A method and system for fault direction determination in new energy transmission lines

Abstract

This invention discloses a fault direction discrimination method and system adapted to new energy transmission lines, belonging to the field of power system relay protection. It acquires the measured current values ​​of the local and opposite sides of the line in real time, performs filtering, and calculates the real-time changes in the current of the local and opposite sides of the line within a fixed time window based on the real-time sampling rate. This is compared with the calculated value at the same position within the previous cycle to distinguish between normal operation and fault status of the AC system. By comparing the real-time calculated and stored current values ​​of the local and opposite sides of the line in the data window, the maximum discrete value of the linear distance between the two current sequences is obtained, and this value is compared with a preset threshold value to confirm faults within and outside the fault zone. The proposed criterion is applicable to various types of new energy transmission line scenarios, exhibiting good speed and reliability performance. It effectively solves the problem of directional misjudgment in phase-type distance protection in new energy scenarios, facilitating reliable fault clearing of new energy transmission lines.

Description

Technical Field

[0001] This invention relates to the field of power system relay protection technology, and in particular to a fault direction determination method and system adapted to new energy transmission lines. Background Technology

[0002] By the end of 2022, renewable energy accounted for 47.3% of my country's installed power capacity, while new energy accounted for 29.6%. High proportions of new energy and power electronic equipment are important technical characteristics of my country's new power system.

[0003] Currently, phase-comparison distance elements are widely used in relay protection systems. However, with the large-scale integration of new energy power sources, the equivalent internal impedance of new energy power sources will change during system faults, which greatly affects the applicability of phase-comparison distance elements for new energy transmission lines. The weak feedback and system impedance instability of wind power systems make distance protection based on power frequency variation unsuitable for wind power integration systems. The high harmonics and frequency deviation characteristics of wind power systems cause phasor extraction problems in power frequency distance protection, resulting in protection failure or false tripping, which seriously endangers the safe and stable operation of the power system. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention is proposed.

[0005] Therefore, the present invention provides a fault direction discrimination method adapted to new energy transmission lines, which can solve the problem of malfunction or failure of phase-comparison distance elements in the prior art.

[0006] To address the aforementioned technical problems, this invention provides the following technical solution: a fault direction discrimination method adapted to new energy transmission lines, comprising: real-time acquisition of measured current values ​​on the local side and the opposite side of the line, and low-pass filter processing; calculation of the real-time change rate of current on the local side and the opposite side of the line within a fixed time window based on the real-time sampling rate; comparison of the real-time change rate with the calculated value at the same position one cycle before the wave front to distinguish between normal operation and fault state of the AC system; after confirming the fault, obtaining the linear distance discrete value of the two current sequences by comparing the real-time calculated amount and the memory amount of the current on the local side and the opposite side of the line in the data window; obtaining the maximum discrete value of the linear distance between the two current sequences and comparing it with a pre-set threshold value to distinguish between faults within and outside the fault zone.

[0007] As a preferred embodiment of the fault direction determination method for new energy transmission lines described in this invention, wherein the calculation of the real-time rate of change of the local current of the line is expressed as follows:

[0008]

[0009] Among them, Im (t0+T w ) indicates that the M side of the line is t0+T w Current at time, I m (t0) represents the current on the M side of the line at time t0, T w It is a pre-set fixed time window.

[0010] As a preferred embodiment of the fault direction determination method for new energy transmission lines described in this invention, wherein: the real-time rate of change of the current on the opposite side of the line, I' n (t0+T w ) is represented as,

[0011]

[0012] Among them, I n (t0+T w ) represents the line N side t0+T w Current at time, I n (t0) represents the current on the N side at time t0.

[0013] As a preferred embodiment of the fault direction discrimination method for new energy transmission lines described in this invention, the comparison and differentiation includes: t0+T on the line side w Real-time rate of change of current I' m (t0+T w ), the opposite side of the line t0+T w Real-time rate of change of current I' n (t0+T w ), respectively with the wavefront line on the same side t0+T, one week later. w -T α Real-time rate of change of current I' m (t0+T w -T α ), the opposite side of the line t0+T w -T α Real-time rate of change of current I' n (t0+T w -T α By comparing the two, the normal operation and fault states of the AC system can be distinguished. α This indicates the number of sampling points per cycle.

[0014] As a preferred embodiment of the fault direction discrimination method for new energy transmission lines described in this invention, the method for obtaining the linear distance discrete value of two current sequences is expressed as follows: the real-time current change rate I' at time t0 is defined as... m (t0) to t0+T β Real-time rate of change of current I' m(t0+T β Let ) be a point set DIS1 in Euclidean space, and define t0-T. α Real-time rate of change of current I' m (t0-T α ) to t0+T β -T α Real-time rate of change of current I' m (t0+T β -T α Let DIS2 be the point set in Euclidean space. Calculate t0+T on the local side of the line using the formula. β The discrete values ​​of the linear distance between the current sequence at time points one and two.

[0015] DISM1(t0+T β )=h(DIS1,DIS2)=max A∈DIS1 min B∈DIS2 ||AB||

[0016] Here, h(A,B) means that we first take the point bj in set B that is closest to set A, then calculate the distance between each point ai in set A and bj, sort the distances, and then take the largest distance as the value of h(A,B). ||AB|| represents the Euclidean distance between A and B. A∈DIS1 A is a point in the point set DIS1, and the same applies to B.

[0017] Calculate t0+T on this side of the line using the formula. β Discrete linear distance values ​​between the current sequence at time two and one.

[0018] DISM2(t0+T β )=h(DIS2,DIS1)=max A∈DIS2 min B∈DIS1 ||AB||

[0019] The linear distance discrete values ​​DISN1 and DISN2, T of the two current sequences on the opposite side of the line are obtained. β The choice should satisfy T β >T w The sampling rate and time window length of the relay protection device can be selected comprehensively.

[0020] The linear distance discrete value of the two current sequences on the opposite side of the line is expressed as follows: the real-time rate of change of current at time t0 is defined as I'. n (t0) to t0+T β Real-time rate of change of current I' n (t0+T β Let ) be the point set DIS3 in Euclidean space, and define t0-T. α Real-time rate of change of current I'n (t0 - T α ) to t0 + T β -T α The real - time change rate of current I’ n (t0 + T β -T α ) is the point set DIS4 in Euclidean space. Calculate the discrete value of the linear distance from the current sequence one to two at the time t0 + T on the opposite side of the line using the formula, β and the discrete value of the linear distance from the current sequence two to one at the time t0 + T on the opposite side of the line,

[0021]

[0022] Calculate the discrete value of the linear distance from the current sequence two to one at the time t0 + T on the opposite side of the line using the formula, β and the discrete value of the linear distance from the current sequence two to one at the time t0 + T on the opposite side of the line,

[0023] [[ID=​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​The DIS_set continuously satisfies the time T. set If the fault occurs on the opposite side of the output line, then a fault has occurred; otherwise, T will be used. set Zeroing confirms that no fault has occurred inside the transmission line on the opposite side; T set The reliability and operating speed of the relay protection should be considered when setting it;

[0030] The maximum discrete value of the linear distance between the two opposite current sequences is expressed as follows:

[0031] DISN(t0+T β ) = max(DISN1(t0+T β ),DISN2(t0+T β ))

[0032] Calculate t0+T on the opposite side of the line β The maximum discrete value of the linear distance between two current sequences at time t0+T is DISN(t0+T). β It is compared with the preset threshold value DIS_set.

[0033] Another objective of this invention is to provide a fault direction discrimination system adapted to new energy transmission lines. The data acquisition and preprocessing module improves data accuracy by acquiring and preprocessing current data in real time, effectively removing high-frequency noise through a low-pass filter, and the rate of change calculation module monitors the current rate of change in real time, rapidly responding to changes in system state and promptly identifying potential problems, providing crucial information for fault early warning. The fault identification module accurately distinguishes between normal operation and fault states of the AC system, improving fault detection accuracy and shortening fault response time. The distance calculation module provides a clearer characterization of fault features by calculating the linear distance discrete values ​​of the current sequence, aiding in precise fault location. The discrimination and decision module accurately determines the fault direction and provides decision support, ensuring the timeliness and effectiveness of fault handling, thereby reducing the impact of the fault on the entire system.

[0034] As a preferred embodiment of the fault direction discrimination system adapted to new energy transmission lines according to the present invention, it includes: a data acquisition and preprocessing module, a rate of change calculation module, a fault identification module, a distance calculation module, and a discrimination decision module;

[0035] The data acquisition and preprocessing module acquires the measured current values ​​of the line side and the opposite side in real time and performs low-pass filter processing.

[0036] The rate of change calculation module calculates the real-time rate of change of current on the local side and the opposite side of the line within a fixed time window based on the real-time sampling rate.

[0037] The fault identification module compares the real-time rate of change with the calculated value at the same position one week before the wave front to distinguish between the normal operation and fault state of the AC system.

[0038] The distance calculation module, after confirming the fault, obtains the linear distance discrete value of the two current sequences by comparing the real-time calculated and stored quantities of the current on the local side and the opposite side of the line in the data window.

[0039] The decision-making module obtains the maximum discrete value of the linear distance between two current sequences and compares it with a pre-set threshold value to distinguish between faults inside and outside the fault zone.

[0040] A computer device includes a memory and a processor, the memory storing a computer program, characterized in that, when the processor executes the computer program, it implements the steps of a method adapted to any one of the fault direction determination methods for new energy transmission lines.

[0041] A computer-readable storage medium having a computer program stored thereon, characterized in that, when the computer program is executed by a processor, it implements the steps of a method adapted to any one of the fault direction determination methods for new energy transmission lines.

[0042] The beneficial effects of the present invention are as follows: The fault direction discrimination element proposed in this invention has good speed and reliability performance, which can effectively solve the problem of direction misjudgment in the new energy scenario of phase-type distance protection, and is conducive to the reliable isolation of faults in new energy transmission lines. Attached Figure Description

[0043] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a schematic flowchart of a fault direction determination method adapted to a new energy transmission line, provided as an embodiment of the present invention.

[0045] Figure 2 An embodiment of the present invention provides a fault direction discrimination method for new energy power station transmission lines. When a system-side reverse fault occurs on the transmission line of a new energy power station, the phase comparison result at the protection installation location is obtained when the system side adopts phase comparison distance protection.

[0046] Figure 3 This invention provides a method for determining the fault direction of a new energy power station's transmission line, which, according to an embodiment of the invention, yields a curve showing the maximum discrete value of the linear distance calculated using the method of the invention when an external fault occurs on the transmission line of a new energy power station.

[0047] Figure 4This invention provides a method for determining the fault direction of a new energy power station's transmission line, which, according to an embodiment of the invention, yields a curve showing the maximum discrete value of the linear distance calculated using the method of the invention when an internal fault occurs in the transmission line of a new energy power station.

[0048] Figure 5 This is a schematic diagram of a fault direction determination system adapted to a new energy transmission line, provided as an embodiment of the present invention. Detailed Implementation

[0049] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0050] Example 1

[0051] Reference Figures 1-4 This is the first embodiment of the present invention, which provides a fault direction determination method adapted to new energy transmission lines, including:

[0052] It should be noted that the following embodiments use a typical new energy wind farm transmission system as an example for illustration, such as... Figure 1 As shown, a typical wind farm transmission system includes an external system equivalent power source us, a relay protection device on the N side of the transmission line, a relay protection device on the M side of the transmission line, and the wind farm.

[0053] A method for implementing a fault direction discrimination element adapted to new energy transmission scenarios is provided, including:

[0054] S1: Real-time acquisition of measured current values ​​on both the local and opposite sides of the line, and low-pass filter processing;

[0055] S2: Calculate the real-time rate of change of current on the local side and the opposite side of the line within a fixed time window based on the real-time sampling rate.

[0056] Using formula Calculate the real-time rate of change of the line current on this side, I' m (t0+T w Similarly, the real-time rate of change of the current on the opposite side of the line, I' n (t0+T w ) can be obtained through formula Find I m (t0+T w ), I n (t0+T w ) represents the M-side and N-side of the line, t0+Tw Current at time, I m (t0), I n (t0) represents the current on the M-side and N-side of the line at time t0, T w It is a pre-set fixed time window; in this embodiment, Tw = 2ms.

[0057] S3: Compare the real-time rate of change with the calculated value at the same position on the wavefront one week later to distinguish between normal operation and fault status of the AC system.

[0058] t0+T on this side of the line w Real-time rate of change of current I' m (t0+T w ), the opposite side of the line t0+T w Real-time rate of change of current I' n (t0+T w ), respectively with the wavefront line on the same side t0+T, one week later. w -T α Real-time rate of change of current I' m (t0+T w -T α ), the opposite side of the line t0+T w -T α Real-time rate of change of current I' n (t0+T w -T α By comparing these parameters, the normal operation and fault states of the AC system can be distinguished. α In this embodiment, T represents the time length of two cycles. α It takes 40ms.

[0059] It should be noted that, for the line side itself, t0+T on the line side is... w Real-time rate of change of current I' m (t0+T w ) and the wavefront line of the week on this side t0+T w -T α Real-time rate of change of current I' m (t0+T w -T α A comparison is performed using a sliding data window. If, within one cycle, a consecutive quarter cycle shows a discrepancy between the instantaneous values ​​of the two data points, a fault condition is identified, and the protection program is activated. If a consecutive quarter cycle does not show a discrepancy, the count is reset to zero, and the protection program is not activated. The fault condition criteria on the opposite side of the line are the same as above.

[0060] S4: After confirming the fault, obtain the linear distance discrete value of the two current sequences by comparing the real-time calculated and stored quantities of the current on the local side and the opposite side of the line in the data window.

[0061] Define the real-time rate of change of current I' at time t0 m (t0) to t0+T β Real-time rate of change of current I' m (t0+T β Let ) be a point set DIS1 in Euclidean space, and define t0-T. α Real-time rate of change of current I' m (t0-T α ) to t0+T β -T α Real-time rate of change of current I' m (t0+T β -T α Let DIS2 be the point set in Euclidean space. Calculate t0+T on the local side of the line using the formula. β The discrete values ​​of the linear distance between the current sequence at time points one and two.

[0062] DISM1(t0+T β )=h(DIS1,DIS2)=max A∈DIS1 min B∈DIS2 ||AB||

[0063] Calculate t0+T on this side of the line using the formula. β Discrete linear distance values ​​between the current sequence at time two and one.

[0064] DISM2(t0+T β )=h(DIS2,DIS1)=max A∈DIS2 min B∈DIS1 ||AB||

[0065] Similarly, the discrete values ​​of the linear distance DISN1 and DISN2 of the two current sequences on the opposite side of the line can be obtained. β The choice should satisfy T β >T w The selection can be made by comprehensively considering the sampling rate and time window length of the relay protection device. β In this embodiment, 5ms is used.

[0066] S5: Obtain the maximum discrete value of the linear distance between the two current sequences and compare it with the preset threshold value to distinguish between faults inside and outside the zone.

[0067] Using the formula DISM(t0+T) β ) = max(DISM1(t0+T β ),DISM2(t0+T β )) Calculate t0+T on this side of the line βThe maximum discrete value of the linear distance between two current sequences at time T is calculated, and then DISM(t) is compared with a preset threshold value DIS_set. In this embodiment, DIS_set is set to 0.3. If DISM(t) < DIS_set, the threshold value is continuously satisfied for time T. set If a fault occurs within the transmitting line on this side, it is considered that a fault has occurred within the transmitting line on this side; otherwise, it is considered that no fault has occurred within the transmitting line on this side. Similarly, the maximum discrete value DISN(t) of the linear distance between the two current sequences on the opposite side of the line can be obtained. If DISN(t) > DIS_set, the condition is continuously satisfied for time T. set If the fault occurs, it is assumed that a fault has occurred inside the opposite transmission line; otherwise, it is assumed that no fault has occurred inside the opposite transmission line. set The reliability and operating speed of the relay protection should be considered when setting the parameters. In this embodiment, T... set Take 10ms.

[0068] In this embodiment, a fault is set at point F3 outside the transmitting line. When the existing phase-comparison distance protection is used on the system side, the phase comparison result at the protection installation location is as follows: Figure 2 As shown. At this time, the phase comparison result enters the protection action range 45ms after the fault, which will cause the system-side protection to malfunction.

[0069] In this embodiment, a fault is assumed to occur at point F1 inside the transmitting line. The calculation result of the maximum discrete value of the linear distance of the fault direction discrimination element of the present invention is as follows: Figure 3 As shown. At this time, the calculated DISM(t) wave after the fault is always less than the set threshold value of 0.3 for two weeks, and the fault direction discrimination element operates reliably.

[0070] In this embodiment, a fault is assumed to occur at point F2 inside the transmitting line. The calculation result of the maximum discrete value of the linear distance of the fault direction discrimination element of the present invention is as follows: Figure 4 As shown. At this time, the calculated DISM(t) wave after the fault is always greater than the set threshold value of 0.3 for two consecutive weeks, and the fault direction discrimination element does not operate reliably.

[0071] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0072] Example 2

[0073] The second embodiment of the present invention differs from the first embodiment in that:

[0074] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0075] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0076] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0077] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0078] Example 4

[0079] refer to Figure 5 This is the third embodiment of the present invention, which provides a fault direction discrimination system adapted to new energy transmission lines, characterized in that it includes: a data acquisition and preprocessing module, a rate of change calculation module, a fault identification module, a distance calculation module, and a discrimination decision module;

[0080] The data acquisition and preprocessing module acquires the measured current values ​​of the line side and the opposite side in real time and performs low-pass filter processing.

[0081] The rate of change calculation module calculates the real-time rate of change of current on the local side and the opposite side of the line within a fixed time window based on the real-time sampling rate.

[0082] The fault identification module compares the real-time rate of change with the calculated value at the same position one week before the wave front to distinguish between the normal operation and fault state of the AC system.

[0083] The distance calculation module, after confirming the fault, obtains the linear distance discrete value of the two current sequences by comparing the real-time calculated and stored quantities of the current on the local side and the opposite side of the line in the data window.

[0084] The decision-making module obtains the maximum discrete value of the linear distance between two current sequences and compares it with a pre-set threshold value to distinguish between faults inside and outside the fault zone.

[0085] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A fault direction determination method adapted to new energy transmission lines, characterized in that: include, The measured current values ​​on both the local and opposite sides of the line are acquired in real time and processed by a low-pass filter. Based on the real-time sampling rate, calculate the real-time rate of change of current on the local side and the opposite side of the line within a fixed time window; The real-time rate of change is compared with the calculated value at the same position on the wavefront of one week to distinguish between the normal operation and fault state of the AC system. After confirming the fault, the linear distance discrete value of the two current sequences is obtained by comparing the real-time calculated and stored quantities of the current on the local side and the opposite side of the line in the data window. The maximum discrete value of the linear distance between two current sequences is obtained and compared with a pre-set threshold value to distinguish between faults inside and outside the zone.

2. The fault direction determination method for new energy transmission lines as described in claim 1, characterized in that: The real-time rate of change of the local current of the calculated line is expressed as follows: ， in, Indicates the M side of the line Current at any moment Indicates the M side of the line Current at any moment It is a pre-set fixed time window.

3. The fault direction determination method adapted to new energy transmission lines as described in claim 2, characterized in that: The real-time rate of change of the current on the opposite side of the line Represented as, ， in, Indicates the N side of the line Current at any moment Indicates the N side of the line Current at any given moment.

4. The fault direction determination method for new energy transmission lines as described in claim 3, characterized in that: The method of comparing the real-time rate of change with the calculated value at the same position on the wavefront of one cycle to distinguish between normal operation and fault status of the AC system includes comparing the line side... Real-time rate of change of current opposite side of the line Real-time rate of change of current Each week, along with the local side of the wavefront line. Real-time rate of change of current opposite side of the line Real-time rate of change of current By comparing and distinguishing between normal operation and fault conditions of the AC system, It indicates the time of one cycle.

5. The fault direction determination method for new energy transmission lines as described in claim 4, characterized in that: The method for obtaining the discrete value of the linear distance between two current sequences is expressed as follows: [Definition] Real-time rate of change of current to Real-time rate of change of current A set of points in Euclidean space , and define Real-time rate of change of current to Real-time rate of change of current A set of points in Euclidean space Calculate the line on this side using the formula The discrete values ​​of the linear distance between the current sequence at time points one and two. ， Calculate the line on this side using the formula Discrete linear distance values ​​between the current sequence at time two and one. ， in, This is expressed as the Euclidean distance between A and B. Let A be a point in set DIS2. Let B be a point in set DIS1. This means taking the point bj in set DIS1 that is closest to set DIS2, then calculating the distance between each point ai in set DIS2 and bj, sorting the distances, and then taking the largest distance as the nearest value. The value of .

6. The fault direction determination method for new energy transmission lines as described in claim 5, characterized in that: The maximum discrete value of the linear distance between the two current sequences is expressed as follows: ， Calculate the line on this side The maximum discrete value of the linear distance between two current sequences at time t is... With preset threshold value Compare them.

7. The fault direction determination method for new energy transmission lines as described in claim 6, characterized in that: The comparison with a pre-set threshold to distinguish between faults inside and outside the zone includes if Continuous satisfaction time If so, it is considered that a fault has occurred inside the sending line on this side. Continuous satisfaction time It was determined that no fault had occurred inside the sending line on this side; The maximum discrete value of the linear distance between the two current sequences on the opposite side of the line is obtained. ,like Continuous satisfaction time If a fault occurs inside the output line on the opposite side, then... Continuous satisfaction time It was determined that no fault had occurred inside the transmission line on the opposite side. The settings should take into account the reliability and operating speed of the relay protection.

8. A system based on any one of claims 1-7, adapted to a fault direction determination method for new energy transmission lines, characterized in that: It includes a data acquisition and preprocessing module, a rate of change calculation module, a fault identification module, a distance calculation module, and a decision-making module; The data acquisition and preprocessing module acquires the measured current values ​​of the line side and the opposite side in real time and performs low-pass filter processing. The rate of change calculation module calculates the real-time rate of change of current on the local side and the opposite side of the line within a fixed time window based on the real-time sampling rate. The fault identification module compares the real-time rate of change with the calculated value at the same position one week before the wave front to distinguish between the normal operation and fault state of the AC system. The distance calculation module, after confirming the fault, obtains the linear distance discrete value of the two current sequences by comparing the real-time calculated and stored quantities of the current on the local side and the opposite side of the line in the data window. The decision-making module obtains the maximum discrete value of the linear distance between two current sequences and compares it with a pre-set threshold value to distinguish between faults inside and outside the fault zone.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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