A new energy sending-out line protection method and device based on a classification multi-fusion criterion

Abstract

This invention discloses a method and device for protecting renewable energy transmission lines based on a classification-based multi-fusion criterion. Its features include: real-time acquisition of real-time voltage and current information at the renewable energy terminal of the transmission line; identification of renewable energy field faults and their fault directions based on the real-time current information; if the fault direction is a transmission line fault, determining the specific fault information of the renewable energy field fault based on the real-time voltage information; calculating the fault criterion for the renewable energy field fault based on the specific fault information; and determining the protection action time through the coordination relationship between the fault criterion and preset protection measures to clear the renewable energy field fault. This invention overcomes the failure of directional elements to operate or maloperate due to fault current frequency offset and eliminates fault phase selection failure caused by unequal positive and negative sequence impedances of renewable energy sources, effectively improving the safety and reliability of the distribution network.

Description

Technical Field

[0001] This invention relates to the field of power system relay protection technology, and in particular to a method and device for protecting new energy transmission lines based on classification and multi-fusion criteria. Background Technology

[0002] Clean energy has become an important direction for future energy development. New energy power plants have become a research hotspot due to their mature technology and high conversion rate. Therefore, it is of great significance to study the impact of new energy grid connection on the power system.

[0003] The transient characteristics of faults in new energy electric fields differ significantly from those in traditional electric fields. When the voltage drop is substantial, a crowbar circuit is activated to protect the rotor-side converter. In this case, the frequency of the short-circuit current shifts, with the shift range being approximately 35°. ~ At 65Hz, vector extraction based on power frequency quantities is no longer accurate. Traditional relay protection devices that operate based on power frequency vectors cannot function accurately and stably at this stage. Simultaneously, the weak power source characteristics of new energy electric fields result in positive and negative sequence impedances being much greater than zero-sequence impedance. Therefore, during ground faults, the proportion of zero-sequence current is very large, while the proportions of positive and negative sequence components are very small. The unique fault characteristics of new energy electric fields reduce the sensitivity of traditional protection systems, severely impacting directional, distance, and phase selection components.

[0004] The unique fault characteristics of new energy power plants have many impacts on traditional protection systems. However, the current relay protection configuration of high-voltage transmission lines of many new energy power plants does not take into account the unique fault characteristics of their grid connection systems and still adopts traditional relay protection schemes, resulting in frequent accidents in new energy power plants. Summary of the Invention

[0005] This invention provides a method and device for protecting new energy transmission lines based on classification and multi-fusion criteria, in order to solve the technical problem that fault protection is difficult in existing new energy transmission lines due to the frequency shift of fault current and the unequal positive and negative sequence impedances of electric field.

[0006] According to one aspect of the present invention, a method for protecting new energy transmission lines based on classification multi-fusion criteria is provided, comprising:

[0007] Real-time voltage and current information are collected at the new energy terminal of the transmission line.

[0008] Based on real-time current information, faults in new energy electric fields and the fault directions of such new energy electric fields are identified.

[0009] If the fault direction is the direction of the transmission line, then the specific fault information of the new energy power plant fault is determined based on the real-time voltage information.

[0010] Based on the specific fault information, the fault criteria for the new energy power plant fault are calculated. The timing of the protection action is determined by the coordination relationship between the fault criteria and the preset protection, so as to clear the fault in the new energy power plant.

[0011] According to another aspect of the present invention, a new energy transmission line protection device based on classification multi-fusion criteria is provided, comprising:

[0012] The data acquisition module is used to collect real-time voltage and current information at the new energy terminal of the transmission line.

[0013] The fault diagnosis module is used to identify faults in the new energy electric field and the fault direction of the new energy electric field based on real-time current information.

[0014] The fault analysis module is used to determine the specific fault information of the new energy power plant based on the real-time voltage information if the fault direction is the direction of the transmission line.

[0015] The fault handling module is used to calculate the fault criteria of the new energy power field based on the specific fault information, and determine the protection action time through the coordination relationship between the fault criteria and the preset protection, so as to clear the fault of the new energy power field.

[0016] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0017] At least one processor; and

[0018] A memory communicatively connected to the at least one processor; wherein,

[0019] The memory stores a computer program that can be executed by the at least one processor, which is then executed by the at least one processor to enable the at least one processor to perform the new energy transmission line protection method based on classification multi-fusion criteria as described in any embodiment of the present invention.

[0020] According to another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing computer instructions, the computer instructions being configured to cause a processor to execute and implement the new energy transmission line protection method based on classification multi-fusion criteria as described in any embodiment of the present invention.

[0021] The technical solution of this invention collects real-time voltage and current information from the renewable energy terminal of the transmission line in real time; identifies renewable energy field faults and their fault directions based on the real-time current information; uses real-time current information to determine the fault direction, overcoming the failure of directional components to operate or maloperate due to fault current frequency deviation, and effectively improving the accuracy of identifying the fault direction of the renewable energy transmission line; if the fault direction is a transmission line fault, then the specific fault information of the renewable energy field fault is determined based on the real-time voltage information.

[0022] Based on the specific fault information, a fault criterion for the new energy electric field fault is calculated. The protection action time is determined through the coordination relationship between the fault criterion and preset protection, thereby clearing the new energy electric field fault. The fault type and fault phase are simultaneously determined by utilizing the correlation of line voltage change trends, eliminating the failure of fault phase selection caused by unequal positive and negative sequence impedances of the new energy source. This achieves accurate and rapid operation of the new energy transmission line. Existing technologies address the technical problems of difficulty in fault protection due to fault current frequency deviation and unequal positive and negative sequence impedances of the electric field in new energy transmission lines. This invention overcomes the failure of directional elements to operate or maloperate caused by fault current frequency deviation and eliminates the failure of fault phase selection caused by unequal positive and negative sequence impedances of the new energy source, effectively improving the safety and reliability of the distribution network.

[0023] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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.

[0025] Figure 1 A flowchart of a new energy transmission line protection method based on classification multi-fusion criteria is provided for an embodiment of the present invention;

[0026] Figure 2 A flowchart of a new energy transmission line protection method based on classification multi-fusion criteria provided in an embodiment of the present invention;

[0027] Figure 3 A flowchart of a new energy transmission line protection method based on classification multi-fusion criteria provided in an embodiment of the present invention;

[0028] Figure 4This invention discloses a schematic diagram of the current amplitude variation in a two-phase (AB) ground fault.

[0029] Figure 5 This invention discloses a schematic diagram of the current amplitude variation in a two-phase (AB) short circuit;

[0030] Figure 6 A schematic diagram of the structure of a simulation model of a new energy transmission line is disclosed.

[0031] Figure 7 A schematic diagram illustrating the current amplitude variation during a phase-A ground fault is disclosed.

[0032] Figure 8 A schematic diagram illustrating the current amplitude variation in a three-phase ground fault is disclosed.

[0033] Figure 9 This is a schematic diagram of the structure of a new energy transmission line protection device based on classification multi-fusion criteria provided in an embodiment of the present invention;

[0034] Figure 10 A schematic diagram of the structure of an electronic device 10 that can be used to implement an embodiment of the present invention is shown. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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 scope of protection of the present invention.

[0036] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0037] Figure 1This invention provides a flowchart of a new energy transmission line protection method based on classification and multi-fusion criteria. This embodiment is applicable to identifying and judging faults in new energy transmission lines when they fail, thereby protecting the transmission lines. This method can be executed by a new energy transmission line protection device based on classification and multi-fusion criteria. This device can be implemented in hardware and / or software and can be configured in electronic equipment. Figure 1 As shown, the method includes:

[0038] S110: Real-time acquisition of voltage and current information at the new energy terminal of the transmission line.

[0039] Optionally, the real-time current information can be the real-time current value at the renewable energy terminal of the transmitting line; the real-time voltage information can be the real-time voltage value at the renewable energy terminal of the transmitting line. It should be noted that a sampling time point is set for each power frequency cycle at the renewable energy terminal of the transmitting line, thereby collecting the current and voltage values ​​for each power frequency cycle in real time to obtain the real-time voltage and real-time current information.

[0040] Optionally, the current and voltage values ​​are collected for each power frequency cycle, and the collected data is recorded and stored in units of power frequency cycles.

[0041] Specifically, it collects real-time voltage and current information from the new energy source at the transmission line in real time.

[0042] S120. Identify the faults in the new energy electric field and the fault direction of the new energy electric field based on real-time current information.

[0043] Optionally, a fault in a renewable energy power plant can be understood as a fault occurring in the power generation equipment, power plant lines, and grid connection of the renewable energy power plant. The power path from the renewable energy power plant to the grid typically involves power generation equipment, collection lines, step-up substations, and transmission lines to the grid, and a fault can occur at any node in this power path. For example, a fault in a renewable energy power plant could be a fault occurring during the transmission of renewable energy to the grid.

[0044] Optionally, when a fault occurs in the new energy transmission line, it will directly affect the voltage amplitude, voltage phase, current value abnormality, current frequency deviation and other phenomena of the three-phase voltage; in this embodiment of the invention, the fault time and fault direction of the new energy electric field fault are determined by detecting the current abnormality of the real-time current information.

[0045] Optionally, the fault direction of a new energy power plant fault can be understood as the phase relationship between the electrical quantities at the fault point in the new energy power plant and the location where the power grid protection is installed. It should be noted that the fault direction of a new energy power plant fault can be either a fault in the direction of the new energy transmission line or a fault in the direction of the power grid system.

[0046] Optionally, a fault in the direction of the new energy transmission line can be understood as a fault located within the protection range of the new energy power plant, and is managed by the protection of the new energy power plant.

[0047] Specifically, faults in the new energy electric field and their fault directions are identified based on real-time current information.

[0048] S130. If the fault direction is a fault in the direction of the transmission line, then the specific fault information of the new energy power plant fault is determined based on the real-time voltage information.

[0049] Optionally, after identifying that the fault direction of the new energy battery is the outgoing line direction, it is necessary to conduct a specific analysis of the new energy battery fault to obtain specific fault information.

[0050] Optionally, the specific fault information can be understood as the fault type and cause of the new energy battery fault; for example, the fault types are single-phase grounding fault, two-phase short circuit fault and three-phase short circuit fault. The fault cause of a single-phase grounding fault can be any one phase grounding, the fault cause of a two-phase short circuit fault can be any two phases grounding, and the fault of a three-phase short circuit fault is all three phases fault.

[0051] Specifically, if the fault direction of the new energy battery is identified as the transmission line direction, the specific fault information of the new energy electric field is determined based on the real-time voltage information.

[0052] S140. Calculate the fault criteria for the new energy power field fault based on the specific fault information, and determine the protection action time through the coordination relationship between the fault criteria and the preset protection, so as to clear the new energy power field fault.

[0053] Optionally, fault criteria can be understood as the electrical and non-electrical information characteristics corresponding to new energy battery faults. For example, electrical information characteristics can be understood as current, voltage, impedance, sequence components, etc.; non-electrical information characteristics can be understood as temperature and equipment fault signals.

[0054] Optionally, the protection action time can be understood as the time parameter by which the protection cuts off the fault in the new energy electric field after the fault criteria are met and the protection is activated.

[0055] Optionally, the preset protection coordination relationship can be a pre-set coordination relationship with other protections. It should be noted that, based on the protection corresponding to the fault in the new energy power plant, other adjacent protections are also set up for coordination as a fallback protection for the fault in the new energy power plant. The fault-corresponding protection for the new energy power plant is used as the main protection, and the main protection takes priority in operation. Other protections coordinate to provide a fallback, while avoiding cascading tripping.

[0056] Specifically, fault criteria for new energy power plant faults are calculated based on specific fault information. The timing of protection action is determined by the coordination relationship between the fault criteria and preset protection, so as to clear the fault in the new energy power plant.

[0057] The technical solution of this invention collects real-time voltage and current information from the renewable energy terminal of the transmission line in real time; identifies renewable energy field faults and their fault directions based on the real-time current information; uses real-time current information to determine the fault direction, overcoming the failure of directional elements to operate or maloperate due to fault current frequency deviation, and effectively improving the accuracy of identifying the fault direction of the renewable energy transmission line; if the fault direction is a transmission line fault, the specific fault information of the renewable energy field fault is determined based on the real-time voltage information; the fault criteria of the renewable energy field fault are calculated based on the specific fault information; and the protection action time is determined by the coordination relationship between the fault criteria and preset protection to clear the renewable energy field fault. By utilizing the correlation of line voltage change trends, the fault type and fault phase can be determined simultaneously, eliminating the failure of fault phase selection caused by the unequal positive and negative sequence impedances of new energy sources. This enables accurate and rapid operation of new energy transmission lines. In existing technologies, the frequency deviation of fault current and the unequal positive and negative sequence impedances of electric field in new energy transmission lines make fault protection difficult. This invention can overcome the failure of directional elements to operate or maloperate caused by the frequency deviation of fault current and eliminate the failure of fault phase selection caused by the unequal positive and negative sequence impedances of new energy sources, effectively improving the safety and reliability of the distribution network.

[0058] Figure 2 This is a flowchart illustrating a new energy transmission line protection method based on classification and multi-fusion criteria, provided as an embodiment of the present invention. The relationship between this embodiment and the previous embodiments is to specifically explain the process of identifying the fault direction of a new energy power plant fault. Figure 2 As shown, the method includes:

[0059] S210: Real-time acquisition of voltage and current information at the new energy terminal of the transmission line.

[0060] S220. Determine the real-time current mutation amount based on the real-time current information; if the real-time current mutation amount exceeds a preset threshold, activate the outgoing line protection and record the fault time corresponding to the real-time current mutation amount.

[0061] Optionally, the real-time current fluctuation can be the change in current at the renewable energy transmission line. It should be noted that this is achieved by real-time monitoring of the real-time current information at the renewable energy end of the transmission line.

[0062] Optionally, the preset threshold can be set by pre-setting a safe value for the current change. It should be noted that if the real-time current change exceeds the preset threshold, a fault is considered to have occurred at the renewable energy end of the transmission line; if the real-time current change does not exceed the preset threshold, no fault is considered to have occurred at the renewable energy end of the transmission line.

[0063] Optionally, the real-time current surge can be used as a triggering element. When the real-time current surge exceeds a preset threshold, the outgoing line protection is activated, and the fault time corresponding to the real-time current surge is recorded. The fault time can be understood as the point in time when a fault occurs in the renewable energy power plant. For example, through i... j This represents the current value at the current moment; via i j-M This represents the current value before one power frequency cycle, and M represents the number of sampling points within one power frequency cycle; through The preset threshold for starting the outgoing line protection is set; the calculation formula for determining the starting outgoing line protection is as follows:

[0064]

[0065] Specifically, the real-time current surge is determined based on real-time current information; if the real-time current surge exceeds a preset threshold, the outgoing line protection is activated, and the fault time corresponding to the real-time current surge is recorded.

[0066] S230. Filter the power frequency cycle signal before and after the fault time to determine the first current data; determine the fault direction of the new energy power plant based on the first current data.

[0067] The first current data can be the smoothed current data. The power frequency cycle signal can be understood as the current data for one power frequency cycle.

[0068] Optionally, in this invention, by taking the fault time as the center, acquiring the power frequency cycle signal before and after the fault time, and filtering based on the current value at the current time, the previous power frequency cycle signal, and the next power frequency cycle signal, the first current data is obtained. For example, i j This represents the current value at the current moment. This represents the first current data after smoothing, i j-1 Indicates the signal of the previous power frequency cycle, i j+1 The formula for smoothing the signal in the next power frequency cycle is shown below:

[0069] Here, Med is used to indicate sorting the data within the brackets from smallest to largest and taking the median value.

[0070] Specifically, the power frequency cycle signal corresponding to the time of the fault is filtered one cycle before and after the fault to determine the first current data; the fault direction of the new energy power plant fault is determined based on the first current data.

[0071] Optionally, in another optional embodiment of the present invention, determining the fault direction of the new energy power plant fault based on the first current data includes:

[0072] Based on the first current data, calculate the number of positive and negative changes of the first derivative in the power frequency cycle before the fault and the number of positive and negative changes of the second derivative in the power frequency cycle after the fault.

[0073] Based on the first current data, calculate the number of the first current inflection point in the power frequency cycle before the fault and the number of the second current inflection point in the power frequency cycle after the fault.

[0074] The similarity coefficient is calculated based on the number of positive and negative changes of the first derivative, the number of positive and negative changes of the second derivative, the number of inflection points of the first current, and the number of inflection points of the second current.

[0075] Based on the first current data, a pre-set current mathematical model is used to determine the pre-fault current fitting function and the post-fault current fitting function.

[0076] The fitting coefficients are determined based on the pre-fault current fitting function and the post-fault current fitting function.

[0077] The fault direction is determined based on the similarity coefficient and the fitting coefficient.

[0078] Optionally, the number of positive and negative changes in the first derivative can be the number of positive and negative changes in the current derivative within the power frequency cycle preceding the fault time; the number of positive and negative changes in the second derivative can be the number of positive and negative changes in the current derivative within the power frequency cycle following the fault time. For example, the number of positive and negative changes in the first derivative is represented by a0, and the number of positive and negative changes in the second derivative is represented by a1. The specific calculation method is as follows:

[0079]

[0080] in, Used to represent the current value obtained after smoothing during the first power frequency cycle after the fault. Used to represent the current value obtained after smoothing during the second power frequency cycle after the fault; It indicates the number of times the derivative changes from positive to negative.

[0081] Optionally, the first current inflection point number can be the number of inflection points of the current waveform in one power frequency cycle before the fault; the second current inflection point number can be the number of inflection points of the current waveform in one power frequency cycle after the fault. For example, the first current inflection point number is represented by b0; the second current inflection point number is represented by b1, and the specific calculation formula is as follows:

[0082]

[0083] Where b represents the number of inflection points of the current within one power frequency cycle.

[0084] Optionally, the number of positive and negative changes of the first derivative in the power frequency cycle before the fault and the number of positive and negative changes of the second derivative in the power frequency cycle after the fault are calculated based on the first current data. The number of the first current inflection point in the power frequency cycle before the fault and the number of the second current inflection point in the power frequency cycle after the fault are also calculated based on the first current data.

[0085] Optionally, the similarity coefficient can be used to represent the current similarity between the power frequency cycle before and after the fault. It should be noted that the similarity coefficient between the power frequency cycle before and after the fault is calculated using the number of positive and negative changes of the first derivative, the number of positive and negative changes of the second derivative, the number of first current inflection points, and the number of second current inflection points. Represents the similarity coefficient. The calculation formula is:

[0086]

[0087] Optionally, the preset current mathematical model can be a pre-set current mathematical model for each power frequency cycle. For example, the preset current mathematical model is... Where I can represent the instantaneous current at the moment of the fault within the power frequency cycle; A can represent the current amplitude within the power frequency cycle; B can represent the angular frequency of the power frequency cycle; and C can represent the initial phase of the power frequency cycle.

[0088] Optionally, based on a preset mathematical model of current, the sum of squared residuals can be calculated using current data from two consecutive power frequency cycles. as well as The three partial derivative equations are used to obtain the optimal parameters of the two sets of model data for the last two power frequency cycles. , , and , , The specific calculation method is as follows:

[0089] Among them, t j It can be a time parameter at the moment of the fault; , , Let be the partial derivative of the sum of squared residuals.

[0090] Furthermore, the current fitting function for the power frequency cycle preceding the fault is: That is, the current fitting function before the fault; the current fitting function one power frequency cycle after the fault is... That is, the current fitting function after the fault.

[0091] Optionally, the fitting coefficient can be understood as being calculated from the pre-fault current fitting function and the post-fault current fitting function. For example, the fitting coefficient is defined as r, and its calculation formula is as follows:

[0092]

[0093] in, , For t j The corresponding values ​​of the fitting function for the previous and next power frequency cycles at time 1; It is t j The average value of the fitted function within the previous power frequency cycle, i.e.

[0094] ;

[0095] It is t j The average value of the fitted function within one power frequency cycle after time point 1, i.e.

[0096] .

[0097] Specifically, based on the first current data, the number of positive and negative changes of the first derivative in the power frequency cycle before the fault and the number of positive and negative changes of the second derivative in the power frequency cycle after the fault are calculated; based on the first current data, the number of first current inflection points in the power frequency cycle before the fault and the number of second current inflection points in the power frequency cycle after the fault are calculated; based on the number of positive and negative changes of the first derivative, the number of positive and negative changes of the second derivative, the number of first current inflection points, and the number of second current inflection points, a similarity coefficient is calculated; based on the first current data using a preset current mathematical model, a current fitting function before the fault and a current fitting function after the fault are determined; based on the current fitting function before the fault and the current fitting function after the fault, a fitting coefficient is determined; and based on the similarity coefficient and the fitting coefficient, the fault direction is determined.

[0098] Optionally, in another optional embodiment of the present invention, determining the fault direction based on the similarity coefficient and the fitting coefficient includes:

[0099] If the similarity coefficient and the fitting coefficient are not greater than the first coefficient threshold, the fault direction is considered to be the fault direction of the outgoing line; if the similarity coefficient and / or the fitting coefficient are greater than the first coefficient threshold, a comprehensive judgment coefficient is calculated based on the similarity coefficient and the fitting coefficient. If the comprehensive judgment coefficient is not greater than the second coefficient threshold, the fault direction is considered to be the fault direction of the outgoing line.

[0100] The first coefficient threshold can be a pre-set coefficient threshold used to identify the direction of the fault; the second coefficient threshold can be a pre-set comprehensive evaluation coefficient threshold used to identify the direction of the fault. For example, the first coefficient threshold is set to 0.3; the second coefficient threshold is set to 0.6.

[0101] Optionally, the comprehensive judgment coefficient can be a combined value calculated from the similarity coefficient and the fitting coefficient. It should be noted that the comprehensive judgment coefficient is obtained by assigning weights to the similarity coefficient and the fitting coefficient respectively, and then calculating them together based on these weights. For example, the weight of the similarity coefficient is set to 0.2; the weight of the fitting coefficient is set to 0.8; the judgment process for the comprehensive judgment coefficient and the second coefficient threshold is as follows: .

[0102] Specifically, if the similarity coefficient and the fitting coefficient are not greater than the first coefficient threshold, the fault direction is considered to be the direction of the sending line. If the similarity coefficient and / or the fitting coefficient are greater than the first coefficient threshold, a comprehensive judgment coefficient is calculated based on the similarity coefficient and the fitting coefficient. If the comprehensive judgment coefficient is not greater than the second coefficient threshold, the fault direction is considered to be the direction of the sending line.

[0103] S240. If the fault direction is a fault in the direction of the transmission line, then the specific fault information of the new energy power plant fault is determined based on the real-time voltage information.

[0104] S250. Calculate the fault criteria for the new energy power field fault based on the specific fault information, and determine the protection action time through the coordination relationship between the fault criteria and the preset protection, so as to clear the new energy power field fault.

[0105] The technical solution of this invention collects real-time voltage and current information from the renewable energy terminal of the transmission line in real time; identifies renewable energy field faults and their fault directions based on the real-time current information; uses real-time current information to determine the fault direction, overcoming the failure of directional elements to operate or maloperate due to fault current frequency deviation, and effectively improving the accuracy of identifying the fault direction of the renewable energy transmission line; if the fault direction is a transmission line fault, the specific fault information of the renewable energy field fault is determined based on the real-time voltage information; the fault criteria of the renewable energy field fault are calculated based on the specific fault information; and the protection action time is determined by the coordination relationship between the fault criteria and preset protection to clear the renewable energy field fault. By utilizing the correlation of line voltage change trends, the fault type and fault phase can be determined simultaneously, eliminating the failure of fault phase selection caused by the unequal positive and negative sequence impedances of new energy sources. This enables accurate and rapid operation of new energy transmission lines. In existing technologies, the frequency deviation of fault current and the unequal positive and negative sequence impedances of electric field in new energy transmission lines make fault protection difficult. This invention can overcome the failure of directional elements to operate or maloperate caused by the frequency deviation of fault current and eliminate the failure of fault phase selection caused by the unequal positive and negative sequence impedances of new energy sources, effectively improving the safety and reliability of the distribution network.

[0106] Figure 3 This is a flowchart of a new energy transmission line protection method based on classification multi-fusion criteria provided in an embodiment of the present invention. The relationship between this embodiment and the above embodiments is as follows: [Example 1] Figure 3 As shown, the method includes:

[0107] S310: Real-time acquisition of real-time voltage and current information at the new energy terminal of the transmission line.

[0108] S320. Determine the real-time current mutation amount based on the real-time current information; if the real-time current mutation amount exceeds a preset threshold, activate the outgoing line protection and record the fault time corresponding to the real-time current mutation amount.

[0109] S330. Filter the power frequency cycle signal before and after the fault time to determine the first current data; determine the fault direction of the new energy power plant based on the first current data.

[0110] S340. If the fault direction is a fault in the direction of the outgoing line, then calculate the first line voltage correlation parameter, the second line voltage correlation parameter, and the third line voltage correlation parameter based on the real-time voltage information.

[0111] Optionally, the first line voltage correlation parameter can be a correlation parameter between a first group of line voltages and a second group of line voltages; the second line voltage correlation parameter can be a correlation parameter between the first group of line voltages and a third group of line voltages; the third line voltage correlation parameter can be a correlation parameter between the second group of line voltages and a third group of line voltages. For example, the first group of line voltages is determined by U... AB The second set of line voltages is represented by U. CA The third group of line voltages is represented by U. BC The first line voltage correlation parameter is represented by... Let's represent it as the first group of line voltages U. AB Second group line voltage U CA The correlation coefficient; the second line voltage correlation parameter is obtained through... Let's represent it as the first group of line voltages U. AB and the third group of line voltages U BC The correlation coefficient; the third line voltage correlation parameter is obtained through... This is represented as the second group of line voltages U. AB and the third group of line voltages U BC The correlation coefficients. The formulas for calculating the correlation parameters of various line voltages can be found in the following formulas:

[0112]

[0113] in, Used to represent line voltage correlation coefficients, such as the first line voltage correlation parameter. Second line voltage correlation parameter Correlation parameters with third line voltage ; and This can be understood as voltage data for two sets of line voltages, such as the first set of line voltage U. AB and the third group of line voltages U BC ; and The average voltage data of this group of line voltages.

[0114] Specifically, if the fault direction is the outgoing line direction, the first line voltage correlation parameter, the second line voltage correlation parameter, and the third line voltage correlation parameter are calculated based on the real-time voltage information.

[0115] S350. Determine the specific information of the fault based on the first line voltage correlation parameter, the second line voltage correlation parameter and the third line voltage correlation parameter.

[0116] Specifically, if the fault direction is the outgoing line direction, the first line voltage correlation parameter, the second line voltage correlation parameter, and the third line voltage correlation parameter are calculated based on the real-time voltage information.

[0117] Optionally, the specific fault information includes single-phase ground fault, two-phase short-circuit fault, and three-phase short-circuit fault; in another optional embodiment of the present invention, determining the specific fault information based on the first line voltage correlation parameter, the second line voltage correlation parameter, and the third line voltage correlation parameter includes:

[0118] If any one of the first line voltage correlation parameters, the second line voltage correlation parameter, and the third line voltage correlation parameter satisfies the first fault condition, then the specific fault information is considered to be a single-phase ground fault; if any one of the first line voltage correlation parameters, the second line voltage correlation parameter, and the third line voltage correlation parameter satisfies the second fault condition, then the specific fault information is considered to be a two-phase short-circuit fault; if none of the first line voltage correlation parameters, the second line voltage correlation parameter, and the third line voltage correlation parameter satisfies both the first fault condition and the second fault condition, then the specific fault information is considered to be a three-phase short-circuit fault.

[0119] Optionally, for a single-phase ground fault, the first fault condition is that if a phase voltage is not greater than the rated phase voltage, and the line voltage correlation parameter associated with that phase voltage is within a first preset fault phase range, then that phase voltage is considered a faulty phase, and the specific fault information is a single-phase ground fault. For example, the faulty phase voltage is determined via U... A U B and U C To represent, U ED The formula for determining the faulty phase voltage is as follows: (The voltage is the rated phase voltage.)

[0120]

[0121] The first preset fault phase range is from -1.05 to -0.95.

[0122] Optionally, for a two-phase short-circuit fault, the short circuit involves two phase voltages, i.e., a set of line voltages. The second fault condition for the first, second, and third sets of line voltages is: determining that the set of line voltages is not greater than a specific value of the rated line voltage, and simultaneously determining that the line voltage correlation parameter corresponding to the set of line voltages is within a second preset fault phase interval. For example, the faulty set of line voltages is U... AB U CA U BC In this case, refer to the following formula for judgment:

[0123]

[0124] The second preset fault phase interval is 0.95 to 1.05. Therefore, U is determined to be...AB U CA or U BC This is a two-phase short-circuit fault. A two-phase short-circuit fault is as follows: Figure 4 As shown, Figure 4 This invention discloses a schematic diagram of the current amplitude variation in a two-phase (AB) ground fault.

[0125] Furthermore, if the detected value of the zero-sequence current of the fault phase is also greater than the set value of the zero-sequence current of the fault phase, i.e., the formula is: Then it is believed that U AB U CA or U BC This is a two-phase-to-ground short-circuit fault; The zero-sequence current detection value of the faulty phase; This is the zero-sequence current setting value for the faulted phase. For a two-phase ground fault, such as... Figure 5 As shown, Figure 5 This invention discloses a schematic diagram of the current amplitude variation in a two-phase (AB) short circuit.

[0126] For a three-phase short-circuit fault, if it cannot be determined as a single-phase ground fault or a two-phase short-circuit fault based on the first line voltage correlation parameter, the second line voltage correlation parameter, and the third line voltage correlation parameter, then the specific fault information is considered to be a three-phase short-circuit fault.

[0127] Specifically, if any one of the first, second, and third line voltage correlation parameters satisfies the first fault condition, the specific fault information is considered to be a single-phase ground fault; if any one of the first, second, and third line voltage correlation parameters satisfies the second fault condition, the specific fault information is considered to be a two-phase short-circuit fault; if none of the first, second, and third line voltage correlation parameters satisfies the first and second fault conditions, the specific fault information is considered to be a three-phase short-circuit fault.

[0128] S360. Calculate the fault criteria for the new energy power field fault based on the specific fault information, and determine the protection action time through the coordination relationship between the fault criteria and the preset protection, so as to clear the new energy power field fault.

[0129] Optionally, in another optional embodiment of the present invention, the step of calculating the fault criterion of the new energy power plant based on the specific fault information includes:

[0130] The peak voltage of the fault phase is obtained based on the specific fault information.

[0131] If the peak voltage of the fault phase does not meet the low-voltage ride-through threshold, and if the specific fault information is a single-phase ground fault, then the frequency domain fault criterion is determined based on the fault phase voltage phasor, fault phase current phasor, zero-sequence current compensation coefficient, and zero-sequence current of the new energy power field fault.

[0132] If the peak voltage of the fault phase does not meet the low-voltage ride-through threshold, and if the specific fault information is not a single-phase ground fault, then the frequency domain fault criterion is determined based on the first fault phase voltage phasor, the first fault phase current phasor, the second fault phase voltage phasor, and the second fault phase current phasor of the new energy power field fault.

[0133] When the peak voltage of the fault phase meets the low-voltage ride-through threshold, the time-domain fault criterion is determined based on the impedance information from the fault point to the protection installation location and the voltage sampling value of the protection installation location.

[0134] Optionally, the peak value of the fault phase voltage can be the highest value of the fault phase line voltage. It should be noted that when a single-phase ground fault, a two-phase short-circuit fault, or a three-phase short-circuit fault is detected, the highest value of the fault phase line voltage is collected as the peak value of the fault phase voltage.

[0135] Optionally, the low-voltage ride-through threshold can be a preset voltage threshold, typically set to 0.5 times the rated phase voltage.

[0136] Optionally, the relationship between the peak fault phase voltage and the low-voltage ride-through threshold is identified. If the peak fault phase voltage is not less than the low-voltage ride-through threshold, and the specific fault information indicates a single-phase ground fault, then the impedance from the fault point to the protection installation location, the fault phase voltage phasor, the fault phase current phasor, the zero-sequence current compensation coefficient, and the zero-sequence current are obtained. Based on these parameters, the frequency domain fault criterion, i.e., the impedance from the fault point to the protection installation location, is calculated. For example, this can be achieved through Z... m Indicates the impedance from the fault point to the protection installation location; via U m Represents the fault phase voltage phasor, via I m The fault phase current phasor is represented by K, the zero-sequence current compensation coefficient is represented by I0, and the specific calculation method is as follows:

[0137]

[0138] Optionally, the relationship between the peak voltage of the fault phase and the low-voltage ride-through threshold is identified. When the peak voltage of the fault phase is not less than the low-voltage ride-through threshold, and the specific fault information is not a single-phase ground fault (i.e., a two-phase short-circuit fault or a three-phase short-circuit fault), the voltage phasor, current phasor, voltage phasor, and current phasor of the first fault phase, the second fault phase, and the third fault phase are obtained in the two-phase or three-phase short-circuit fault. The voltage and current phasors of the first and second fault phases can be understood as the voltage and current phasors of any fault phase; the voltage and current phasors of the second and third fault phases can be understood as the voltage and current phasors of any other fault phase. Based on the voltage and current phasors of the first and second fault phases, the frequency domain fault criterion, i.e., the impedance from the fault point to the protection installation point, is determined. For example, through U... m1 Represents the voltage phasor of the first fault phase, via I m1 This represents the phasor of the first fault phase current, via U m2 This represents the voltage phasor of the second fault phase, via I m2 The phasor of the second fault phase current is represented by the following formula:

[0139]

[0140] Optionally, when the peak voltage of the fault phase is less than the low-voltage ride-through threshold, a time-domain fault criterion is selected, which is the impedance amplitude and impedance angle from the fault point to the protection installation point.

[0141] Optionally, the impedance information from the fault point to the protection installation point includes the resistance and inductance from the fault point to the protection installation point.

[0142] Optionally, the voltage sampling value of the protection installation can be understood as the voltage value collected at the protection installation location.

[0143] Optionally, when the peak voltage of the fault phase is less than the low-voltage ride-through threshold, the fault criterion is calculated based on real-time current information by obtaining the resistance and inductance from the fault point to the protection installation point, and acquiring the voltage sampling value of the protection installation point. For example, the resistance from the fault point to the protection installation point is represented by R, the inductance is calculated by L, and the impedance magnitude from the fault point to the protection installation point is represented by A. This represents the impedance angle from the fault point to the protection installation location, expressed as u. j and u j+1 The voltage sampling value for the protection installation is shown in the following calculation process:

[0144] Specifically, the peak value of the fault phase voltage is obtained based on the specific fault information. If the peak value of the fault phase voltage does not meet the low-voltage ride-through threshold, and the specific fault information indicates a single-phase ground fault, then the frequency domain fault criterion is determined based on the fault phase voltage phasor, fault phase current phasor, zero-sequence current compensation coefficient, and zero-sequence current of the new energy electric field fault. If the peak value of the fault phase voltage does not meet the low-voltage ride-through threshold, and the specific fault information indicates a non-single-phase ground fault, then the frequency domain fault criterion is determined based on the first fault phase voltage phasor, first fault phase current phasor, second fault phase voltage phasor, and second fault phase current phasor of the new energy electric field fault. If the peak value of the fault phase voltage meets the low-voltage ride-through threshold, then the time domain fault criterion is determined based on the impedance information from the fault point to the protection installation location and the voltage sampling value of the protection installation location.

[0145] For example, Figure 6 A schematic diagram of a simulation model of a new energy transmission line is disclosed. For example... Figure 6 As shown, N side is the power grid system side, M side is the new energy power plant side, bus M is the new energy power plant outlet bus after the current is collected by the collection line, the transmission line length is 200km, the impedance per unit length of the line is 0.08+j0.406 (Ω / km), where j0.406 is the inductive reactance; the main transformer ratio is 110kV / 35kV, the system side voltage is 110kV. Based on the simulation model of the new energy transmission line, this invention conducts multiple sets of experiments for different fault points and fault types. The fault direction determination results, fault phase selection results, and protection action results for different fault points and fault types are shown in Examples 1 to 14. The following cases all take the protection of the M side (new energy power plant side) as an example, specifically:

[0146] Example 1: Figure 7 A schematic diagram illustrating the current amplitude variation during a phase-A ground fault is disclosed. When a phase-A ground fault occurs 80km from the M-side of the transmitting line, the M-side protection detects a current surge exceeding a threshold, and the protection is activated. The direction criteria are as follows: , The fault was correctly identified as occurring in the direction of the outgoing line. Furthermore, the correlation coefficient of the line voltage was [missing information]. The fault type was accurately determined to be a single-phase ground fault, and the faulty phase was phase A. At this time, the voltage of the outgoing line was 0.55 times the rated voltage, which was greater than the low-voltage ride-through threshold and did not meet the conditions for electric field initiation of low-voltage ride-through. The frequency domain method was selected to calculate the fault criterion, and the impedance value from side M to the fault point was found to be 6.327 + j32.447Ω, which is approximately 40% of the total impedance of the outgoing line. The protection operated correctly.

[0147] Example 2: When a two-phase short circuit fault (phases B and C) occurs 140km from the M-side transmission line, the M-side protection detects a current surge exceeding the threshold and activates. The direction criteria are as follows: , The fault was correctly identified as occurring in the direction of the outgoing line. Furthermore, the correlation coefficient of the line voltage was [missing information]. The fault type was accurately determined to be a two-phase short-circuit fault, with the faulty phases being phases B and C. At this time, the voltage drop of the outgoing line was 0.4 times the rated voltage, which was below the low-voltage ride-through threshold and met the conditions for electric field-initiated low-voltage ride-through. The time-domain method was selected to calculate the fault criterion, and the impedance value from side M to the fault point was found to be 10.841 + j52.658Ω, which is approximately 70% of the total impedance of the outgoing line. The protection system operated correctly.

[0148] Example 3: Figure 8 A schematic diagram illustrating the current amplitude variation during a three-phase ground fault is disclosed. When a three-phase short circuit fault occurs 180km from the M-side of the transmitting line, the M-side protection detects a current surge exceeding a threshold and activates the protection. The direction criteria are as follows: , The fault was correctly identified as occurring in the direction of the outgoing line. Since the correlation coefficients of the three line voltages were equal, the fault type was determined to be a three-phase short circuit. At this time, the outgoing line voltage dropped to 0.3 times the rated voltage, meeting the conditions for low-voltage ride-through during the startup of the new energy power plant. Using the time-domain method to calculate the fault criterion, the impedance value from side M to the fault point was found to be 13.164 + j71.38 Ω, approximately 90% of the total impedance of the outgoing line. The protection action was completed and performed correctly.

[0149] Example 4: When a fault occurs in the collector line within the new energy power plant to the right of point M, the protection on the M side detects a current surge exceeding the threshold and activates. The direction criteria are as follows: , The fault was correctly identified as occurring in the direction of the new energy field, and the protection system did not activate.

[0150] The technical solution of this invention collects real-time voltage and current information from the renewable energy terminal of the transmission line in real time; identifies renewable energy field faults and their fault directions based on the real-time current information; uses real-time current information to determine the fault direction, overcoming the failure of directional elements to operate or maloperate due to fault current frequency deviation, and effectively improving the accuracy of identifying the fault direction of the renewable energy transmission line; if the fault direction is a transmission line fault, the specific fault information of the renewable energy field fault is determined based on the real-time voltage information; the fault criteria of the renewable energy field fault are calculated based on the specific fault information; and the protection action time is determined by the coordination relationship between the fault criteria and preset protection to clear the renewable energy field fault. By utilizing the correlation of line voltage change trends, the fault type and fault phase can be determined simultaneously, eliminating the failure of fault phase selection caused by the unequal positive and negative sequence impedances of new energy sources. This enables accurate and rapid operation of new energy transmission lines. In existing technologies, the frequency deviation of fault current and the unequal positive and negative sequence impedances of electric field in new energy transmission lines make fault protection difficult. This invention can overcome the failure of directional elements to operate or maloperate caused by the frequency deviation of fault current and eliminate the failure of fault phase selection caused by the unequal positive and negative sequence impedances of new energy sources, effectively improving the safety and reliability of the distribution network.

[0151] Figure 9 This is a schematic diagram of a new energy transmission line protection device based on classification multi-fusion criteria, provided as an embodiment of the present invention. Figure 9 As shown, the device includes: a data acquisition module 910, a fault diagnosis module 920, a fault analysis module 930, and a fault processing module 940; wherein,

[0152] The data acquisition module 910 is used to collect real-time voltage and current information at the new energy terminal of the transmission line.

[0153] The fault diagnosis module 920 is used to identify faults in the new energy electric field and the fault direction of the new energy electric field based on real-time current information.

[0154] The fault analysis module 930 is used to determine the specific fault information of the new energy power plant based on the real-time voltage information if the fault direction is a fault in the direction of the transmission line.

[0155] The fault handling module 940 is used to calculate the fault criteria of the new energy power field based on the specific fault information, and determine the protection action time through the coordination relationship between the fault criteria and the preset protection, so as to clear the fault of the new energy power field.

[0156] The technical solution of this invention collects real-time voltage and current information from the renewable energy terminal of the transmission line in real time; identifies renewable energy field faults and their fault directions based on the real-time current information; uses real-time current information to determine the fault direction, overcoming the failure of directional components to operate or maloperate due to fault current frequency deviation, and effectively improving the accuracy of identifying the fault direction of the renewable energy transmission line; if the fault direction is a transmission line fault, then the specific fault information of the renewable energy field fault is determined based on the real-time voltage information.

[0157] Based on the specific fault information, a fault criterion for the new energy electric field fault is calculated. The protection action time is determined through the coordination relationship between the fault criterion and preset protection, thereby clearing the new energy electric field fault. The fault type and fault phase are simultaneously determined by utilizing the correlation of line voltage change trends, eliminating the failure of fault phase selection caused by unequal positive and negative sequence impedances of the new energy source. This achieves accurate and rapid operation of the new energy transmission line. Existing technologies address the technical problems of difficulty in fault protection due to fault current frequency deviation and unequal positive and negative sequence impedances of the electric field in new energy transmission lines. This invention overcomes the failure of directional elements to operate or maloperate caused by fault current frequency deviation and eliminates the failure of fault phase selection caused by unequal positive and negative sequence impedances of the new energy source, effectively improving the safety and reliability of the distribution network.

[0158] Optionally, the fault diagnosis module 920 is specifically used for:

[0159] The real-time current mutation amount is determined based on the real-time current information;

[0160] If the real-time current surge exceeds a preset threshold, the outgoing line protection is activated, and the fault time corresponding to the real-time current surge is recorded.

[0161] Filter the power frequency cycle signal before and after the fault time to determine the first current data;

[0162] The fault direction of the new energy power plant is determined based on the first current data.

[0163] Optionally, the fault diagnosis module 920 is further used for:

[0164] Based on the first current data, calculate the number of positive and negative changes of the first derivative in the power frequency cycle before the fault and the number of positive and negative changes of the second derivative in the power frequency cycle after the fault.

[0165] Based on the first current data, calculate the number of the first current inflection point in the power frequency cycle before the fault and the number of the second current inflection point in the power frequency cycle after the fault.

[0166] The similarity coefficient is calculated based on the number of positive and negative changes of the first derivative, the number of positive and negative changes of the second derivative, the number of inflection points of the first current, and the number of inflection points of the second current.

[0167] Based on the first current data, a pre-set current mathematical model is used to determine the pre-fault current fitting function and the post-fault current fitting function.

[0168] The fitting coefficients are determined based on the pre-fault current fitting function and the post-fault current fitting function.

[0169] The fault direction is determined based on the similarity coefficient and the fitting coefficient.

[0170] Optionally, the fault diagnosis module 920 is further used for:

[0171] If the similarity coefficient and the fitting coefficient are not greater than the first coefficient threshold, the fault direction is considered to be a fault in the direction of the delivery line.

[0172] If the similarity coefficient and / or the fitting coefficient are greater than the first coefficient threshold, a comprehensive judgment coefficient is calculated based on the similarity coefficient and the fitting coefficient. If the comprehensive judgment coefficient is not greater than the second coefficient threshold, the fault direction is considered to be the fault direction of the sending line.

[0173] Optionally, the fault analysis module 930 is specifically used for:

[0174] Calculate the first line voltage correlation parameter, the second line voltage correlation parameter, and the third line voltage correlation parameter based on the real-time voltage information;

[0175] The specific information about the fault is determined based on the first line voltage correlation parameter, the second line voltage correlation parameter, and the third line voltage correlation parameter.

[0176] Optionally, the fault analysis module 930 is further used for:

[0177] The specific information about the faults includes single-phase grounding faults, two-phase short-circuit faults, and three-phase short-circuit faults.

[0178] If any one of the first line voltage correlation parameter, the second line voltage correlation parameter, and the third line voltage correlation parameter satisfies the first fault condition, then the specific fault information is considered to be the single-phase ground fault;

[0179] If any one of the first line voltage correlation parameter, the second line voltage correlation parameter, and the third line voltage correlation parameter satisfies the second fault condition, then the specific fault information is considered to be the two-phase short-circuit fault;

[0180] If none of the first line voltage correlation parameters, the second line voltage correlation parameters, and the third line voltage correlation parameters satisfy the first fault condition and the second fault condition, then the specific fault information is considered to be the three-phase short-circuit fault.

[0181] Optionally, the fault handling module 940 is specifically used for:

[0182] The peak voltage of the fault phase is obtained based on the specific fault information.

[0183] If the peak voltage of the fault phase does not meet the low-voltage ride-through threshold, and if the specific fault information is a single-phase ground fault, then the frequency domain fault criterion is determined based on the fault phase voltage phasor, fault phase current phasor, zero-sequence current compensation coefficient, and zero-sequence current of the new energy power field fault.

[0184] If the peak voltage of the fault phase does not meet the low-voltage ride-through threshold, and if the specific fault information is not a single-phase ground fault, then the frequency domain fault criterion is determined based on the first fault phase voltage phasor, the first fault phase current phasor, the second fault phase voltage phasor, and the second fault phase current phasor of the new energy power field fault.

[0185] When the peak voltage of the fault phase meets the low-voltage ride-through threshold, the time-domain fault criterion is determined based on the impedance information from the fault point to the protection installation location and the voltage sampling value of the protection installation location.

[0186] The new energy transmission line protection device based on classification and multi-fusion criteria provided in the embodiments of the present invention can execute the new energy transmission line protection method based on classification and multi-fusion criteria provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0187] Figure 10 A schematic diagram of an electronic device 10 that can be used to implement embodiments of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital assistants, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their patterns are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0188] like Figure 10As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 can also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0189] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of monitors, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer grids such as the Internet and / or various telecommunications grids.

[0190] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, central processing unit (CPU), graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as the new energy transmission line protection method based on classification multi-fusion criteria.

[0191] In some embodiments, the renewable energy transmission line protection method based on classification multi-fusion criteria can be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the renewable energy transmission line protection method based on classification multi-fusion criteria described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to perform the renewable energy transmission line protection method based on classification multi-fusion criteria by any other suitable means (e.g., by means of firmware).

[0192] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0193] Computer programs used to implement the methods of the present invention can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the patterns / operations specified in the flowcharts and / or block diagrams to be implemented. The computer programs can be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0194] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0195] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0196] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or middleware components (e.g., application servers), or frontend components (e.g., user computers with graphical user interfaces or grid browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., a communication grid). Examples of communication grids include local area networks (LANs), wide area networks (WANs), blockchain grids, and the Internet.

[0197] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS servers, such as high management difficulty and weak business scalability.

[0198] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0199] This embodiment provides a computer-readable storage medium storing a computer program thereon. When executed by a processor, the program implements the steps of the new energy transmission line protection method based on classification multi-fusion criteria provided in any embodiment of the present invention. The method includes:

[0200] Real-time voltage and current information are collected at the new energy terminal of the transmission line.

[0201] Based on real-time current information, faults in new energy electric fields and the fault directions of such new energy electric fields are identified.

[0202] If the fault direction is the direction of the transmission line, then the specific fault information of the new energy power plant fault is determined based on the real-time voltage information.

[0203] Based on the specific fault information, the fault criteria for the new energy power plant fault are calculated. The timing of the protection action is determined by the coordination relationship between the fault criteria and the preset protection, so as to clear the fault in the new energy power plant.

[0204] The computer storage medium of this invention can be any combination of one or more computer-readable media. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0205] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0206] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to: wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0207] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages—such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of mesh, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0208] Those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a grid of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby allowing them to be stored in a storage device for execution by a computing device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0209] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0210] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A protection method for new energy transmission lines based on classification and multi-fusion criteria, characterized in that, include: Real-time voltage and current information are collected at the new energy terminal of the transmission line. Based on real-time current information, faults in new energy electric fields and the fault directions of such new energy electric fields are identified. If the fault direction is the direction of the transmission line, then the specific fault information of the new energy power plant fault is determined based on the real-time voltage information. Based on the specific fault information, the fault criteria for the new energy power plant fault are calculated. The timing of the protection action is determined by the coordination relationship between the fault criteria and the preset protection, so as to clear the fault in the new energy power plant.

2. The method according to claim 1, characterized in that, The method of identifying faults in new energy power fields and their fault directions based on real-time current information includes: The real-time current mutation amount is determined based on the real-time current information; If the real-time current surge exceeds a preset threshold, the outgoing line protection is activated, and the fault time corresponding to the real-time current surge is recorded. Filter the power frequency cycle signal before and after the fault time to determine the first current data; The fault direction of the new energy power plant is determined based on the first current data.

3. The method according to claim 2, characterized in that, Determining the fault direction of the new energy power plant based on the first current data includes: Based on the first current data, calculate the number of positive and negative changes of the first derivative in the power frequency cycle before the fault and the number of positive and negative changes of the second derivative in the power frequency cycle after the fault. Based on the first current data, calculate the number of the first current inflection point in the power frequency cycle before the fault and the number of the second current inflection point in the power frequency cycle after the fault. The similarity coefficient is calculated based on the number of positive and negative changes of the first derivative, the number of positive and negative changes of the second derivative, the number of inflection points of the first current, and the number of inflection points of the second current. Based on the first current data, a pre-set current mathematical model is used to determine the pre-fault current fitting function and the post-fault current fitting function. The fitting coefficients are determined based on the pre-fault current fitting function and the post-fault current fitting function. The fault direction is determined based on the similarity coefficient and the fitting coefficient.

4. The method according to claim 3, characterized in that, Determining the fault direction based on the similarity coefficient and the fitting coefficient includes: If the similarity coefficient and the fitting coefficient are not greater than the first coefficient threshold, the fault direction is considered to be a fault in the direction of the delivery line. If the similarity coefficient and / or the fitting coefficient are greater than the first coefficient threshold, a comprehensive judgment coefficient is calculated based on the similarity coefficient and the fitting coefficient. If the comprehensive judgment coefficient is not greater than the second coefficient threshold, the fault direction is considered to be the fault direction of the sending line.

5. The method according to claim 1, characterized in that, The specific fault information determined based on the real-time voltage information for the new energy power plant fault includes: Calculate the first line voltage correlation parameter, the second line voltage correlation parameter, and the third line voltage correlation parameter based on the real-time voltage information; The specific information about the fault is determined based on the first line voltage correlation parameter, the second line voltage correlation parameter, and the third line voltage correlation parameter.

6. The method according to claim 5, characterized in that, The specific information about the faults includes single-phase grounding faults, two-phase short-circuit faults, and three-phase short-circuit faults. The step of determining the specific fault information based on the first line voltage correlation parameter, the second line voltage correlation parameter, and the third line voltage correlation parameter includes: If any one of the first line voltage correlation parameter, the second line voltage correlation parameter, and the third line voltage correlation parameter satisfies the first fault condition, then the specific fault information is considered to be the single-phase ground fault; If any one of the first line voltage correlation parameter, the second line voltage correlation parameter, and the third line voltage correlation parameter satisfies the second fault condition, then the specific fault information is considered to be the two-phase short-circuit fault; If none of the first line voltage correlation parameters, the second line voltage correlation parameters, and the third line voltage correlation parameters satisfy the first fault condition and the second fault condition, then the specific fault information is considered to be the three-phase short-circuit fault.

7. The method according to claim 1, characterized in that, The fault criteria include frequency domain fault criteria and time domain fault criteria; the fault criteria for calculating the fault of the new energy power plant based on the specific fault information include: The peak voltage of the fault phase is obtained based on the specific fault information. If the peak voltage of the fault phase does not meet the low-voltage ride-through threshold, and if the specific fault information is a single-phase ground fault, then the frequency domain fault criterion is determined based on the fault phase voltage phasor, fault phase current phasor, zero-sequence current compensation coefficient, and zero-sequence current of the new energy power field fault. If the peak voltage of the fault phase does not meet the low-voltage ride-through threshold, and if the specific fault information is not a single-phase ground fault, then the frequency domain fault criterion is determined based on the first fault phase voltage phasor, the first fault phase current phasor, the second fault phase voltage phasor, and the second fault phase current phasor of the new energy power field fault. When the peak voltage of the fault phase meets the low-voltage ride-through threshold, the time-domain fault criterion is determined based on the impedance information from the fault point to the protection installation location and the voltage sampling value of the protection installation location.

8. A new energy transmission line protection device based on classification multi-fusion criteria, characterized in that, include: The data acquisition module is used to collect real-time voltage and current information at the new energy terminal of the transmission line. The fault diagnosis module is used to identify faults in the new energy electric field and the fault direction of the new energy electric field based on real-time current information. The fault analysis module is used to determine the specific fault information of the new energy power plant based on the real-time voltage information if the fault direction is the direction of the transmission line. The fault handling module is used to calculate the fault criteria of the new energy power field based on the specific fault information, and determine the protection action time through the coordination relationship between the fault criteria and the preset protection, so as to clear the fault of the new energy power field.

9. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the new energy transmission line protection method based on classification multi-fusion criteria as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that are used to cause a processor to execute the new energy transmission line protection method based on classification multi-fusion criteria as described in any one of claims 1-7.

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