CN116660682A

CN116660682A - Line fault direction identification method, device, computer equipment and storage medium

Info

Publication number: CN116660682A
Application number: CN202310661058.XA
Authority: CN
Inventors: 卢正飞; 黄福全; 马帅; 张安龙; 周瑜; 许伯阳; 李洪卫
Original assignee: Shenzhen Power Supply Co ltd
Current assignee: Shenzhen Power Supply Co ltd
Priority date: 2023-06-05
Filing date: 2023-06-05
Publication date: 2023-08-29

Abstract

The application relates to a line fault direction identification method, a line fault direction identification device, a computer device, a storage medium and a computer program product. The method comprises the following steps: acquiring current and voltage component sets respectively corresponding to target detection points in a failed line before and after line failure; obtaining positive sequence impedance corresponding to the target detection point based on the difference between current positive sequence components respectively corresponding to the target detection point before and after the line fault and the difference between voltage positive sequence components respectively corresponding to the target detection point before and after the line fault, and obtaining negative sequence impedance corresponding to the target detection point based on the difference between current negative sequence components respectively corresponding to the target detection point before and after the line fault and the difference between voltage negative sequence components respectively corresponding to the target detection point before and after the line fault; a fault direction of a target fault point in the failed line to the target detection point is determined based on the positive sequence impedance and the negative sequence impedance. By adopting the method, the accuracy of line fault direction identification can be improved.

Description

Line fault direction identification method, device, computer equipment and storage medium

Technical Field

The present application relates to the field of computer technology, and in particular, to a line fault direction identification method, a line fault direction identification device, a computer device, a storage medium, and a computer program product.

Background

In the power system, each power generation device is connected with an external power grid system through a sending-out line, when the sending-out line corresponding to the power generation device fails, the power data collected by a circuit protection device on the sending-out line is required to be analyzed, the failure direction is determined in time, and then corresponding protection measures are adopted based on the failure direction.

However, in analyzing the power data, the conventional analysis method is based on the power generation apparatus being a conventional synchronous generator, depending on the failure characteristics of the synchronous generator. When the power generation equipment is a new energy power supply utilizing new energy such as wind, light and the like, the fault characteristics of the power generation equipment are obviously different from those of the synchronous generator, so that the traditional analysis method is not applicable any more.

Disclosure of Invention

In view of the foregoing, it is desirable to provide a line fault direction identification method, apparatus, computer device, computer readable storage medium, and computer program product that can improve the accuracy of line fault direction identification.

The application provides a line fault direction identification method. The method comprises the following steps:

aiming at a failed line of the power generation equipment, acquiring current and voltage component sets respectively corresponding to target detection points in the failed line before and after the line fails; the faults of the failed line are single-phase ground faults of the line outlet area, and the current-voltage component set comprises a current positive sequence component, a current negative sequence component, a voltage positive sequence component and a voltage negative sequence component;

obtaining positive sequence impedance corresponding to the target detection point based on the difference between current positive sequence components respectively corresponding to the target detection point before and after the line fault and the difference between voltage positive sequence components respectively corresponding to the target detection point before and after the line fault, and obtaining negative sequence impedance corresponding to the target detection point based on the difference between current negative sequence components respectively corresponding to the target detection point before and after the line fault and the difference between voltage negative sequence components respectively corresponding to the target detection point before and after the line fault;

based on the difference between the positive sequence impedance and the negative sequence impedance, a fault direction of a target fault point in the failed line to the target detection point is determined.

The application also provides a line fault direction identification device. The device comprises:

The component set acquisition module is used for acquiring current and voltage component sets respectively corresponding to a target detection point in a failed line before and after the line failure aiming at the failed line of the power generation equipment; the faults of the failed line are single-phase ground faults of the line outlet area, and the current-voltage component set comprises a current positive sequence component, a current negative sequence component, a voltage positive sequence component and a voltage negative sequence component;

the impedance determining module is used for obtaining positive sequence impedance corresponding to the target detection point based on the difference between the current positive sequence components respectively corresponding to the target detection point before and after the line fault and the difference between the voltage positive sequence components respectively corresponding to the target detection point before and after the line fault, and obtaining negative sequence impedance corresponding to the target detection point based on the difference between the current negative sequence components respectively corresponding to the target detection point before and after the line fault and the difference between the voltage negative sequence components respectively corresponding to the target detection point before and after the line fault;

the fault direction determining module is used for determining the fault direction of a target fault point in the failed line aiming at the target detection point based on the difference between the positive sequence impedance and the negative sequence impedance.

A computer device comprises a memory and a processor, wherein the memory stores a computer program, and the processor realizes the steps of the line fault direction identification method when executing the computer program.

A computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the steps of the line fault direction identification method described above.

A computer program product comprising a computer program which, when executed by a processor, implements the steps of the line fault direction identification method described above.

The line fault direction identification method, the line fault direction identification device, the computer equipment, the storage medium and the computer program product are used for acquiring the current and voltage component sets respectively corresponding to the target detection points in the failed line of the power generation equipment before and after the line fault. Based on the difference between the positive sequence components of the current respectively corresponding to the target detection point before and after the line fault, the difference between the positive sequence components of the voltage respectively corresponding to the target detection point before and after the line fault is obtained, the positive sequence impedance corresponding to the target detection point is obtained, and based on the difference between the negative sequence components of the current respectively corresponding to the target detection point before and after the line fault, the difference between the negative sequence components of the voltage respectively corresponding to the target detection point before and after the line fault is obtained. Based on the difference between the positive sequence impedance and the negative sequence impedance, determining a fault direction of a target fault point in the failed line to the target detection point. Thus, the positive sequence impedance and the negative sequence impedance corresponding to the target detection point are calculated based on the voltage-current component sets respectively corresponding to the line fault. Because the differences between the positive sequence impedance and the negative sequence impedance which correspond to different line fault directions are obviously different, the fault direction corresponding to the target fault point aiming at the target detection point can be rapidly and accurately determined based on the differences between the positive sequence impedance and the negative sequence impedance, the line fault direction identification efficiency is improved, and meanwhile, the line fault direction identification accuracy is improved.

Drawings

FIG. 1 is an application environment diagram of a line fault direction identification method in one embodiment;

FIG. 2 is a flow chart of a method for identifying a direction of a circuit fault in one embodiment;

FIG. 3 is a flow diagram of determining impedance in one embodiment;

FIG. 4 is a flow chart of a method of identifying circuit faults in another embodiment;

FIG. 5 is a schematic diagram of a fault of a doubly fed wind turbine accessing a power system in one embodiment;

FIG. 6 is a block diagram of a circuit fault direction identification device in one embodiment;

FIG. 7 is a block diagram showing a circuit fault direction recognition device according to another embodiment;

FIG. 8 is an internal block diagram of a computer device in one embodiment;

fig. 9 is an internal structural view of a computer device in another embodiment.

Detailed Description

The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

The line fault direction identification method provided by the embodiment of the application can be applied to an application environment shown in fig. 1. Wherein the terminal 102 communicates with the server 104 via a network. The data storage system may store data that the server 104 needs to process. The data storage system may be integrated on the server 104 or may be located on a cloud or other network server. The terminal 102 may be, but not limited to, various personal computers, notebook computers, smart phones, tablet computers, internet of things devices, and portable wearable devices, which may be smart televisions, smart car devices, and the like. The portable wearable device may be a smart watch, smart bracelet, headset, or the like. The server 104 may be implemented as a stand-alone server or as a server cluster of multiple servers. The terminal 102 and the server 104 may be directly or indirectly connected through wired or wireless communication, and the present application is not limited herein.

The terminal and the server can be independently used for executing the line fault direction identification method provided by the embodiment of the application.

For example, the terminal acquires a failed line for the power generation device, and acquires current-voltage component sets corresponding to target detection points in the failed line before and after the line fault, wherein the fault of the failed line is a single-phase ground fault of a line outlet area, and the current-voltage component sets comprise a current positive sequence component, a current negative sequence component, a voltage positive sequence component and a voltage negative sequence component. The terminal obtains positive sequence impedance corresponding to the target detection point based on the difference between current positive sequence components respectively corresponding to the target detection point before and after the line fault and the difference between voltage positive sequence components respectively corresponding to the target detection point before and after the line fault, and obtains negative sequence impedance corresponding to the target detection point based on the difference between current negative sequence components respectively corresponding to the target detection point before and after the line fault and the difference between voltage negative sequence components respectively corresponding to the target detection point before and after the line fault. The terminal determines a fault direction of a target fault point in the failed line to the target detection point based on a difference between the positive sequence impedance and the negative sequence impedance.

The terminal and the server can also cooperate to perform the line fault direction identification method provided in the embodiments of the present application.

For example, the terminal acquires a failed line for the power generation device from the server, acquires current-voltage component sets respectively corresponding to the target detection points in the failed line before and after the line fault, and sends the current-voltage component sets to the server, wherein the fault of the failed line is a single-phase ground fault of the line outlet area, and the current-voltage component sets comprise a current positive sequence component, a current negative sequence component, a voltage positive sequence component and a voltage negative sequence component. The server obtains positive sequence impedance corresponding to the target detection point based on the difference between the current positive sequence components respectively corresponding to the target detection point before and after the line fault and the difference between the voltage positive sequence components respectively corresponding to the target detection point before and after the line fault, and obtains negative sequence impedance corresponding to the target detection point based on the difference between the current negative sequence components respectively corresponding to the target detection point before and after the line fault and the difference between the voltage negative sequence components respectively corresponding to the target detection point before and after the line fault. The server determines a fault direction of a target fault point in the failed line for the target detection point based on a difference between the positive sequence impedance and the negative sequence impedance. The server sends the target fault point in the failed line to the terminal aiming at the fault direction of the target detection point, and the terminal makes corresponding protection action based on the fault direction.

In one embodiment, as shown in fig. 2, a line fault direction identification method is provided, and the method is applied to a computer device, which is a terminal or a server, and is executed by the terminal or the server, or may be implemented through interaction between the terminal and the server. The line fault direction identification method comprises the following steps:

step S202, aiming at a failed line of power generation equipment, acquiring current and voltage component sets respectively corresponding to target detection points in the failed line before and after the line failure; the fault of the failed line is a single-phase ground fault of the line outlet area, and the current-voltage component set comprises a current positive sequence component, a current negative sequence component, a voltage positive sequence component and a voltage negative sequence component.

The power generation equipment refers to equipment which is connected into a power grid to supply power for the power grid.

The failed line refers to a line in which the power generation device is connected to an external power grid, and a single-phase ground fault occurs in a line outlet area in a power supply line for supplying power to the external power grid. The power supply line is a three-phase power transmission line.

The target detection point is the position where the protection device is installed on the line outlet area of the failed line. The protection device can detect the current and the voltage of the circuit, and when the forward fault of the line outlet area is detected, the protection action is started.

The line outlet area refers to a line outlet vicinity area of a power supply line of the power generation device connected to an external power grid, that is, a portion of the line near one side of the power generation device, for example, the length of the line outlet area may be 10% of the entire power supply line.

The single-phase earth fault refers to the fact that one phase in the three-phase power transmission line is grounded, and the three phases are A phase, B phase and C phase respectively.

The current-voltage component set corresponding to the line fault refers to a set comprising a current positive sequence component, a voltage positive sequence component, a current negative sequence component and a voltage negative sequence component corresponding to the target detection point before the line fault.

The set of current and voltage components corresponding to the line fault refers to a set comprising a current positive sequence component, a voltage positive sequence component, a current negative sequence component and a voltage negative sequence component corresponding to the target detection point after the line fault.

Any group of asymmetric three-phase sinusoidal voltage vectors or three-phase sinusoidal current vectors can be decomposed into three groups of symmetric components, one group is a positive sequence component, the phase sequence is consistent with the phase sequence of the original asymmetric sinusoidal quantity, namely the sequence of clockwise A-B-C, the phase differences among the phases are 120 degrees, one group is a negative sequence component, the phase sequence is opposite to the original asymmetric positive sequence quantity, namely the sequence of clockwise A-C-B, the phase differences among the phases are 120 degrees, the other group is a zero sequence component, and the phases of the three phases are the same. The current positive sequence component is a positive sequence component obtained by decomposing a three-phase sinusoidal current vector corresponding to the target detection point. The current negative sequence component is a negative sequence component obtained by decomposing the three-phase sinusoidal current vector corresponding to the target detection point. The positive voltage sequence component is a positive sequence component obtained by decomposing a three-phase sinusoidal voltage vector corresponding to the target detection point. The negative sequence component of the voltage is a negative sequence component obtained by decomposing the three-phase sinusoidal voltage vector corresponding to the target detection point.

In order to determine the fault direction in time when a single-phase ground fault occurs in a line outlet area of a power supply line between power generation equipment and an external power grid, computer equipment acquires a current positive sequence component, a current negative sequence component, a voltage positive sequence component and a voltage negative sequence component corresponding to a target detection point in a failed line of the power generation equipment before the line fault, and obtains a current voltage component set corresponding to the target detection point before the line fault. And acquiring a current positive sequence component, a current negative sequence component, a voltage positive sequence component and a voltage negative sequence component corresponding to the target detection point in the line fault of the failed line of the power generation equipment, and obtaining a current voltage component set corresponding to the target detection point after the line fault. And further, based on current and voltage component sets respectively corresponding to the front and rear of the line fault of the target detection point, positive sequence impedance and negative sequence impedance corresponding to the target detection point are calculated, and the fault direction of the target fault point to the target detection point is determined based on the difference between the positive sequence impedance and the negative sequence impedance. Because the difference between the positive sequence impedance and the negative sequence impedance which correspond to the positive fault and the reverse fault respectively is obviously different, the fault direction of the target fault point aiming at the target detection point can be rapidly and accurately determined based on the difference between the positive sequence impedance and the negative sequence impedance, and the line fault direction identification efficiency is improved.

Step S204, obtaining positive sequence impedance corresponding to the target detection point based on the difference between the positive sequence components of the current respectively corresponding to the target detection point before and after the line fault and the difference between the positive sequence components of the voltage respectively corresponding to the target detection point before and after the line fault, and obtaining negative sequence impedance corresponding to the target detection point based on the difference between the negative sequence components of the current respectively corresponding to the target detection point before and after the line fault and the difference between the negative sequence components of the voltage respectively corresponding to the target detection point before and after the line fault.

The positive sequence impedance is the impedance calculated based on the difference between the positive sequence components of the voltage and the positive sequence components of the current before and after the line fault. The negative sequence impedance refers to an impedance calculated based on a difference between negative sequence components of voltage and a difference between negative sequence components of current before and after a line fault.

The computer device uses the difference between the positive sequence components of the current respectively corresponding to the target detection point before and after the line fault as the positive sequence current difference, uses the difference between the positive sequence components of the voltage respectively corresponding to the target detection point before and after the line fault as the positive sequence voltage difference, and obtains the positive sequence impedance corresponding to the target detection point based on the positive sequence current difference and the positive sequence voltage difference.

And taking the difference between the current negative sequence components corresponding to the target detection points before and after the line fault as a negative sequence current difference, taking the difference between the voltage negative sequence components corresponding to the target detection points before and after the line fault as a negative sequence voltage difference, and obtaining the negative sequence impedance corresponding to the target detection points based on the negative sequence current difference and the negative sequence voltage difference.

For example, the current positive sequence components corresponding to the target detection points before and after the line fault are respectively given corresponding current weights, the current positive sequence components corresponding to the target detection points before and after the line fault are adjusted based on the corresponding current weights, and the difference between the adjusted current positive sequence components corresponding to the line fault before and after the line fault is used as the positive sequence current difference. And respectively endowing corresponding voltage positive sequence components of the target detection point before and after the line fault with corresponding voltage weights, adjusting the voltage positive sequence components of the target detection point before and after the line fault based on the corresponding voltage weights, and taking the difference between the adjusted voltage positive sequence components before and after the line fault as a positive sequence voltage difference. And fusing the ratio between the positive sequence voltage difference and the positive sequence current difference with a preset value to obtain the positive sequence impedance corresponding to the target detection point. And determining the negative sequence impedance corresponding to the target detection point based on the current positive sequence component and the voltage positive sequence component respectively corresponding to the target detection point before and after the line fault by the same method.

Step S206, determining a fault direction of the target fault point in the faulty line with respect to the target detection point based on the difference between the positive sequence impedance and the negative sequence impedance.

The target fault point refers to a position where a fault occurs in the failed line, and the target fault point is located in a line outlet area of the failed line. The fault direction of the target fault point for the target detection point refers to the position relationship between the target fault point and the target detection point, when the target fault point is located on the external grid side of the target detection point, namely, on a line between the target detection point and the external grid, the fault direction of the target fault point for the target detection point is indicated to be forward, and when the target fault point is located on the power generation equipment side of the target detection point, namely, on a line between the target detection point and the power generation equipment, the fault direction of the target fault point for the target detection point is indicated to be reverse.

Illustratively, the computer device calculates a difference between the positive sequence impedance and the negative sequence impedance. For example, calculating the difference between the positive sequence impedance and the negative sequence impedance to obtain an impedance difference, calculating the sum of the positive sequence impedance and the negative sequence impedance to obtain a fused impedance, and taking the ratio between the impedance difference and the fused impedance as the difference between the positive sequence impedance and the negative sequence impedance; setting corresponding weights for positive sequence impedance and negative sequence impedance respectively, adjusting the positive sequence impedance based on the weight corresponding to the positive sequence impedance to obtain adjusted positive sequence impedance, adjusting the negative sequence impedance based on the weight corresponding to the negative sequence impedance to obtain adjusted negative sequence impedance, and obtaining the difference between the positive sequence impedance and the negative sequence impedance based on the difference between the adjusted positive sequence impedance and the adjusted negative sequence impedance; etc.

And comparing the difference between the positive sequence impedance and the negative sequence impedance with a preset value, and determining the fault direction of a target fault point in the faulty line aiming at the target detection point. For example, a preset difference range is obtained, when the difference between the positive sequence impedance and the negative sequence impedance is within the preset difference range, the fault direction corresponding to the target fault point in the failed line is determined to be reverse, and when the difference between the positive sequence impedance and the negative sequence impedance is outside the preset difference range, the fault direction corresponding to the target fault point in the failed line is determined to be forward.

In the line fault direction identification method, the current and voltage component sets respectively corresponding to the target detection points in the failed line of the power generation equipment before and after the line fault are obtained. Based on the difference between the positive sequence components of the current respectively corresponding to the target detection point before and after the line fault, the difference between the positive sequence components of the voltage respectively corresponding to the target detection point before and after the line fault is obtained, the positive sequence impedance corresponding to the target detection point is obtained, and based on the difference between the negative sequence components of the current respectively corresponding to the target detection point before and after the line fault, the difference between the negative sequence components of the voltage respectively corresponding to the target detection point before and after the line fault is obtained. Based on the difference between the positive sequence impedance and the negative sequence impedance, determining a fault direction of a target fault point in the failed line to the target detection point. Thus, the positive sequence impedance and the negative sequence impedance corresponding to the target detection point are calculated based on the voltage-current component sets respectively corresponding to the line fault. Because the differences between the positive sequence impedance and the negative sequence impedance which correspond to different line fault directions are obviously different, the fault direction corresponding to the target fault point aiming at the target detection point can be rapidly and accurately determined based on the differences between the positive sequence impedance and the negative sequence impedance, the line fault direction identification efficiency is improved, and meanwhile, the line fault direction identification accuracy is improved.

In one embodiment, as shown in fig. 3, the obtaining the positive sequence impedance corresponding to the target detection point based on the difference between the positive sequence components of the current respectively corresponding to the target detection point before and after the line fault and the difference between the positive sequence components of the voltage respectively corresponding to the target detection point before and after the line fault, and the obtaining the negative sequence impedance corresponding to the target detection point based on the difference between the negative sequence components of the current respectively corresponding to the target detection point before and after the line fault and the difference between the negative sequence components of the voltage respectively corresponding to the target detection point before and after the line fault includes:

step S302, calculating the difference value between the current positive sequence components corresponding to the target detection points before and after the line fault, and obtaining the current positive sequence variation.

Step S304, calculating the difference value between the voltage positive sequence components corresponding to the target detection points before and after the line fault, and obtaining the voltage positive sequence variation.

Step S306, the ratio between the voltage positive sequence variation and the current positive sequence variation is used as the positive sequence impedance corresponding to the target detection point.

Step S308, calculating the difference value between the current negative sequence components corresponding to the target detection points before and after the line fault, and obtaining the current negative sequence variation.

Step S310, calculating the difference value between the voltage negative sequence components corresponding to the target detection points before and after the line fault, and obtaining the voltage negative sequence variation.

Step S312, the ratio between the voltage negative sequence variation and the current negative sequence variation is used as the negative sequence impedance corresponding to the target detection point.

The positive sequence variation of the current refers to the variation among positive sequence components of the current corresponding to the line faults of the target detection point. The positive voltage sequence variation is the variation between the positive voltage sequence components corresponding to the line faults of the target detection points respectively. The current negative sequence variation is the variation between the current negative sequence components corresponding to the line faults of the target detection point in sequence. The voltage negative sequence variation is the variation between the voltage negative sequence components corresponding to the line faults of the target detection point in sequence.

The computer device calculates a difference between a positive current sequence component corresponding to the target detection point before the line fault and a positive current sequence component corresponding to the target detection point after the line fault, so as to obtain a positive current sequence variation. And calculating the difference value between the voltage positive sequence component corresponding to the target detection point before the line fault and the voltage positive sequence component corresponding to the target detection point after the line fault to obtain the voltage positive sequence variation. And calculating the ratio between the voltage positive sequence variation and the current positive sequence variation to obtain the positive sequence impedance corresponding to the target detection point. And calculating the difference value between the current negative sequence component corresponding to the target detection point before the line fault and the current negative sequence component corresponding to the target detection point after the line fault, and obtaining the current negative sequence variation. And calculating the difference value between the voltage negative sequence component corresponding to the target detection point before the line fault and the voltage negative sequence component corresponding to the target detection point after the line fault, and obtaining the voltage negative sequence variation. And calculating the ratio between the voltage negative sequence variation and the current negative sequence variation to obtain the negative sequence impedance corresponding to the target detection point.

In one embodiment, the positive and negative sequence impedances corresponding to the target detection point may be calculated by the following formula:

wherein,,and->Respectively positive sequence impedance and negative sequence impedance corresponding to the target detection point，/>Respectively corresponding to a voltage positive sequence component, a voltage negative sequence component, a current positive sequence component and a current negative sequence component of the target detection point P after the line fault>The voltage positive sequence component, the voltage negative sequence component, the current positive sequence component and the current negative sequence component corresponding to the target detection point P before the line fault are respectively adopted.

In the above embodiment, the ratio between the current positive sequence variation and the voltage positive sequence variation corresponding to the target detection point is taken as the positive sequence impedance corresponding to the target detection point, and the ratio between the current negative sequence variation and the voltage negative sequence variation corresponding to the target detection point is taken as the negative sequence impedance corresponding to the target detection point. The positive sequence impedance and the negative sequence impedance corresponding to the target detection point can be obtained rapidly and accurately, and the efficiency and the accuracy of fault direction identification are improved.

In one embodiment, the line anomaly direction identification method further includes:

when a single-phase earth fault is detected to occur through a fault phase selection element in a sending-out line of the power generation equipment, acquiring a voltage amplitude set corresponding to a target detection point on the sending-out line after the line fault, and determining a target fault area to which the target fault point in the sending-out line belongs based on the voltage amplitude set; and when the target fault area is an outlet area corresponding to the outgoing line, taking the outgoing line as a failed line of the power generation equipment.

The sending-out line of the power generation equipment refers to a power transmission line of the power generation equipment connected to an external power grid, namely a power supply line of the power generation equipment for transmitting power to the external power grid.

The phase selection element refers to an identification element for identifying a fault type when a circuit fails, and the single-phase earth fault is one of the fault types.

The voltage amplitude set refers to a set comprising voltage amplitudes of each phase in the outgoing line, namely a set comprising voltage amplitudes corresponding to the phase a, the phase B and the phase C respectively. When the outgoing line operates normally, the voltage amplitude values of all phases are equal, and when a single-phase earth fault occurs in the outgoing line, the corresponding voltage amplitude value with the fault is reduced.

The target fault area is the area where the target fault point is located on the outgoing line. The outlet area refers to an area near a line outlet of a power supply line of the power generation device connected to an external power grid, that is, a part of the line near one side of the power generation device. The non-outlet region refers to a region other than a region near the outlet of the line, i.e., a portion of the line away from the power generation device, on the power supply line to which the power generation device is connected to the external power grid.

When the fault type corresponding to the outgoing line is identified as a single-phase earth fault by the fault phase selection element, the computer device needs to further determine whether the target fault point occurs in an outlet area corresponding to the outgoing line, so as to acquire a set of voltage amplitudes corresponding to the target detection point on the outgoing line after the line fault. Specifically, after the line fault of the target detection point is obtained, voltage amplitude values corresponding to each phase are obtained, and a voltage amplitude value set is obtained. And acquiring fault area judgment conditions, and determining a target fault area corresponding to the target fault point based on the voltage amplitude set corresponding to the target detection point after the line faults and the fault area judgment conditions. For example, the fault region determination condition may be that, when differences between voltage amplitudes corresponding to respective phases in the voltage amplitude set are smaller than or equal to a preset threshold, the target fault region corresponding to the target fault point is a non-exit region, and when there is a difference between voltage amplitudes corresponding to at least two phases in the voltage amplitude set that is greater than the preset threshold, the target fault region corresponding to the target fault point is an exit region.

If the target fault area corresponding to the target fault point is the outlet area corresponding to the outgoing line, it is indicated that a single-phase ground fault occurs in the outlet area corresponding to the outgoing line, and at this time, it is necessary to further determine the fault direction of the target fault point with respect to the target detection point, and reduce the specific position of the target fault point on the outlet area corresponding to the outgoing line, so that the outgoing line is used as a failed line corresponding to the power generation device, and the fault direction of the failed line is further identified.

In the above embodiment, when it is determined that the fault occurring on the outgoing line of the power generation device is a single-phase earth fault, the target fault area corresponding to the target fault point in the outgoing line can be rapidly and accurately determined through the voltage amplitude set corresponding to the target detection point after the line fault, so that the efficiency and accuracy of fault direction identification are improved.

In one embodiment, determining a target fault region to which a target fault point in a outgoing line belongs based on a set of voltage magnitudes includes:

acquiring a preset voltage threshold corresponding to a target detection point; when the voltage amplitudes respectively corresponding to all the phase sub-lines in the voltage amplitude set are larger than or equal to a preset voltage threshold value, determining a fault area corresponding to a target fault point in the sending line as a non-outlet area corresponding to the sending line; when at least one voltage amplitude value in the voltage amplitude values corresponding to the sub-lines of each phase in the voltage amplitude value set is smaller than a preset voltage threshold value, determining a fault area corresponding to a target fault point in the sending line as an outlet area corresponding to the sending line.

The preset voltage threshold is a preset voltage amplitude, and is used for judging whether faults generated by each phase of sub-line are located in an outlet area of the sending-out line. The sub-line refers to any one phase line among three-phase power transmission lines included in the outgoing line.

For example, since the target detection point is located in the exit area of the outgoing line, and the voltage amplitudes of the phases are equal when the outgoing line is in normal operation, when a single-phase earth fault occurs in the outgoing line, a corresponding voltage amplitude of the fault is reduced. Therefore, when the target fault point with single-phase earth fault is located in the outlet area of the outgoing line, it is indicated that the outlet area of the outgoing line is faulty, and for the voltage amplitude set corresponding to the target detection point after the line fault, a corresponding voltage amplitude with the fault is reduced and is smaller than the preset voltage threshold. When the target fault point with single-phase earth fault is located in the non-outlet area of the outgoing line, for the voltage amplitude set corresponding to the target detection point after the line fault, the corresponding voltage amplitude with fault is reduced but greater than or equal to the preset voltage threshold.

In order to determine a target fault area corresponding to a target fault point, the computer equipment acquires a preset voltage threshold corresponding to the target fault point. Comparing the voltage amplitude value corresponding to each phase of sub-line in the voltage amplitude value set with a preset voltage threshold value, and when the voltage amplitude value corresponding to each phase of sub-line in the voltage amplitude value set is larger than or equal to the preset voltage threshold value, indicating that the outlet area of the sending line is not abnormal, namely the target fault node is positioned in the non-outlet area corresponding to the sending line. When at least one voltage amplitude value in the voltage amplitude values corresponding to the sub-circuits of each phase in the voltage amplitude value set is smaller than a preset voltage threshold value, the fault occurs in the outlet area of the sending circuit, namely the target fault point in the sending circuit is located in the outlet area corresponding to the sending circuit.

In the above embodiment, when it is determined that a single-phase ground fault occurs in the outgoing line of the power generation device, the voltage amplitude set and the preset voltage threshold corresponding to the target detection point are obtained, and the target fault area corresponding to the target fault point in the outgoing line can be rapidly and accurately determined by comparing the voltage amplitude set with the preset voltage threshold, so that the efficiency of determining the fault area can be effectively improved, and the efficiency of identifying the line fault direction is improved.

In one embodiment, determining a fault direction of a target fault point in a faulty line for a target detection point based on a difference between positive sequence impedance and negative sequence impedance includes:

when the difference between the positive sequence impedance and the negative sequence impedance is larger than a preset difference value, determining that the fault direction of a target fault point in the faulty line aiming at the target detection point is a positive fault; when the difference between the positive sequence impedance and the negative sequence impedance is smaller than or equal to a preset difference value, determining that the fault direction of the target fault point in the failed line aiming at the target detection point is reverse fault.

The preset difference value is an absolute value of a difference value between a preset positive sequence impedance and a preset negative sequence impedance, and is used for judging a fault direction of a target fault point in the failed line aiming at the target detection point. The forward fault refers to the external grid side of the target fault point, i.e. the target fault point is located on the line between the target fault point and the external grid. The reverse fault refers to the power generation equipment side of the target fault point located at the target detection point, that is, the target fault point is located on the line between the target detection point and the power generation equipment.

The computer device may be configured to determine the absolute value of the difference between the positive sequence impedance and the negative sequence impedance as a difference between the positive sequence impedance and the negative sequence impedance, and determine that the target fault point is on the line between the target detection point and the external grid, i.e. the target fault point is a positive fault with respect to the fault direction of the target detection point, when the difference between the positive sequence impedance and the negative sequence impedance is greater than a preset difference. When the target fault point is a positive fault, the voltage and the current on the outlet area of the faulty line are provided by the power generation equipment, and when the power generation equipment is in fault, the negative sequence current is restrained due to the self control strategy, so that the negative sequence impedance is changed, the difference between the positive sequence impedance and the negative sequence impedance is increased, and in addition, when the power generation equipment is in serious fault on the line, the generated crowbar protection action can cause the positive sequence impedance and the negative sequence impedance to be not approximately equal. Therefore, when the difference between the positive sequence impedance and the negative sequence impedance is larger than the preset difference, it can be determined that the failure direction of the target failure point with respect to the target detection point is a positive failure.

When the difference between the positive sequence impedance and the negative sequence impedance is smaller than or equal to a preset difference value, the target fault point is indicated to be positioned on a line between the target detection point and the power generation equipment, namely the fault direction of the target fault point aiming at the target detection point is reverse fault. Since the voltage and current on the outlet area of the failed line are provided by the external grid when the target fault point is a reverse fault, and the positive sequence impedance and the negative sequence impedance corresponding to the external grid are still approximately equal when the line fails. Therefore, when the difference between the positive sequence impedance and the negative sequence impedance is less than or equal to the preset difference, it can be determined that the failure direction of the target failure point with respect to the target detection point is a reverse failure.

In the above embodiment, the positive sequence impedance and the negative sequence impedance corresponding to the line fault of the power generation device are not approximately equal any more, but the positive sequence impedance and the negative sequence impedance corresponding to the line fault of the external power grid are still approximately equal, so that the fault direction of the target fault point to the target detection point can be rapidly and accurately determined based on the difference between the positive sequence impedance and the negative sequence impedance corresponding to the target detection point, and the accuracy and the efficiency of line fault direction identification can be effectively improved.

In one embodiment, the line fault direction identification method further comprises:

when the fault direction of the target fault point in the failed line to the target detection point is a positive fault, the protection element on the target detection point is started.

The protection element is a component which is arranged on the target detection point and used for protecting the power supply line.

When the computer equipment determines that the fault direction of the target fault point in the faulty line for the target detection point is a forward fault, the computer equipment indicates that the target fault point is within the protection range of the protection element at the target detection point, at this time, a protection starting instruction is sent to the protection element at the target detection point, and after the protection element at the target detection point receives the protection starting instruction, the line protection action is started.

In the above embodiment, when the fault direction of the target fault point to the target detection point is determined to be a forward fault, the protection element on the target detection point is started in time, so that the loss caused by the line fault can be effectively reduced.

In a specific embodiment, the line fault direction identification method can be applied to a power system, and the line fault direction is identified when the doubly-fed wind power generator has single-phase earth fault in the near-outlet area. As shown in fig. 4, the line fault direction identification method includes the steps of:

1. collecting voltage and current sampling values of doubly-fed wind generator outlet protection position

As shown in fig. 5, the topology diagram of the power system is that the doubly-fed wind generator (DFIG, doubly fed Induction Generator) is connected to the external power grid system through the outgoing line, M is a side of the outgoing line close to the doubly-fed wind generator, N is a side of the outgoing line close to the external power grid system, P is a directional element located on the outgoing line M side, and faults F1 and F2 occur in the forward direction and the reverse direction of the directional element P, respectively. The area close to the direction element P is defined as an outlet area on the side of the feeding line M, and the area far from the direction element P is defined as a non-outlet area on the side of the feeding line M. The power system collects the voltage positive sequence component, the current positive sequence component, the voltage negative sequence component and the current negative sequence component of the installation position of the protection device in real time, wherein the installation position of the protection device is the position of the direction element P, and the direction element P is a part of the protection device.

2. When the line protection is started, judging the line fault type

When the protection device on the side of the outgoing line M is started, the power system determines the fault type through the fault phase selection element, and when the fault type is determined to be a metallic unidirectional grounding fault, whether the installation position of the protection device meets the outlet near zone fault criterion or not is detected. And if the outlet near zone fault criterion is met, indicating that the outlet area of the outgoing line has a metallic unidirectional ground fault.

The power system may determine whether a fault occurs in an outlet area of the outgoing line according to a near zone fault criterion that determines that the fault occurs in an outlet area of the outgoing line M side when at least one of the voltage magnitudes of the phases at which the protection device is installed is less than a low voltage threshold:

U _P& <U _lowvoltage

wherein U is _P& For the voltage amplitude of each phase at the outlet protection,&taking A phase, B phase or C phase, U _lowvoltage Is a low voltage threshold (i.e., a preset voltage threshold).

3. Identifying the direction of the fault as either a reverse fault or a forward fault

When a metallic unidirectional grounding fault occurs near an outlet area on the side of the delivery line M, the electric power system acquisition and protection device is installed at a position corresponding to a voltage positive sequence component, a current positive sequence component, a voltage negative sequence component and a current negative sequence component after the fault. The power system obtains the positive sequence variation measuring impedance (namely positive sequence impedance) corresponding to the installation position of the protection device based on the difference between the voltage positive sequence components and the current positive sequence components which are respectively corresponding to the installation position of the protection device before and after the fault, and obtains the negative sequence variation measuring impedance (namely negative sequence impedance) corresponding to the installation position of the protection device based on the difference between the voltage negative sequence components and the current negative sequence components which are respectively corresponding to the installation position of the protection device before and after the fault.

The power system can calculate the corresponding positive sequence variation measuring impedance and negative sequence variation measuring impedance of the installation part of the protection device through the following formulas:

the power system further judges whether the line fault is a forward fault according to a positive and negative sequence variation impedance differential criterion, wherein the positive and negative sequence variation impedance differential criterion is as follows:

wherein Z is _d.set The value is set for the variation impedance difference (i.e., the preset difference value).

When the absolute value of the difference between the positive sequence variation measured impedance and the negative sequence variation measured impedance is larger than the variation impedance difference setting value, the power system determines that the line fault is a forward fault, and otherwise, the line fault is a reverse fault.

In the above embodiment, since the fault characteristics of the doubly-fed wind generator are affected by the fault ride-through control strategy and the crowbar protection action condition, the difference between the fault characteristics of the doubly-fed wind generator and the power supply fault characteristics of the traditional synchronous generator is large, especially when the doubly-fed wind generator is in short circuit fault at the near zone of the outlet of the line, the traditional direction element constructed based on the power supply system of the synchronous generator cannot accurately judge the fault direction, so that the protection is refused or misplaced. Therefore, when the doubly-fed wind power generator has metallic single-phase earth faults at the outlet of the outlet line, positive and negative sequence impedance of the doubly-fed wind power generator is unequal due to a fault ride-through control strategy and crowbar protection action, a positive and negative sequence variation impedance differential criterion is obtained, and the outlet fault direction of the doubly-fed wind power generator is judged based on the positive and negative sequence variation impedance differential criterion. When the metallic single-phase grounding fault occurs at the outlet of the feed-out line of the doubly-fed wind power generator, the fault direction can still be accurately identified.

It should be understood that, although the steps in the flowcharts related to the embodiments described above are sequentially shown as indicated by arrows, these steps are not necessarily sequentially performed in the order indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least some of the steps in the flowcharts described in the above embodiments may include a plurality of steps or a plurality of stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of the steps or stages is not necessarily performed sequentially, but may be performed alternately or alternately with at least some of the other steps or stages.

Based on the same inventive concept, the embodiment of the application also provides a line fault direction identification device for realizing the above related line fault direction identification method. The implementation of the solution provided by the device is similar to the implementation described in the above method, so the specific limitation in the embodiments of the line fault direction identifying device or devices provided below may be referred to the limitation of the line fault direction identifying method hereinabove, and will not be repeated herein.

In one embodiment, as shown in fig. 6, there is provided a line fault direction recognition apparatus, including: a component set acquisition module 602, an impedance determination module 604, and a fault direction determination module 606, wherein:

the component set acquisition module 602 is configured to acquire, for a failed line of the power generation device, current and voltage component sets respectively corresponding to a target detection point in the failed line before and after a line fault; the fault of the failed line is a single-phase ground fault of the line outlet area, and the current-voltage component set comprises a current positive sequence component, a current negative sequence component, a voltage positive sequence component and a voltage negative sequence component.

The impedance determining module 604 is configured to obtain positive sequence impedance corresponding to the target detection point based on a difference between positive sequence components of current respectively corresponding to the target detection point before and after the line fault and a difference between positive sequence components of voltage respectively corresponding to the target detection point before and after the line fault, and obtain negative sequence impedance corresponding to the target detection point based on a difference between negative sequence components of current respectively corresponding to the target detection point before and after the line fault and a difference between negative sequence components of voltage respectively corresponding to the target detection point before and after the line fault.

The fault direction determining module 606 is configured to determine a fault direction of a target fault point in the faulty line with respect to the target detection point based on a difference between the positive sequence impedance and the negative sequence impedance.

In one embodiment, the impedance determination module 604 is further configured to:

calculating the difference value between the current positive sequence components corresponding to the target detection points before and after the line fault to obtain the current positive sequence variation; calculating the difference value between the voltage positive sequence components corresponding to the target detection points before and after the line fault to obtain the voltage positive sequence variation; taking the ratio between the voltage positive sequence variation and the current positive sequence variation as the positive sequence impedance corresponding to the target detection point; calculating the difference value between the current negative sequence components corresponding to the target detection points before and after the line fault to obtain the current negative sequence variation; calculating the difference value between the voltage negative sequence components corresponding to the target detection points before and after the line fault to obtain the voltage negative sequence variation; and taking the ratio between the voltage negative sequence variation and the current negative sequence variation as the negative sequence impedance corresponding to the target detection point.

In one embodiment, the fault direction determination module 606 is further to:

In one embodiment, as shown in fig. 7, the line fault direction identifying apparatus further includes:

the failure detection circuit determining module 702 is configured to obtain a voltage amplitude set corresponding to a target detection point on a sending line after a line fault when a single-phase earth fault is detected to occur through a fault phase selection element in the sending line of the power generating device, and determine a target fault area to which the target fault point in the sending line belongs based on the voltage amplitude set; and when the target fault area is an outlet area corresponding to the outgoing line, taking the outgoing line as a failed line of the power generation equipment.

The forward fault handling module 704 is configured to activate the protection element at the target detection point when the fault direction of the target fault point in the failed line with respect to the target detection point is a forward fault.

In one embodiment, the failed circuit determination module 702 is further to:

According to the line fault direction identification device, the positive sequence impedance and the negative sequence impedance corresponding to the target detection point are calculated based on the voltage and current component sets respectively corresponding to the front and the back of the line fault. Because the differences between the positive sequence impedance and the negative sequence impedance which correspond to different line fault directions are obviously different, the fault direction corresponding to the target fault point aiming at the target detection point can be rapidly and accurately determined based on the differences between the positive sequence impedance and the negative sequence impedance, the line fault direction identification efficiency is improved, and meanwhile, the line fault direction identification accuracy is improved.

The above-described respective modules in the line fault direction identifying apparatus may be implemented in whole or in part by software, hardware, and a combination thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules.

In one embodiment, a computer device is provided, which may be a server, and the internal structure of which may be as shown in fig. 8. The computer device includes a processor, a memory, an Input/Output interface (I/O) and a communication interface. The processor, the memory and the input/output interface are connected through a system bus, and the communication interface is connected to the system bus through the input/output interface. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The database of the computer device is used for storing data such as a current-voltage component set, positive sequence impedance, negative sequence impedance and the like. The input/output interface of the computer device is used to exchange information between the processor and the external device. The communication interface of the computer device is used for communicating with an external terminal through a network connection. The computer program is executed by a processor to implement a line fault direction identification method.

In one embodiment, a computer device is provided, which may be a terminal, and the internal structure thereof may be as shown in fig. 9. The computer device includes a processor, a memory, an input/output interface, a communication interface, a display unit, and an input means. The processor, the memory and the input/output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input/output interface. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input/output interface of the computer device is used to exchange information between the processor and the external device. The communication interface of the computer device is used for carrying out wired or wireless communication with an external terminal, and the wireless mode can be realized through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. The computer program is executed by a processor to implement a line fault direction identification method. The display unit of the computer device is used for forming a visual picture, and can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer equipment can be a touch layer covered on the display screen, can also be a key, a track ball or a touch pad arranged on the shell of the computer equipment, and can also be an external keyboard, a touch pad or a mouse and the like.

It will be appreciated by persons skilled in the art that the structures shown in fig. 8 and 9 are merely block diagrams of portions of structures associated with aspects of the application and are not intended to limit the computer apparatus to which aspects of the application may be applied, and that a particular computer apparatus may include more or less components than those shown, or may combine some of the components, or have a different arrangement of components.

In one embodiment, a computer device is provided, comprising a memory and a processor, the memory having stored therein a computer program, the processor implementing the steps of the method embodiments described above when the computer program is executed.

In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored which, when executed by a processor, implements the steps of the method embodiments described above.

In one embodiment, a computer program product or computer program is provided that includes computer instructions stored in a computer readable storage medium. The processor of the computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device performs the steps in the above-described method embodiments.

It should be noted that, the user information (including but not limited to user equipment information, user personal information, etc.) and the data (including but not limited to data for analysis, stored data, presented data, etc.) related to the present application are information and data authorized by the user or sufficiently authorized by each party, and the collection, use and processing of the related data need to comply with the related laws and regulations and standards of the related country and region.

Those skilled in the art will appreciate that implementing all or part of the above described methods may be accomplished by way of a computer program stored on a non-transitory computer readable storage medium, which when executed, may comprise the steps of the embodiments of the methods described above. Any reference to memory, database, or other medium used in embodiments provided herein may include at least one of non-volatile and volatile memory. The nonvolatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical Memory, high density embedded nonvolatile Memory, resistive random access Memory (ReRAM), magnetic random access Memory (Magnetoresistive Random Access Memory, MRAM), ferroelectric Memory (Ferroelectric Random Access Memory, FRAM), phase change Memory (Phase Change Memory, PCM), graphene Memory, and the like. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, and the like. By way of illustration, and not limitation, RAM can be in the form of a variety of forms, such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), and the like. The databases referred to in the embodiments provided herein may include at least one of a relational database and a non-relational database. The non-relational database may include, but is not limited to, a blockchain-based distributed database, and the like. The processor referred to in the embodiments provided in the present application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, or the like, but is not limited thereto.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The foregoing examples illustrate only a few embodiments of the application and are described in detail herein without thereby limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of the application should be assessed as that of the appended claims.

Claims

1. A method for identifying a direction of a line fault, the method comprising:

aiming at a failed line of power generation equipment, acquiring current and voltage component sets respectively corresponding to target detection points in the failed line before and after line faults; the fault of the failed line is a single-phase earth fault of a line outlet area, and the current-voltage component set comprises a current positive sequence component, a current negative sequence component, a voltage positive sequence component and a voltage negative sequence component;

and determining a fault direction of a target fault point in the failed line for the target detection point based on the difference between the positive sequence impedance and the negative sequence impedance.

2. The method according to claim 1, wherein the obtaining positive sequence impedance corresponding to the target detection point based on the difference between positive sequence components of current respectively corresponding to the target detection point before and after the line fault and the difference between positive sequence components of voltage respectively corresponding to the target detection point before and after the line fault, and obtaining negative sequence impedance corresponding to the target detection point based on the difference between negative sequence components of current respectively corresponding to the target detection point before and after the line fault and the difference between negative sequence components of voltage respectively corresponding to the target detection point before and after the line fault, includes:

Calculating the difference value between the current positive sequence components respectively corresponding to the target detection points before and after the line fault to obtain the current positive sequence variation;

calculating the difference value between the voltage positive sequence components corresponding to the target detection points before and after the line fault to obtain the voltage positive sequence variation;

taking the ratio between the voltage positive sequence variation and the current positive sequence variation as the positive sequence impedance corresponding to the target detection point;

calculating the difference value between the current negative sequence components corresponding to the target detection points before and after the line fault to obtain the current negative sequence variation;

calculating the difference value between the voltage negative sequence components corresponding to the target detection points before and after the line fault to obtain the voltage negative sequence variation;

and taking the ratio between the voltage negative sequence variation and the current negative sequence variation as the negative sequence impedance corresponding to the target detection point.

3. The method according to claim 1, wherein the method further comprises:

when a single-phase earth fault is detected to occur through a fault phase selection element in a sending-out line of the power generation equipment, acquiring a voltage amplitude set corresponding to a target detection point on the sending-out line after the line fault, and determining a target fault area to which the target fault point in the sending-out line belongs based on the voltage amplitude set;

And when the target fault area is an outlet area corresponding to the sending-out line, taking the sending-out line as the failed line of the power generation equipment.

4. A method according to claim 3, wherein said determining a target fault region to which a target fault point in the outgoing line belongs based on the set of voltage magnitudes comprises:

acquiring a preset voltage threshold corresponding to the target detection point;

when the voltage amplitudes respectively corresponding to all the phase sub-lines in the voltage amplitude set are larger than or equal to the preset voltage threshold value, determining a fault area corresponding to a target fault point in the sending line as a non-outlet area corresponding to the sending line;

when at least one voltage amplitude value in the voltage amplitude values respectively corresponding to all the phase sub-lines in the voltage amplitude value set is smaller than the preset voltage threshold value, determining a fault area corresponding to a target fault point in the sending line as an outlet area corresponding to the sending line.

5. The method of claim 1, wherein the determining a fault direction of a target fault point in the failed line for the target detection point based on a difference between the positive sequence impedance and the negative sequence impedance comprises:

When the difference between the positive sequence impedance and the negative sequence impedance is larger than a preset difference value, determining that a fault direction of a target fault point in the failed line aiming at the target detection point is a positive fault;

and when the difference between the positive sequence impedance and the negative sequence impedance is smaller than or equal to the preset difference value, determining that a fault direction of a target fault point in the failed line aiming at the target detection point is reverse fault.

6. The method according to claim 1, wherein the method further comprises:

and when the fault direction of the target fault point in the failed line aiming at the target detection point is a positive fault, starting the protection element on the target detection point.

7. A line fault direction identification device, the device comprising:

the component set acquisition module is used for acquiring current and voltage component sets respectively corresponding to target detection points in a failed line of the power generation equipment before and after the line failure; the fault of the failed line is a single-phase earth fault of a line outlet area, and the current-voltage component set comprises a current positive sequence component, a current negative sequence component, a voltage positive sequence component and a voltage negative sequence component;

The impedance determining module is used for obtaining positive sequence impedance corresponding to the target detection point based on the difference between current positive sequence components respectively corresponding to the target detection point before and after the line fault and the difference between voltage positive sequence components respectively corresponding to the target detection point before and after the line fault, and obtaining negative sequence impedance corresponding to the target detection point based on the difference between current negative sequence components respectively corresponding to the target detection point before and after the line fault and the difference between voltage negative sequence components respectively corresponding to the target detection point before and after the line fault;

and the fault direction determining module is used for determining the fault direction of a target fault point in the failed line aiming at the target detection point based on the difference between the positive sequence impedance and the negative sequence impedance.

8. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method of any of claims 1 to 6 when the computer program is executed.

9. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 1 to 6.

10. A computer program product comprising a computer program, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 1 to 6.