Fault direction determination method suitable for new energy outgoing line, and system

Abstract

The present invention belongs to the field of relay protection for power systems. Disclosed are a fault direction determination method suitable for a new energy outgoing line, and a system. The method comprises: acquiring in real time a measured current value of a local end of a line and a measured current value of a remote end of the line; after filtering processing is performed, calculating real-time current change amounts of the local end of the line and the remote end of the line in a fixed time window on the basis of a real-time sampling rate; comparing the real-time current change amounts with calculated values of the same locations within the last cycle, so as to distinguish a normal operation state and a faulty state of an alternating-current system; by means of comparing real-time calculated amounts and memorized amounts of currents at the local end of the line and the remote end of the line in a data window, obtaining the maximum discrete value of the linear distance between two current sequences, and then comparing the maximum discrete value with a preset threshold value, so as to discriminate between an internal fault and an external fault. The proposed criterion is suitable for various types of new energy outgoing line scenarios, rapid response and high reliability are achieved, the directional misjudgment problem of phase-comparison distance protection in a new energy scenario is solved, and the reliable removal of a fault of a new energy outgoing line is facilitated.

Description

Fault direction discrimination method and system suitable for new energy sending-out line TECHNICAL FIELD

[0001] The present application relates to the technical field of power system relay protection, and in particular to a fault direction discrimination method and system suitable for new energy sending-out line. BACKGROUND

[0002] Under the goal of "carbon peak before 2030 and carbon neutrality before 2060", the 9th meeting of the Central Financial Commission (2021.3.15) proposed to build a clean, low-carbon, safe and efficient energy system, control the total amount of fossil energy, strive to improve the utilization efficiency, implement renewable energy replacement action, deepen the reform of the power system, and build a new type of power system with new energy as the main body. By the end of 2022, the installed capacity of renewable energy in China's power grid accounted for 47.3%, and the installed capacity of new energy accounted for 29.6%. High proportion of new energy and high proportion of power electronic equipment are important technical features of China's new power system.

[0003] At present, the phase comparison type distance element is widely used in the relay protection system, but with the access of large-scale new energy power supply, the equivalent internal impedance of the new energy power supply will change during system failure, which has a great influence on the applicability of the phase comparison type distance element of the new energy sending-out line. The weak feedability of the wind power system and the instability of the system impedance make the distance protection based on the power frequency variation not applicable to the wind power system. The high harmonic and frequency offset characteristics of the wind power system cause the problem of phasor extraction of the power frequency quantity distance protection, resulting in protection refusal or misoperation, which seriously endangers the safe and stable operation of the power system.

[0004] SUMMARY

[0005] In view of the problems existing in the prior art, the present application is proposed.

[0006] Therefore, the present application provides a fault direction discrimination method suitable for new energy sending-out line, which can solve the problem of misoperation or refusal of the phase comparison type distance element in the prior art.

[0007] To solve the above technical problems, the present invention provides the following technical solutions: a method for determining the fault direction of a new energy transmission line, comprising: obtaining the measured current values ​​on the line side and the opposite side of the line in real time, and performing low-pass filter processing; calculating the real-time change rate of the current on the line side and the opposite side of the line in a fixed time window according to the real-time sampling rate; comparing the real-time change rate with the calculated value at the same position one cycle ago to distinguish between normal operation and fault status of the AC system; after confirming the fault, obtaining the discrete value of the linear distance between the two current sequences by comparing the real-time calculated value and the stored value of the current on the line side and the opposite side in the data window; obtaining the maximum discrete value of the linear distance between the two current sequences and comparing it with a preset threshold value to determine whether the fault is within the zone or outside the zone.

[0008] As a preferred solution of the method for determining the fault direction of a new energy transmission line according to the present invention, the real-time change rate of the current on the calculated line side is expressed as:

[0009] Among them, I m (t0+T w ) represents line M side t0+T w Current at the moment, 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 solution of the method for determining the fault direction of a new energy transmission line according to the present invention, wherein: the real-time change rate of the current on the opposite side of the line I' n (t0+T w ) is expressed as,

[0011] Among them, I n (t0+T w ) represents line N side t0+T w Current at the moment, I n (t0) represents the current on the N side at time t0.

[0012] As a preferred solution of the method for determining the fault direction of a new energy transmission line according to the present invention, the comparison and distinction includes: w Real-time current change rate I' m (t0+T w ), t0+T on the opposite side of the line w Real-time current change rate I' n (t0+T w ), respectively with the line side t0+T of one wave front w -T α Real-time current change rate I'm (t0+T w -T α ), t0+T on the opposite side of the line w -T α Real-time current change rate I' n (t0+T w -T α ) to distinguish the normal operation and fault state of the AC system, T α Indicates the number of sampling points per cycle.

[0013] As a preferred solution of the fault direction determination method for a new energy transmission line according to the present invention, wherein: the linear distance discrete value of the two current sequences is obtained as follows: the real-time current change rate I' at time t0 is defined as m (t0) to t0+T β Current real-time change rate I' m (t0+T β ) is the point set DIS1 in Euclidean space, and t0-T is defined at the same time α Current real-time change rate I' m (t0-T α ) to t0+T β -T α Current real-time change rate I' m (t0+T β -T α ) is the point set DIS2 in Euclidean space, and the formula is used to calculate the line side t0+T β The linear distance discrete value from the current sequence 1 to 2, DISM1(t0+T β )=h(DIS1,DIS2)=max A∈DIS1 min B∈DIS2 ||AB||

[0014] Among them, h(A,B) means first taking the point bj closest to set A in set B, then calculating the distance between each point ai in set A and bj, sorting the distances, and then taking the value with 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 goes for B.

[0015] Calculate the line side t0+T using the formula β The linear distance discrete value of the current sequence from 2 to 1, DISM2(t0+T β )=h(DIS2,DIS1)=max A∈DIS2 min B∈DIS1 ||AB||

[0016] Obtain the discrete linear distance values ​​DISN1 and DISN2 of the two current sequences on the opposite side of the line, T β The choice should satisfy T β >T w , the sampling rate of the relay protection device and the length of the time window can be comprehensively selected;

[0017] The linear distance discrete value of the two current sequences on the opposite side of the line is expressed as follows: The real-time current change rate I' at time t0 is defined as n (t0) to t0+T β Current real-time change rate I' n (t0+T β ) is the point set DIS3 in Euclidean space, and t0-T is defined at the same time α Current real-time change rate I' n (t0-T α ) to t0+T β -T α Current real-time change rate I' n (t0+T β -T α ) is the point set DIS4 in Euclidean space, and the formula is used to calculate the opposite side of the line t0+T β The linear distance discrete value from moment current sequence one to two,

[0018] Calculate t0+T on the opposite side of the line using the formula β The linear distance discrete value of the current sequence from two to one at a time,

[0019] The discrete linear distance values ​​DISN1 and DISN2 of the two current sequences on the opposite sides of the line are obtained.

[0020] As a preferred solution of the fault direction determination method for a new energy transmission line according to the present invention, wherein: the maximum discrete value of the linear distance between two current sequences is obtained as, DISM(t0+T β )=max(DISM1(t0+T β ),DISM2(t0+T β ))

[0021] Calculate t0+T on the line side β The maximum discrete value of the linear distance between the two current sequences at time t0+T is calculated for the line side. β The maximum discrete value of the linear distance between the two current sequences at time t0+T β ), DISM(t0+T β ) is compared with a preset threshold value DIS_set.

[0022] As a preferred scheme of the fault direction discrimination method suitable for the new energy sending-out line, wherein: the comparison between the discrimination area and the area outside the discrimination area includes that if DISM(t) < DIS_set continuously satisfies time T set , it is considered that the fault occurs inside the local side of the sending-out line, otherwise T set is cleared, and it is determined that the fault does not occur inside the local side of the sending-out line;

[0023] The linear distance maximum discrete value DISN(t) of the two current sequence lines on the opposite side of the line is obtained, if DISN(t0+T β ) > DIS_set continuously satisfies time T set , the fault occurs inside the opposite side of the sending-out line, otherwise T set is cleared, and it is determined that the fault does not occur inside the opposite side of the sending-out line; T set should be set considering the reliability and action speed of the relay protection;

[0024] The linear distance maximum discrete value of the two current sequence lines on the opposite side of the line is obtained, and is expressed as DISN(t0+T β ) = max(DISN1(t0+T β ), DISN2(t0+T β ))

[0025] The linear distance maximum discrete value of the two current sequence lines on the opposite side of the line at t0+T β is calculated, and DISN(t0+T β ) is compared with a preset threshold value DIS_set.

[0026] Another object of the present application is to provide a fault direction discrimination system suitable for a new energy sending-out line. The acquisition and preprocessing module improves the accuracy of data by real-time acquisition and preprocessing of current data, and effectively removes high-frequency noise through a low-pass filter. The change rate calculation module monitors the current change rate in real time, quickly responds to changes in system state, and timely discovers potential problems, providing key information for fault warning. The fault recognition module can accurately distinguish the normal operation and fault state of the alternating current system, improve the accuracy of fault detection, and shorten the fault response time. The distance calculation module calculates the linear distance discrete value of the current sequence, provides a more explicit representation of the fault feature, and helps accurate positioning of the fault. The discrimination and decision module accurately discriminates 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.

[0027] As a preferred scheme of the fault direction discrimination system suitable for the new energy sending-out line, wherein: it includes an acquisition and preprocessing module, a change rate calculation module, a fault recognition module, a distance calculation module, and a discrimination and decision module.

[0028] The acquisition pre-processing module acquires the measured current values of the line local side and the line opposite side in real time and performs low-pass filter processing.

[0029] The rate of change calculation module calculates the real-time change rate of the line local side and the line opposite side current in a fixed time window according to the real-time sampling rate.

[0030] The fault identification module compares the real-time change rate with the calculation value at the same position before a cycle to distinguish the normal operation and the fault state of the alternating current system.

[0031] The distance calculation module obtains the linear distance discrete value of the two current sequences by comparing the real-time calculation amount and the memory amount of the line local side and the line opposite side current in the data window after the fault is confirmed.

[0032] The discrimination decision module obtains the maximum discrete value of the linear distance of the two current sequences and compares it with the pre-set threshold value to discriminate the in-zone fault and the out-of-zone fault.

[0033] A computer device comprises a memory and a processor, the memory stores a computer program, characterized in that the processor implements the steps of any one of the methods of the fault direction discrimination method suitable for a new energy sending line when executing the computer program.

[0034] A computer readable storage medium stores a computer program, characterized in that the computer program implements the steps of any one of the methods of the fault direction discrimination method suitable for a new energy sending line when executed by a processor.

[0035] The fault direction discrimination element has good quick action and reliable performance, and can effectively solve the problem of direction misjudgment of the phase comparison type distance protection in the new energy scene, and is conducive to reliable removal of the new energy sending line fault. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0037] Fig. 1 is a flowchart of a fault direction discrimination method suitable for a new energy sending line according to an embodiment of the present application.

[0038] Fig. 2 is the phase comparison result of the protection installation when the system side adopts the phase comparison type distance protection when the system side reverse fault occurs in the new energy station sending line according to the fault direction discrimination method suitable for the new energy sending line according to an embodiment of the present application.

[0039] FIG3 is a curve of the maximum discrete value of the linear distance calculated by the method of the present invention when an external fault occurs on a new energy station transmission line, according to a method for determining the fault direction of a new energy transmission line provided by an embodiment of the present invention.

[0040] FIG4 is a curve of the maximum discrete value of the linear distance calculated by the method of the present invention when an internal fault occurs in a new energy station transmission line according to a method for determining the fault direction of a new energy transmission line provided by an embodiment of the present invention.

[0041] FIG5 is a flow chart of a fault direction determination system for a new energy transmission line provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0042] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of the present invention.

[0043] Example 1

[0044] 1 to 4 , which are the first embodiment of the present invention, provide a method for determining the fault direction of a new energy transmission line, including:

[0045] It should be noted that the following embodiments are described using a typical new energy wind farm transmission system as an example. As shown in FIG1 , a typical wind farm transmission system includes an external system equivalent power source us, a transmission line N-side relay protection device, a transmission line M-side relay protection device, and a wind farm.

[0046] A method for implementing a fault direction discrimination element suitable for renewable energy transmission scenarios is provided, including:

[0047] S1: Obtain the measured current values ​​on the line side and the opposite side of the line in real time and perform low-pass filter processing;

[0048] S2: Calculate the real-time rate of change of the current on the line side and the opposite side of the line in a fixed time window based on the real-time sampling rate.

[0049] Using the formula Calculate the real-time change rate of the current on the line side I' m (t0+T w ), similarly, the real-time change rate of the current on the opposite side of the line is I' n (t0+T w ) can be obtained by the formula Obtain, I m (t0+T w ), I n (t0+T w ) represents the M side and N side of the line t0+T w Current at the moment, I m (t0), I n (t0) represents the current on the M and N sides of the line at time t0, T w It is a pre-set fixed time window, and in this embodiment, Tw=2ms.

[0050] S3: Compare the real-time rate of change with the calculated value at the same position one cycle ago to distinguish between normal operation and fault status of the AC system.

[0051] Set t0+T on the line side w Real-time current change rate I' m (t0+T w ), t0+T on the opposite side of the line w Real-time current change rate I' n (t0+T w ), respectively with the line side t0+T of one wave front w -T α Real-time current change rate I' m (t0+T w -T α ), t0+T on the opposite side of the line w -T α Real-time current change rate I' n (t0+T w -T α ) to distinguish the normal operation and fault state of the AC system, T α Indicates the length of two cycles. In this embodiment, T α is 40ms.

[0052] It should be noted that for the line side, the line side t0+T w Real-time current change rate I' m (t0+T w ) and one-cycle-front line side t0+T w -T α Real-time current change rate I' m (t0+T w -T α) using a sliding data window. If the two instantaneous values ​​are inconsistent for a quarter of a cycle in a row, a fault condition is identified and the protection program is activated. If the two instantaneous values ​​are inconsistent for a quarter of a cycle in a row, the count is reset to zero and the protection program is not activated. The fault condition judgment criteria for the opposite side of the line are the same as above.

[0053] S4: After the fault is confirmed, the linear distance discrete values ​​of the two current sequences are obtained by comparing the real-time calculated value and the stored value of the current on the current side and the opposite side of the line in the data window.

[0054] Define the real-time current change rate I' at time t0 m (t0) to t0+T β Current real-time change rate I' m (t0+T β ) is the point set DIS1 in Euclidean space, and t0-T is defined at the same time α Current real-time change rate I' m (t0-T α ) to t0+T β -T α Current real-time change rate I' m (t0+T β -T α ) is the point set DIS2 in Euclidean space, and the formula is used to calculate the line side t0+T β The linear distance discrete value from the current sequence 1 to 2, DISM1(t0+T β )=h(DIS1,DIS2)=max A∈DIS1 min B∈DIS2 ||AB||

[0055] Calculate the line side t0+T using the formula β The linear distance discrete value of the current sequence from 2 to 1, DISM2(t0+T β )=h(DIS2,DIS1)=max A∈DIS2 min B∈DIS1 ||AB||

[0056] Similarly, the discrete linear distance values ​​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 , can be selected by comprehensively considering the sampling rate of the relay protection device and the length of the time window, T β In this embodiment, 5ms is used.

[0057] S5: Obtain the maximum discrete value of the linear distance between the two current sequences and compare it with the preset threshold value to determine whether the fault is inside or outside the zone.

[0058] Use the formula DISM(t0+T β )=max(DISM1(t0+T β ),DISM2(t0+T β )) Calculate t0+T on the line side β The linear distance between the two current sequences at the moment is the maximum discrete value, and then DISM(t) is compared with the preset threshold value DIS_set. In this embodiment, DIS_set is 0.3. If DISM(t)<DIS_set continuously satisfies the time T set , then it is considered that a fault has occurred inside the transmission line on this side, otherwise it is considered that no fault has occurred inside the transmission 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 is continuously satisfied for time T set , it is considered that a fault occurs inside the opposite side transmission line, otherwise it is considered that no fault occurs inside the opposite side transmission line, T set The reliability and action speed of the relay protection should be considered when setting. set Take 10ms.

[0059] In this embodiment, a fault occurs at F3 outside the transmission line. When the system side uses existing phase-comparison distance protection, the phase comparison results at the protection installation are shown in Figure 2. In this case, the phase comparison value enters the protection action range 45ms after the fault, causing malfunction of the system side protection.

[0060] In this embodiment, a fault occurs at F1 within the transmission line. The calculation results of the maximum discrete value of the linear distance of the fault direction discriminating element of the present invention are shown in Figure 3. In this case, the calculated DISM(t) two-cycle post-fault period is consistently less than the set threshold of 0.3, indicating that the fault direction discriminating element is operating reliably.

[0061] In this embodiment, a fault occurs at F2 within the transmission line. The calculation results of the maximum discrete linear distance of the fault direction discriminating element of the present invention are shown in Figure 4. In this case, the calculated DISM(t) is consistently greater than the set threshold of 0.3 for the first two cycles after the fault, indicating that the fault direction discriminating element is reliably inoperative.

[0062] It will be easily understood by those skilled in the art 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 in the scope of protection of the present invention.

[0063] Example 2

[0064] The second embodiment of the present invention is different from the previous embodiment in that:

[0065] If the functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the parts of the technical solutions that essentially contribute to the prior art or the parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0066] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a list of executable instructions for implementing logic functions, which can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus or device, such as a computer-based system, a system including a processor or other system that can fetch the instructions from the instruction execution system, apparatus or device and execute the instructions, or in conjunction with these instructions execution systems, apparatus or devices. For the purpose of this specification, the "computer-readable medium" can be any device that can contain, store, communicate, propagate or transport programs for use by or in connection with an instruction execution system, apparatus or device, or in conjunction with these instruction execution systems, apparatus or devices.

[0067] More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection having one or more wires (electrical devices), a portable computer diskette (magnetic devices), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium can even be paper or other suitable medium on which the program can be printed, because the program can be electronically obtained, for example, by optical scanning of the paper or other medium, followed by editing, interpreting or otherwise processing, if necessary, in other suitable ways, to be electronically obtained and then stored in the computer memory.

[0068] It should be understood that various parts of the present application can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, a plurality of steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, and as in another embodiment, it can be implemented using any or a combination of the following technologies, which are known in the art: discrete logic circuitry having logic gates for implementing logic functions on data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), etc.

[0069] Embodiment 4

[0070] Referring to FIG. 5, a third embodiment of the present application provides a fault direction discrimination system adapted to a new energy sending line, characterized in that it comprises a collection and preprocessing module, a rate of change calculation module, a fault recognition module, a distance calculation module, and a discrimination decision module.

[0071] The collection and preprocessing module acquires real-time measurement current values of the line local side and the line opposite side, and performs low-pass filter processing.

[0072] The rate of change calculation module calculates real-time rates of change of the line local side and the line opposite side current in a fixed time window according to a real-time sampling rate.

[0073] The fault recognition module compares the real-time rate of change with a same position calculation value before a cycle to distinguish normal operation and fault state of the alternating current system.

[0074] The distance calculation module confirms the fault, and obtains linear distance discrete values of two current sequences by comparing real-time calculation amounts and memory amounts of the line local side and the line opposite side current in a data window.

[0075] The discrimination decision module obtains maximum discrete values of linear distances of two current sequences, and compares them with a pre-set threshold value to discriminate in-zone and out-of-zone faults.

[0076] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A fault direction discrimination method suitable for new energy sending-out line, characterized in that: The method comprises the following steps: Real-time current values of the line side and the opposite side are acquired and processed by a low-pass filter; Real-time change rates of the current of the line side and the opposite side are calculated in a fixed time window according to a real-time sampling rate; The real-time change rates are compared with the calculated values of the same position in a cycle to distinguish the normal operation and the fault state of the alternating current system; After confirming the fault, linear distance discrete values of the two current sequences are obtained by comparing the real-time calculation values and the memory values of the current of the line side and the opposite side in the data window; The maximum linear distance discrete values of the two current sequences are obtained and compared with a preset threshold value to distinguish the in-zone fault and the out-of-zone fault.

2. The fault direction discrimination method for a new energy sending-out line according to claim 1, characterized in that: The real-time change rate of the current on the computing line is expressed as, where I m (t0+T w ) denotes the current at the line M side at t0+T w , I m (t0) denotes the current at the line M side at t0, and T w is a fixed time window set in advance.

3. The fault direction discrimination method for a new energy sending-out line according to claim 2, characterized in that: the line opposite side current real-time change rate I' n (t0+T w ) is expressed as, where I n (t0+T w ) represents the current at the line N side at t0+T w , and I n (t0) represents the current at the N side at t0.

4. The fault direction discrimination method for a new energy sending-out line of claim 3, characterized in that: The comparison of the real-time change rate with the same position calculation value before a cycle to distinguish the normal operation and fault state of the alternating current system includes comparing the line local side t0+T w moment current real-time change rate I' m (t0+T w ), the line opposite side t0+T w moment current real-time change rate I' n (t0+T w ) respectively with the line local side t0+T w -T α moment current real-time change rate I' m (t0+T w -T α ), the line opposite side t0+T w -T α moment current real-time change rate I' n (t0+T w -T α ) before a cycle to distinguish the normal operation and fault state of the alternating current system, T α represents the sampling point number of a cycle.

5. The fault direction identification method for new energy sending lines of claim 4, characterized in that: The linear distance discrete value of the two current sequences is represented as DIS1, and the real-time current change rate I' at t0 is defined m (t0) to t0+T β The real-time current change rate I' at t0+T m (t0+T β ) is a point set DIS1 in the Euclidean space, and t0-T α The real-time current change rate I' at t0-T m (t0-T α ) to t0+T β -T α The real-time current change rate I' at t0+T m (t0+T β -T α ) is a point set DIS2 in the Euclidean space, and the linear distance discrete value of the current sequence one and two at the line local t0+T β is calculated by the formula DISM1(t0+T β ) = h(DIS1, DIS2) = max A∈DIS1 min B∈DIS2 ||A-B|| The formula is used to calculate the line side t0+T β The linear distance discrete value of the current sequence two to one at the moment DISM2(t0+T β ) = h(DIS2, DIS1) = max A∈DIS2 min B∈DIS1 ||A-B|| where ||A-B|| represents the Euclidean distance between A and B, x A∈DIS2 where A e DIS2 represents a point in set DIS2, B e DIS1 represents a point in set DIS1, and h(DIS2, DIS1) represents taking the point bj in set B closest to set A, then calculating the distance between each point ai in set A and bj, sorting the distances, and taking the largest value as the value of h(A, B).

6. The fault direction identification method for new energy sending lines of claim 5, characterized in that: The obtained two current sequence linear distance maximum discrete values are expressed as DISM(t0+T β ) = max(DISM1(t0+T β ), DISM2(t0+T β )) The computing line is on the side of the t0+T β The maximum discrete value of the linear distance of the two current sequences at the time t0+T β ) is compared with the preset threshold value DIS_set.

7. The fault direction identification method for new energy sending lines of claim 6, wherein: The comparison with the preset threshold value to determine the in-zone and out-of-zone fault includes if DISM(t) < DIS_set continuously satisfies time T set , it is considered that the fault occurs inside the local side of the outgoing line, if DISM(t) > DIS_set continuously satisfies time T set , it is determined that the fault does not occur inside the local side of the outgoing line; The maximum discrete value DISN(t) of linear distance of two current sequences on the opposite side of the line is obtained, if DISN(t)>DIS_set, the internal fault occurs on the opposite side of the outgoing line pair if DISN(t)<DIS_set, the internal fault does not occur on the opposite side of the outgoing line pair; T set set set The reliability and action speed of the relay protection are considered for setting.​​ 8. A system for fault direction discrimination for a new energy sending-out line based on any one of claims 1-7, characterized in that: The method comprises a collection and preprocessing module, a change rate calculation module, a fault identification module, a distance calculation module, and a discrimination and decision module. The collection and preprocessing module acquires real-time current values of the line side and the opposite side and processes the current values by a low-pass filter; The change rate calculation module calculates real-time change rates of the current of the line side and the opposite side in a fixed time window according to a real-time sampling rate; The fault identification module compares the real-time change rates with the calculated values of the same position in a cycle to distinguish the normal operation and the fault state of the alternating current system; The distance calculation module obtains linear distance discrete values of the two current sequences by comparing the real-time calculation values and the memory values of the current of the line side and the opposite side in the data window after confirming the fault; The discrimination and decision module obtains the maximum linear distance discrete values of the two current sequences and compares the values with a preset threshold value to distinguish the in-zone fault and the out-of-zone fault. 9.A computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the computer device is configured to perform the method according to any one of claims 1-8 when the computer program is executed by the processor. The processor executes the computer program to realize the steps of the method in any one of claims 1 to 7.

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

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