Novel power system toughness comprehensive evaluation method considering source-network-load-storage

Abstract

The invention provides a novel power system toughness comprehensive evaluation method considering source-network-load-storage, belongs to the technical field of power system evaluation, and solves the problems that an existing evaluation system is incomplete in coverage and high in subjectivity. The method comprises the following steps: constructing an evaluation index system considering the toughness of the novel power system of source-network-load-storage; respectively calculating an evaluation index result of the evaluation index system corresponding to the to-be-evaluated scheme of each novel power system; constructing a standardized matrix according to the evaluation index results of all the to-be-evaluated schemes; based on the standardized matrix, an entropy weight method is combined with a CRITIC method, and the comprehensive weight of each evaluation index is calculated; and based on the standardized matrix and the comprehensive weight of each assessment, performing comprehensive value assessment on all the to-be-assessed schemes by using a TOPSIS method.

Description

Technical Field

[0001] This invention relates to the field of power system assessment technology, and in particular to a novel comprehensive assessment method for power system resilience that takes into account power generation, grid, load and storage. Background Technology

[0002] As a critical national infrastructure, the safe and stable operation of the power system is vital to the national economy and people's livelihood. Currently, driven by energy transition, the power system is evolving from the traditional "source follows load" model to a new type of power system with deep integration and synergistic interaction of "source-grid-load-storage". While this transformation brings advantages of cleanliness and efficiency, it also introduces new challenges: On the "source" side, the large-scale integration of high-proportion renewable energy significantly enhances the randomness and volatility of power output; on the "grid" side, the grid structure is becoming increasingly complex, and its capacity to carry and regulate distributed resources urgently needs to be quantified; on the "load" side, the charging behavior of new loads, represented by electric vehicles, has significant spatiotemporal uncertainty, exacerbating the pressure on peak-valley regulation of the system; on the "storage" side, energy storage, as a key flexible regulation resource, has its configuration capacity and operational efficiency directly affecting the system's resistance to disturbances and its recovery capabilities.

[0003] Faced with the aforementioned multi-dimensional and cross-segment complex characteristics, traditional power system security and stability evaluation systems are no longer sufficient to meet the assessment needs of new power systems. Existing technologies mainly suffer from the following shortcomings: First, in terms of evaluation dimensions, most studies are still limited to the "source-grid-load" three-sided or partial segments, failing to incorporate the crucial "storage" aspect into a unified framework for comprehensive consideration. This results in an incomplete evaluation system that cannot accurately depict the full picture of new power systems. Second, in determining indicator weights, subjective weighting often relies on expert experience, making it susceptible to human bias and leading to insufficient comparability and objectivity of the evaluation results. Although some studies employ a single objective weighting method (such as the entropy weighting method), these often only consider the dispersion of the indicator data itself, failing to simultaneously account for the conflicts and correlations between indicators, thus requiring improvement in the scientific rigor and robustness of the weighting.

[0004] Therefore, there is an urgent need in this field for a new comprehensive assessment method for power system resilience that can fully cover the four elements of "source-grid-load-storage" and adopt a scientific and objective weighting method, so as to accurately identify the weak links in the system and provide effective guidance for the planning, construction and operation of the power grid. Summary of the Invention

[0005] Based on the above analysis, the embodiments of the present invention aim to provide a novel comprehensive assessment method for the resilience of power systems that takes into account the source-grid-load-storage system, in order to solve the problems of incomplete coverage and strong subjectivity in the existing evaluation system.

[0006] This invention provides a novel comprehensive assessment method for power system resilience considering power generation, grid, load, and storage, the method comprising:

[0007] Construct a new evaluation index system for the resilience of the power system, taking into account the power generation, grid, load, and storage.

[0008] Calculate the evaluation index results for each new power system scheme to be evaluated; construct a standardized matrix based on the evaluation index results of all schemes to be evaluated.

[0009] Based on the standardized matrix, the entropy weight method combined with the CRITIC method is used to calculate the comprehensive weight of each evaluation indicator;

[0010] Based on the standardized matrix and the comprehensive weights of each evaluation, the TOPSIS method is used to conduct a comprehensive value assessment of all the proposed solutions.

[0011] Based on the above solution, the present invention also makes the following improvements:

[0012] Furthermore, based on the "source-grid-load-storage" four-sided structure of the new power system, the evaluation index system is constructed.

[0013] Furthermore, the evaluation index system includes:

[0014] Source-side assessment indicators include the proportion of flexible retrofitting of thermal power plants, the penetration rate of new energy sources, and the volatility of new energy sources;

[0015] Grid-side evaluation indicators include smart meter installation rate and grid line margin;

[0016] Load-side assessment indicators include the charging volatility of smart electric vehicles;

[0017] Energy storage side assessment indicators include the installation rate of energy storage equipment.

[0018] Furthermore, the new energy penetration rate, new energy volatility, and smart electric vehicle charging volatility are all negative indicators.

[0019] Furthermore, the construction of the standardized matrix is ​​performed by:

[0020] Based on the evaluation index results of all the proposed solutions, an evaluation matrix is ​​constructed.

[0021] The elements corresponding to the negative indicators in the evaluation matrix are positiveized, and the positiveized evaluation matrix is ​​then standardized to construct a standardized matrix.

[0022] Furthermore, for element a of the i-th negative index in the j-th scheme to be evaluated in the evaluation matrix... ij The forward processing is performed according to the following formula:

[0023]

[0024] in, Let a be the optimal value of the element representing the i-th negative index among all the schemes to be evaluated. i ′ j This is the result of positiveening the element of the i-th negative index in the j-th scheme to be evaluated.

[0025] Furthermore, the standardization process includes maximum and minimum value normalization and standardization shift.

[0026] Furthermore, the calculation of the comprehensive weight of each evaluation indicator is performed as follows:

[0027] Calculate the weights of each evaluation index under the CRITIC method based on the standardized matrix;

[0028] Based on the standardized matrix, calculate the weights of each evaluation index under the entropy weight method;

[0029] Based on the weights of each evaluation indicator under the CRITIC method and the entropy weight method, the comprehensive weight of the corresponding evaluation indicator is obtained.

[0030] Furthermore, the TOPSIS method is used to conduct a comprehensive value assessment of all proposed solutions, and the following steps are performed:

[0031] A weighted matrix is ​​constructed based on the standardized matrix and the comprehensive weights of each evaluation item;

[0032] Based on the weighting matrix, calculate the positive ideal solution and negative ideal solution for each evaluation index;

[0033] Calculate the Euclidean distance from each proposed solution to the positive and negative ideal solutions.

[0034] Calculate the relative similarity of each proposed solution to be evaluated;

[0035] The overall evaluation result is determined based on the relative similarity between the various proposed solutions.

[0036] Furthermore, the step of determining the corresponding comprehensive evaluation result based on the relative similarity of each proposed solution is executed as follows:

[0037] The relative similarity of each evaluation scheme is sorted in descending order to form a comprehensive value ranking of the evaluation schemes from high to low.

[0038] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0039] The novel comprehensive assessment method for power system resilience considering power generation, grid, load, and energy storage provided by this invention has the following beneficial effects:

[0040] (1) Multi-dimensional coverage and comprehensive system: Indicators are selected from four aspects of “source-grid-load-storage”, covering power supply flexibility, grid reliability, load volatility and energy storage regulation capability, and comprehensively reflecting the resilience of the power system;

[0041] (2) Objective weighting to avoid subjective bias: The entropy weighting method (based on index dispersion) and the CRITIC method (based on index conflict and correlation) are combined to obtain a comprehensive weight, making the evaluation results more scientific and reliable.

[0042] (3) Highly practical and comparable: applicable to the evaluation and ranking of power system resilience in different provincial-level administrative regions, providing decision support for power system planning and transformation.

[0043] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0044] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0045] Figure 1 The flowchart of the novel power system resilience comprehensive assessment method considering source-grid-load-storage provided by the present invention. Detailed Implementation

[0046] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0047] A specific embodiment of the present invention discloses a novel comprehensive assessment method for power system resilience considering power generation, grid, load, and storage, as shown in the flowchart below. Figure 1 As shown.

[0048] Step S1: Construct a new evaluation index system for the resilience of the power system that takes into account the source-grid-load-storage.

[0049] Specifically, in this embodiment, based on the "source-grid-load-storage" four-sided structure of the new power system, seven evaluation indicators were selected to construct an evaluation indicator system. The details are as follows.

[0050] (1) Source-side assessment indicators

[0051] The source-side assessment indicators include the proportion of flexible retrofitting of thermal power plants, the penetration rate of new energy sources, and the volatility of new energy sources.

[0052] 1) Proportion of flexible retrofitting of thermal power plants The expression is:

[0053]

[0054] In the formula, N th,flex N represents the total number of urban thermal power units undergoing flexible retrofitting. th,total This indicates the total number of thermal power units in the city.

[0055] 2) New energy penetration rate η NE As a negative indicator, the larger the value, the worse the system's performance in that aspect, and the lower its contribution or benefit to the overall evaluation objective. η NE The expression is:

[0056]

[0057] In the formula, P NE P represents the total installed capacity of new energy power generation. total This represents the total output power of the city's power generation system.

[0058] It should be noted that assessing the high penetration rate of new energy sources, which indicates the resulting system regulation pressure, leads to increased uncertainty and decreased system stability. Therefore, the larger the value, the greater the volatility, which is negative for system reliability. Hence, it is defined as a negative indicator.

[0059] 3) New energy volatility σ NE For negative indicators, the expression is:

[0060]

[0061] In the formula, P pv For photovoltaic output power, P w σ represents the output power of the wind turbine unit. Δpv Let σ be the photovoltaic power fluctuation rate. Δω This refers to the fluctuation rate of wind power.

[0062] Photovoltaic power fluctuation σ Δpv The expression is as follows:

[0063]

[0064] Where, p pv (l) represents the output power of the l-th photovoltaic panel. L represents the average output power of urban photovoltaic panels, and L represents the total number of photovoltaic panels installed.

[0065] Wind power fluctuation rate σ Δω The expression is as follows:

[0066]

[0067] Where, p ω (r) represents the output power of the r-th wind turbine unit. The average output power of urban wind turbine units, where R is the total number of wind turbine units installed.

[0068] (2) Network-side evaluation indicators

[0069] The grid-side evaluation indicators include the smart meter installation rate and the grid line margin.

[0070] 1) Smart meter coverage R install The expression is as follows:

[0071]

[0072] Where, N install U represents the number of users who have installed smart meters, and U represents the total number of users.

[0073] 2) Power grid line margin η m The expression is as follows:

[0074]

[0075] Where, N m N represents the number of margin cables and cable trays. total This represents the total number of cables.

[0076] (3) Load-side evaluation indicators

[0077] The load-side assessment indicators include the charging volatility of smart electric vehicles.

[0078] Smart electric vehicle charging volatility σ c For negative indicators, the expression is as follows:

[0079]

[0080] In the formula, p c (d) represents the power of the d-th charging device, μ Δc Let be the average power of the charging pile, and D be the total number of charging piles in the city.

[0081] (4) Reservoir-side assessment indicators

[0082] Energy storage side assessment indicators include the energy storage equipment installation rate, which is the power ratio of energy storage equipment.

[0083] Energy storage equipment installation rate η s The expression is as follows:

[0084]

[0085] Among them, P s This represents the total installed capacity of the energy storage equipment.

[0086] Step S2: Calculate the evaluation index results of the evaluation index system corresponding to each new power system scheme to be evaluated; construct a standardized matrix based on the evaluation index results of all schemes to be evaluated.

[0087] Step S21: Construct an evaluation matrix based on the evaluation index results of all the schemes to be evaluated.

[0088] This embodiment aims to systematically organize the indicator data (i.e., the evaluation indicator results of each evaluation scheme) of multiple objects to be evaluated (i.e., the "schemes to be evaluated", such as power systems in different provinces and regions) under various evaluation indicators into a mathematical matrix, laying the foundation for subsequent data standardization and calculation.

[0089] If each of the proposed solutions is characterized by m evaluation indicators, then the evaluation matrix A formed by the n proposed solutions is represented as:

[0090]

[0091] The column vectors of the evaluation matrix represent the evaluation indicators of a scheme to be evaluated.

[0092] Step S22: Perform positive transformation on the elements corresponding to the negative indicators in the evaluation matrix, and then standardize the positively transformed evaluation matrix to construct a standardized matrix.

[0093] In the specific implementation process, there are several elements corresponding to negative indicators in the evaluation matrix. The elements corresponding to the negative indicators in the evaluation matrix A (see the explanation of step S1) are positiveized and standardized respectively, as shown in the following formula.

[0094]

[0095] In the formula, a ij This is the element representing the i-th negative indicator in the j-th scheme to be evaluated; Let a′ be the optimal value of the element of the i-th negative indicator among all the schemes to be evaluated (for a negative indicator, its optimal value refers to the minimum value of that indicator among all evaluation objects, that is, the smaller the value, the better the performance of the scheme, so the minimum value is used as the benchmark for positiveization), ij This is the result of positiveening the element of the i-th negative index in the j-th scheme to be evaluated.

[0096] The evaluation matrix after positive transformation is denoted as:

[0097]

[0098] Because of the dimensional differences between different indicators, the accuracy of the evaluation is affected. To eliminate the impact of these differences on accuracy, the data must be standardized before calculating the weights. Since all evaluation indicators in the positively oriented evaluation matrix are positive indicators, the standardization methods include maximum and minimum value normalization and standardized shifting.

[0099] The formula for normalizing the maximum and minimum values ​​is expressed as:

[0100]

[0101] To ensure the definition of information entropy holds true during subsequent entropy weighting calculations, it is necessary to ensure that the standardized matrix does not contain non-positive numbers (where non-positive numbers refer to 0). Therefore, the data is also subjected to positive shifting, i.e., z... ij +0.01.

[0102] The standardized matrix is ​​denoted as Y = (y ij ) m×n .

[0103] Step S3: Based on the standardized matrix, the entropy weight method combined with the CRITIC method is used to calculate the comprehensive weight of each evaluation indicator.

[0104] The entropy weight method, combined with the CRITIC method, is highly compatible with the "source-grid-load-storage" indicator system. The advantage of the CRITIC method lies in handling the complex relationships between indicators, meeting the evaluation needs of multi-link coupling in new power systems; while the TOPSIS method can effectively utilize the weighting results of CRITIC to output a clear and reliable resilience ranking, together forming a scientific and practical comprehensive evaluation scheme.

[0105] Step S31: Calculate the weights of each evaluation index under the CRITIC method based on the standardization matrix.

[0106] Step S311: Calculate the standard deviation of each indicator based on the standardization matrix.

[0107] The standard deviation σ of the i-th evaluation indicator i Represented as:

[0108]

[0109] In the formula, This is the average value of all schemes to be evaluated under the i-th evaluation metric.

[0110] The comparative strength of the evaluation factors is calculated, that is, the comparative strength of different evaluation schemes on the same evaluation factor (indicator) is calculated.

[0111] Step S312: Calculate the conflict of each indicator.

[0112] Conflict R of the i-th evaluation indicator i Represented as:

[0113]

[0114] In the formula, r ik Let be the correlation coefficient between the i-th indicator and the k-th indicator. This formula clearly shows that the total conflict coefficient of indicator i is obtained by summing the conflict coefficients of indicator i with each other indicator k. This correction ensures that the conflict coefficient information of each indicator is independent and relevant.

[0115] Step S313: Calculate the information content of each indicator.

[0116] The information content C of the i-th evaluation indicator i Represented as:

[0117] C i =σ i ×R i (16)

[0118] Step S314: Calculate the weights of each indicator under the CRITIC method.

[0119] The weight W of the i-th evaluation indicator under the CRITIC method i，1 Represented as:

[0120]

[0121] Step S32: Calculate the weights of each evaluation index under the entropy weight method based on the standardization matrix.

[0122] This process is implemented using existing methods, and will not be described in detail here.

[0123] The weight of the i-th evaluation indicator under the entropy weight method is denoted as W. i，2 .

[0124] Step S33: Based on the weights of each evaluation indicator under the CRITIC method and the entropy weight method, obtain the comprehensive weight of the corresponding evaluation indicator.

[0125] In practice, the two evaluation results are assigned different weights for comprehensive evaluation, which is the entropy-weighted CRITIC evaluation method, and their average value is taken. Therefore, the comprehensive weight W of the i-th evaluation indicator is... i Represented as:

[0126]

[0127] Step S4: Based on the standardized matrix and the comprehensive weights of each evaluation, use the TOPSIS method to conduct a comprehensive value assessment of all the proposed solutions.

[0128] Step S41: Construct a weighted matrix based on the standardized matrix and the comprehensive weights of each evaluation.

[0129] Weighted matrix V m×n Represented as:

[0130]

[0131] Among them, v ij =W i *y ij .

[0132] Step S42: Calculate the positive and negative ideal solutions for each evaluation index based on the weighting matrix.

[0133] In the specific implementation process, since all negative indicators (such as new energy penetration rate, new energy volatility, etc.) have been positiveized in step S22, it is ensured that all indicators in the standardized matrix are positive. Therefore, in step S42, the positive ideal solution is naturally composed of the maximum values ​​of all indicators in their respective dimensions, while the negative ideal solution is composed of the minimum values. This processing makes the classical definition of the ideal solution in the TOPSIS method applicable under the evaluation system constructed in this application.

[0134] Determine the ideal solution V of the right theorem i + and negative ideal solution V i - :

[0135]

[0136] Step S43: Calculate the Euclidean distance from each scheme to be evaluated to the positive and negative ideal solutions.

[0137] Euclidean distance from each j-th scheme to the positive and negative ideal solutions They are represented as follows:

[0138]

[0139] Step S44: Calculate the relative proximity of each scheme to be evaluated.

[0140] Calculate the relative proximity G of the j-th scheme to be evaluated. j Represented as:

[0141]

[0142] Sort by size, with larger values ​​appearing earlier in the sorting list, indicating lower risk.

[0143] Finally, output the relative similarity G of all the schemes to be evaluated. j According to G j All schemes are ranked from largest to smallest. The ranking result is a comprehensive ranking of the schemes in terms of the resilience of the new power system of "source-grid-load-storage". This ranking can provide a direct and quantitative basis for planning and decision-making on improving grid resilience.

[0144] Step S45: Determine the corresponding comprehensive evaluation result based on the relative similarity of each scheme to be evaluated.

[0145] The relative similarity of each evaluation scheme is sorted in descending order to form a comprehensive value ranking of the evaluation schemes from high to low.

[0146] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0147] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A novel comprehensive assessment method for power system resilience considering power generation, grid, load, and storage, characterized in that, The method includes: Construct a new evaluation index system for the resilience of the power system, taking into account the power generation, grid, load, and storage. Calculate the evaluation index results for each new power system scheme to be evaluated; construct a standardized matrix based on the evaluation index results of all schemes to be evaluated. Based on the standardized matrix, the entropy weight method combined with the CRITIC method is used to calculate the comprehensive weight of each evaluation indicator; Based on the standardized matrix and the comprehensive weights of each evaluation, the TOPSIS method is used to conduct a comprehensive value assessment of all the proposed solutions.

2. The novel comprehensive assessment method for power system resilience considering source-grid-load-storage as described in claim 1, characterized in that, Based on the "source-grid-load-storage" four-sided structure of the new power system, the evaluation index system is constructed.

3. The novel comprehensive assessment method for power system resilience considering source-grid-load-storage as described in claim 2, characterized in that, The evaluation index system includes: Source-side assessment indicators include the proportion of flexible retrofitting of thermal power plants, the penetration rate of new energy sources, and the volatility of new energy sources; Grid-side evaluation indicators include smart meter installation rate and grid line margin; Load-side assessment indicators include the charging volatility of smart electric vehicles; Energy storage side assessment indicators include the installation rate of energy storage equipment.

4. The novel comprehensive assessment method for power system resilience considering source-grid-load-storage as described in claim 3, characterized in that, The new energy penetration rate, new energy volatility, and smart electric vehicle charging volatility are all negative indicators.

5. The novel comprehensive assessment method for power system resilience considering source-grid-load-storage according to any one of claims 1-4, characterized in that, The process of constructing the standardized matrix involves: Based on the evaluation index results of all the proposed solutions, an evaluation matrix is ​​constructed. The elements corresponding to the negative indicators in the evaluation matrix are positiveized, and the positiveized evaluation matrix is ​​then standardized to construct a standardized matrix.

6. The novel comprehensive assessment method for power system resilience considering source-grid-load-storage as described in claim 5, characterized in that, For element a of the i-th negative index in the j-th scheme to be evaluated in the evaluation matrix ij The forward processing is performed according to the following formula: in, Let a′ be the optimal value of the element representing the i-th negative index among all the schemes to be evaluated. ij This is the result of positiveening the element of the i-th negative index in the j-th scheme to be evaluated.

7. The novel comprehensive assessment method for power system resilience considering source-grid-load-storage as described in claim 6, characterized in that, The standardization process includes maximum and minimum value normalization and standardized shift.

8. The novel comprehensive assessment method for power system resilience considering source-grid-load-storage as described in claim 7, characterized in that, The calculation of the comprehensive weight of each evaluation indicator is performed as follows: Calculate the weights of each evaluation index under the CRITIC method based on the standardized matrix; Based on the standardized matrix, calculate the weights of each evaluation index under the entropy weight method; Based on the weights of each evaluation indicator under the CRITIC method and the entropy weight method, the comprehensive weight of the corresponding evaluation indicator is obtained.

9. The novel comprehensive assessment method for power system resilience considering source-grid-load-storage as described in claim 8, characterized in that, The TOPSIS method is used to conduct a comprehensive value assessment of all proposed solutions, and the following steps are performed: A weighted matrix is ​​constructed based on the standardized matrix and the comprehensive weights of each evaluation item; Based on the weighting matrix, calculate the positive ideal solution and negative ideal solution for each evaluation index; Calculate the Euclidean distance from each proposed solution to the positive and negative ideal solutions. Calculate the relative similarity of each proposed solution to be evaluated; The overall evaluation result is determined based on the relative similarity between the various proposed solutions.

10. The novel comprehensive assessment method for power system resilience considering source-grid-load-storage as described in claim 9, characterized in that, The process involves determining the corresponding comprehensive evaluation result based on the relative similarity of each proposed solution, and then executing the following steps: The relative similarity of each evaluation scheme is sorted in descending order to form a comprehensive value ranking of the evaluation schemes from high to low.

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