Relay protection algorithm adaptability evaluation method and device, equipment and storage medium

Abstract

The embodiment of the invention discloses a relay protection algorithm adaptability evaluation method and device, equipment and a storage medium, and relates to the technical field of power system protection. The method comprises the steps of obtaining to-be-evaluated power grid information and a relay protection algorithm corresponding to a to-be-evaluated power grid; simulating the to-be-evaluated power grid according to a relay protection algorithm to obtain simulated electrical data of the to-be-evaluated power grid in a fault state; determining a fitness value of a relay protection algorithm of the to-be-evaluated power grid according to the simulation electrical data of the to-be-evaluated power grid in the fault state; and determining an adaptability evaluation result of the relay protection algorithm according to the fitness value of the relay protection algorithm. According to the embodiment of the invention, the simulation electrical data obtained through simulation is converted into the fitness value of the specific relay protection algorithm, and the evaluation of the adaptability of the relay protection algorithm under a complex operation condition is realized.

Description

Technical Field

[0001] This application belongs to the field of power system protection technology, and particularly relates to a method, apparatus, equipment and storage medium for adaptive evaluation of relay protection algorithms. Background Technology

[0002] With the rapid construction of new power systems, the high proportion of renewable energy grid connection, the large-scale access of power electronic equipment, and the increasing complexity of AC / DC hybrid power grids, relay protection algorithms face severe challenges in terms of operational reliability.

[0003] Existing evaluation methods for relay protection algorithms mostly focus on the reliability of protection actions under a single fault scenario, i.e. whether the correct protection can be performed when a fault occurs. However, with the formation of AC / DC hybrid power grids and the increasing complexity of user load characteristics, there are often multiple fault conditions in power networks. Relay protection algorithms often need to face multiple operational faults and perform protection. Existing evaluation methods are difficult to assess the adaptability of relay protection algorithms under complex operating conditions. Summary of the Invention

[0004] This application provides a method, apparatus, device, and storage medium for evaluating the adaptability of relay protection algorithms, in order to solve the problem that existing evaluation methods are difficult to evaluate the adaptability of relay protection algorithms under complex operating conditions.

[0005] In a first aspect, embodiments of this application provide a method for evaluating the adaptability of relay protection algorithms, the method comprising:

[0006] Obtain information about the power grid to be evaluated and the corresponding relay protection algorithm for the power grid to be evaluated;

[0007] The power grid to be evaluated is simulated based on the relay protection algorithm to obtain the simulated electrical data of the power grid under fault conditions.

[0008] The fitness value of the relay protection algorithm for the power grid under fault conditions is determined based on the simulated electrical data of the power grid under fault conditions.

[0009] The fitness evaluation result of the relay protection algorithm is determined based on the fitness value of the relay protection algorithm.

[0010] Secondly, embodiments of this application provide an apparatus for evaluating the adaptability of relay protection algorithms, the apparatus comprising:

[0011] The acquisition module is used to acquire information about the power grid to be evaluated and the corresponding relay protection algorithm for the power grid to be evaluated.

[0012] The simulation module is used to simulate the power grid to be evaluated based on the relay protection algorithm, and obtain the simulated electrical data of the power grid to be evaluated under fault conditions.

[0013] The determination module is used to determine the fitness value of the relay protection algorithm of the power grid to be evaluated based on the simulated electrical data of the power grid under fault conditions.

[0014] The determination module is also used to determine the fitness evaluation result of the relay protection algorithm based on the fitness value of the relay protection algorithm.

[0015] Thirdly, embodiments of this application provide a terminal device, which includes: a processor and a memory storing computer program instructions; the processor executes the computer program instructions to implement the method for adaptive evaluation of relay protection algorithms as described in the first aspect.

[0016] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer program instructions, which, when executed by a processor, implement the method for adaptive evaluation of relay protection algorithms as described in the first aspect.

[0017] Fifthly, embodiments of this application provide a computer program product in which instructions, when executed by a processor of an electronic device, cause the electronic device to perform a method for adaptive evaluation of relay protection algorithms as described in the first aspect.

[0018] This application provides a method for evaluating the adaptability of relay protection algorithms. This method converts simulated electrical data obtained from simulations into fitness values ​​for specific relay protection algorithms. The fitness value reflects the adaptability of the relay protection algorithm under various fault conditions. Simultaneously, by acquiring simulated electrical data, the electrical data of the power grid under various fault conditions can be simulated, comprehensively reflecting the corresponding situation of the relay protection algorithm under different fault conditions, and providing comprehensive information for subsequent accurate evaluation of the algorithm's adaptability. Therefore, this application achieves the evaluation of the adaptability of relay protection algorithms under complex operating conditions. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart illustrating the method for evaluating the adaptability of relay protection algorithms provided in an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of a digital model of a multi-area DC asynchronous interconnected power grid provided in an embodiment of this application;

[0022] Figure 3This is a schematic diagram of the differential current and braking current under a single-phase ground fault of phase A with a fault location percentage of 0%, as provided in the embodiments of this application.

[0023] Figure 4 This is a schematic diagram of the differential current and braking current under a single-phase ground fault of phase A with a fault location percentage of 50%, as provided in the embodiments of this application.

[0024] Figure 5 This is a schematic diagram of the differential current and braking current under a single-phase ground fault of phase A with a fault location percentage of 100%, as provided in the embodiments of this application.

[0025] Figure 6 This is a schematic diagram of the differential current and braking current under a two-phase short-circuit fault of phase AB with a fault location percentage of 0%, as provided in the embodiments of this application.

[0026] Figure 7 This is a schematic diagram of the differential current and braking current under a two-phase short-circuit fault of phase AB with a fault location percentage of 50%, as provided in the embodiments of this application.

[0027] Figure 8 This is a schematic diagram of the differential current and braking current under a two-phase short-circuit fault of phase AB with a fault location percentage of 100%, as provided in the embodiments of this application.

[0028] Figure 9 This is a schematic diagram of the limit safety domain for single-phase ground fault protection provided in an embodiment of this application;

[0029] Figure 10 This is a schematic diagram of the limit safety domain of two-phase short-circuit fault protection provided in the embodiments of this application;

[0030] Figure 11 This is a schematic diagram of the structure of the device for evaluating the adaptability of relay protection algorithms provided in the embodiments of this application;

[0031] Figure 12 This is a schematic diagram of the structure of the terminal device provided in the embodiments of this application. Detailed Implementation

[0032] The features and exemplary embodiments of various aspects of the embodiments of this application will be described in detail below. To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the embodiments of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the embodiments of this application and are not intended to limit the embodiments of this application. For those skilled in the art, the embodiments of this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of the embodiments of this application by illustrating examples of them.

[0033] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0034] Traditional relay protection algorithm evaluation methods primarily focus on the reliability of protection actions under single fault scenarios, i.e., whether correct protection can be provided when a fault occurs. This evaluation method typically assumes that the fault type and location are known and considers only one or a few typical fault conditions. However, in actual operation, power networks may face various fault conditions, including but not limited to ground faults, phase-to-phase faults, three-phase short-circuit faults, and various complex mixed faults. Furthermore, the location of the fault point, transition resistance, and the grid operating state at the time of the fault all significantly impact the performance of the protection algorithm.

[0035] Therefore, existing evaluation methods are insufficient to comprehensively assess the adaptability of relay protection algorithms under various fault scenarios and cannot accurately reflect the performance of protection algorithms in actual power grids. This may lead to the protection algorithms failing to operate correctly in certain fault scenarios during actual operation, thereby affecting the safe and stable operation of the power grid.

[0036] To address the problems in existing technologies, this application proposes a method for evaluating the adaptability of relay protection algorithms. This method transforms simulated electrical data obtained from simulations into fitness values ​​for specific relay protection algorithms. These fitness values ​​reflect the adaptability of the relay protection algorithm under various fault conditions. Simultaneously, by acquiring simulated electrical data, the electrical data of the power grid under various fault conditions can be simulated, comprehensively reflecting the corresponding situation of the relay protection algorithm under different fault conditions. This provides comprehensive information for accurately evaluating the adaptability of the relay protection algorithm. Therefore, this application achieves the evaluation of the adaptability of relay protection algorithms under complex operating conditions.

[0037] The method for evaluating the adaptability of relay protection algorithms provided in the embodiments of this application will be described below with reference to the accompanying drawings.

[0038] Figure 1This illustration shows a flowchart of a method for adaptive evaluation of relay protection algorithms provided in one embodiment of this application. Figure 1 As shown, the method may include the following steps: S101 to S104.

[0039] S101, Obtain the information of the power grid to be evaluated and the corresponding relay protection algorithm of the power grid to be evaluated.

[0040] The power grid information to be evaluated consists of detailed information describing the power grid structure, parameters, and operating status. Relay protection algorithms refer to the logical methods used to detect power grid faults and trigger the operation of protection devices.

[0041] In some embodiments, the power grid to be evaluated is a multi-area DC interconnected power grid.

[0042] In some embodiments, the present application embodiments can obtain power grid structure information from the power grid design drawings of the power grid to be evaluated, and identify the topology of the power grid from the power grid design drawings, which may include the location of each component and the connection relationship of components such as transmission lines, substations, buses, generators, and loads.

[0043] In some embodiments, the parameters of the power grid to be evaluated are obtained from the technical manual of the power grid to be evaluated or from field tests. The technical manual typically contains parameter information such as the rated parameters of the equipment, performance curves, and protection settings, or the parameter information of the power grid is measured by testing equipment during field tests.

[0044] In some embodiments, real-time operating status data of the power grid can be obtained from the power grid monitoring system corresponding to the power grid to be evaluated. This can be achieved by connecting to the power grid monitoring system via a network connection or data interface and using the data reading function of the monitoring system to obtain the real-time operating status data of the power grid.

[0045] In some embodiments, the relay protection algorithm can be a distance protection algorithm, which determines whether a fault is within the protection range based on the measured impedance. For example, when the measured impedance is less than a set value, it is determined to be a fault within the zone, triggering the protection action.

[0046] In some embodiments, the relay protection algorithm can be a differential protection algorithm, which determines the fault by comparing the magnitude and direction of the current at both ends of the line. For example, when the current difference between the two ends of the line exceeds a set threshold, it is determined to be a fault, and the protection action is triggered.

[0047] This application embodiment obtains the power grid information to be evaluated and the corresponding relay protection algorithm of the power grid to be evaluated, thereby providing comprehensive and complete input data for subsequent steps and providing a data foundation for the evaluation process.

[0048] S102, Simulate the power grid to be evaluated according to the relay protection algorithm to obtain the simulated electrical data of the power grid under fault conditions.

[0049] In some embodiments, the present application uses a relay protection algorithm to simulate the power grid to be evaluated, and obtains electrical quantity data at the installation location of the relay protection device under fault conditions, such as voltage, current and impedance data of the power grid under fault conditions.

[0050] In some embodiments, the present application can use power system simulation software to perform fault simulation on the power grid to be evaluated using batch automated simulation methods.

[0051] In some embodiments, the present application may use the simulation engine of Power Systems Computer-Aided Design (PSCAD / EMTDC) (Electromagnetic Transients including DC, EMTDC) or the mathematical calculation software MATLAB to simulate the power grid to be evaluated.

[0052] In actual power grids, faults occur randomly and uncontrollably. The embodiments of this application can simulate various fault scenarios, including common faults and extreme faults, thereby providing comprehensive and detailed simulation data and improving the comprehensiveness and accuracy of subsequent evaluation results.

[0053] S103, determine the fitness value of the relay protection algorithm of the power grid to be evaluated based on the simulated electrical data of the power grid under fault conditions.

[0054] The fitness value is a comprehensive indicator used to quantitatively evaluate the protection performance of relay protection algorithms under various fault scenarios. A high fitness value indicates that the relay protection algorithm can correctly trigger protection actions under various fault states of the power grid being evaluated.

[0055] In some embodiments, the fitness value can be determined based on the proportion of times the relay protection algorithm correctly triggers protection actions in the simulation count, according to the simulated electrical data under fault conditions.

[0056] This application embodiment converts simulated electrical data into specific fitness values. Fitness values ​​provide a clear quantitative indicator of the performance of relay protection algorithms, thereby realizing a quantitative evaluation of the performance of relay protection algorithms.

[0057] S104, Determine the fitness evaluation result of the relay protection algorithm based on the fitness value of the relay protection algorithm.

[0058] In some embodiments, the present application can determine the fitness evaluation result of the corresponding numerical range of the fitness value based on the fitness value of the relay protection algorithm. For example, the fitness value can be divided into three numerical ranges: low fitness, medium fitness, and high fitness. When the calculated fitness value of the relay protection algorithm of the power grid to be evaluated is in the numerical range corresponding to high fitness, the fitness evaluation result of high fitness is output.

[0059] The embodiments of this application determine the final adaptability evaluation result by using fitness values, which can clarify the applicability of the relay protection algorithm in the power grid to be evaluated and provide a clear evaluation conclusion to determine whether the relay protection algorithm is suitable for the power grid to be evaluated.

[0060] This application embodiment transforms simulated electrical data obtained from simulation into fitness values ​​for specific relay protection algorithms. The fitness value reflects the adaptability of the relay protection algorithm under various fault conditions. Simultaneously, by acquiring simulated electrical data, the electrical data of the power grid under various fault conditions can be simulated, comprehensively reflecting the corresponding situation of the relay protection algorithm under different fault conditions. This provides comprehensive information for subsequent accurate evaluation of the adaptability of the relay protection algorithm. Therefore, this application embodiment realizes the evaluation of the adaptability of relay protection algorithms under complex operating conditions.

[0061] In some embodiments, the power grid information to be evaluated includes power grid structure information. The power grid to be evaluated is simulated according to a relay protection algorithm to obtain simulated electrical data of the power grid under fault conditions, which may include:

[0062] Based on the grid structure information of the power grid to be evaluated, a digital model of the grid structure of the power grid to be evaluated is determined;

[0063] Based on the relay protection algorithm corresponding to the power grid to be evaluated, a digital model of the grid structure of the power grid to be evaluated is used to simulate and obtain the simulated electrical data of the power grid under fault conditions.

[0064] Existing technologies often simplify complex power grid results when simulating power grids under evaluation, and perform simulations based on general power grid structures, thus making them applicable to various power grid scenarios. However, such general power grid structures can only consider common fault scenarios and cannot reflect the complex characteristics of actual power grids and fault conditions under extreme operating conditions. Therefore, the data obtained from the simulation cannot comprehensively and accurately evaluate the adaptability of relay protection algorithms.

[0065] This application embodiment converts the power grid structure into a digital form for simulation. It can generate customized digital models for the actual power grid structure in different regions, thereby simulating the actual operation of the power grid more accurately, improving the reliability of the simulation results, and providing more comprehensive data for the adaptive evaluation of subsequent relay protection algorithms.

[0066] In some embodiments, the present application embodiments may use the PSCAD / EMTDC user graphical interface PSCAD or the Simulink module of the mathematical calculation software MATLAB to generate a digital model of the power grid to be evaluated.

[0067] In some embodiments, the power grid structure information includes the components in the power grid to be evaluated and how those components are connected.

[0068] In one example, this embodiment of the application generates a corresponding digital model based on the grid structure information of a multi-regional DC asynchronous interconnected power grid. The power supply nodes of the first region are connected to the main power supply node via AC lines. The power supply nodes of the second region are connected to the main power supply node sequentially via transformers, two Modular Multilevel Converters (MMCs), and another transformer. The power supply nodes of the third region are connected to the main power supply node sequentially via transformers, two Line Commutated Converters (LCCs), and another transformer. The main power supply is connected to the load elements. The generated digital model is as follows: Figure 2 As shown.

[0069] In some embodiments, the fault state includes at least one; based on the relay protection algorithm corresponding to the power grid to be evaluated, a digital model of the grid structure of the power grid to be evaluated is simulated to obtain the simulated electrical data of the power grid to be evaluated under the fault state, including:

[0070] Based on the relay protection algorithm corresponding to the power grid to be evaluated, the power grid to be evaluated is simulated under different operating conditions of various fault states, and the simulation electrical data of the installation location of the relay protection device corresponding to the relay protection algorithm is obtained under different operating conditions of various fault states.

[0071] This application embodiment obtains simulated electrical data covering multiple fault types and operating conditions by performing simulations under various fault states and operating conditions, ensuring the accuracy of subsequent relay protection algorithm evaluation results and avoiding the problem of low evaluation accuracy due to omission of some fault types or operating conditions.

[0072] In some embodiments, the fault state may include multiple fault types, such as ground fault, phase-to-phase fault, three-phase short-circuit fault, etc. Different operating conditions of the fault state may include different fault situations under the same fault state, such as different fault locations, different fault lines and different transition resistance values ​​under the same fault state.

[0073] In one example, for a 100-kilometer-long transmission line network, simulations were performed for ground faults, phase-to-phase faults, and three-phase short-circuit faults occurring at 10 km, 50 km, and 90 km, respectively, to obtain simulated electrical data for the transmission line network at these locations.

[0074] In some embodiments, the electrical data includes the maximum withstand resistance value of the relay protection algorithm and the fault location and the fault distance between the fault location and the installation location of the relay protection device corresponding to the relay protection algorithm. The fitness value of the relay protection algorithm for the power grid under fault conditions is determined based on the simulated electrical data of the power grid under fault conditions, including:

[0075] The tolerance value for each fault condition is obtained by multiplying the ratio of the maximum withstand protection resistance value of the relay protection algorithm to the preset maximum required protection resistance value, the ratio of the fault distance to the preset protection installation line length, and the preset coefficient.

[0076] The required value for each fault state is obtained by multiplying the ratio of the fault distance to the preset protection installation line length under each fault state by a preset coefficient.

[0077] The fitness value of the relay protection algorithm for the power grid to be evaluated is obtained by dividing the sum of the tolerance values ​​of all fault states by the sum of the demand values ​​of all fault states.

[0078] This application embodiment converts simulated electrical data into quantified fitness values, realizing a quantitative evaluation of the adaptability of relay protection algorithms. Furthermore, this application embodiment comprehensively considers the tolerance and demand values ​​of relay protection algorithms under different fault conditions, making the evaluation process more comprehensive and thus improving the accuracy of fitness value calculation.

[0079] In some embodiments, the fitness value calculation formula for the relay protection algorithm, as shown in formula (1), can be:

[0080]

[0081] Where δ is the fitness value, a is the number of fault states, b is the simulation number corresponding to fault state a, and λ is the number of simulations. a l is the preset coefficient for fault state a. abLet l0 be the fault distance of fault state a in the b-th simulation, l0 be the length of the protection installation line, and R be the distance to the fault. ab R is the maximum withstand protection resistance for fault state a during the b-th simulation. seta The maximum required protection resistance for fault condition a.

[0082] In one example, when the fault conditions include both ground faults and phase-to-phase faults, the fitness value calculation formula for the relay protection algorithm, as shown in formula (2), can be:

[0083]

[0084] Where i represents the simulation number corresponding to the ground fault state, and λ g For the preset coefficient of the ground fault state, l i R represents the fault distance in the ground fault state during the i-th simulation. gi R is the maximum withstand resistance for the ground fault state during the i-th simulation. setg Let λ be the maximum required protective resistance under ground fault conditions, j be the simulation number corresponding to phase-to-phase fault conditions, and λ be the resistance value. ph For the preset coefficient of phase-to-phase fault state, l j Let R be the fault distance of the phase-to-phase fault state in the j-th simulation. phj R is the maximum withstand protection resistance under phase-to-phase fault conditions in the j-th simulation. setph The maximum required protection resistor for phase-to-phase fault conditions.

[0085] In some embodiments, before multiplying the ratio of the maximum withstand protection resistance value of the relay protection algorithm to the preset maximum required protection resistance value, the ratio of the fault distance to the preset protection installation line length, and a preset coefficient to obtain the withstand capability value for each fault state, the method may further include:

[0086] The preset coefficient corresponding to the ratio is determined based on the ratio of the fault distance to the preset length of the protection installation line;

[0087] If the ratio of the fault distance to the preset protection installation line length is less than a set threshold, the fault distance is determined based on the difference between the preset protection installation line length and the fault distance.

[0088] The ratio of the fault distance to the preset protection installation line length is equivalent to the relative position of the fault point in the circuit.

[0089] Since the location of the fault point has a significant impact on the performance of the relay protection algorithm, different fault locations may lead to differences in the response time, sensitivity, and accuracy of the protection algorithm. The ratio of the fault distance to the preset protection installation line length is equivalent to the relative position of the fault point in the circuit. Therefore, this embodiment of the application determines a preset coefficient and redetermines the fault distance based on the ratio of the fault distance to the preset protection installation line length, which can more accurately evaluate the performance of the protection algorithm under different fault locations.

[0090] In some embodiments, as shown in formula (3), the formula for calculating the preset coefficient can be:

[0091]

[0092] Wherein, β is the percentage of the fault location, which is the percentage value of the fault distance and the preset protection installation line length.

[0093] In some embodiments, as shown in formula (4), the formula for calculating the fault distance can be:

[0094]

[0095] Wherein, β is the percentage of the fault location, which is the ratio of the fault distance to the preset length of the protection installation line.

[0096] In some embodiments, the method may further include:

[0097] Obtain the fault location and transition resistance corresponding to different fault states in the power grid to be evaluated using the relay protection algorithm;

[0098] The protection limit safety domain of the power grid to be evaluated is determined based on the fault location and transition resistance corresponding to different fault states.

[0099] The maximum required protection resistance value preset by the protection limit safety domain is compared with that of the relay protection algorithm, and the evaluation result of the protection resistance value of the relay protection algorithm is determined based on the comparison result.

[0100] By defining the protection limit safety domain, the embodiments of this application can clarify the safety boundary of the protection algorithm under extreme conditions, which helps to ensure that the protection algorithm can perform protection actions normally in actual operation and avoid malfunctions or failures to operate due to exceeding the safety boundary.

[0101] In some embodiments, if the maximum protection resistance value within the protection limit safety domain is lower than the preset maximum required protection resistance value, it indicates that the protection algorithm may not meet the requirements under certain fault scenarios.

[0102] In one example, embodiments of this application refer to, for example... Figure 2The relay protection algorithm of the multi-area DC asynchronous interconnected power grid is evaluated. The length l0 of the protection installation line of the multi-area DC asynchronous interconnected power grid is 100km. The maximum required protection resistance of the relay protection algorithm for ground fault state is 200Ω, and the maximum required protection resistance of the relay protection algorithm for phase-to-phase fault state is 200Ω.

[0103] A digital model of this multi-area DC asynchronous interconnected power grid was built in PSCAD / EMTDC. The established digital model is as follows: Figure 2 As shown, based on this digital model, automated batch simulations of single-phase grounding faults and two-phase short-circuit faults were performed with fault location percentages of 0%, 50%, and 100%, and transition resistances of 0.1Ω, 1Ω, 10Ω, and 50Ω, to obtain the corresponding differential current and braking current data.

[0104] Differential current and braking current under a single-phase-to-ground fault in phase A with a fault location percentage of 0% are as follows: Figure 3 As shown, Figure 3 The transition resistance in (a) is 0.1Ω. Figure 3 In section (b), the transition resistance is 50Ω, and the differential current and braking current under a single-phase ground fault in phase A with a fault location percentage of 50% are as follows: Figure 4 As shown, Figure 4 The transition resistance in (a) is 0.1Ω. Figure 4 In (b), the transition resistance is 50Ω, and the differential current and braking current under a single-phase ground fault in phase A with a fault location percentage of 100% are as follows: Figure 5 As shown, Figure 5 The transition resistance in (a) is 0.1Ω. Figure 5 The transition resistance in (b) is 50Ω. From Figures 3-5 As can be seen from this, when a single-phase ground fault occurs, the typical current differential protection fails to operate when the transition resistance reaches 50Ω.

[0105] The differential current and braking current under a two-phase short-circuit fault in phase AB with a fault location percentage of 0% are as follows: Figure 6 As shown, Figure 6 In diagram (a), phase A current is represented, and the transition resistance is 0.1Ω. Figure 6 In diagram (b), the current in phase A is shown, and the transition resistance is 10Ω. Figure 6 In diagram (a), the current in phase B is shown, and the transition resistance is 0.1Ω. Figure 6 In diagram (a), the current in phase B is shown, and the transition resistance is 10Ω. The differential current and braking current under a two-phase short-circuit fault in phases A and B with a fault location percentage of 50% are shown below. Figure 7 As shown, Figure 7 In diagram (a), phase A current is represented, and the transition resistance is 0.1Ω. Figure 7 In diagram (b), the current in phase A is shown, and the transition resistance is 10Ω. Figure 7 In diagram (a), the current in phase B is shown, and the transition resistance is 0.1Ω. Figure 7 In diagram (a), the current in phase B is shown, and the transition resistance is 10Ω. The differential current and braking current under a two-phase short-circuit fault in phases A and B with a fault location percentage of 100% are shown below. Figure 8 As shown. Figure 8 In diagram (a), phase A current is represented, and the transition resistance is 0.1Ω. Figure 8 In diagram (b), the current in phase A is shown, and the transition resistance is 10Ω. Figure 8 In diagram (a), the current in phase B is shown, and the transition resistance is 0.1Ω. Figure 8 In diagram (a), the current in phase B is shown, and the transition resistance is 10Ω. From... Figures 6-8 It can be seen that when a two-phase short-circuit fault occurs, the adaptability of the typical current differential protection is related to the transition resistance, the distance between the fault point and the MMC. It fails to operate when the fault is at 0% and the transition resistance reaches 10Ω; while it can operate correctly when the fault is at 50% and the transition resistance reaches 10Ω; and it fails to operate when the fault is at 100% and the transition resistance reaches 25Ω.

[0106] In summary, the fitness value of the protection algorithm can be calculated according to formula (5), which can be expressed as:

[0107]

[0108] Where, λ g1 =1,λ g2 =0.5, λ g3 =1, l1=100km, l2=50km, l3=100km, R g1 =50Ω, R g2 =50Ω, R g3 =50Ω, λ ph1 =1,λ ph2 =0.5, λ ph3 =1,R ph1 =10Ω, R ph2 =10Ω, R ph3 =25Ω.

[0109] The calculated fitness of the typical current differential protection in a typical multi-area DC asynchronous interconnected power grid in a certain province is: δ=0.2917<1. Therefore, the fitness of this relay protection algorithm is seriously insufficient.

[0110] Finally, the limit safety domain of the relay protection algorithm in a multi-regional DC asynchronous interconnected power grid is generated, and the limit safety domain for single-phase ground fault protection is as follows: Figure 9 As shown, the limit safety domain of two-phase short-circuit fault protection is as follows: Figure 10 As shown.

[0111] like Figure 4As shown, when a single-phase ground fault occurs in this power grid, a typical current differential protection can withstand a transition resistance of 50Ω, regardless of the fault location. The protection limit safety domain is the non-shaded area, which cannot reach the required 200Ω. Figure 5 When a two-phase short-circuit fault occurs in this power grid, the transition resistance value that typical current differential protection can withstand is related to the fault location. The farther the fault location is from the converter, the stronger its ability to withstand transition resistance. The protection limit safety domain is the non-shaded part, and it cannot reach the required 50Ω, thus obtaining the evaluation results.

[0112] Figure 11 This application illustrates an apparatus 1100 for evaluating the adaptability of a relay protection algorithm, which may include:

[0113] The acquisition module 1101 is used to acquire the power grid information to be evaluated and the relay protection algorithm corresponding to the power grid to be evaluated;

[0114] The simulation module 1102 is used to simulate the power grid to be evaluated according to the relay protection algorithm, and obtain the simulated electrical data of the power grid to be evaluated under fault conditions.

[0115] The determination module 1103 is used to determine the fitness value of the relay protection algorithm of the power grid to be evaluated based on the simulated electrical data of the power grid under fault conditions.

[0116] The determination module 1103 is also used to determine the fitness evaluation result of the relay protection algorithm based on the fitness value of the relay protection algorithm.

[0117] This application embodiment transforms simulated electrical data obtained from simulation into fitness values ​​for specific relay protection algorithms. The fitness value reflects the adaptability of the relay protection algorithm under various fault conditions. Simultaneously, by acquiring simulated electrical data, the electrical data of the power grid under various fault conditions can be simulated, comprehensively reflecting the corresponding situation of the relay protection algorithm under different fault conditions. This provides comprehensive information for subsequent accurate evaluation of the adaptability of the relay protection algorithm. Therefore, this application embodiment realizes the evaluation of the adaptability of relay protection algorithms under complex operating conditions.

[0118] In some embodiments, the determining module 1103 is further configured to determine a digital model of the grid structure of the power grid to be evaluated based on the grid structure information of the power grid to be evaluated.

[0119] The simulation module 1102 is also used to simulate the digital model of the grid structure of the power grid to be evaluated based on the relay protection algorithm corresponding to the power grid to be evaluated, and obtain the simulation electrical data of the power grid to be evaluated under fault conditions.

[0120] In some embodiments, the simulation module 1102 is further configured to perform simulations of the power grid under different operating conditions in various fault states based on the relay protection algorithm corresponding to the power grid to be evaluated, and obtain the simulation electrical data of the installation location of the relay protection device corresponding to the relay protection algorithm in various fault states of the power grid to be evaluated.

[0121] In some embodiments, the apparatus 1100 for evaluating the adaptability of relay protection algorithms may further include:

[0122] The calculation module is used to multiply the ratio of the maximum withstand protection resistance value of the relay protection algorithm to the preset maximum required protection resistance value, the ratio of the fault distance to the preset protection installation line length, and the preset coefficient under each fault condition to obtain the withstand capability value of each fault condition.

[0123] The calculation module is also used to multiply the ratio of the fault distance to the preset protection installation line length under each fault condition and the preset coefficient to obtain the required value for each fault condition.

[0124] The calculation module is also used to divide the sum of the tolerance values ​​of all fault states by the sum of the demand values ​​of all fault states to obtain the fitness value of the relay protection algorithm of the power grid to be evaluated.

[0125] In some embodiments, the determining module 1103 is further configured to determine a preset coefficient corresponding to the ratio based on the ratio of the fault distance to the preset length of the protection installation line;

[0126] The determination module 1103 is also used to determine the fault distance based on the difference between the preset protection installation line length and the fault distance when the ratio of the fault distance to the preset protection installation line length is less than a set threshold.

[0127] In some embodiments, the acquisition module 1101 is further configured to acquire the fault location and transition resistance corresponding to different fault states in the power grid to be evaluated by the relay protection algorithm;

[0128] The determination module 1103 is also used to determine the protection limit safety domain of the power grid to be evaluated based on the fault location and transition resistance corresponding to different fault states.

[0129] The determination module 1103 is also used to compare the protection limit safety domain with the maximum required protection resistance value preset by the relay protection algorithm, and determine the evaluation result of the protection resistance value of the relay protection algorithm based on the comparison result.

[0130] Figure 11 The various modules in the illustrated device can achieve Figure 1 The various steps involved, and the corresponding technical effects achieved, will not be elaborated upon here for the sake of brevity.

[0131] Figure 12 A schematic diagram of the hardware structure of the terminal device provided in an embodiment of this application is shown.

[0132] The terminal device may include a processor 1201 and a memory 1202 storing computer program instructions.

[0133] Specifically, the processor 1201 may include a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0134] Memory 1202 may include mass storage for data or instructions. For example, and not limitingly, memory 1202 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. In one instance, memory 1202 may include removable or non-removable (or fixed) media, or memory 1202 may be non-volatile solid-state memory. Memory 1202 may be internal or external to the integrated gateway disaster recovery device.

[0135] In one example, memory 1202 may include read-only memory (ROM), random access memory (RAM), disk storage media device, optical storage media device, flash memory device, electrical, optical, or other physical / tangible memory storage device. Therefore, typically, memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method for adaptive evaluation of relay protection algorithms according to this disclosure.

[0136] The processor 1201 reads and executes computer program instructions stored in the memory 1202 to achieve... Figure 1 The method for evaluating the adaptability of relay protection algorithms in the illustrated embodiment.

[0137] In one example, the terminal device may also include a communication interface 1203 and a bus 1204. Wherein, for example... Figure 12 As shown, the processor 1201, memory 1202, and communication interface 1203 are connected through bus 1204 and complete communication with each other.

[0138] The communication interface 1203 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0139] Bus 1204 includes hardware, software, or both, that couples components of an end device together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Extended Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a Hyper Transport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 1204 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, embodiments of this application contemplate any suitable bus or interconnect.

[0140] Furthermore, in conjunction with the relay protection algorithm adaptability evaluation method in the above embodiments, this application embodiment can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the relay protection algorithm adaptability evaluation methods in the above embodiments.

[0141] This application also provides a computer program product, including a computer program, which, when executed, implements a method for adaptive evaluation of any of the relay protection algorithms described in the above embodiments.

[0142] It should be clarified that the embodiments of this application are not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the embodiments of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of the embodiments of this application.

[0143] The functional blocks shown in the above-described structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application embodiment are programs or text segments used to perform the required tasks. Programs or text segments can be stored in a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, read-only memory (ROM), flash memory, erasable read-only memory (EROM), floppy disks, compact disc read-only memory (CD-ROM), optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Text segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0144] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or apparatus. However, the embodiments of this application are not limited to the order of the above steps. That is, the steps can be performed in the order mentioned in the embodiments, or in a different order than that in the embodiments, or several steps can be performed simultaneously.

[0145] The aspects of this disclosure have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by special-purpose hardware performing the specified functions or actions, or can be implemented by a combination of special-purpose hardware and computer instructions.

[0146] The above description is merely a specific implementation of the embodiments of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of the embodiments of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the embodiments of this application, and these modifications or substitutions should all be covered within the protection scope of the embodiments of this application.

Claims

1. A method for evaluating the adaptability of relay protection algorithms, characterized in that, include: Obtain information about the power grid to be evaluated and the corresponding relay protection algorithm for the power grid to be evaluated; The power grid to be evaluated is simulated based on the relay protection algorithm to obtain the simulated electrical data of the power grid under fault conditions. The fitness value of the relay protection algorithm for the power grid under fault conditions is determined based on the simulated electrical data of the power grid to be evaluated. The fitness evaluation result of the relay protection algorithm is determined based on the fitness value of the relay protection algorithm.

2. The method for evaluating the adaptability of relay protection algorithms according to claim 1, characterized in that, The power grid information to be evaluated includes power grid structure information. The step of simulating the power grid under fault conditions using the relay protection algorithm to obtain simulated electrical data of the power grid under fault conditions includes: Based on the grid structure information of the power grid to be evaluated, a digital model of the grid structure of the power grid to be evaluated is determined; Based on the relay protection algorithm corresponding to the power grid to be evaluated, the digital model of the grid structure of the power grid to be evaluated is simulated to obtain the simulated electrical data of the power grid under fault conditions.

3. The method for evaluating the adaptability of relay protection algorithms according to claim 2, characterized in that, The fault state includes at least one; the simulation of the digital model of the grid structure of the power grid under the fault state, based on the relay protection algorithm corresponding to the power grid under the assessment, to obtain the simulation electrical data of the power grid under the fault state includes: Based on the relay protection algorithm corresponding to the power grid to be evaluated, the power grid to be evaluated is simulated under different operating conditions of various fault states, and the simulation electrical data of the installation location of the relay protection device corresponding to the relay protection algorithm is obtained under different operating conditions of various fault states of the power grid to be evaluated.

4. The method for evaluating the adaptability of relay protection algorithms according to claim 1, characterized in that, The simulated electrical data includes the maximum withstand resistance value of the relay protection algorithm and the fault distance between the fault location and the installation location of the relay protection device corresponding to the relay protection algorithm. Determining the fitness value of the relay protection algorithm for the power grid under fault conditions based on the simulated electrical data of the power grid under fault conditions includes: The tolerance value for each fault condition is obtained by multiplying the ratio of the maximum withstand protection resistance value of the relay protection algorithm to the preset maximum required protection resistance value, the ratio of the fault distance to the preset protection installation line length, and the preset coefficient. The required value for each fault state is obtained by multiplying the ratio of the fault distance to the preset protection installation line length under each fault state by a preset coefficient. The fitness value of the relay protection algorithm for the power grid to be evaluated is obtained by dividing the sum of the tolerance values ​​of all fault states by the sum of the demand values ​​of all fault states.

5. The method for evaluating the adaptability of relay protection algorithms according to claim 4, characterized in that, Before multiplying the ratio of the maximum withstand protection resistance value of the relay protection algorithm to the preset maximum required protection resistance value, the ratio of the fault distance to the preset protection installation line length, and the preset coefficient under each fault condition to obtain the withstand capability value for each fault condition, the method further includes: The preset coefficient corresponding to the ratio is determined based on the ratio of the fault distance to the preset length of the protection installation line; If the ratio of the fault distance to the preset protection installation line length is less than a set threshold, the fault distance is determined based on the difference between the preset protection installation line length and the fault distance.

6. The method for evaluating the adaptability of relay protection algorithms according to claim 1, characterized in that, The method further includes: Obtain the fault location and transition resistance corresponding to different fault states in the power grid to be evaluated using the relay protection algorithm; The protection limit safety domain of the power grid to be evaluated is determined based on the fault location and transition resistance corresponding to the different fault states. The protection limit safety domain is compared with the maximum required protection resistance value preset by the relay protection algorithm, and the evaluation result of the protection resistance value of the relay protection algorithm is determined based on the comparison result.

7. A device for evaluating the adaptability of relay protection algorithms, characterized in that, The device includes: The acquisition module is used to acquire information about the power grid to be evaluated and the corresponding relay protection algorithm for the power grid to be evaluated. The simulation module is used to simulate the power grid to be evaluated according to the relay protection algorithm, and obtain the simulated electrical data of the power grid to be evaluated under fault conditions. The determination module is used to determine the fitness value of the relay protection algorithm of the power grid to be evaluated based on the simulated electrical data of the power grid under fault conditions. The determination module is also used to determine the fitness evaluation result of the relay protection algorithm based on the fitness value of the relay protection algorithm.

8. A terminal device, characterized in that, The device includes: a processor and a memory storing computer program instructions; the processor, when executing the computer program instructions, implements the method for adaptive evaluation of relay protection algorithms as described in any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer program instructions, which, when executed by a processor, implement the method for adaptive evaluation of relay protection algorithms as described in any one of claims 1-6.

10. A computer program product, characterized in that, When the instructions in the computer program product are executed by the processor of the electronic device, the electronic device performs the method for adaptive evaluation of relay protection algorithms as described in any one of claims 1-6.

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