Power distribution network safety assessment method and device and storage medium

Abstract

The invention discloses a power distribution network safety assessment method and device and a storage medium, and belongs to the technical field of power distribution network safety assessment, and the method comprises the steps: obtaining the operation data of a power distribution network, and calculating each power distribution network safety assessment index; calculating the subjective weight and the objective weight of each power distribution network safety evaluation index; calculating the final weight of each power distribution network safety evaluation index through a game theory method; and finally calculating the comprehensive score of the power distribution network safety. According to the method, evaluation is carried out through multiple indexes, multiple aspects are covered, game theory combination weighting is comprehensively improved, and accurate evaluation of safety is achieved; when the weights are determined, subjective weights are determined by comprehensively using an analytic hierarchy process improved by an ordered weighting operator, objective weights are determined by using an entropy weight method, and then combined weighting is carried out based on the game theory thought. According to the subjective and objective combined weight determination method, deviation possibly caused by pure subjective weighting or objective weighting is avoided, and the accuracy and reliability of an evaluation result are improved.

Description

Technical Field

[0001] The present invention relates to a distribution network security assessment method, device and storage medium, and belongs to the technical field of distribution network security assessment. Background Art

[0002] With the advancement of the "dual carbon" goals, the penetration of distributed photovoltaic power generation in low-voltage distribution networks has increased significantly. However, the intermittent, fluctuating, and reverse current characteristics of photovoltaic power generation can easily lead to voltage over-limit, harmonic pollution, and line overload, threatening the safe operation of distribution networks. Currently, there is a lack of a comprehensive and systematic assessment method to quantify the impact of photovoltaic power generation on the safety of low-voltage distribution networks. Summary of the Invention

[0003] The purpose of the present invention is to provide a distribution network security assessment method, device and storage medium to achieve a comprehensive and systematic assessment of the distribution network security.

[0004] To achieve the above objectives, the present invention is implemented by adopting the following technical solutions: In a first aspect, the present invention provides a distribution network security assessment method, comprising: After obtaining the distribution network operation data, calculate various distribution network security assessment indicators; After obtaining the expert prior data, the subjective weights of various distribution network security assessment indicators are calculated using the improved analytic hierarchy process based on the ordered weighted operator. Based on various distribution network security assessment indicators, the entropy weight of each distribution network security assessment indicator is calculated by an entropy weight method, and the objective weight of the corresponding distribution network security assessment indicator is calculated based on the entropy weight; Based on the subjective and objective weights of various distribution network security assessment indicators, the final weights of various distribution network security assessment indicators are calculated using the game theory method; Based on various distribution network security assessment indicators and their final weights, as well as distribution network operation data, the comprehensive distribution network security score is calculated to complete the distribution network security assessment.

[0005] Furthermore, the distribution network security assessment indicators include voltage stability indicators, power flow distribution and power balance indicators, equipment reliability indicators and power quality indicators; The voltage stability index includes voltage deviation rate and voltage fluctuation rate; The power distribution and power balance index includes an active power balance index, a reactive power balance index and a power distribution imbalance index; The equipment reliability indicators include transformer overload rate and line overload rate; The power quality indicators include harmonic distortion rate and three-phase imbalance.

[0006] Furthermore, the voltage deviation rate is calculated by the following formula: ; in, VBR is the voltage deviation rate, V i For nodes i The actual voltage, V rated is the rated voltage, n is the total number of nodes; The voltage fluctuation rate is calculated by the following formula: ; in, VFR is the voltage fluctuation rate, max means taking the maximum value, min means taking the minimum value; The active power balance index is calculated by the following formula: ; in, APBI is the active power balance index, P gen is the active power output of the photovoltaic power generation system, P load It is the total active power consumed by all electrical equipment in the distribution network; The reactive power balance index is calculated by the following formula: ; in, QPB is the reactive power balance indicator, Q gen is the reactive power output of the photovoltaic power generation system, Q load It is the sum of reactive power consumed by all electrical equipment in the distribution network; The power distribution imbalance index is calculated by the following formula: ; in, PFDI is the indicator of imbalanced power distribution, P i is the power of node i, P avg is the average power of all nodes; The transformer overload rate is calculated by the following formula: ; in, TOR is the transformer overload rate, P trans is the actual operating power of the transformer, P rated_trans is the rated power of the transformer; The line overload rate is calculated using the following formula: ; in, LOR is the line overload rate, I line is the actual load current of the line during operation, I rated_line is the rated current of the line; The harmonic distortion rate is calculated by the following formula: ; in, HDR is the harmonic distortion rate, I h For the h The effective value of the subharmonic current, I 1 is the effective value of the fundamental current; The three-phase imbalance is calculated by the following formula: ; in, TPUI is the three-phase imbalance, V a is the voltage amplitude of phase A, V b is the voltage amplitude of phase B, V c is the voltage amplitude of phase C, avg Indicates finding the average value.

[0007] Furthermore, after obtaining the expert prior data, the subjective weights of various distribution network security assessment indicators are calculated based on the ordered weighted operator improved analytic hierarchy process, including: After obtaining the expert prior data, the weight matrix is ​​constructed using the 1-9 scaling method based on the expert prior data. B ,B=(b ab ) d×e , where b ab represents the score of the bth expert on the importance of the ath distribution network security assessment indicator, d represents the number of experts, and e represents the number of distribution network security assessment indicators; Calculate the maximum eigenvalue of the weight matrix by the power method; Based on the maximum eigenvalue of the weight matrix, the consistency index and consistency ratio are calculated using the following formula: ; ; in, s is the order of the weight matrix, RI is the average random consistency index corresponding to the order of the weight matrix, CR is the consistency ratio, CI is the consistency index, is the maximum eigenvalue of the weight matrix; The consistency of the judgment matrix is ​​verified by the consistency index and the consistency ratio. If the consistency check of the judgment matrix passes, all the experts will be a The scores of the distribution network security assessment indicators are sorted in descending order to obtain the score sequence (p0, p1, ..., p d-1 ), where p0 represents the first expert’s evaluation of the a The score of the yth distribution network security assessment index is represented by p1, which represents the score of the second expert on the yth distribution network security assessment index in the scoring sequence. d-1 represents the score of the dth expert on the yth distribution network security assessment index in the scoring sequence; Select t data in the scoring sequence to get the number of combinations , and then calculate the ordered weight vector by the following formula: ; in, represents an ordered weighted vector; Based on the ordered weighted vector, the first a The absolute weight of each distribution network security assessment indicator: ; in, Indicates the a The absolute weight of each distribution network security assessment index, Indicates the tth expert's a Scoring of distribution network security assessment indicators; Based on the a The absolute weight of the distribution network security assessment index is calculated by the following formula a The subjective weight of each distribution network security assessment indicator: ; in, Indicates the a The subjective weight of each distribution network security assessment indicator.

[0008] Furthermore, the entropy weight of each distribution network security assessment indicator is calculated by the entropy weight method based on each distribution network security assessment indicator, including: Construct the original matrix X , X=(x ac ) e×f ,in, x ac Indicates thea The distribution network security assessment index is c The values ​​in the sample, e represents the number of distribution network security assessment indicators, f Indicates the number of sampling times; For the original matrix X Perform normalization to obtain a standardized matrix G , G=(g ac ) e×f ,in, g ac Express x ac The value obtained after normalization; Calculate the characteristic weights of various distribution network security assessment indicators based on the standardized matrix: ; in, Indicates the a The distribution network security assessment index is c The proportion of features in the sample; The entropy weight of each distribution network security assessment indicator is calculated based on the characteristic proportion: ; in, Indicates the a The entropy weight of the distribution network security assessment index is used.

[0009] Furthermore, the objective weight of the corresponding distribution network security assessment index is calculated based on the entropy weight, including: Based on the entropy weight, the differentiation coefficient of the corresponding distribution network security assessment index is calculated by the following formula: ; in, Indicates the a The differentiation coefficient of the distribution network security assessment index is Indicates the a The entropy weight of the distribution network security assessment index; Based on the differentiation coefficient, the objective weight of the corresponding distribution network security assessment index is calculated using the following formula: ; in, Indicates the a The objective weight of each distribution network security assessment indicator, e Indicates the number of distribution network security assessment indicators.

[0010] Furthermore, the final weight of each distribution network security assessment indicator is calculated by a game theory method based on the subjective weight and objective weight of each distribution network security assessment indicator, including: Initialize the coefficients of subjective weights k 1 and the coefficient of objective weight k 2 ; Solve the following optimization model to get the coefficients k 1 and coefficients k 2 The optimal value of: ; in, Indicates the a The subjective weight of each distribution network security assessment indicator, Indicates the a The objective weight of each distribution network security assessment indicator; The coefficients k 1 and coefficients k 2 The coefficient is obtained by normalizing the optimal value of and coefficients ; Based on coefficient and coefficients , the final weights of various distribution network security assessment indicators are calculated using the following formula: ; in, Indicates the a The final weight of the distribution network security assessment index.

[0011] In a second aspect, the present invention provides a distribution network security assessment device, comprising: The indicator calculation module is configured to: calculate various distribution network security assessment indicators after obtaining distribution network operation data; The subjective weight calculation module is configured to: after obtaining expert prior data, calculate the subjective weights of various distribution network security assessment indicators based on the ordered weighted operator improved analytic hierarchy process; The objective weight calculation module is configured to: calculate the entropy weight of each distribution network security assessment indicator by an entropy weight method based on each distribution network security assessment indicator, and calculate the objective weight of the corresponding distribution network security assessment indicator based on the entropy weight; The final weight calculation module is configured to: calculate the final weight of each distribution network security assessment indicator by using a game theory method based on the subjective weight and objective weight of each distribution network security assessment indicator; The distribution network security assessment module is configured to calculate the comprehensive distribution network security score based on various distribution network security assessment indicators and their final weights, as well as distribution network operation data, and complete the distribution network security assessment.

[0012] Furthermore, the subjective weight calculation module is specifically used to: After obtaining the expert prior data, the weight matrix is ​​constructed using the 1-9 scaling method based on the expert prior data. B ,B=(b ab ) d×e , where b ab represents the score of the bth expert on the importance of the ath distribution network security assessment indicator, d represents the number of experts, and e represents the number of distribution network security assessment indicators; Calculate the maximum eigenvalue of the weight matrix by the power method; Based on the maximum eigenvalue of the weight matrix, the consistency index and consistency ratio are calculated using the following formula: ; ; in, s is the order of the weight matrix, RI is the average random consistency index corresponding to the order of the weight matrix, CR is the consistency ratio, CI is the consistency index, is the maximum eigenvalue of the weight matrix; The consistency of the judgment matrix is ​​verified by the consistency index and the consistency ratio. If the consistency check of the judgment matrix passes, all the experts will be a The scores of the distribution network security assessment indicators are sorted in descending order to obtain the score sequence (p0, p1, ..., p d-1 ), where p0 represents the first expert’s evaluation of the a The score of the yth distribution network security assessment index is represented by p1, which represents the score of the second expert on the yth distribution network security assessment index in the scoring sequence. d-1 represents the score of the dth expert on the yth distribution network security assessment index in the scoring sequence; Select t data in the scoring sequence to get the number of combinations , and then calculate the ordered weight vector by the following formula: ; in, represents an ordered weighted vector; Based on the ordered weighted vector, the first a The absolute weight of each distribution network security assessment indicator: ; in, Indicates the a The absolute weight of each distribution network security assessment index, Indicates the tth expert's a Scoring of distribution network security assessment indicators; Based on the a The absolute weight of the distribution network security assessment index is calculated by the following formula a The subjective weight of each distribution network security assessment indicator: ; in, Indicates the a The subjective weight of each distribution network security assessment indicator.

[0013] In a third aspect, the present invention provides a computer-readable storage medium having a computer program / instruction stored thereon. When the computer program / instruction is executed by a processor, the steps of the distribution network security assessment method described in any one of the first aspects are implemented.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a distribution network security assessment method, device, and storage medium. The method evaluates the security of the distribution network through multiple distribution network security assessment indicators, covering various aspects such as safety, environmental protection, and economy. It comprehensively improves the game theory combined weighting to achieve an accurate assessment of the safety of the photovoltaic grid-connected process, filling the technical gap in this field. When determining the weight, the hierarchical analysis method improved by the ordered weighting operator is comprehensively used to determine the subjective weight, and the entropy weight method is used to determine the objective weight, and then the combined weighting is performed based on the game theory. This subjective and objective weight determination method takes into account the experience and judgment of experts and makes full use of objective data information, avoiding the deviation that may be caused by purely subjective or objective weighting, improving the rationality and scientific nature of weight distribution, and thus improving the accuracy and reliability of the assessment results.

[0015] The evaluation method of the present invention helps to deeply understand and quantitatively analyze the impact of photovoltaic power generation on the security of distribution networks, provide technical support for the rational planning, design and operation management of photovoltaic power generation, promote the coordinated development of photovoltaic power generation and low-voltage distribution networks, improve the overall efficiency of the power system, and promote the effective utilization and sustainable development of clean energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a flow chart of a distribution network security assessment method corresponding to Example 1; Figure 2 is a flow chart of a distribution network security assessment method corresponding to Example 2; Figure 3 Schematic diagram of the evaluation index system provided in Example 2. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0018] Example 1

[0019] like Figure 1 As shown, this embodiment provides a distribution network security assessment method, including: After obtaining the distribution network operation data, calculate various distribution network security assessment indicators; After obtaining the expert prior data, the subjective weights of various distribution network security assessment indicators are calculated using the improved analytic hierarchy process based on the ordered weighted operator. Based on various distribution network security assessment indicators, the entropy weight of each distribution network security assessment indicator is calculated by the entropy weight method, and the objective weight of the corresponding distribution network security assessment indicator is calculated based on the entropy weight; Based on the subjective and objective weights of various distribution network security assessment indicators, the final weights of various distribution network security assessment indicators are calculated using the game theory method; Based on various distribution network security assessment indicators and their final weights, as well as distribution network operation data, the comprehensive distribution network security score is calculated to complete the distribution network security assessment.

[0020] The present invention evaluates the safety of the distribution network through multiple distribution network safety assessment indicators, covering various aspects such as safety, environmental protection, and economy. It comprehensively improves the game theory combined weighting to achieve an accurate assessment of the safety of the photovoltaic grid connection process, filling the technical gap in this field. When determining the weights, the hierarchical analysis method improved with an ordered weighting operator is used to determine the subjective weights, and the entropy weight method is used to determine the objective weights. The combined weighting is then performed based on the principles of game theory. This subjective and objective weight determination method takes into account the experience and judgment of experts and fully utilizes objective data information. It avoids the deviations that may be caused by purely subjective or objective weighting, improves the rationality and scientific nature of weight allocation, and thus improves the accuracy and reliability of the assessment results.

[0021] Example 2

[0022] In this example, a low-voltage distribution network consisting of 10 distributed photovoltaic access points, covering five residential communities and two industrial users, is used as an example. These distributed photovoltaic systems vary in size and are connected to various feeders and nodes. Their total installed capacity accounts for approximately 30% of the total load capacity of the distribution network, making them representative and demonstrating the effectiveness of the method in complex distribution network scenarios.

[0023] like Figure 2 As shown, this embodiment provides a distribution network security assessment method, which is specifically implemented through the following steps: Step 1: Determine the distribution network area to be evaluated and establish a distribution network security assessment index system. In this embodiment, it is specifically a distribution network security assessment index system for large-scale distributed photovoltaic access (i.e., the target layer), such as Figure 3 As shown, the benchmark layer includes voltage stability indicators, power balance and flow distribution indicators, equipment reliability indicators and power quality indicators.

[0024] like Figure 3 As shown, the indicator layer is divided as follows: The specific indicators and calculation formulas are as follows: voltage stability indicators include voltage deviation rate and voltage fluctuation rate; power flow distribution and power balance indicators include active power balance index, reactive power balance index and power flow distribution imbalance index; equipment reliability indicators include transformer overload rate and line overload rate; power quality indicators include harmonic distortion rate and three-phase imbalance.

[0025] After obtaining the specific distribution network operation data, various distribution network security assessment indicators are calculated using the following method: Install voltage monitors at each node of the distribution network, collect node voltages every 15 minutes for one week, and record the actual voltage. V i , rated voltage V rated According to the national grid standard, the voltage data of all nodes within a week are collected and substituted into the calculation formula to obtain the voltage deviation rate: ; in, VBR is the voltage deviation rate, V i For nodes i The actual voltage, V rated is the rated voltage, and n is the total number of nodes.

[0026] Similarly, use the voltage monitor to collect data and calculate the voltage fluctuation rate within a specified time (such as 1 hour): ; in, VFR is the voltage fluctuation rate, max means taking the maximum value, and min means taking the minimum value.

[0027] Collect active power output from photovoltaic power generation systems P gen And the total active power consumed by all electrical equipment in the distribution network P load . P gen It can be obtained through the power monitoring device of the photovoltaic system. P load The active power balance index is calculated by summarizing the load monitoring data of each node in the distribution network: ; in, APBI is the active power balance index, P gen is the active power output of the photovoltaic power generation system, P load It is the total active power consumed by all electrical equipment in the distribution network.

[0028] Obtaining reactive power output of photovoltaic power generation system Q gen The total reactive power consumed by all electrical equipment in the distribution network Q load , the reactive power balance index is calculated by the following formula: ; in, QPB is the reactive power balance indicator, Q gen is the reactive power output of the photovoltaic power generation system, Q load It is the total reactive power consumed by all electrical equipment in the distribution network.

[0029] Count the power of each line P i , calculate the average power of all nodes P avg , and then the imbalance degree of power flow distribution is obtained: ; in, PFDI is the indicator of imbalanced power distribution, P i is the power of node i, P avg is the average power of all nodes.

[0030] Real-time monitoring of the actual operating power of the transformerP trans , combined with the transformer's rated power P rated_trans , calculate the transformer overload rate: ; in, TOR is the transformer overload rate, P trans is the actual operating power of the transformer, P rated_trans is the rated power of the transformer.

[0031] Monitor the actual load current of the line during operation I line , and the rated current of the line I rated_line By comparison, we can get the line overload rate: ; in, LOR is the line overload rate, I line is the actual load current of the line during operation, I rated_line is the rated current of the line.

[0032] Use power quality analyzers to collect current waveform data at key nodes of the distribution network and extract the effective value of each harmonic current I h and the effective value of the fundamental current I 1. Substitute the following formula to calculate the harmonic distortion rate: ; in, HDR is the harmonic distortion rate, I h For the h The effective value of the subharmonic current, I 1 is the effective value of the fundamental current.

[0033] Collect three-phase voltage amplitude Va ( Vb , Vc ) data, calculate its average amplitude avg( Va , Vb , Vc ), and then the three-phase imbalance is obtained: ; in, TPUI is the three-phase imbalance, V a is the voltage amplitude of phase A, V bis the voltage amplitude of phase B, V c is the voltage amplitude of phase C, avg Indicates finding the average value.

[0034] Step 2: Use the ordered weighted operator to improve the hierarchical analysis method to construct a weight matrix, calculate the subjective weight of each distribution network security assessment indicator, and perform a consistency test. Calculate the objective weight of each distribution network security assessment indicator using the entropy weight method, and determine the final weight of each distribution network security assessment indicator based on game theory.

[0035] The subjective weights of distribution network security assessment indicators are calculated using the following method: After obtaining the expert prior data, the weight matrix is ​​constructed using the 1-9 scaling method based on the expert prior data. B ,B=(b ab ) d×e , where b ab represents the score of the bth expert on the importance of the ath distribution network security assessment indicator, d represents the number of experts, and e represents the number of distribution network security assessment indicators; Calculate the weight matrix by the power method B The maximum eigenvalue of Based on the weight matrix B The consistency index and consistency ratio are calculated using the following formula: ; ; in, s is the order of the weight matrix, RI is the average random consistency index corresponding to the order of the weight matrix (according to the random consistency index table, find the average random consistency index corresponding to the order s The corresponding average random consistency index), CR is the consistency ratio, CI is the consistency indicator, is the maximum eigenvalue of the weight matrix; The consistency of the judgment matrix is ​​checked by consistency index and consistency ratio. If the consistency check of the judgment matrix passes (i.e. CR <1), then all experts’ scores on the yth distribution network security assessment index are sorted in descending order to obtain the score sequence (p0, p1, …, p d-1 ), where p0 represents the score of the first expert in the scoring sequence for the yth distribution network security assessment index, p1 represents the score of the second expert in the scoring sequence for the yth distribution network security assessment index, and p d-1 represents the score of the dth expert on the yth distribution network security assessment index in the scoring sequence; Select t data in the scoring sequence to get the number of combinations , and then calculate the ordered weight vector by the following formula: ; in, represents an ordered weighted vector; Based on the ordered weighted vector, the first a The absolute weight of each distribution network security assessment indicator: ; in, Indicates the a The absolute weight of each distribution network security assessment index, Indicates the tth expert's a Scoring of distribution network security assessment indicators; Based on the a The absolute weight of the distribution network security assessment index is calculated by the following formula a The subjective weight of each distribution network security assessment indicator: ; in, Indicates the a The subjective weight of each distribution network security assessment indicator.

[0036] Based on various distribution network security assessment indicators, the entropy weight of each distribution network security assessment indicator is calculated using the entropy weight method, including: Construct the original matrix X , X=(x ac ) e×f ,in, x ac Indicates the a The distribution network security assessment index is c The values ​​in the sample, e represents the number of distribution network security assessment indicators, f Indicates the number of sampling times; For the original matrix X Perform normalization to obtain a standardized matrix G , G=(g ac ) e×f ,in, g ac Express x ac The value obtained after normalization; Calculate the characteristic weights of various distribution network security assessment indicators based on the standardized matrix: ; in, Indicates the a The distribution network security assessment index is c The proportion of features in the sample; The entropy weight of each distribution network security assessment indicator is calculated based on the characteristic proportion: ; in, Indicates the a The entropy weight of the distribution network security assessment index is used.

[0037] The above normalization process is performed by the following formula: .

[0038] Then, the objective weights of the corresponding distribution network security assessment indicators are calculated based on the entropy weight, including: Based on the entropy weight, the differentiation coefficient of the corresponding distribution network security assessment index is calculated by the following formula: ; in, Indicates the a The differentiation coefficient of the distribution network security assessment index is Indicates the a The entropy weight of the distribution network security assessment index; Based on the differentiation coefficient, the objective weight of the corresponding distribution network security assessment index is calculated using the following formula: ; in, Indicates the a The objective weight of each distribution network security assessment indicator, e Indicates the number of distribution network security assessment indicators.

[0039] Then, based on the subjective and objective weights of each distribution network security assessment indicator, the final weights of each distribution network security assessment indicator are calculated using the game theory method, including: Initialize the coefficients of subjective weights k 1 and the coefficient of objective weight k 2 ; Solve the following optimization model to get the coefficients k 1 and coefficients k 2 The optimal value of: ; in, Indicates the a The subjective weight of each distribution network security assessment indicator, Indicates the a The objective weight of each distribution network security assessment indicator; The coefficients k 1 and coefficients k 2 The coefficient is obtained by normalizing the optimal value of and coefficients ; Based on coefficient and coefficients , the final weights of various distribution network security assessment indicators are calculated using the following formula: ; in, Indicates the a The final weight of the distribution network security assessment index.

[0040] Step 3: Based on the obtained comprehensive evaluation index weights and actual operating data, calculate the comprehensive score of the impact of photovoltaic power generation on the security of the low-voltage distribution network, analyze the comprehensive evaluation results, find out the main factors and weak links that affect the security of the low-voltage distribution network due to the access of photovoltaic power generation, and put forward corresponding improvement suggestions and measures, such as optimizing the access location and capacity of the photovoltaic power generation system, configuring reactive power compensation devices, installing harmonic control equipment, and strengthening equipment maintenance and management.

[0041] Example 3

[0042] Based on the same technical concept as Example 1, this embodiment provides a distribution network security assessment device, including: The indicator calculation module is configured to: calculate various distribution network security assessment indicators after obtaining distribution network operation data; The subjective weight calculation module is configured to: after obtaining expert prior data, calculate the subjective weights of various distribution network security assessment indicators based on the ordered weighted operator improved analytic hierarchy process; The objective weight calculation module is configured to: calculate the entropy weight of each distribution network security assessment indicator by an entropy weight method based on each distribution network security assessment indicator, and calculate the objective weight of the corresponding distribution network security assessment indicator based on the entropy weight; The final weight calculation module is configured to: calculate the final weight of each distribution network security assessment indicator by using a game theory method based on the subjective weight and objective weight of each distribution network security assessment indicator; The distribution network security assessment module is configured to calculate the comprehensive distribution network security score based on various distribution network security assessment indicators and their final weights, as well as distribution network operation data, and complete the distribution network security assessment.

[0043] Example 4

[0044] Based on the same technical concept as Example 1, this embodiment provides a computer-readable storage medium having a computer program / instruction stored thereon. When the computer program / instruction is executed by a processor, the steps of the distribution network security assessment method provided in Example 1 are implemented: After obtaining the distribution network operation data, calculate various distribution network security assessment indicators; After obtaining the expert prior data, the subjective weights of various distribution network security assessment indicators are calculated using the improved analytic hierarchy process based on the ordered weighted operator. Based on various distribution network security assessment indicators, the entropy weight of each distribution network security assessment indicator is calculated by an entropy weight method, and the objective weight of the corresponding distribution network security assessment indicator is calculated based on the entropy weight; Based on the subjective and objective weights of various distribution network security assessment indicators, the final weights of various distribution network security assessment indicators are calculated using the game theory method; Based on various distribution network security assessment indicators and their final weights, as well as distribution network operation data, the comprehensive distribution network security score is calculated to complete the distribution network security assessment.

[0045] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0046] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, 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, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0047] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0048] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0049] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A distribution network security assessment method, characterized in that: include: After obtaining the distribution network operation data, calculate various distribution network security assessment indicators; After obtaining the expert prior data, the subjective weights of various distribution network security assessment indicators are calculated using the improved analytic hierarchy process based on the ordered weighted operator. Based on various distribution network security assessment indicators, the entropy weight of each distribution network security assessment indicator is calculated by an entropy weight method, and the objective weight of the corresponding distribution network security assessment indicator is calculated based on the entropy weight; Based on the subjective and objective weights of various distribution network security assessment indicators, the final weights of various distribution network security assessment indicators are calculated using the game theory method; Based on various distribution network security assessment indicators and their final weights, as well as distribution network operation data, the comprehensive distribution network security score is calculated to complete the distribution network security assessment.

2. The distribution network security assessment method according to claim 1, characterized in that: The distribution network security assessment indicators include voltage stability indicators, power flow distribution and power balance indicators, equipment reliability indicators and power quality indicators; The voltage stability index includes voltage deviation rate and voltage fluctuation rate; The power distribution and power balance index includes an active power balance index, a reactive power balance index and a power distribution imbalance index; The equipment reliability indicators include transformer overload rate and line overload rate; The power quality indicators include harmonic distortion rate and three-phase imbalance.

3. The distribution network security assessment method according to claim 2, characterized in that: The voltage deviation rate is calculated by the following formula: ； in, VBR is the voltage deviation rate, V i For nodes i The actual voltage, V rated is the rated voltage, n is the total number of nodes; The voltage fluctuation rate is calculated by the following formula: ； in, VFR is the voltage fluctuation rate, max(*) means taking the maximum value of *, min(*) means taking the minimum value of *; The active power balance index is calculated by the following formula: ； in, APBI is the active power balance index, P gen is the active power output of the photovoltaic power generation system, P load It is the total active power consumed by all electrical equipment in the distribution network; The reactive power balance index is calculated by the following formula: ； in, QPB is the reactive power balance indicator, Q gen is the reactive power output of the photovoltaic power generation system, Q load It is the sum of reactive power consumed by all electrical equipment in the distribution network; The power distribution imbalance index is calculated by the following formula: ； in, PFDI is the indicator of imbalanced power distribution, P i is the power of node i, P avg is the average power of all nodes; The transformer overload rate is calculated by the following formula: ； in, TOR is the transformer overload rate, P trans is the actual operating power of the transformer, P rated_trans is the rated power of the transformer; The line overload rate is calculated by the following formula: ； in, LOR is the line overload rate, I line is the actual load current of the line during operation, I rated_line is the rated current of the line; The harmonic distortion rate is calculated by the following formula: ； in, HDR is the harmonic distortion rate, I h For the h The effective value of the subharmonic current, I 1 is the effective value of the fundamental current; The three-phase imbalance is calculated by the following formula: ； in, TPUI is the three-phase imbalance, V a is the voltage amplitude of phase A, V b is the voltage amplitude of phase B, V c is the voltage amplitude of phase C, avg Indicates finding the average value.

4. The distribution network security assessment method according to claim 1, characterized in that: After obtaining the expert prior data, the subjective weights of various distribution network security assessment indicators are calculated based on the ordered weighted operator improved analytic hierarchy process, including: After obtaining the expert prior data, the weight matrix is ​​constructed using the 1-9 scaling method based on the expert prior data. B ,B=(b ab ) d×e , where b ab represents the score of the bth expert on the importance of the ath distribution network security assessment indicator, d represents the number of experts, and e represents the number of distribution network security assessment indicators; Calculate the maximum eigenvalue of the weight matrix by the power method; Based on the maximum eigenvalue of the weight matrix, the consistency index and consistency ratio are calculated using the following formula: ； ； in, s is the order of the weight matrix, RI is the average random consistency index corresponding to the order of the weight matrix, CR is the consistency ratio, CI is the consistency index, is the maximum eigenvalue of the weight matrix; The consistency of the judgment matrix is ​​verified by the consistency index and the consistency ratio. If the consistency check of the judgment matrix passes, all the experts will be a The scores of the distribution network security assessment indicators are sorted in descending order to obtain the score sequence (p0, p1, ..., p d-1 ), where p0 represents the first expert’s evaluation of the a The score of the yth distribution network security assessment index is represented by p1, which represents the score of the second expert on the yth distribution network security assessment index in the scoring sequence. d-1 represents the score of the dth expert on the yth distribution network security assessment index in the scoring sequence; Select t data in the scoring sequence to get the number of combinations , and then calculate the ordered weight vector by the following formula: ； in, represents an ordered weighted vector; Based on the ordered weighted vector, the first a The absolute weight of each distribution network security assessment indicator: ； in, Indicates the a The absolute weight of each distribution network security assessment index, Indicates the tth expert's a Scoring of distribution network security assessment indicators; Based on the a The absolute weight of the distribution network security assessment index is calculated by the following formula a The subjective weight of each distribution network security assessment indicator: ； in, Indicates the a The subjective weight of each distribution network security assessment indicator.

5. The distribution network security assessment method according to claim 1, characterized in that: The entropy weight of each distribution network security assessment indicator is calculated by the entropy weight method based on each distribution network security assessment indicator, including: Construct the original matrix X , X=(x ac ) e×f ,in, x ac Indicates the a The distribution network security assessment index is c The values ​​in the sample, e represents the number of distribution network security assessment indicators, f Indicates the number of sampling times; For the original matrix X Perform normalization to obtain a standardized matrix G , G=(g ac ) e×f ,in, g ac Express x ac The value obtained after normalization; Calculate the characteristic weights of various distribution network security assessment indicators based on the standardized matrix: ； in, Indicates the a The distribution network security assessment index is c The proportion of features in the sample; The entropy weight of each distribution network security assessment indicator is calculated based on the characteristic proportion: ； in, Indicates the a The entropy weight of the distribution network security assessment index is used.

6. The distribution network security assessment method according to claim 1, characterized in that: The objective weight of the corresponding distribution network security assessment index calculated based on the entropy weight includes: Based on the entropy weight, the differentiation coefficient of the corresponding distribution network security assessment index is calculated by the following formula: ； in, Indicates the a The differentiation coefficient of the distribution network security assessment index is Indicates the a The entropy weight of the distribution network security assessment index; Based on the differentiation coefficient, the objective weight of the corresponding distribution network security assessment index is calculated using the following formula: ； in, Indicates the a The objective weight of each distribution network security assessment indicator, e Indicates the number of distribution network security assessment indicators.

7. The distribution network security assessment method according to claim 1, characterized in that: The final weight of each distribution network security assessment indicator is calculated based on the subjective weight and objective weight of each distribution network security assessment indicator by using a game theory method, including: Initialize the coefficients of subjective weights k 1 and the coefficient of objective weight k 2 ; Solve the following optimization model to get the coefficients k 1 and coefficients k 2 The optimal value of: ； in, Indicates the a The subjective weight of each distribution network security assessment indicator, Indicates the a The objective weight of each distribution network security assessment indicator; The coefficients k 1 and coefficients k 2 The coefficient is obtained by normalizing the optimal value of and coefficients ; Based on coefficient and coefficients , the final weights of various distribution network security assessment indicators are calculated using the following formula: ； in, Indicates the a The final weight of the distribution network security assessment index.

8. A distribution network security assessment device, characterized in that: include: The indicator calculation module is configured to: calculate various distribution network security assessment indicators after obtaining distribution network operation data; The subjective weight calculation module is configured to: after obtaining expert prior data, calculate the subjective weights of various distribution network security assessment indicators based on the ordered weighted operator improved analytic hierarchy process; The objective weight calculation module is configured to: calculate the entropy weight of each distribution network security assessment indicator by an entropy weight method based on each distribution network security assessment indicator, and calculate the objective weight of the corresponding distribution network security assessment indicator based on the entropy weight; The final weight calculation module is configured to: calculate the final weight of each distribution network security assessment indicator by using a game theory method based on the subjective weight and objective weight of each distribution network security assessment indicator; The distribution network security assessment module is configured to calculate the comprehensive distribution network security score based on various distribution network security assessment indicators and their final weights, as well as distribution network operation data, and complete the distribution network security assessment.

9. The distribution network security assessment device according to claim 8, characterized in that: The subjective weight calculation module is specifically used to: After obtaining the expert prior data, the weight matrix is ​​constructed using the 1-9 scaling method based on the expert prior data. B ,B=(b ab ) d×e , where b ab represents the score of the bth expert on the importance of the ath distribution network security assessment indicator, d represents the number of experts, and e represents the number of distribution network security assessment indicators; Calculate the maximum eigenvalue of the weight matrix by the power method; Based on the maximum eigenvalue of the weight matrix, the consistency index and consistency ratio are calculated using the following formula: ； ； in, s is the order of the weight matrix, RI is the average random consistency index corresponding to the order of the weight matrix, CR is the consistency ratio, CI is the consistency index, is the maximum eigenvalue of the weight matrix; The consistency of the judgment matrix is ​​verified by the consistency index and the consistency ratio. If the consistency check of the judgment matrix passes, all the experts will be a The scores of the distribution network security assessment indicators are sorted in descending order to obtain the score sequence (p0, p1, ..., p d-1 ), where p0 represents the first expert’s evaluation of the a The score of the yth distribution network security assessment index is represented by p1, which represents the score of the second expert on the yth distribution network security assessment index in the scoring sequence. d-1 represents the score of the dth expert on the yth distribution network security assessment index in the scoring sequence; Select t data in the scoring sequence to get the number of combinations , and then calculate the ordered weight vector by the following formula: ； in, represents an ordered weighted vector; Based on the ordered weighted vector, the first a The absolute weight of each distribution network security assessment indicator: ； in, Indicates the a The absolute weight of each distribution network security assessment index, Indicates the tth expert's a Scoring of distribution network security assessment indicators; Based on the a The absolute weight of the distribution network security assessment index is calculated by the following formula a The subjective weight of each distribution network security assessment indicator: ； in, Indicates the a The subjective weight of each distribution network security assessment indicator.

10. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instruction is executed by a processor, the steps of the distribution network security assessment method according to any one of claims 1 to 7 are implemented.

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