CN114895144B - Line selection evaluation method, device, electronic equipment and storage medium - Google Patents

Abstract

The embodiment of the present invention discloses a line selection evaluation method, device, electronic device and storage medium. The method includes calculating the line zero-sequence current of each line in the power system when a metallic ground fault occurs based on the historical zero-sequence current of each line and the historical zero-sequence voltage of the system; obtaining a target fault line based on the line zero-sequence current of each line; if the target fault line is the same as the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection of the line selection device is correct; if the target fault line is different from the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection of the line selection device is wrong; wherein the line selection device is used to select a fault line. Through the technical solution of the embodiment of the present invention, the accuracy of the line selection evaluation of the line selection device is improved.

Description

Line selection evaluation method, device, electronic equipment and storage medium

Technical Field

The present invention relates to the technical field of power distribution networks, and in particular to a line selection evaluation method, device, electronic equipment and storage medium.

Background Art

Among the current distribution network faults, single-phase grounding faults account for the majority. If a single-phase grounding fault is not discovered in time and runs for a long time, it will damage the insulation between the equipment and the power grid, and it is possible that the instantaneous grounding fault will evolve into a permanent fault. For the occurrence of single-phase grounding faults, the line selection device can screen out the faulty line and prompt the staff so that the staff can take corresponding remedial measures.

However, the line selection effect of the line selection device is not good at present, and there are still cases of line selection errors. If the fault line is not discovered in time, it may cause serious consequences. Therefore, it is necessary to first evaluate whether the line selection of the line selection device is accurate, and then take corresponding corrective measures when it is determined that the line selection of the line selection device is not accurate enough. At present, the correctness of the line selection of the line selection device still requires manual judgment by the staff, which consumes a lot of human resources.

Therefore, a line selection evaluation method is needed to solve the above problems.

Summary of the invention

In view of this, the embodiments of the present invention provide a line selection evaluation method, device, electronic device and storage medium, which realize the evaluation of the line selection correctness of the line selection device and improve the efficiency and accuracy of the evaluation.

In a first aspect, an embodiment of the present invention provides a line selection evaluation method, the method comprising:

For each line in the power system, based on the historical zero-sequence current of each line and the historical zero-sequence voltage of the system, the line zero-sequence current of each line when a metallic grounding fault occurs is calculated;

Obtaining a target fault line based on the line zero-sequence current of each line;

If the target fault line is the same as the fault line selected by the line selection device, then the line selection evaluation result of the line selection device is that the line selection of the line selection device is correct;

If the target fault line is different from the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection device makes a wrong line selection; wherein the line selection device is used to select a fault line.

Preferably, obtaining the target fault line based on the line zero-sequence current of each line includes: obtaining the line capacitance current of each line, calculating the difference between the line zero-sequence current and the line capacitance current of each line, determining the maximum difference among the differences, and taking the line corresponding to the maximum difference as the target fault line.

Preferably, the obtaining of the line capacitance current of each line includes:

The obtaining of the line capacitance current of each line includes:

Input a preset number of input voltages to each line, obtain a line capacitance current to be calculated corresponding to each input voltage, and obtain a line capacitance current of the line based on the preset number of line capacitance currents to be calculated; wherein each input voltage has a different voltage frequency, the input voltage refers to a voltage input into the line by an external power supply, and for each line, each input voltage is input into the line at a different time; obtaining the line capacitance current to be calculated corresponding to each input voltage includes: Among them, I is the line capacitance current to be calculated, _U1 is the system nominal phase voltage, F is the power frequency, _it is the input current, _u is the input voltage, _f is the voltage frequency of the input voltage, and t represents the serial number of the input voltage.

Preferably, before calculating the line zero-sequence current of each line when a metallic ground fault occurs, the method further includes:

For at least one set of historical data, a historical zero-sequence current of each line and a historical zero-sequence voltage of the system are obtained from the historical data; wherein the historical data include historical moments of occurrence of historical ground faults, historical zero-sequence currents of each line corresponding to the historical moments, and historical zero-sequence voltages of the system.

Preferably, obtaining the target fault line based on the line zero-sequence current of each line includes: for each historical moment, obtaining the target fault line corresponding to the historical moment based on the line zero-sequence current of each line.

Preferably, if the target fault line is the same as the fault line selected by the line selection device, obtaining a line selection evaluation result of the line selection device that the line selection device selects the line correctly includes:

For each historical moment, if the target fault line corresponding to the historical moment and the fault line selected by the line selection device at the historical moment are the same, then the line selection evaluation result of the line selection device at the historical moment is that the line selection of the line selection device is correct; if the target fault line and the fault line selected by the line selection device are different, then the line selection evaluation result of the line selection device is that the line selection of the line selection device is wrong, including: for each historical moment, if the target fault line corresponding to the historical moment and the fault line selected by the line selection device at the historical moment are different, then the line selection evaluation result of the line selection device at the historical moment is that the line selection of the line selection device is wrong.

Preferably, the calculating of the line zero-sequence current of each line when a metallic ground fault occurs includes:

The line zero-sequence current of each line in the case of a metallic ground fault is calculated using the following formula: Among them, _I1 is the line zero-sequence current, _U1 is the system nominal phase voltage, _U2 is the historical zero-sequence voltage, and _I2 is the historical zero-sequence current.

In a second aspect, an embodiment of the present invention further provides a line selection evaluation device, the device comprising:

A line zero-sequence current acquisition module is used to calculate the line zero-sequence current of each line in the power system when a metallic grounding fault occurs based on the historical zero-sequence current of each line and the historical zero-sequence voltage of the system;

A fault line acquisition module, used for obtaining a target fault line based on the line zero-sequence current of each line;

An evaluation result acquisition module is used to obtain a line selection evaluation result that the line selection device selects the line correctly if the target fault line is the same as the fault line selected by the line selection device; if the target fault line is different from the fault line selected by the line selection device, obtain a line selection evaluation result that the line selection device selects the line incorrectly;

Wherein, the line selection device is used to select the faulty line.

In a third aspect, an embodiment of the present invention further provides an electronic device, the electronic device comprising:

one or more processors;

a storage device for storing one or more programs,

When the one or more programs are executed by the one or more processors, the one or more processors implement the line selection evaluation method in any embodiment of the present invention.

In a fourth aspect, an embodiment of the present invention further provides a storage medium comprising computer executable instructions, wherein the computer executable instructions, when executed by a computer processor, are used to execute a line selection evaluation method as in any embodiment of the present invention.

The technical solution of the embodiment of the present invention calculates the line zero-sequence current of each line in the power system during a metallic ground fault by using the historical zero-sequence current of each line and the zero-sequence voltage of the system, and obtains the target fault line according to the line zero-sequence current of each line. If the target fault line is different from the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection of the line selection device is wrong. If the target fault line is the same as the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection of the line selection device is correct. Through the technical solution of the embodiment of the present invention, it is possible to evaluate the correctness of the line selection of the line selection device, thereby improving the accuracy of the evaluation. Compared with manually evaluating the line selection of the line selection device, the technical solution of the embodiment of the present invention improves the efficiency of the line selection evaluation.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

in:

FIG1 is a schematic diagram of a flow chart of a line selection evaluation method in Embodiment 1 of the present invention;

FIG2 is a schematic diagram of a flow chart of a line selection evaluation method in Embodiment 2 of the present invention;

FIG3 is a schematic diagram of the structure of a line selection evaluation device in Embodiment 3 of the present invention;

FIG. 4 is a schematic diagram of the structure of an electronic device in Embodiment 4 of the present invention.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Embodiment 1

Figure 1 is a flow chart of a line selection evaluation method provided by an embodiment of the present invention. This embodiment is applicable to the situation of evaluating the line selection correctness of a line selection device. The method can be executed by the line selection evaluation device, which can be implemented in the form of software and/or hardware.

As shown in FIG1 , the line selection evaluation method according to the embodiment of the present invention specifically includes the following steps:

S110. For each line in the power system, based on the historical zero-sequence current of each line and the historical zero-sequence voltage of the system, calculate the line zero-sequence current of each line when a metallic grounding fault occurs.

Among them, the power system includes multiple lines.

Specifically, for each line in the power system, the historical zero-sequence current of each line and the historical zero-sequence voltage of the system are obtained, and then the line zero-sequence current of each line is calculated based on the historical zero-sequence current and the historical zero-sequence voltage of the system when a metallic grounding fault occurs. Calculating the line zero-sequence current of each line is a preparation for the subsequent determination of the target fault line.

Further, in an embodiment of the present invention, calculating the line zero-sequence current of each line when a metallic ground fault occurs includes: calculating the line zero-sequence current of each line when a metallic ground fault occurs by the following formula: Among them, _I1 is the line zero-sequence current, _U1 is the system nominal phase voltage, _U2 is the historical zero-sequence voltage, and _I2 is the historical zero-sequence current.

Among them, the system nominal phase voltage is a fixed value.

Specifically, the line zero-sequence current of each line is obtained through the line zero-sequence current acquisition formula. By obtaining the line zero-sequence current of each line, preparation work is made for the subsequent determination of the target fault line.

S120. Obtain a target fault line based on the line zero-sequence current of each line.

The fault line refers to a line where a fault occurs, and in the embodiment of the present invention, it may refer to a line where a single-phase grounding fault occurs. It should be understood that the target fault line involved in the embodiment of the present invention refers to a line.

Specifically, the target fault line is obtained according to the line zero-sequence current of each line, so as to prepare for the subsequent evaluation of the correctness of the line selection of the line selection device.

Furthermore, in an embodiment of the present invention, a target fault line is obtained based on the line zero-sequence current of each line, including: obtaining the line capacitance current of each line, calculating the difference between the line zero-sequence current and the line capacitance current of each line, determining the maximum difference among the differences, and taking the line corresponding to the maximum difference as the target fault line.

Specifically, the line capacitance current of each line is first obtained, and then the target fault line is determined according to the difference between the line zero-sequence current and the line capacitance current. The maximum difference among the differences is determined, and the line corresponding to the maximum difference is used as the target fault line, thereby improving the accuracy of determining the target fault line.

Further, in an embodiment of the present invention, the obtaining of the line capacitance current of each line includes: inputting a preset number of input voltages to each line, obtaining a line capacitance current to be calculated corresponding to each input voltage, and obtaining the line capacitance current of the line based on the preset number of line capacitance currents to be calculated; wherein the voltage frequency of each input voltage is different, the input voltage refers to the voltage input into the line by an external power supply, and for each line, the time when each input voltage is input into the line is different; the obtaining of the line capacitance current to be calculated corresponding to each input voltage includes: Among them, I is the line capacitance current to be calculated, _U1 is the system nominal phase voltage, F is the power frequency, _it is the input current, _u is the input voltage, _f is the voltage frequency of the input voltage, and t represents the serial number of the input voltage.

In an embodiment of the present invention, the line is first disconnected from the power system, and the three-phase line of the line is short-circuited, and one end of the short circuit is used as the line end, and then the external power supply inputs input voltages of different voltage frequencies between the line end and the ground. In this way, input voltages of different voltage frequencies, that is, sinusoidal voltages, are input into the line in sequence. Similarly, input voltages are input to each line. The time when each input voltage is input into the line is different, and each input voltage can be input in sequence according to a time series. Alternatively, the input voltages are sorted according to the voltage magnitude and input into the line in sequence. Optionally, at least three voltage frequencies can be selected from the voltage frequency range of 1Hz to 100Hz as the input voltage frequency. The input voltage is input to the line based on the input voltage frequency. It should be understood that the preset voltage frequency here can be a voltage frequency within the voltage frequency range of 1Hz to 100Hz.

Specifically, the line capacitance current to be calculated of each line under each input voltage is obtained through the acquisition formula of the line capacitance current to be calculated, and then the average value of a preset number of line capacitance currents to be calculated is calculated to obtain the line capacitance current of the line.

S130. If the target fault line is the same as the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection of the line selection device is correct.

Among them, the line selection device is used to select the faulty line.

Specifically, when the target fault line and the fault line selected by the line selection device are the same, the line selection evaluation result of the line selection device is that the line selection device selects the line correctly. For example, the target fault line is line 4, the fault line selected by the line selection device is line 4, and the target fault line and the fault line selected by the line selection device are the same, then the line selection device selects the line correctly.

S140. If the target fault line is different from the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection device selects the line incorrectly.

Specifically, when the target fault line and the fault line selected by the line selection device are different, the line selection evaluation result of the line selection device is that the line selection device selects the line incorrectly. For example, if the target fault line is line 4 and the fault line selected by the line selection device is line 3, the target fault line and the fault line selected by the line selection device are different, then the line selection device selects the line incorrectly.

Optionally, when the line selection evaluation result of the selection device is that the line selection device has selected a wrong line, an early warning message is issued to remind the staff to check the line selection device. The early warning message can be issued by sound effects, flashing indicator lights, etc. For example, when the line selection evaluation result is that the line selection device has selected a wrong line, a continuous whistle sound is issued to remind the staff that the line selection device has selected a wrong line.

Optionally, the line selection evaluation result of the line selection device is that the line selection device has an error in line selection. The line selection evaluation result also includes information such as the line selection device identification and evaluation time for easy viewing by staff.

Furthermore, in an embodiment of the present invention, after obtaining the line selection evaluation result of the line selection device, the line selection evaluation result can be displayed on a display interface for easy viewing by staff.

The technical solution of the embodiment of the present invention calculates the line zero-sequence current of each line in the power system during a metallic ground fault by using the historical zero-sequence current of each line and the zero-sequence voltage of the system, and obtains the target fault line according to the line zero-sequence current of each line. If the target fault line is different from the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection of the line selection device is wrong. If the target fault line is the same as the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection of the line selection device is correct. Through the technical solution of the embodiment of the present invention, the correctness of the line selection of the line selection device is evaluated, and the accuracy of the evaluation is improved.

Embodiment 2

Fig. 2 is a flow chart of a line selection evaluation method provided by an embodiment of the present invention, and the embodiment of the present invention adds a step of obtaining the historical zero-sequence current of each line and the historical zero-sequence voltage of the system on the basis of the optional scheme of the above embodiment. Among them, the technical terms that are the same or similar to the above embodiment will not be repeated.

As shown in 2, a line selection evaluation method provided by an embodiment of the present invention includes the following steps:

S210. For at least one set of historical data, obtain historical zero-sequence current of each line and historical zero-sequence voltage of the system from the historical data.

The historical data includes the historical time when the historical ground fault occurred, the historical zero-sequence current of each line corresponding to the historical time, and the historical zero-sequence voltage of the system. The historical data can be stored in an internal memory. The historical ground fault time can refer to a single-phase ground fault, and of course, it can also refer to other ground faults.

Specifically, the historical zero-sequence current of each line and the historical zero-sequence voltage of the system are obtained from the historical data. Optionally, for each historical ground fault moment, the historical zero-sequence voltage of the system corresponding to each historical ground fault moment and the historical zero-sequence current of each line are used as a group of historical data. When it is necessary to obtain the historical zero-sequence current of each line and the historical zero-sequence voltage of the system, the historical zero-sequence current and the historical zero-sequence voltage in each group of historical data can be obtained in order to improve the efficiency and accuracy of the acquisition.

S220. For each line in the power system, based on the historical zero-sequence current of each line and the historical zero-sequence voltage of the system, calculate the line zero-sequence current of each line when a metallic grounding fault occurs.

S230. Obtain a target fault line based on the line zero-sequence current of each line.

Further, in an embodiment of the present invention, obtaining a target fault line based on the line zero-sequence current of each line includes: for each historical moment, obtaining a target fault line corresponding to the historical moment based on the line zero-sequence current of each line.

Specifically, for each historical moment when a ground fault occurs, based on the line zero-sequence current of each line, the target fault line corresponding to the historical moment is obtained, thereby preparing for the subsequent determination of the line selection evaluation result of the line selection device at each historical moment.

S240. If the target fault line is the same as the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection of the line selection device is correct.

S250. If the target fault line is different from the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection device selects the line incorrectly.

Further, in an embodiment of the present invention, if the target fault line is the same as the fault line selected by the line selection device, then the line selection evaluation result of the line selection device is that the line selection device selects the line correctly, including: for each historical moment, if the target fault line corresponding to the historical moment and the fault line selected by the line selection device at the historical moment are the same, then the line selection evaluation result of the line selection device at the historical moment is that the line selection of the line selection device is correct. If the target fault line is different from the fault line selected by the line selection device, then the line selection evaluation result of the line selection device is that the line selection of the line selection device is wrong, including: for each historical moment, if the target fault line corresponding to the historical moment and the fault line selected by the line selection device at the historical moment are different, then the line selection evaluation result of the line selection device at the historical moment is that the line selection of the line selection device is wrong.

For example, the historical time is 2022.2.15, 12:12:23, and the line selection result of the line selection device is line 2. The historical time is 2022.2.30, 12:34:12, and the line selection result of the line selection device is line 3.

Specifically, if there is a target fault line corresponding to a historical moment, which is different from the fault line selected by the line selection device at the historical moment, then the line selection evaluation result of the line selection device at the historical moment is that the line selection device is wrong. If there is a target fault line corresponding to a historical moment, which is the same as the fault line selected by the line selection device at the historical moment, then the line selection evaluation result of the line selection device at the historical moment is that the line selection device is correct. In this way, the line selection evaluation result of the line selection device at each historical moment can be obtained. Optionally, the line selection evaluation result of the line selection device at each historical moment can be output, which improves the convenience for the staff to adjust the line selection device and other operations.

Optionally, the line selection evaluation result of the line selection device is that the line selection device has an error in line selection. The line selection evaluation result also includes information such as the line selection device identification, evaluation time, historical data corresponding to the line selection evaluation result, etc., for the convenience of staff viewing.

For example, in a 10KV power system, there are 4 lines, namely line 1, line 2, line 3 and line 4. The line capacitance currents of lines 1 to 4 are calculated to be 1.7A, 3.3A, 6.3A and 12.9A respectively. A set of historical data is obtained, and the line selection result of the line selection device at the historical moment is obtained as line 4. The historical zero-sequence voltage of the system when the historical grounding fault occurred is 3250V, and the historical zero-sequence current of each line is 3.6A, 1.8A, 3.7A and 7.3A respectively. According to the historical zero-sequence voltage and the historical zero-sequence current of each line, the line zero-sequence current of each line under the metallic grounding fault is calculated to be 6.4A, 3.2A, 6.5A and 13A respectively. The difference between the line zero-sequence current and the line capacitance circuit of each line is calculated to be 4.7A, 0.1A, 0.2A, and 0.1A, respectively, and the maximum difference of 4.7A is determined. Optionally, the difference here can refer to the absolute value of the difference. Line 1 corresponding to the maximum difference is taken as the target fault line. If the fault line selected by the line selection device is line 4, the line selection evaluation result of the line selection device is that the line selection device selects the line incorrectly.

The technical solution of the embodiment of the present invention obtains the historical zero-sequence current of each line and the historical zero-sequence voltage of the system from historical data, and calculates the line zero-sequence current of each line during a metallic grounding fault based on the historical zero-sequence current of each line and the historical zero-sequence voltage of the system. A target fault line is obtained based on the line zero-sequence current of each line. If the target fault line is the same as the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection of the line selection device is correct. If the target fault line is different from the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection of the line selection device is wrong. Through the technical solution of the embodiment of the present invention, the line selection evaluation of the line selection device is realized, and the accuracy of the line selection evaluation is improved.

Embodiment 3

FIG3 is a schematic diagram of the structure of a line selection evaluation device provided by an embodiment of the present invention. The line selection evaluation device provided by an embodiment of the present invention can execute the line selection evaluation method provided by any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method. The device includes: a line zero-sequence current acquisition module 310, a fault line acquisition module 320 and an evaluation result acquisition module 330; wherein:

The line zero-sequence current acquisition module 310 is used to calculate the line zero-sequence current of each line in the power system when a metallic ground fault occurs based on the historical zero-sequence current of each line and the historical zero-sequence voltage of the system; the fault line acquisition module 320 is used to obtain the target fault line based on the line zero-sequence current of each line; the evaluation result acquisition module 330 is used to obtain the line selection evaluation result that the line selection device selects the line correctly if the target fault line is the same as the fault line selected by the line selection device; if the target fault line is different from the fault line selected by the line selection device, then obtain the line selection evaluation result that the line selection device selects the line incorrectly;

Among them, the line selection device is used to select the faulty line.

Furthermore, the fault line acquisition module 320 is also used to: obtain the line capacitance current of each line, calculate the difference between the line zero-sequence current and the line capacitance current of each line, determine the maximum difference among the differences, and use the line corresponding to the maximum difference as the target fault line.

Further, the fault line acquisition module 320 is further used to: input a preset number of input voltages to each line, obtain the line capacitance current to be calculated corresponding to each input voltage, and obtain the line capacitance current of the line based on the preset number of line capacitance currents to be calculated; wherein the voltage frequency of each input voltage is different, the input voltage refers to the voltage input into the line by the external power supply, and for each line, the time when each input voltage is input into the line is different; the obtaining of the line capacitance current to be calculated corresponding to each input voltage includes: Among them, I is the line capacitance current to be calculated, _U1 is the system nominal phase voltage, F is the power frequency, _it is the input current, _u is the input voltage, _f is the voltage frequency of the input voltage, and t represents the serial number of the input voltage.

Furthermore, the device also includes: a data acquisition module, which is used to obtain the historical zero-sequence current of each line and the historical zero-sequence voltage of the system from the historical data for at least one set of historical data; wherein the historical data includes the historical time when the historical grounding fault occurred, the historical zero-sequence current of each line corresponding to the historical time, and the historical zero-sequence voltage of the system.

Furthermore, the fault line acquisition module 320 is further used to: for each historical moment, based on the line zero-sequence current of each line, obtain a target fault line corresponding to the historical moment.

Furthermore, the evaluation result acquisition module 330 is also used for: for each historical moment, if the target fault line corresponding to the historical moment and the fault line selected by the line selection device at the historical moment are the same, then the line selection evaluation result of the line selection device at the historical moment is that the line selection device has selected the line correctly; for each historical moment, if the target fault line corresponding to the historical moment and the fault line selected by the line selection device at the historical moment are different, then the line selection evaluation result of the line selection device at the historical moment is that the line selection device has selected the line incorrectly.

Furthermore, the line zero-sequence current acquisition module 310 is further used to calculate the line zero-sequence current of each line when a metallic grounding fault occurs by using the following formula: Among them, _I1 is the line zero-sequence current, _U1 is the system nominal phase voltage, _U2 is the historical zero-sequence voltage, and _I2 is the historical zero-sequence current.

The technical solution of the embodiment of the present invention calculates the line zero-sequence current of each line in the power system during a metallic ground fault by using the historical zero-sequence current of each line and the zero-sequence voltage of the system, and obtains the target fault line according to the line zero-sequence current of each line. If the target fault line is different from the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection of the line selection device is wrong. If the target fault line is the same as the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection of the line selection device is correct. Through the technical solution of the embodiment of the present invention, the correctness of the line selection of the line selection device is evaluated, and the accuracy of the evaluation is improved.

It is worth noting that the various modules included in the above-mentioned device are only divided according to functional logic, but are not limited to the above-mentioned division, as long as the corresponding functions can be achieved; in addition, the specific names of the various functional modules are only for the convenience of distinguishing each other, and are not used to limit the protection scope of the embodiments of the present invention.

Embodiment 4

FIG4 is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. FIG4 shows a block diagram of an exemplary electronic device 50 suitable for implementing an embodiment of the present invention. The electronic device 50 shown in FIG4 is only an example and should not bring any limitation to the functions and scope of use of the embodiment of the present invention.

As shown in Fig. 4, the electronic device 50 is in the form of a general computing device. The components of the electronic device 50 may include but are not limited to: one or more processors or processing units 501, a system memory 502, and a bus 503 connecting different system components (including the system memory 502 and the processing unit 501).

Bus 503 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor or a local bus using any of a variety of bus structures. For example, these architectures include but are not limited to Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MAC) bus, Enhanced ISA bus, Video Electronics Standards Association (VESA) local bus and Peripheral Component Interconnect (PCI) bus.

The electronic device 50 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the electronic device 50, including volatile and non-volatile media, removable and non-removable media.

The system memory 502 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 504 and/or cache memory 505. The electronic device 50 may further include other removable/non-removable, volatile/non-volatile computer system storage media. By way of example only, the storage system 506 may be used to read and write non-removable, non-volatile magnetic media (not shown in FIG. 4 , commonly referred to as a “hard drive”). Although not shown in FIG. 4 , a disk drive for reading and writing a removable non-volatile disk (such as a “floppy disk”) and an optical disk drive for reading and writing a removable non-volatile optical disk (such as a CD-ROM, DVD-ROM or other optical media) may be provided. In these cases, each drive may be connected to the bus 503 via one or more data medium interfaces. The memory 502 may include at least one program product having a set (e.g., at least one) of program modules that are configured to perform the functions of the various embodiments of the present invention.

A program/utility 508 having a set (at least one) of program modules 507 may be stored, for example, in the memory 502, such program modules 507 including but not limited to an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment. The program modules 507 generally perform the functions and/or methods of the embodiments described herein.

The electronic device 50 may also communicate with one or more external devices 509 (e.g., keyboard, pointing device, display 510, etc.), may also communicate with one or more devices that enable a user to interact with the electronic device 50, and/or communicate with any device that enables the electronic device 50 to communicate with one or more other computing devices (e.g., network card, modem, etc.). Such communication may be performed via an input/output (I/O) interface 511. Furthermore, the electronic device 50 may also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN) and/or public network, such as the Internet) via a network adapter 512. As shown, the network adapter 512 communicates with other modules of the electronic device 50 via a bus 503. It should be understood that, although not shown in FIG. 4 , other hardware and/or software modules may be used in conjunction with the electronic device 50, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems, etc.

The processing unit 501 executes various functional applications and data processing by running the programs stored in the system memory 502, such as implementing the line selection evaluation method provided in the embodiment of the present invention.

Embodiment 5

An embodiment of the present invention further provides a storage medium containing computer executable instructions, and when the computer executable instructions are executed by a computer processor, they are used to execute a line selection evaluation method, the method comprising:

For each line in the power system, based on the historical zero-sequence current of each line and the historical zero-sequence voltage of the system, the line zero-sequence current of each line during a metallic grounding fault is calculated; based on the line zero-sequence current of each line, a target fault line is obtained; if the target fault line is the same as the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection of the line selection device is correct; if the target fault line is different from the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection of the line selection device is wrong; wherein, the line selection device is used to select the fault line.

The computer storage medium of the embodiment of the present invention can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, - but not limited to - an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, a computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it.

Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

Computer program code for performing the operation of embodiments of the present invention may be written in one or more programming languages or a combination thereof, including object-oriented programming languages, such as Java, Smalltalk, C++, and conventional procedural programming languages, such as "C" or similar programming languages. The program code may be executed entirely on a user's computer, partially on a user's computer, as an independent software package, partially on a user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of 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).

The above disclosure is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims (7)

1. A line selection evaluation method, characterized by comprising: For each line in the power system, based on the historical zero-sequence current of each line and the historical zero-sequence voltage of the system, the line zero-sequence current of each line when a metallic grounding fault occurs is calculated; Obtaining a target fault line based on the line zero-sequence current of each line; If the target fault line is the same as the fault line selected by the line selection device, then the line selection evaluation result of the line selection device is obtained to be that the line selection of the line selection device is correct; If the target fault line is different from the fault line selected by the line selection device, the line selection evaluation result of the line selection device is that the line selection device selects the wrong line; Wherein, the line selection device is used to select the fault line; The obtaining a target fault line based on the line zero-sequence current of each line comprises: Obtaining the line capacitance current of each line, calculating the difference between the line zero-sequence current and the line capacitance current of each line, determining the maximum difference among the differences, and taking the line corresponding to the maximum difference as the target fault line; The obtaining of the line capacitance current of each line includes: Inputting a preset number of input voltages to each line, obtaining a line capacitance current to be calculated corresponding to each input voltage, and obtaining a line capacitance current of the line based on the preset number of line capacitance currents to be calculated; The voltage frequency of each input voltage is different, and the input voltage refers to the voltage inputted into the circuit by an external power source, and for each circuit, the time at which each input voltage is inputted into the circuit is different; The obtaining of the to-be-calculated line capacitance current corresponding to each input voltage comprises: Where, I is the line capacitance current to be calculated, _U1 is the system nominal phase voltage, F is the power frequency, _it is the input current, _u is the input voltage, _f is the voltage frequency of the input voltage, and t represents the serial number of the input voltage; The calculating of the line zero-sequence current of each line when a metallic ground fault occurs includes: The line zero-sequence current of each line in the case of a metallic ground fault is calculated using the following formula: Among them, _I1 is the line zero-sequence current, _U1 is the system nominal phase voltage, _U2 is the historical zero-sequence voltage, and _I2 is the historical zero-sequence current. 2. The line selection evaluation method according to claim 1, characterized in that before calculating the line zero-sequence current of each line when a metallic ground fault occurs, it further comprises: For at least one set of historical data, obtaining a historical zero-sequence current of each line and a historical zero-sequence voltage of the system from the historical data; The historical data include the historical time when the historical ground fault occurred, the historical zero-sequence current of each line corresponding to the historical time, and the historical zero-sequence voltage of the system. 3. The line selection evaluation method according to claim 2, characterized in that obtaining the target fault line based on the line zero-sequence current of each line comprises: For each historical moment, based on the line zero-sequence current of each line, the target fault line corresponding to the historical moment is obtained. 4. The line selection evaluation method according to claim 3, characterized in that if the target fault line is the same as the fault line selected by the line selection device, then obtaining the line selection evaluation result of the line selection device is that the line selection of the line selection device is correct, comprising: For each historical moment, if the target fault line corresponding to the historical moment and the fault line selected by the line selection device at the historical moment are the same, then the line selection evaluation result of the line selection device at the historical moment is that the line selection device selects the line correctly; If the target fault line is different from the fault line selected by the line selection device, obtaining the line selection evaluation result of the line selection device as a line selection error by the line selection device includes: For each historical moment, if the target fault line corresponding to the historical moment and the fault line selected by the line selection device at the historical moment are different, the line selection evaluation result of the line selection device at the historical moment is that the line selection device selects the wrong line. 5. A line selection evaluation device, characterized in that it comprises: A line zero-sequence current acquisition module is used to calculate the line zero-sequence current of each line in the power system when a metallic grounding fault occurs based on the historical zero-sequence current of each line and the historical zero-sequence voltage of the system; A fault line acquisition module, used for obtaining a target fault line based on the line zero-sequence current of each line; An evaluation result acquisition module is used to obtain a line selection evaluation result that the line selection device selects the line correctly if the target fault line is the same as the fault line selected by the line selection device; if the target fault line is different from the fault line selected by the line selection device, obtain a line selection evaluation result that the line selection device selects the line incorrectly; Wherein, the line selection device is used to select the fault line; The obtaining a target fault line based on the line zero-sequence current of each line comprises: Obtaining the line capacitance current of each line, calculating the difference between the line zero-sequence current and the line capacitance current of each line, determining the maximum difference among the differences, and taking the line corresponding to the maximum difference as the target fault line; The obtaining of the line capacitance current of each line includes: Inputting a preset number of input voltages to each line, obtaining a line capacitance current to be calculated corresponding to each input voltage, and obtaining a line capacitance current of the line based on the preset number of line capacitance currents to be calculated; The voltage frequency of each input voltage is different, and the input voltage refers to the voltage inputted into the circuit by an external power source, and for each circuit, the time at which each input voltage is inputted into the circuit is different; The obtaining of the to-be-calculated line capacitance current corresponding to each input voltage comprises: Where, I is the line capacitance current to be calculated, _U1 is the system nominal phase voltage, F is the power frequency, _it is the input current, _u is the input voltage, _f is the voltage frequency of the input voltage, and t represents the serial number of the input voltage; The calculating of the line zero-sequence current of each line when a metallic ground fault occurs includes: The line zero-sequence current of each line in the case of a metallic ground fault is calculated using the following formula: Among them, _I1 is the line zero-sequence current, _U1 is the system nominal phase voltage, _U2 is the historical zero-sequence voltage, and _I2 is the historical zero-sequence current. 6. An electronic device, characterized in that the electronic device comprises: one or more processors; a storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the line selection evaluation method as described in any one of claims 1 to 4. 7. A storage medium comprising computer executable instructions, wherein the computer executable instructions are used to perform the line selection evaluation method according to any one of claims 1 to 4 when executed by a computer processor.