software-defined functionality approach, which separates the application software from the operating system and underlying hardware, and facilitates the expansion and upgrading of the functional modules.

[0008] The design method for the software functional modules includes: Step 1: Each functional module is made into a set of functions that can be called repeatedly, including initialization interface functions and running interface functions. Input and output data and internal cache space are all allocated memory space through compilation in the form of N-dimensional structure, where N is the maximum number of times the functional module can be called. Step 2: In each function, design and construct the corresponding input / output configuration and algorithm logic according to different fault location functions; Step 3: Each functional module program is compiled by the compilation system to generate a static library file, which is then added to the compilation of the main program to generate an executable object file; Step 4: In the main program of the device, the initialization interface functions of each functional module are called during the initialization phase, and the running interface functions of each functional module are called during the task running phase. Data interaction between each functional module and the communication management process is realized through shared memory.

[0009] The method for establishing a one-to-one correspondence between the software functional modules designed according to different fault location functions and the logical devices of the ICD includes: first, adding the ICD file as an independent IED to the SCD file of the substation or distribution station; after configuring the virtual terminal connection at the process layer, exporting the CID file and downloading it to the fault location device; the fault location device uses a CID file parsing module to read and parse the CID; and based on the identifiers of each functional module in the CID file and the module number of the dataset short address, realizing the access mapping between IEC61850 model data and the real-time database.

[0010] The method for software functional modules to work collaboratively by sharing data within the device is as follows: the optimal criteria are constructed through data interaction between modules to achieve collaborative fault location function, and the output results of these modules are weighted and averaged to output the fault location result.

[0011] The specific steps for fault location include: Step S510: For all possible fault location function modules in the distribution network, create corresponding logical devices and logical nodes in the ICD file of the fault location device, fill in the corresponding module number in the short address of each dataset, and at the same time establish a data constant list of all function module numbers in the private information area. Step S520: Write the initialization interface function and the running interface function of each fault location function module in a software-defined manner, and compile them into a static library and add it to the executable target program; Step S530: Based on different application scenarios and input conditions, configure the corresponding ICD logic devices and software function modules by copying and pasting, and generate a CID file to download to the fault location device; Step S450: After the device is running, the mapping relationship between each logical device and the software function module in the CID file is parsed, and then each software function module is executed; Step S450: Multiple fault location software modules work together to output the optimal fault location result.

[0012] Beneficial effects of this invention: The fault location device of this invention is designed in a multi-functional integrated manner. On-site, corresponding functions can be configured according to input conditions. These functions include: various protection functions, feeder automation functions, low current grounding line selection functions, fault location functions, etc. One IED device can replace multiple fault location devices, saving investment and construction costs of secondary equipment in the power distribution network.

[0013] Various fault location functions are implemented according to the IEC61850 standard and software-defined functions. The entire fault location device is designed as a physical device (IED), and the data models of various fault location functions are designed according to object-oriented logical devices (LDs). Different logical devices are mapped through short address module numbers. This achieves the separation of software from the underlying hardware and operating system, as well as software standardization. The device's data communication model is designed according to the IEC61850 standard. This facilitates the configuration of functions in different application scenarios, improves the applicability of the fault location device, and enhances the convenience of maintenance and upgrades.

[0014] The proposed fault location device can achieve multi-functional collaborative operation, which is conducive to improving the comprehensiveness and reliability of fault location function in power distribution networks.

[0015] With the emergence of new algorithms for fault location in power distribution networks, these algorithms can be easily implemented in this device by upgrading or expanding software modules.

[0016] The collaborative operation of various functional modules is achieved by using internal data sharing within the device.

[0017] This invention addresses several technical challenges in existing fault location devices. These challenges include the different functions and lack of coordination among various types of fault location devices, particularly when deployed at different substations in power distribution networks. The large number of device types leads to high investment costs and a heavy maintenance workload. Furthermore, the independent operation of each device without coordination results in multiple location results for the same fault point. Additionally, it addresses the difficulties in upgrading algorithms and expanding new functions. Attached Figure Description

[0018] Figure 1 This is a typical workflow diagram of the fault location device of the present invention; Figure 2 This is a software module structure diagram of the fault location device of the present invention; Figure 3 This is a functional configuration diagram of the fault location device of the present invention in a 10kV substation; Figure 4 This is a functional configuration diagram of the fault location device of the present invention in a 10kV substation. Specific Implementation

[0019] To more clearly explain the technical solutions and advantages of the present invention, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for a more thorough and complete understanding of the present invention and are not intended to limit the scope of protection of the present invention.

[0020] A fault location method for a power distribution network fault location device, wherein the software of the fault location device consists of an ICD configuration file model based on the IEC 61850 standard and software functional modules. The ICD configuration file model contains multiple logical devices used to establish mapping relationships between various fault location functional modules and data communication modules. The software functional modules are designed according to different fault location functions, maintaining a one-to-one correspondence with the logical devices of the ICD, and can be repeatedly invoked. The software functional modules work collaboratively through internal data sharing within the device, specifically including: 1. Existing IED ICD model structures, such as their logic devices (LDs) divided according to the functions of the station control layer, include common, protection, measurement, control, waveform recording, etc., which are functionally limited and fail to fully utilize the freely configurable features of the IEC61850 standard. The ICD model structure of this invention expands the two logic devices, common and protection, into multiple modules (Module 1_common, Module 1_protection, Module 2_common, Module 2_protection, ....), with each pair of modules (common + protection) corresponding to one function (e.g., various protection functions, low-current grounding line selection function, feeder automation function, fault location function, etc.). Each logical device is configured with multiple logical nodes (LNs), and each logical node is configured with multiple data object instances (DOIs). Mapped data values ​​(i.e., short addresses) are added under the data attribute sAddr node of the data object instance. The last byte of the short address represents the module number. At the same time, a data constant table is established in the private information area of ​​the ICD to represent the module identifier and module number of each functional module. Using this private information data constant table as a connecting link, an internal mapping between IEC61850 data and the device real-time database is formed, thereby completing the modeling of the fault location device of the present invention based on the ICD file of the IEC61850 standard.

[0021] like Figure 2 As shown, the software for each functional module of the fault location device is designed using a software-defined functionality approach. This separates the application software from the operating system and underlying hardware, facilitating the expansion and upgrade of the functional modules. The design process is as follows: (1) Each functional module is made into a set of functions that can be called repeatedly (including initialization interface function and running interface function). Its input and output data and internal cache space are allocated memory space through compilation in the form of N-dimensional structure, where N is the maximum number of times the functional module can be called.

[0022] (2) In each function, the corresponding input / output configuration and algorithm logic are designed and constructed according to different fault location functions.

[0023] (3) Each set of functional module programs is compiled by the compilation system to generate a static library file, which is then added to the compilation of the main program to generate an executable target file.

[0024] (4) In the main program of the device, the initialization interface function of each functional module is called during the initialization phase, the running interface function of each functional module is called during the task running phase, and the data interaction between each functional module and the communication management process is realized through shared memory.

[0025] 3. Establish the connection relationship between ICD file and functional module: First, add the ICD file as an independent IED to the SCD file of the substation or distribution station. After the process layer virtual terminal connection configuration, export the CID file and download it to the fault location device. The fault location device enables a CID file parsing module to read and parse the CID. Based on the identifier of each functional module in the CID file and the module number of the dataset short address, realize the access mapping between IEC61850 model data and real-time database.

[0026] 4. Establish data interaction between different fault location function modules to achieve multi-module collaboration.

[0027] for Figure 3 The substation shown has a 10kV busbar line L. The distribution network fault location device is equipped with the protection function and fault location function of the line. At the same time, the line also participates in the low current grounding line selection function. The multi-module collaboration is reflected in: (1) When a phase-to-phase fault occurs on line L, the protection function module identifies that the line has an overcurrent, and then transmits the start signal to the fault location function module through data sharing (e.g., global variables) inside the device to start the fault location function. (2) When a single-phase grounding fault occurs on line L, the zero-sequence overcurrent protection of the protection function module may be started (or may not be started), while the low current grounding line selection module will determine that a single-phase grounding fault has occurred on line L. However, in some cases, both function modules may make misjudgments. At this time, the optimal criterion can be constructed through the data interaction of the two modules to achieve the collaboration of the fault location function.

[0028] for Figure 4The substation shown can be configured with the following module functions: bus protection function, low current grounding fault location function, line protection function of each bay, feeder automation function and fault location function, etc. The multi-module collaboration is reflected in: (1) When a fault occurs on the bus, under normal circumstances, both the bus protection function module and the low current grounding fault location module will locate the fault to the bus. However, under special circumstances, the low current grounding fault location module may also make a misjudgment. Through the collaboration of these two modules (for example, the fault location result of the bus protection module is given priority), the output result of the low current grounding fault location module can be blocked; (2) When a fault occurs on a branch, the line protection module, the feeder automation module, and the low current grounding fault location module (if the fault is a single-phase grounding fault) will all locate the fault to the branch. The multi-module collaboration is reflected in the fact that the output results of these modules can be weighted and averaged to output a more reliable fault location result, and then the fault location module is started to calculate the fault distance.

[0029] The implementation process of the fault location device is as follows: Figure 1 As shown.

[0030] Step S510: For all possible fault location function modules in the distribution network, create corresponding logical devices and logical nodes in the ICD file of the fault location device, fill in the corresponding module number in the short address of each dataset, and at the same time, establish a data constant list of all function module numbers in the private information area.

[0031] Step S520: Write the initialization interface function and running interface function of each fault location function module in a software-defined manner, and compile them into a static library and add it to the executable target program.

[0032] Step S530: Based on different application scenarios and input conditions, configure the corresponding ICD logic devices and software function modules by copying and pasting, and generate a CID file to download to the fault location device.

[0033] Step S450: After the device is running, the mapping relationship between each logical device and the software function module in the CID file is parsed, and then each software function module is executed.

[0034] Step S450: Multiple fault location software modules work together to output the optimal fault location result.

Claims

1. A fault location method for a power distribution network fault location device, characterized in that: The software of the fault location device consists of an ICD file model based on the IEC61850 standard and software functional modules. The ICD configuration file contains one or more logical devices to establish the mapping relationship between various fault location functional modules and data communication modules. The software functional modules are designed according to different fault location functions and maintain a one-to-one correspondence with the logical devices of the ICD. The software functional modules work together in a way that shares data within the device to ultimately achieve fault location. The modeling method based on the IEC61850 standard ICD file model is as follows: Two logical devices, public and protection, are expanded into more than one module, with each pair of modules corresponding to one function; each logical device is configured with more than one logical node (LN), and each logical node is configured with more than one data object instance (DOI). Mapped data values, i.e., short addresses, are added under the data attribute (sAddr) node of the data object instance. The last byte of this short address represents the module number. Simultaneously, a data constant table is established in the ICD's private information area to represent the module identifier and module number of each functional module. Using the private information data constant table as a connecting link, an internal mapping between IEC61850 data and the device's real-time database is formed, completing the modeling of the fault location device based on the IEC61850 standard ICD file. The software functional modules are designed based on software-defined functions, which separates the application software from the operating system and underlying hardware, and facilitates the expansion and upgrading of functional modules. The design method for the software functional modules includes: Step 1: Each functional module is made into a set of functions that can be called repeatedly, including initialization interface functions and running interface functions. Input and output data and internal cache space are all allocated memory space through compilation in the form of N-dimensional structure, where N is the maximum number of times the functional module can be called. Step 2: In each function, design and construct the corresponding input / output configuration and algorithm logic according to different fault location functions; Step 3: Each functional module program is compiled by the compilation system to generate a static library file, which is then added to the compilation of the main program to generate an executable object file; Step 4: In the main program of the device, the initialization interface function of each functional module is called during the initialization phase, and the running interface function of each functional module is called during the task running phase. Data interaction between each functional module and the communication management process is realized through shared memory. The method for software functional modules to work collaboratively by sharing data within the device is as follows: the optimal criteria are constructed through data interaction between modules to achieve collaborative fault location function, and the output results of these modules are weighted and averaged to output the fault location result.

2. The fault location method of a power distribution network fault location device according to claim 1, characterized in that: The hardware of the fault location device is designed according to the functional integration method, and is equipped with corresponding functions including various protection functions, feeder automation functions, low current grounding line selection functions, and fault location functions.

3. The fault location method of a power distribution network fault location device according to claim 1, characterized in that: The method for establishing a one-to-one correspondence between the software functional modules designed according to different fault location functions and the logical devices of the ICD includes: first, adding the ICD file as an independent IED to the SCD file of the substation or distribution station; after configuring the virtual terminal connection at the process layer, exporting the CID file and downloading it to the fault location device; the fault location device uses a CID file parsing module to read and parse the CID; and based on the identifiers of each functional module in the CID file and the module number of the dataset short address, realizing the access mapping between IEC61850 model data and the real-time database.

4. The fault location method of a power distribution network fault location device according to claim 1, characterized in that: The specific steps for fault location include: Step S510: For all possible fault location function modules in the distribution network, create corresponding logical devices and logical nodes in the ICD file of the fault location device, fill in the corresponding module number in the short address of each dataset, and at the same time establish a data constant list of all function module numbers in the private information area. Step S520: Write the initialization interface function and running interface function of each fault location function module in a software-defined manner, and compile them into a static library and add it to the executable target program; Step S530: Based on different application scenarios and input conditions, configure the corresponding ICD logic devices and software function modules by copying and pasting, and generate a CID file to download to the fault location device; Step S450: After the device is running, the mapping relationship between each logical device and the software function module in the CID file is parsed, and then each software function module is executed; Step S450: Multiple fault location software modules work together to output the optimal fault location result.

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