New energy grid-connected line inter-phase distance protection adaptability quantitative evaluation method and system

Abstract

The invention relates to the technical field of relay protection, in particular to a new energy grid-connected line phase-to-phase distance protection adaptability quantitative evaluation method and a new energy grid-connected line phase-to-phase distance protection adaptability quantitative evaluation system. Calculating conventional power supply and new energy short-circuit current data of the bus at the side when the three-phase fault of the bus at the receiving end occurs, and preprocessing the short-circuit current data; calculating a short-circuit ratio of a conventional power supply to new energy based on the preprocessed short-circuit current data; and judging the distance protection adaptability of the output grid-connected line according to the short-circuit comparison. According to the method, the ratio of the conventional power supply to the new energy short-circuit current is calculated, and the short-circuit ratio threshold value 1.73 is introduced as a criterion, so that quantitative evaluation of the new energy grid-connected line distance protection adaptability is realized. According to the method, the defect that a traditional evaluation method depends on complex transient simulation is overcome, the evaluation efficiency is remarkably improved, and meanwhile the accuracy of an evaluation result is guaranteed. The invention provides a quantitative criterion of new energy grid-connected line distance protection adaptability for the first time.

Description

Technical Field

[0001] The present invention relates to the technical field of relay protection, and in particular to a method and system for quantitatively evaluating adaptability of phase-to-phase distance protection of a new energy grid-connected line. Background Art

[0002] The response characteristics of power electronic equipment such as new energy and flexible direct current converter stations after AC system faults are highly affected by control strategies. The equivalent method of traditional synchronous power supply cannot accurately reflect the fault characteristics of AC power grid under the access of new energy and flexible direct current. At the same time, considering that the traditional AC line protection principle is designed based on the characteristics of synchronous power supply, the access of power electronic equipment will also have an adverse effect on its operating performance.

[0003] Traditional distance protection has the risk of failure to operate or false operation in renewable energy transmission lines, but this risk cannot be quantified and assessed, and a definite protection adaptability boundary cannot be given in engineering applications. Summary of the invention

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

[0005] The problem to be solved by the present invention is that the traditional distance protection has the risk of refusal to operate or malfunction in the new energy transmission line, which is specifically reflected in:

[0006] The response characteristics of power electronic equipment such as new energy and flexible DC after AC system faults are highly affected by control strategies. The equivalent method of traditional synchronous power supply is difficult to accurately reflect the fault characteristics of the AC power grid after the new energy is connected to the grid.

[0007] The traditional AC line protection principle is mainly designed based on the characteristics of synchronous machine power supply. When a large number of power electronic equipment are connected, it will have a significant impact on the performance of distance protection.

[0008] In engineering practice, due to the lack of effective quantitative evaluation methods, it is impossible to accurately judge the adaptability boundary of distance protection in renewable energy grid-connected lines, and it is difficult to provide a clear technical basis for protection configuration.

[0009] These problems lead to large blind spots in the relay protection configuration of renewable energy grid-connected lines, affecting the safe and stable operation of the power grid. Therefore, it is urgent to propose a method that can quantitatively evaluate the adaptability of phase-to-phase distance protection of renewable energy grid-connected lines to provide reliable technical support for engineering practice.

[0010] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0011] In a first aspect, an embodiment of the present invention provides a method for quantitatively evaluating the adaptability of phase-to-phase distance protection of a new energy grid-connected line, which includes calculating the conventional power supply and new energy short-circuit current data of the local bus when a three-phase fault occurs on the receiving end bus, and preprocessing the short-circuit current data;

[0012] Calculating the short circuit ratio of the conventional power source and the new energy source based on the preprocessed short circuit current data;

[0013] The adaptability of the distance protection of the outgoing grid-connected line is determined based on the short-circuit ratio.

[0014] As a preferred solution of the adaptability quantitative evaluation method of phase-to-phase distance protection of the new energy grid-connected line of the present invention, the conventional power supply short-circuit current calculation includes:

[0015] Obtain conventional power supply electromotive force, grid-connected line impedance and conventional power supply system impedance;

[0016] The short-circuit current under the minimum operation mode is calculated based on the conventional power supply electromotive force, the grid-connected line impedance and the conventional power supply system impedance.

[0017] As a preferred solution of the adaptability quantitative evaluation method of phase-to-phase distance protection of the new energy grid-connected line described in the present invention, the new energy short-circuit current calculation includes:

[0018] Obtain the rated active power, rated voltage amplitude and short-circuit capacity multiples of new energy stations;

[0019] The short-circuit current is calculated based on the rated active power of the new energy station, the rated voltage amplitude and the multiple of the new energy short-circuit capacity.

[0020] As a preferred solution of the quantitative evaluation method for adaptability of phase-to-phase distance protection of new energy grid-connected lines described in the present invention, the value range of the new energy short-circuit capacity multiple is 1.2 to 1.5.

[0021] As a preferred solution of the quantitative evaluation method for adaptability of phase-to-phase distance protection of new energy grid-connected lines of the present invention, the calculation of the short-circuit ratio includes:

[0022] Obtain the short-circuit current of conventional power supply and new energy;

[0023] The short circuit ratio is calculated based on the short circuit current of the conventional power supply and the short circuit current of the new energy source.

[0024] As a preferred solution of the quantitative evaluation method for adaptability of phase-to-phase distance protection of new energy grid-connected lines of the present invention, the distance protection adaptability determination includes:

[0025] The distance protection adopts a phase-comparison distance relay based on positive sequence voltage polarization;

[0026] comparing the short circuit ratio with a preset short circuit ratio threshold value;

[0027] When the short circuit ratio is greater than the short circuit ratio threshold value, it is determined that the phase distance protection is applicable to the grid-connected line.

[0028] As a preferred solution of the quantitative evaluation method for adaptability of phase-to-phase distance protection of new energy grid-connected lines described in the present invention, the short-circuit ratio threshold value is set to 1.73.

[0029] In a second aspect, an embodiment of the present invention provides a system for quantitatively evaluating the adaptability of phase-to-phase distance protection of a new energy grid-connected line, which includes:

[0030] A data acquisition module calculates the short-circuit current data of the conventional power supply and the new energy source of the busbar on this side when the three-phase fault occurs on the receiving-end busbar, and pre-processes the short-circuit current data;

[0031] A short circuit ratio calculation module, which calculates the short circuit ratio of the conventional power source and the new energy source based on the preprocessed short circuit current data;

[0032] The adaptability determination module determines the adaptability of the distance protection of the outgoing grid-connected line according to the short-circuit ratio.

[0033] In a third aspect, an embodiment of the present invention provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: when the computer program instructions are executed by the processor, the steps of the method for quantitatively evaluating the adaptability of phase-to-phase distance protection of new energy grid-connected lines as described in the first aspect of the present invention are implemented.

[0034] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program instructions are executed by a processor, the steps of the method for quantitatively evaluating the adaptability of phase-to-phase distance protection of new energy grid-connected lines as described in the first aspect of the present invention are implemented.

[0035] The beneficial effects of the present invention are as follows: the present invention introduces the short-circuit ratio as a new evaluation index, and provides a clear critical value relationship between the short-circuit ratio and the distance protection adaptability, which provides a new approach to solving the protection adaptability determination problem that has long plagued the industry.

[0036] The threshold value of 1.73 obtained through theoretical analysis and practical verification can not only effectively judge the applicability of protection, but also has good adaptability to various control strategies of new energy and has universal guiding significance.

[0037] The quantitative evaluation method of the present invention shows excellent universality in practical applications and brings unexpected extended application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 A flow chart of the quantitative evaluation method for adaptability of phase-to-phase distance protection of renewable energy grid-connected lines;

[0040] Figure 2 A computer equipment diagram for a quantitative evaluation method of adaptability of phase-to-phase distance protection for new energy grid-connected lines;

[0041] Figure 3 A schematic diagram of a new energy and conventional energy bundled transmission system for a quantitative evaluation method of the adaptability of phase-to-phase distance protection for new energy grid-connected lines;

[0042] Figure 4 This is the relationship diagram between the short-circuit ratio and the distance protection action of the quantitative evaluation method for the adaptability of the phase-to-phase distance protection of the new energy grid-connected line. DETAILED DESCRIPTION

[0043] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0044] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0045] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0046] Example 1

[0047] Reference Figure 1 to Figure 4 , which is the first embodiment of the present invention, and provides a quantitative evaluation method for adaptability of phase-to-phase distance protection of a new energy grid-connected line, comprising:

[0048] like Figure 3 As shown in the figure, bundling new energy and conventional energy is the main way of connecting new energy to the grid. When a phase-to-phase fault occurs on the line, due to the negative-sequence current suppression strategy on the new energy side, the fault current is composed only of positive-sequence components with controlled direction. At the end of the transmission line, especially when there is a fault through a transition resistor, the angle between the fault phase-to-phase current and the fault phase-to-phase voltage is near 0°, which may cause the distance protection to refuse to operate or malfunction when a phase-to-phase fault occurs near the new energy side or behind the grid side, seriously affecting the safe operation of the grid.

[0049] After bundling with conventional energy, since the fault current provided by the conventional power source lags the fault voltage by about 90°, it is the most favorable situation for the distance protection to operate. The higher the proportion of conventional power access, the smaller the probability of abnormal distance protection operation. However, there is a lack of an indicator that can quantitatively analyze this adaptability. Therefore, it is urgent to propose a quantitative evaluation method for the adaptability of distance protection in the scenario of new energy bundling transmission to guide the analysis of the adaptability of distance protection in actual projects.

[0050] S100: Calculate the short-circuit current data of the conventional power supply and the new energy source of the busbar on this side when the three-phase fault occurs on the receiving end busbar, and pre-process the short-circuit current data;

[0051] S101: Conventional power supply short-circuit current calculation includes:

[0052] Obtain conventional power supply electromotive force, grid-connected line impedance and conventional power supply system impedance;

[0053] The short-circuit current under the minimum operation mode is calculated based on the conventional power supply electromotive force, grid-connected line impedance and conventional power supply system impedance.

[0054] S102: The new energy short-circuit current calculation includes:

[0055] Obtain the rated active power, rated voltage amplitude and short-circuit capacity multiples of new energy stations;

[0056] The short-circuit current is calculated based on the rated active power of the new energy station, the rated voltage amplitude and the multiple of the new energy short-circuit capacity.

[0057] Preferably, the short-circuit current provided by the conventional power supply in the minimum operating mode includes:

[0058] The short-circuit current can be expressed as:

[0059]

[0060] in, Represents the electromotive force of the conventional power supply; Z L Indicates the grid-connected line impedance; Z S Indicates the impedance of the conventional power system.

[0061] S103: The value range of the new energy short-circuit capacity multiple is 1.2 to 1.5.

[0062] Preferably, the short-circuit current provided by the new energy source includes:

[0063] The short-circuit current can be expressed as:

[0064]

[0065] Among them, P re Indicates the rated active power of the new energy station; U N Indicates the rated voltage amplitude; k represents the multiple relationship between the short-circuit capacity of the new energy and the rated active power, generally ranging from 1.2 to 1.5.

[0066] S200: Calculating the short circuit ratio of the conventional power source and the new energy source based on the preprocessed short circuit current data;

[0067] S201: The calculation of the short circuit ratio includes:

[0068] Obtain the short-circuit current of conventional power supply and new energy;

[0069] The short-circuit ratio is calculated based on the short-circuit current of conventional power sources and the short-circuit current of new energy sources.

[0070] Preferably, obtaining the short-circuit ratio of the conventional power source to the new energy source includes:

[0071]

[0072] S300: Determine the adaptability of the distance protection of the outgoing grid-connected line according to the short-circuit comparison.

[0073] S301: Distance protection adaptability determination includes:

[0074] The distance protection adopts a phase-comparison distance relay based on positive sequence voltage polarization;

[0075] comparing the short circuit ratio with a preset short circuit ratio threshold value;

[0076] When the short-circuit ratio is greater than the short-circuit ratio threshold value, it is determined that the phase-to-phase distance protection is applicable to the grid-connected line.

[0077] S302: The short circuit ratio threshold is set to 1.73.

[0078] Preferably, judging the adaptability of the distance protection of the outgoing grid-connected line according to the short-circuit ratio includes:

[0079] k SRC >k SET

[0080] Among them, k SETis the short circuit ratio threshold, which is generally 1.73. When this criterion is met, phase distance protection can be applied.

[0081] Preferably, for k SET The value of is explained as follows: Figure 4 As shown, in Figure 3 When a phase-to-phase fault occurs at point F1, the short-circuit current provided by the conventional power supply is Its angle is the lagging phase positive sequence voltage The positive sequence impedance angle is close to 90°; the short-circuit current provided by the new energy is The worst possible working condition is that the new energy source still delivers active power during the fault, that is, near 0°; the two combined total fault current on the M side is From the short-circuit ratio of conventional power supply and new energy expressed by formula (7), we can know that The positive sequence voltage between phases on the M side Angle Similarly, when a phase-to-phase fault occurs at point F2, Here, it is assumed that the new energy source outputs a current of fixed amplitude in the form of a current source during the fault period. And it is known that the fault current provided by the conventional power supply when the F1 point fault occurs is larger than that provided when the F2 point fault occurs, so α F1 >α F2 , further, in α F2 When it is closer to 90°, the F2 point fault distance protection will not be misoperated, and the F1 point fault distance protection will not refuse to operate. Considering the differences in different types of new energy control strategies when the F2 point fault occurs and the angle deviation caused by sampling and calculation, α is taken. F2 =60° is an acceptable empirical value in engineering applications. Therefore, k SRC >tan60°=1.73, it can ensure that when a phase-to-phase fault occurs at the F1 point near the new energy source, the P M When a phase-to-phase fault occurs at point F2 behind the power grid, the protection P N No misoperation.

[0082] Furthermore, this embodiment also provides a new energy grid-connected line phase distance protection adaptability quantitative evaluation system, including:

[0083] The data acquisition module calculates the short-circuit current data of the conventional power supply and new energy of the busbar on this side when the three-phase fault occurs on the receiving end busbar, and pre-processes the short-circuit current data;

[0084] A short-circuit ratio calculation module calculates the short-circuit ratio of conventional power sources and new energy sources based on preprocessed short-circuit current data;

[0085] The adaptability determination module determines the adaptability of the distance protection of the outgoing grid-connected line based on the short-circuit comparison.

[0086] In summary, by calculating the short-circuit current of conventional power supply and new energy when the receiving end busbar has a three-phase fault, and performing preprocessing, and introducing the ratio of the short-circuit current of conventional power supply to that of new energy as an evaluation index, the contribution of two different types of power supplies is creatively quantified and compared. This ratio index is not only simple and intuitive, but also can effectively reflect the degree of influence of new energy grid connection on distance protection, and provides a quantifiable basis for protection configuration. By setting the short-circuit ratio threshold value (1.73) and comparing the calculated short-circuit ratio with it, a set of scientific adaptability judgment criteria is established. This judgment method realizes the quantitative evaluation of the adaptability of distance protection of new energy grid-connected lines for the first time, and solves the problem that the protection adaptability boundary cannot be determined in engineering practice. In particular, the threshold value of 1.73 determined by theoretical analysis takes into account the particularity of new energy and the needs of actual engineering, and has important practical guiding significance. The present invention organically combines short-circuit current calculation, short-circuit ratio analysis and adaptability judgment to construct a complete evaluation system. This scheme can not only accurately judge whether the distance protection is applicable, but also guide the selection of protection schemes and parameter setting in engineering practice. Compared with the traditional empirical judgment method, the present invention has achieved an important breakthrough from qualitative to quantitative, and significantly improved the reliability of the protection of new energy grid-connected lines.

[0087] By introducing the new evaluation indicator of short-circuit ratio, a clear critical value relationship between it and the adaptability of distance protection is given, which provides a new idea for solving the problem of protection adaptability determination that has long plagued the industry.

[0088] The threshold value of 1.73 obtained through theoretical analysis and practical verification can not only effectively judge the applicability of protection, but also has good adaptability to various control strategies of new energy and has universal guiding significance.

[0089] The quantitative evaluation method of the present invention shows excellent universality in practical applications and brings unexpected extended application value.

[0090] Example 2

[0091] Reference Figure 2 - Figure 4 , which is the second embodiment of the present invention, and this embodiment provides a quantitative evaluation method for the adaptability of phase-to-phase distance protection of a new energy grid-connected line. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through simulation experiments.

[0092] In this experiment, the following Figure 3 The new energy and conventional energy bundled transmission system model is shown, and two fault points F1 and F2 are set. The new energy control strategy and output ratio can be adjusted. A total of 200 tests are carried out and the protection action results are recorded.

[0093] The following are the results of the data analysis collected in the experiment:

[0094] Table 1 Relationship between short-circuit ratio and M-side protection action characteristics

[0095]

[0096]

[0097] Table 2 Relationship between F1 phase fault output ratio and M side protection action characteristics

[0098] New energy output (%) Short circuit ratio Protection correct action rate 20 5.00 100％ 40 2.50 100％ 60 1.67 93.3％ 80 1.25 78.5％ 100 1.00 69.6％

[0099] Table 3 Relationship between F2 phase fault output ratio and M side protection action characteristics

[0100] New energy output (%) Short circuit ratio Protection correct action rate 20 5.00 100％ 40 2.50 100％ 60 1.67 94.1％ 80 1.25 76.2％ 100 1.00 70.3％

[0101] Through in-depth analysis of experimental data, the method of the present invention shows significant advantages in the following aspects:

[0102] Engineering application efficiency:

[0103] In terms of evaluation time, the method of the present invention can instantly calculate the judgment result after obtaining the relevant parameters. This efficiency improvement comes from the simplicity of the method itself, avoiding complex transient process calculations while maintaining high accuracy. This feature makes the method particularly suitable for the rapid evaluation of large-scale new energy grid-connected systems.

[0104] Adaptive Boundary Validation:

[0105] From the data in the table, we can see that when Kr≥1.73, the correct action rate of protection is 100% regardless of the control strategy, which fully verifies the rationality of the critical value of 1.73 obtained by theoretical analysis. The discovery of this critical value provides a clear criterion for engineering practice.

[0106] New energy output adaptability:

[0107] Data shows that as the output of renewable energy increases, the short-circuit ratio gradually decreases, and the correct protection action rate decreases accordingly. When the output of renewable energy reaches more than 60%, the short-circuit ratio is lower than the critical value of 1.73, and the reliability of distance protection begins to be affected. This discovery provides an important reference for optimizing the operation mode of renewable energy power stations.

[0108] Innovative verification:

[0109] Compared with the prior art, the method of the present invention has unique advantages in the following aspects:

[0110] Applicable to the phase-comparison distance protection method based on positive sequence voltage polarization;

[0111] The evaluation process is simple and intuitive, without the need for complex transient simulation;

[0112] The evaluation results have a clear quantitative basis;

[0113] It has strong applicability and can be extended to various new energy grid-connected systems;

[0114] The calculation amount is small, which is convenient for engineering implementation.

[0115] These data fully demonstrate the innovative value of this invention in improving the reliability assessment of renewable energy grid-connected line protection, and provide a practical solution to solve industry problems.

[0116] Example 3

[0117] This embodiment also provides a computer device, which is applicable to a method for quantitatively evaluating the adaptability of phase-to-phase distance protection of a new energy grid-connected line, and includes a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions to implement a forced oscillation detection and positioning method for a distribution network as proposed in the above embodiment.

[0118] This embodiment further provides a storage medium on which a computer program is stored. When the program is executed by a processor, a forced oscillation detection and positioning method for a distribution network is implemented as proposed in the above embodiment.

[0119] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used 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 the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0120] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it 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 the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0121] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0122] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering, or processing in another suitable manner as necessary, and then stored in a computer memory.

[0123] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0124] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A quantitative evaluation method for adaptability of phase-to-phase distance protection of new energy grid-connected lines, characterized by: include, Calculate the short-circuit current data of the conventional power supply and the new energy source of the busbar on the receiving end when the three-phase fault occurs on the receiving end busbar, and pre-process the short-circuit current data; Calculating the short circuit ratio of the conventional power source and the new energy source based on the preprocessed short circuit current data; The adaptability of the distance protection of the outgoing grid-connected line is determined based on the short-circuit ratio.

2. The adaptability quantitative evaluation method for phase-to-phase distance protection of a new energy grid-connected line according to claim 1 is characterized in that: The conventional power supply short-circuit current calculation includes: Obtain conventional power supply electromotive force, grid-connected line impedance and conventional power supply system impedance; The short-circuit current under the minimum operation mode is calculated based on the conventional power supply electromotive force, the grid-connected line impedance and the conventional power supply system impedance.

3. The adaptability quantitative evaluation method for phase-to-phase distance protection of new energy grid-connected lines according to claim 2 is characterized by: The new energy short-circuit current calculation includes: Obtain the rated active power, rated voltage amplitude and short-circuit capacity multiples of new energy stations; The short-circuit current is calculated based on the rated active power of the new energy station, the rated voltage amplitude and the multiple of the new energy short-circuit capacity.

4. The adaptability quantitative evaluation method for phase-to-phase distance protection of a new energy grid-connected line according to claim 3 is characterized by: The value range of the new energy short-circuit capacity multiple is 1.2 to 1.

5.

5. The adaptability quantitative evaluation method for phase-to-phase distance protection of a new energy grid-connected line according to claim 4 is characterized by: The calculation of the short circuit ratio includes: Obtain the short-circuit current of conventional power supply and new energy; The short circuit ratio is calculated based on the short circuit current of the conventional power supply and the short circuit current of the new energy source.

6. The adaptability quantitative evaluation method for phase-to-phase distance protection of a new energy grid-connected line according to claim 5 is characterized by: The distance protection adaptability determination includes: The distance protection adopts a phase-comparison distance relay based on positive sequence voltage polarization; comparing the short circuit ratio with a preset short circuit ratio threshold value; When the short circuit ratio is greater than the short circuit ratio threshold value, it is determined that the phase distance protection is applicable to the grid-connected line.

7. The adaptability quantitative evaluation method for phase-to-phase distance protection of a new energy grid-connected line according to claim 6 is characterized by: The short circuit ratio threshold value is set to 1.

73.

8. A system for quantitatively evaluating the adaptability of phase-to-phase distance protection of a new energy grid-connected line, based on the method for quantitatively evaluating the adaptability of phase-to-phase distance protection of a new energy grid-connected line according to any one of claims 1 to 7, characterized in that: Also includes, A data acquisition module calculates the short-circuit current data of the conventional power supply and the new energy source of the busbar on this side when the three-phase fault occurs on the receiving-end busbar, and pre-processes the short-circuit current data; A short circuit ratio calculation module, which calculates the short circuit ratio of the conventional power source and the new energy source based on the preprocessed short circuit current data; The adaptability determination module determines the adaptability of the distance protection of the outgoing grid-connected line according to the short-circuit ratio.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for quantitatively evaluating the adaptability of phase-to-phase distance protection of new energy grid-connected lines described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for quantitatively evaluating the adaptability of phase-to-phase distance protection of new energy grid-connected lines described in any one of claims 1 to 7 are implemented.

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