Method and device for evaluating network frame project of power distribution network

Abstract

The invention discloses a network frame project evaluation method and device for a power distribution network, and the method comprises the steps: obtaining a power distribution network data set based on power grid equipment data and a power grid topological graph, and the power grid equipment data is the data of all equipment in the power distribution network; analyzing the power distribution network data set, and determining a network frame project; giving a plurality of evaluation dimensions of the net rack project, and configuring a corresponding evaluation index for each evaluation dimension; evaluating the network frame project in combination with the power distribution network data set to obtain an evaluation result; wherein the evaluation dimension comprises a green development dimension, and the green development dimension is used for evaluating the sustainability of the net rack project. Through integration of various data in the power distribution network and extraction of the network frame project, a good data basis is provided for evaluation of various network frame projects in the power distribution network, on the basis, multiple dimensions including the green development dimension of the network frame project are evaluated, and the comprehensiveness and accuracy of evaluation of the power distribution network and the network frame project are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power distribution network grid project evaluation, and specifically relates to a power distribution network grid project evaluation method and device Background Art

[0002] The gradual deepening of power marketization and power enterprise system reform, the volatility of new energy power generation and the diversification of external transmission projects, coupled with the large investment scale and long payback period of the original power grid construction projects, have made economic factors increasingly important in decision-making. At the same time, new features such as the complexity of decision-making factors, the increase in uncertain influencing factors and the diversification of decision-making subjects have raised new issues and challenges for the construction evaluation and decision-making of distribution network grid projects.

[0003] With the accelerated advancement of the construction of new power systems and modern smart distribution networks, the importance of distribution networks as the link between power generation / transmission systems and users has become increasingly prominent. However, with limited funds and increasingly strict investment control, how to scientifically, reasonably and accurately arrange distribution network projects and improve the efficiency of fund utilization has become an important problem today.

[0004] As the data integration of distribution network system diagnosis becomes higher and higher, the use of multi-dimensional data fusion for panoramic diagnosis is also a strong trend nowadays. However, as the diagnosis becomes more comprehensive and detailed, how to optimize and integrate these diagnoses and conduct a comprehensive assessment of the distribution system is a problem that needs to be solved at present. Summary of the invention

[0005] In view of the defects existing in the above-mentioned prior art, the present invention provides a grid project evaluation method for a distribution network, comprising:

[0006] Based on the power grid equipment data and the power grid topology map, a distribution network data set is obtained, wherein the power grid equipment data is the data of each device in the distribution network, and the power grid topology map is the connection relationship between each device in the distribution network;

[0007] Analyze the distribution network data set and determine the grid project;

[0008] Provide multiple evaluation dimensions for grid projects and configure corresponding evaluation indicators for each evaluation dimension;

[0009] Combined with the distribution network data set, the grid project is evaluated to obtain evaluation results, where the evaluation dimension includes the green development dimension, which is used to evaluate the sustainability of the grid project. The green development dimension includes network loss indicators and power load change indicators. The network loss indicator is the network loss generated in the grid project, and the power load change indicator is the power load change generated in the grid project.

[0010] It can be seen from the above technical solution that by integrating the power grid equipment data and the power grid topology map in the distribution network, a distribution network data set is obtained, and the grid project is determined from the distribution network data set, which provides a good data basis for the evaluation of various grid projects in the distribution network. On this basis, the grid project is evaluated in multiple dimensions including the green development dimension, which improves the comprehensiveness and accuracy of the evaluation of the distribution network and grid projects.

[0011] In a possible implementation, the evaluation dimension further includes at least one of a grid structure dimension, a power supply capability dimension, an operation capability dimension, an intelligent controllable dimension, and a grid coordination dimension;

[0012] The grid project is evaluated in combination with the distribution network data set to obtain evaluation results, including:

[0013] Based on the distribution network data set and grid projects, the evaluation coefficient and evaluation weight of each evaluation indicator are determined. The evaluation coefficient is the evaluation proportion of each evaluation indicator, and the evaluation weight is the importance of the evaluation indicator to the grid project.

[0014] The evaluation result is determined based on the evaluation coefficient and evaluation weight.

[0015] In a possible implementation, determining the evaluation coefficient of each evaluation indicator specifically includes:

[0016] Construct an evaluation matrix Y of q evaluation indicators for each p grid project mn ) p×q ,m=1,2,…,p; n=1,2,…,q,y mn is the value of the nth evaluation index of the mth grid project;

[0017] The evaluation matrix is ​​standardized to obtain m=1,2,...,p; n=1,2,...,q;

[0018] Determine the entropy value of each evaluation index Among them, F n is the entropy value of the nth evaluation index of the mth grid project;

[0019] Give the evaluation coefficients of each evaluation index Among them, W F,n is the evaluation coefficient of the nth evaluation indicator of the mth grid project.

[0020] In a possible implementation, the evaluation index of the grid structure dimension includes the satisfaction degree of grid structure standardization and the power supply radius, and satisfies the relationship RA=kY D α , where Y Dis the satisfaction degree of grid structure standardization in the grid project, RA is the power supply radius of the grid project, k is the comprehensive influence coefficient, and α is the influence degree of the satisfaction degree of grid structure standardization on the power supply radius;

[0021] The satisfaction degree of grid structure standardization in grid projects is specifically expressed as:

[0022]

[0023] Among them, Y D is the satisfaction degree of grid structure standardization in grid projects, C is the total demand for grid structure standardization, θ c is the standardized satisfaction coefficient of the grid structure c;

[0024] The power supply radius of the grid project is specifically expressed as:

[0025]

[0026] Among them, RA is the power supply radius of the grid project, Q is the capacity of the substation in the grid project, L is the distance from the substation to the user end in the grid project, B is the farthest distance of power transmission of the substation in the grid project, q is the capacity of energy storage at the user end, ρ is the user density in the corresponding area of ​​the grid project, To round down.

[0027] In a possible implementation, the evaluation index of the power supply capacity dimension includes the system average power outage rate and the substation power supply balance index, and satisfies the relationship H u =δ×(1-σ) β , where H u is the average power outage rate of the system in the grid project, σ is the power supply balance index of the substation in the grid project, δ is the basic power outage rate when the power supply is completely unbalanced, and β is the influence of the power supply balance index of the substation in the grid project on the basic power outage rate;

[0028] The average power outage rate of the system in the grid project is specifically expressed as:

[0029]

[0030] Where N is the total number of substations in the grid project, T u，i is the power outage time of the ith substation in the grid project, and T0 is the total working time of the substation in the grid project;

[0031] The substation power supply balance index in the grid project is specifically expressed as:

[0032]

[0033] Among them, σ is the power supply balance index of substation in the grid project.

[0034] In a possible implementation, the network loss index and the power load change index satisfy the relationship Among them, P loss is the network loss index generated in the grid project, RE is the line resistance in the grid project, U is the line voltage in the grid project, cosφ is the power factor, ΔP is the power load change index generated in the grid project, P1 is the initial power load of the grid project, and P2 is the power load after the change of the grid project;

[0035] The network loss index generated in the grid project is specifically expressed as:

[0036]

[0037] Among them, P i is the active power of network node i in the grid project, Q i is the reactive power of network node i in the grid project, R i is the resistance value of the branch where the network node i is located in the grid project, U i is the voltage of network node i in the grid project;

[0038] The power load change index generated in the grid project is specifically expressed as:

[0039] ΔP=P max -P min

[0040] Among them, P max is the maximum value of the operating day load in the grid project, P min It is the minimum value of the operating day load in the grid project.

[0041] In a possible implementation, the evaluation index of the operating capability dimension includes a line overload index and a hidden danger defect index, and satisfies the relationship Among them, ΔI CZZ is the line overload index of the grid project, ΔL is the hidden danger defect index of the grid project, b1 is the basic hidden danger defect level of the grid project, a1 is the influence coefficient of the line overload index on the hidden danger defect index, α1 is the relationship between the overload degree and the hidden danger defect index, and α1 is nonlinear or linear;

[0042] The line overload index of the grid project is specifically expressed as follows:

[0043]

[0044] Among them, ΔI CZZ is the line overload index of the grid project, Tj0 is the time that line j is in free flow state, T tj T is the overload time of the line j after the substation in the grid construction project within the time interval t, tj0 is the overload time of line j in front of the substation in the grid project within the time interval t, J is the total number of lines in the grid project, and T is the total working time of the substation in the grid project;

[0045] The hidden danger and defect indicators of grid projects are specifically expressed as follows:

[0046]

[0047] Among them, ΔL is the hidden danger defect index of the grid project, α tj is the overload risk coefficient of line j in period t after the substation in the grid construction project, α tj0 G is the overload potential risk coefficient of the substation front line j in the construction grid project in the time period t, j is the line level of line j

[0048] In a possible implementation, the evaluation index of the intelligent controllable dimension includes distribution automation coverage and smart meter coverage, and satisfies the relationship Among them, ε is the distribution automation coverage rate of the grid project, τ is the smart meter coverage rate of the grid project, b2 is the basic smart meter coverage rate of the grid project, a2 is the influence coefficient of the distribution automation coverage rate on the smart meter coverage rate, α2 is the relationship between the distribution automation coverage rate and the smart meter coverage rate, and α2 is nonlinear or linear;

[0049] The distribution automation coverage index of the grid project is specifically expressed as:

[0050]

[0051] Among them, ε is the distribution automation coverage index of the grid project, M is the actual automation coverage number in the grid project, and M N Determine the amount of automation coverage expected in the grid project;

[0052] The smart meter coverage index of the grid project is specifically expressed as:

[0053]

[0054] Among them, τ is the smart meter coverage index of the grid project, E is the actual number of smart meters covered in the grid project, and E N is the expected number of smart meters covered in the grid project.

[0055] In a possible implementation, the evaluation index of the grid coordination dimension includes the overhead insulation rate and the cable rate, and satisfies the relationship Where I is the overhead insulation rate in the grid project, D is the cable rate in the grid project, b3 is the basic overhead insulation rate in the grid project, a3 is the influence coefficient of the cable rate on the overhead insulation rate, α3 represents the relationship between the cable rate and the overhead insulation rate, and α3 is nonlinear or linear;

[0056] The overhead insulation rate in the grid project is specifically expressed as:

[0057]

[0058] Where I is the overhead insulation rate in the grid project, V J For overhead lines in grid projects that have insulation requirements and meet insulation requirements, D J The total amount of overhead lines that need insulation in the grid project;

[0059] The cable ratio in the grid project is specifically expressed as:

[0060]

[0061] Where D is the cable ratio in the grid project, V D For overhead lines that meet the cable requirements in grid projects, D D The total amount of overhead lines that require cabling in grid projects.

[0062] The present invention also discloses a grid project evaluation device for a distribution network, comprising:

[0063] A data integration module is used to obtain a distribution network data set based on the power grid equipment data and the power grid topology map, wherein the power grid equipment data is the data of each device in the distribution network, and the power grid topology map is the connection relationship between each device in the distribution network;

[0064] The project determination module is used to analyze the distribution network data set and determine the grid project;

[0065] The indicator configuration module is used to provide multiple evaluation dimensions of the grid project and configure corresponding evaluation indicators for each evaluation dimension;

[0066] The evaluation and analysis module is used to evaluate the grid project in combination with the distribution network data set to obtain the evaluation results; wherein, the evaluation dimension includes the green development dimension, which is used to evaluate the sustainability of the grid project. The green development dimension includes the network loss index and the power load change index. The network loss index is the network loss generated in the grid project, and the power load change index is the power load change generated in the grid project.

[0067] The present invention provides a method for evaluating a grid project of a distribution network, which has at least the following beneficial effects:

[0068] By integrating the power grid equipment data and power grid topology in the distribution network, the distribution network data set is obtained, and the grid projects are determined from the distribution network data set, which provides a good data basis for the evaluation of various grid projects in the distribution network. On this basis, the grid projects are evaluated in multiple dimensions including the green development dimension, which improves the comprehensiveness and accuracy of the evaluation of the distribution network and grid projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 A flow chart of a grid project evaluation method for a distribution network provided by an embodiment of the present invention;

[0070] Figure 2 A flow chart for determining evaluation weights provided in an embodiment of the present invention;

[0071] Figure 3 A structural diagram of a grid project evaluation device for a distribution network provided in an embodiment of the present invention.

[0072] Among them, 201 is a data integration module; 202 is a project determination module; 203 is an indicator configuration module; 204 is an evaluation and analysis module. DETAILED DESCRIPTION

[0073] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0074] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.

[0075] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.

[0076] In order to measure the level of regional distribution network construction, the present invention constructs an evaluation method for grid projects in distribution networks from six aspects: grid structure dimension, grid coordination dimension, power supply capacity dimension, operation capacity dimension, green development dimension, and intelligent controllable dimension. By collecting and analyzing various data of the distribution network, a more accurate indicator evaluation system is determined.

[0077] like Figure 1 As shown, the present invention provides a grid project evaluation method for a distribution network, and the specific steps are as follows:

[0078] S101: Based on the power grid equipment data and the power grid topology map, a distribution network data set is obtained.

[0079] Specifically, the power grid equipment data is the data of each device in the distribution network. The power grid equipment data includes the actual operation data of various devices in the distribution network, as well as the inherent parameters and performance data of the equipment itself. Various devices in the distribution network include substations, outgoing line switches, conductor segments, towers, distribution transformers, section switches, and tie switches. The power grid topology diagram is the connection relationship between various devices in the distribution network. The distribution network data set integrates the power grid equipment data and the device connection relationship in the power grid topology diagram, which is convenient for directly querying the device data in the distribution network and the connection relationship between devices. The distribution network data set includes the device connection relationship and the line loss of the connecting line, line length, line complexity, etc.

[0080] S102: Analyze the distribution network data set and determine the grid project.

[0081] Specifically, after obtaining the distribution network data set, you can intuitively see the equipment data of various devices in the distribution network and the distribution of the equipment, clarify the problems existing in some equipment or areas in the distribution network, and determine the grid project. The grid project is a data set of some equipment or areas in the distribution network. For example, when evaluating whether the connection between any two devices in the distribution network is reasonable, the grid project is the data set corresponding to the above two devices, including the inherent parameters, performance data of the two devices, and the connection relationship between the two devices; when evaluating whether the equipment settings and distribution in some areas of the distribution network are balanced, the grid project is the data set corresponding to the equipment in some areas of the distribution network; when evaluating whether the distribution settings of the entire distribution network are balanced, the grid project is the data set corresponding to the entire distribution network.

[0082] S103: providing multiple evaluation dimensions of the grid project, and configuring corresponding evaluation indicators for each evaluation dimension.

[0083] Specifically, the evaluation dimensions include at least one of the green development dimension, the grid structure dimension, the power supply capacity dimension, the operation capacity dimension, the intelligent controllable dimension and the grid coordination dimension. The green development dimension is used to evaluate the sustainability of the grid project.

[0084] The present invention evaluates the current coordination ability and operation ability of the grid project in the distribution network by considering the grid structure dimension, power supply capacity dimension, operation ability dimension, intelligent controllable dimension and grid coordination dimension. By evaluating the green development dimension of the grid project in the distribution network, the sustainable usability of the grid project in the distribution network is evaluated. While ensuring the current availability of the distribution network, the sustainable use performance of the distribution network is also considered, the maintenance frequency of the distribution network is reduced to a certain extent, and the utilization rate of each device in the distribution network is maximized.

[0085] S104: Evaluate the grid project based on the distribution network data set to obtain evaluation results.

[0086] Specifically, based on the distribution network data set and the grid project, the evaluation coefficient and evaluation weight of each evaluation indicator are determined. The evaluation coefficient is the evaluation proportion of each evaluation indicator, and the evaluation weight is the importance of the evaluation indicator to the grid project. According to the evaluation coefficient and evaluation weight, the evaluation result is determined.

[0087] Furthermore, the process of determining the evaluation coefficient is as follows:

[0088] Construct an evaluation matrix Y of q evaluation indicators for each p grid project mn ) p×q ,m=1,2,…,p; n=1,2,…,q,y mn is the value of the nth evaluation index of the mth grid project, y mnIt is a value calculated based on the calculation formula corresponding to the nth evaluation index and various parameters in the mth grid project. The specific calculation formula is described in the subsequent description and will not be repeated here.

[0089] The evaluation matrix is ​​standardized to obtain

[0090] m=1,2,...,p; n=1,2,...,q;

[0091] Determine the entropy value of each evaluation index Among them, F n is the entropy value of the nth evaluation index of the mth grid project;

[0092] Give the evaluation coefficients of each evaluation index n=1,2,...,q,where W F,n is the evaluation coefficient of the nth evaluation indicator of the mth grid project.

[0093] The entropy value is a measure of the uncertainty of each indicator. The greater the amount of information, the smaller the uncertainty and the smaller the entropy; the smaller the amount of information, the greater the uncertainty and the greater the entropy. According to the characteristics of entropy, the randomness and disorder of an event can be judged by calculating the entropy value. The degree of discreteness of an indicator can also be judged by the entropy value. The greater the degree of discreteness of the indicator, the greater the impact of the indicator on the comprehensive evaluation. In this embodiment, the value of q is 12, and each evaluation dimension is realized by two indicators. In other implementations, the number and content of indicators are adjusted according to the selection of grid projects, the focus of analysis, etc., and there is no limitation on this.

[0094] Further, refer to Figure 2 , the process of determining the evaluation weight is as follows:

[0095] Step 1: According to the preset evaluation index comparison rules, compare the evaluation indexes pairwise and construct the judgment matrix A;

[0096] Step 2: Determine the maximum eigenvalue λ of the judgment matrix A max and eigenvector λ, where the largest eigenvalue λ max and the eigenvector λ must satisfy the relationship Aλ=λ max λ;

[0097] Step 3: Check the consistency of the judgment matrix:

[0098]

[0099] Among them, C R is the consistency test coefficient, λ is the eigenvector, C Im Indicates that C is calculated based on the mth element in λI , C I is the consistency index, R I Parameters for measuring consistency indicators;

[0100] Step 4: Determine the total hierarchical ranking W based on the consistency check results of the judgment matrix c,n .

[0101] When the judgment matrix passes the consistency check, the total hierarchical order W is determined. c,n ; When the judgment matrix fails the consistency check, it is necessary to return to step 1, adjust the judgment matrix, and redetermine the total hierarchical order.

[0102] Further, the process of determining the evaluation results is as follows:

[0103] n=1,2,...,q, where W is the evaluation result.

[0104] In addition, in other implementations, the consideration of the correlation between the various evaluation indicators is added to the hierarchical analysis method to optimize the evaluation results. The specific steps are as follows:

[0105] Step 1: Based on the analytic hierarchy process, first establish the evaluation index set Y = {Y1, Y2, ..., Y n},n=1,2,...,q, where q represents q evaluation indicators;

[0106] Step 2: Divide the evaluation index set into p subsets Y i = {Y i1 ,Y i2 ,...,Y iq}, i = 1, 2, ..., p, p represents p grid projects, and

[0107] Step 3: Normalize the evaluation index layer data to obtain Y i ={y i (1),y i (2)......,y i (n)}, i=1,2,...,p and set Y0={1,1,...,1};

[0108] Step 4: Calculate Y0 = {1,1,...,1} and Y i ={y i (1),y i (2)……,y i (n)},i=1,2,...,pThe correlation coefficient ξ about the kth element i (k) and determine Y i The corresponding correlation matrix Ri ;

[0109]

[0110] Δ i (k)=|y0(k)-y i (k)

[0111] Where ρ is the resolution coefficient, and the range of the resolution coefficient is [0,1]. In this example, ρ = 0.5, Δ min Y0 and Y i The minimum value of the difference between the elements in , Δ max Y0 and Y i The maximum value of the difference between the elements in , Δ i (k) is Y0 and Y i In a specific example, when i=1, R1=[ξ1(1),ξ1(2),…,ξ1(n)]. i (n) is the normalized value of the data calculated by the formula corresponding to the nth evaluation index in the i-th grid project, where the maximum value of n is q, the maximum value of i is p, and the maximum value of k is q.

[0112] Step 5: Determine the association assessment results.

[0113] B i =w i R i =(b i1 ,b i2 ,...,b iq )

[0114]

[0115] Among them, w is the weight vector composed of the weights of each evaluation index, R i Y i The corresponding correlation matrix, B is the correlation evaluation result. In a specific example, when i = 1, R1 = [ξ1(1), ξ1(2), …, ξ1(n)], R1 is the correlation matrix corresponding to the first grid project.

[0116] The above weight vector changes according to the actual situation and the different evaluation indicators. In a specific example, for the grid project of the distribution network, the grid structure, grid coordination, power supply capacity, operation capacity, green development, and intelligent controllable six dimensions and 12 indicators are evaluated and analyzed. Each evaluation dimension has a preset standard. Referring to Table 1, the level classification is general, important, urgent, and supervision. Referring to Table 2, the corresponding evaluation scores are formulated according to the different levels of the indicators. The evaluation scores include basic scores and bonus scores. The grid project is evaluated according to the grid structure, grid coordination, power supply capacity, operation capacity, green development, and intelligent controllable six dimensions and 12 indicators. The weights of each indicator in the grid project are calculated according to the preset level scoring rules. Weight = project basic score + project cumulative bonus score, where the project basic score is the basic score corresponding to the highest level in the project evaluation index, and the project cumulative bonus score is the sum of the bonus scores corresponding to all other indicators except the highest level in the project evaluation index. The upper limit of the project cumulative bonus score is 20. In a specific example, there are two grid projects, of which the value calculated by the grid structure standardization index in the grid structure dimension of one grid project is 0.85, and the value calculated by the grid structure standardization index in the grid structure dimension of the other grid project is 0.75. The level corresponding to 0.85 is important, and the level corresponding to 0.75 is urgent. The urgent level is higher than the important level. The weight corresponding to the grid structure standardization index is the basic project score of 60 corresponding to the urgent level plus the cumulative project score of 2 corresponding to the important level, and the evaluation weight of the grid structure standardization index is obtained.

[0117] In this example, the evaluation indicators of the range not specifically indicated in Table 1 are fixed weights. In other examples, the numerical ranges corresponding to different levels can be set according to actual needs, and there is no limitation on this.

[0118] Table 1

[0119]

[0120] Table 2

[0121] Serial number Weight Level Basic score Bonus points 1 Supervision indicators 80 4 2 Emergency indicators 60 3 3 Important indicators 40 2 4 General indicators 20 1

[0122] The above-mentioned green development dimensions include network loss indicators and power load change indicators. The network loss indicators are the network losses generated by the equipment or areas corresponding to the grid project, and the power load change indicators are the changes in power load generated by the equipment or areas corresponding to the grid project.

[0123] Specifically, the network loss index and the power load change index satisfy the relationship Among them, P lossis the network loss index generated in the grid project, RE is the line resistance in the grid project, U is the line voltage in the grid project, cosφ is the power factor, and the power factor is the ratio of active power to apparent power. Changes in power load may cause changes in the power factor. When the power factor is low, more reactive power needs to be transmitted in the power grid to meet the demand for active power. ΔP is the power load change index generated in the grid project, P1 is the initial power load of the grid project, and P2 is the power load after the change of the grid project.

[0124] The network loss index generated in the grid project is specifically expressed as:

[0125]

[0126] Among them, P i is the active power of network node i in the grid project, Q i is the reactive power of network node i in the grid project, R i is the resistance value of the branch where the network node i is located in the grid project, U i is the voltage of network node i in the grid project;

[0127] The power load change index generated in the grid project is specifically expressed as:

[0128] ΔP=P max -P min

[0129] Among them, P max is the maximum value of the operating day load in the grid project, P min It is the minimum value of the operating day load in the grid project.

[0130] In this example, the green development dimension is evaluated using network loss indicators and power load change indicators. In a simple radial power grid structure, the impact of power load changes on network loss is relatively intuitive. The lines from the power source to each user are relatively independent. An increase in power load will increase the current of the line, thereby increasing the loss of the line and its connected transformer.

[0131] In a ring network structure, the situation is relatively complicated. When the power load changes, the current will be redistributed in the ring network. If the power load in a certain area increases, the current will not only increase on the line in that area, but may also be diverted through other lines in the ring network, causing the loss distribution of the entire network to change.

[0132] The evaluation indicators of the above-mentioned grid structure dimensions include the degree of satisfaction of grid structure standardization and the power supply radius. The degree of satisfaction of grid structure standardization is the ratio of the standard grid structure to the total grid structure in the area corresponding to the grid project, and the power supply radius is the power supply radius of the area corresponding to the grid project.

[0133] Specifically, the grid structure standardization degree and the power supply radius satisfy the relationship RA = kY D α , where Y D is the satisfaction degree of grid structure standardization in the grid project, RA is the power supply radius of the grid project, k is the comprehensive influence coefficient, and α is the influence degree of grid structure standardization satisfaction degree on the power supply radius. D It can be quantified through some indicators such as rationality of line layout, uniformity of equipment selection, etc. D The value range of is [0,1], 0 means that the grid structure is completely non-standard, and 1 means that the grid structure is completely standardized. The unit of RA is kilometers. k reflects the influence of factors such as terrain and load density on the relationship between the standardization degree of the grid structure and the power supply radius. α is a parameter greater than 0. When α=1, it means that the standardization degree of the grid structure is linearly related to the power supply radius; when α>1, it means that the influence of the standardization degree of the grid structure on the power supply radius is accelerating; when 0>α>1, it means that the influence of the standardization degree of the grid structure on the power supply radius is gradually weakening.

[0134] The satisfaction degree of grid structure standardization in grid projects is specifically expressed as:

[0135]

[0136] Among them, Y D is the satisfaction degree of grid structure standardization in grid projects, C is the total demand for grid structure standardization, θ c is the standardized satisfaction coefficient of the grid structure c;

[0137] The power supply radius of the grid project is specifically expressed as:

[0138]

[0139] Among them, RA is the power supply radius of the grid project, Q is the capacity of the substation in the grid project, L is the distance from the substation to the user end in the grid project, B is the farthest distance of power transmission of the substation in the grid project, q is the capacity of energy storage at the user end, ρ is the user density in the corresponding area of ​​the grid project, To round down.

[0140] In this example, the two indicators of grid structure standardization satisfaction and power supply radius are used to evaluate the grid structure dimension. This is based on the important influence between grid structure standardization and power supply radius. Standardized grid structures usually have clear levels and reasonable layouts. For example, the hierarchical and partitioned structure mode can clarify the functions and scopes of grids at different voltage levels, making the transmission of electricity more orderly. This clear structure helps to reasonably plan the power supply radius and avoid the power supply range being too large or too small. Standardized grid structures are conducive to improving the reliability and stability of the power grid. When the reliability of the power grid is improved, the power supply radius can be appropriately extended to a certain extent. Because even at a longer power supply radius, due to the good stability of the power grid, reliable power transmission can be guaranteed to meet the power demand of users. At the same time, the adjustment of the power supply radius indicator will also affect the operation and management of the standardized grid structure. If the power supply radius changes, it may be necessary to make corresponding adjustments to the dispatching strategy and protection configuration of the power grid to ensure the safe and stable operation of the power grid. This requires the grid structure to fully consider the impact of changes in the power supply radius during the standardization process and formulate corresponding countermeasures.

[0141] In other embodiments, the grid structure dimension may also include indicators such as overhead line branch line ratio and connection rate, which are not limited here.

[0142] The evaluation indicators of the power supply capacity dimension include the average power outage rate of the system and the power supply balance index of the substation. Specifically, the average power outage rate of the system and the power supply balance index of the substation satisfy the relationship H u =δ×(1-σ) β , where H u is the average power outage rate of the system in the grid project, H u The value range of is [0,1], which indicates the probability of system power outage in unit time. S is the substation power supply balance index in the grid project. The value range of S is [0,1]. When S=0, it means that the substation power supply in the corresponding area of ​​the grid project is completely unbalanced. When S=1, it means that the substation power supply in the corresponding area of ​​the grid project is completely balanced. δ is the basic power outage rate when the power supply is completely unbalanced. β is the influence of the substation power supply balance index in the grid project on the basic power outage rate. The larger β is, the more significant the influence of the change of the substation power supply balance index on the basic power outage rate.

[0143] The average power outage rate of the system in the grid project is specifically expressed as:

[0144]

[0145] Where N is the total number of substations in the grid project, T u，i is the power outage time of the ith substation in the grid project, and T0 is the total working time of the substation in the grid project;

[0146] The substation power supply balance index in the grid project is specifically expressed as:

[0147]

[0148] Among them, σ is the power supply balance index of substations in the grid project. σ reflects the difference in power supply levels of different substations and also reflects the discrete degree of utilization of different substations.

[0149] In this example, the evaluation of the power supply capacity dimension using the two indicators of system average power outage rate and substation power supply balance index is based on the important influence between the system average power outage rate and substation power supply balance index. When the substation power supply balance is good, it means that the load distribution of each substation is more reasonable, and there will not be a situation where some substations are overloaded and others are underloaded. This can reduce the probability of failure of a single substation due to overload, thereby reducing the number of power outages in the system and reducing the average power outage rate of the system. For example, if the power supply of the substation is unbalanced, some heavily loaded substations may frequently experience equipment overheating, tripping and other failures, resulting in power outages in the area under their jurisdiction, thereby increasing the average power outage rate of the system. In the case of balanced power supply, each substation operates within a reasonable load range, the equipment operation is more stable, and the risk of power outages is greatly reduced. When the average power outage rate of the system is high, it means that the reliability of the entire power system is low, and frequent power outages may disrupt the normal power consumption order and power dispatching plan. In order to reduce the power outage rate, the power department may adjust the power supply range and load of the substation to improve the stability of the system. In this process, the balance of substation power supply may be affected. For example, in order to quickly restore power supply to a certain area, part of the load may be temporarily transferred to other substations, resulting in an increase in the load of these substations, which disrupts the original power supply balance. If the average power outage rate of the system is low and the power system operation is relatively stable, it will be more conducive to maintaining the balance of substation power supply, so that each substation can continue to operate in a relatively ideal state.

[0150] In other embodiments, the power supply capacity dimension may also include related indicators such as line overload ratio, line N-1 pass rate, substation full stop and full rotation rate, etc., which are not limited to this.

[0151] The evaluation indicators of the above-mentioned operation capacity dimension include line overload indicators and hidden danger defect indicators. Specifically, the line overload indicators and hidden danger defect indicators satisfy the relationship Among them, ΔI CZZis the line overload index of the grid project, ΔL is the hidden danger defect index of the grid project, b1 is the basic hidden danger defect level of the grid project, indicating the inherent defects that exist even without overload, a1 is the influence coefficient of the line overload index on the hidden danger defect index, α1 is the relationship between the overload degree and the hidden danger defect index, and α1 is nonlinear or linear. When α1>0, it indicates the nonlinear relationship between the line overload index and the hidden danger defect index, when α1=1, it indicates that there is a linear relationship between the line overload index and the hidden danger defect index, when α1>1, it indicates that the influence of the line overload index on the hidden danger defect index is accelerating, and when α1<1, it indicates that the influence of the line overload index on the hidden danger defect index is gradually weakening.

[0152] The line overload index of the grid project is specifically expressed as follows:

[0153]

[0154] Among them, ΔI CZZ is the line overload index of the grid project. The larger the line overload index is, the more serious the line overload situation is. j0 is the time that line j is in free flow state, T tj T is the overload time of the line j after the substation in the grid construction project within the time interval t, tj0 It is the overload time of line j in front of the substation in the grid project within the time interval t, J is the total number of lines in the grid project, and T is the total working time of the substation in the grid project. The free flow state in the distribution network usually refers to the flow state of power in the distribution network under normal circumstances. At this time, the voltage and frequency of the power grid remain within the normal range, the power supply is stable, and there are no problems such as voltage fluctuations or frequency deviations.

[0155] The hidden danger and defect indicators of grid projects are specifically expressed as follows:

[0156]

[0157] Among them, ΔL is the hidden danger defect index of the grid project, α tj is the overload risk coefficient of line j in period t after the substation in the grid construction project, α tj0 G is the overload potential risk coefficient of the substation front line j in the construction grid project in the time period t, j is the line level of line j.

[0158] Line Class G j Set the step interval and assign the value according to the line power. jUsually there are five levels, which represent not overloaded, basically not overloaded, slightly overloaded, moderately overloaded and severely overloaded. j Determine the overload risk coefficient α within the scope of tj , overload hazard coefficient α tj Typically set to 0 or 1.

[0159] In this example, the evaluation of the operating capacity dimension using the line overload index and the hidden danger defect index is based on the mutual influence between the line overload index and the hidden danger defect index. Line overload is prone to cause hidden danger defects. When the line is in an overload state, the current exceeds its design carrying capacity, which will cause problems such as line heating and increased mechanical stress of the line, thereby causing hidden danger defects. If there are hidden danger defects in the line, such as damage to some wires leading to increased resistance, the loss of the line will increase. Under the same power supply demand, the load of other normal lines may be increased, resulting in overload. When there are hidden danger defects in the equipment in the line, such as the switch failure that cannot normally disconnect the current, the fault current may not be isolated in time, resulting in an abnormal increase in the current on the line, causing overload. If the hidden danger defects are not discovered and handled in time, they may trigger a chain reaction under certain circumstances, further worsening the load situation of the line and aggravating the degree of overload.

[0160] In other embodiments, the operational capability dimension may also include indicators such as equipment obsolescence and the number of failures in the past year, without limitation.

[0161] The evaluation indicators of the above intelligent controllable dimension include distribution automation coverage and smart meter coverage. Specifically, the distribution automation coverage and smart meter coverage satisfy the relationship Among them, ε is the distribution automation coverage rate of the grid project, and the value range of ε is [0,1], which indicates the proportion of the area in the corresponding area of ​​the grid project that has realized distribution automation to the total area; τ is the smart meter coverage rate of the grid project, and the value range of τ is [0,1], which indicates the proportion of users who have installed smart meters in the corresponding area of ​​the grid project to the total number of users; b2 is the basic smart meter coverage rate of the grid project, a2 is the influence coefficient of the distribution automation coverage rate on the smart meter coverage rate, α2 is the relationship between the distribution automation coverage rate and the smart meter coverage rate, and α2 is nonlinear or linear. When ε = 0, b2 is the basic smart meter coverage rate, indicating that even if there is no distribution automation, there is a certain proportion of smart meter installation. When α2>0, it indicates the nonlinear relationship between distribution automation coverage and smart meter coverage. When α2=1, it indicates the linear relationship between distribution automation coverage and smart meter coverage. When α2>1, it indicates that the impact of distribution automation coverage on smart meter coverage is accelerating. When α2<1, it indicates that the impact of distribution automation coverage on smart meter coverage is gradually weakening.

[0162] The distribution automation coverage index of the grid project is specifically expressed as:

[0163]

[0164] Among them, ε is the distribution automation coverage index of the grid project, M is the actual automation coverage number in the grid project, and M N Determine the amount of automation coverage expected in the grid project;

[0165] The smart meter coverage index of the grid project is specifically expressed as:

[0166]

[0167] Among them, τ is the smart meter coverage index of the grid project, E is the actual number of smart meters covered in the grid project, and E N is the expected number of smart meters covered in the grid project.

[0168] The evaluation indicators of the above-mentioned grid coordination dimension include overhead insulation rate and cable rate. Specifically, the overhead insulation rate and cable rate satisfy the relationship Among them, I is the overhead insulation rate in the grid project, D is the cable rate in the grid project, b3 is the basic overhead insulation rate in the grid project, a3 is the influence coefficient of the cable rate on the overhead insulation rate, α3 represents the relationship between the cable rate and the overhead insulation rate, and α3 is nonlinear or linear. The value range of D is [0,1], which represents the proportion of the cable line in the corresponding area of ​​the grid project to the total line length. When D = 0, b3 is the basic overhead insulation rate, indicating that even if there is no cable, there is a certain degree of overhead insulation. a3>0 represents the nonlinear relationship between the cable rate and the overhead insulation rate, when α3=1, it means that the cable rate and the overhead insulation rate are in a linear relationship, when α3>1, it means that the influence of the cable rate on the overhead insulation rate is accelerating, and when α3<1, it means that the influence of the cable rate on the overhead insulation rate is gradually weakening.

[0169] The overhead insulation rate in the grid project is specifically expressed as:

[0170]

[0171] Where I is the overhead insulation rate in the grid project, V J For overhead lines in grid projects that have insulation requirements and meet insulation requirements, D J The total amount of overhead lines that require insulation in the grid project;

[0172] The cable ratio in the grid project is specifically expressed as:

[0173]

[0174] Where D is the cable ratio in the grid project, V D For overhead lines that meet the cable requirements in grid projects, D D The total amount of overhead lines that need to be cabled in the grid project.

[0175] In this example, the two indicators of overhead insulation rate and cable rate are used to evaluate the grid coordination dimension because both overhead insulation rate and cable rate are intended to improve the safety and reliability of power transmission. Overhead insulation mainly reduces line failures caused by external factors (such as tree branches touching, birds staying, etc.) by using insulated wires on overhead lines. When the overhead insulation rate increases, it means that more overhead lines have better insulation performance, reducing the probability of line short circuit, grounding and other faults. Cableization is to replace overhead lines with underground cables. Cables have better protection performance, can resist external physical damage, bad weather and other influences, and occupy less space and have high aesthetics. With the increase of cable rate, power transmission is more reliable, and it also reduces the potential safety hazards of overhead lines, such as the risk of line breakage and falling.

[0176] The present invention provides a grid project evaluation method for a distribution network. Through a panoramic diagnosis of the distribution network, the status of the distribution network is deeply analyzed from multiple dimensions such as power supply capacity, grid structure, green intelligence, etc., the existing problems and needs are identified, and the existing problems and needs are analyzed and evaluated. This method can more effectively manage and optimize the distribution network and improve energy efficiency and economic benefits.

[0177] Reference Figure 3 The embodiment of the present application provides a grid project evaluation device for a distribution network, comprising:

[0178] The data integration module 201 is used to obtain a distribution network data set based on the power grid equipment data and the power grid topology map, wherein the power grid equipment data is the data of each device in the distribution network, and the power grid topology map is the connection relationship between each device in the distribution network;

[0179] A project determination module 202 is used to analyze the distribution network data set and determine the grid project;

[0180] The indicator configuration module 203 is used to provide multiple evaluation dimensions of the grid project and configure corresponding evaluation indicators for each evaluation dimension;

[0181] The evaluation and analysis module 204 is used to evaluate the grid project in combination with the distribution network data set to obtain the evaluation results; wherein, the evaluation dimension includes the green development dimension, the green development dimension is used to evaluate the sustainability of the grid project, the green development dimension includes the network loss index and the power load change index, the network loss index is the network loss generated in the grid project, and the power load change index is the power load change generated in the grid project.

[0182] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the described module can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0183] Although preferred embodiments of the present invention have been described, additional changes and modifications may be made to these embodiments by those skilled in the art once the basic inventive concepts are known. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for evaluating a grid project of a distribution network, characterized in that: include: Based on the power grid equipment data and the power grid topology map, a distribution network data set is obtained, wherein the power grid equipment data is the data of each device in the distribution network, and the power grid topology map is the connection relationship between each device in the distribution network; Analyze the distribution network data set and determine the grid project; Provide multiple evaluation dimensions for grid projects and configure corresponding evaluation indicators for each evaluation dimension; Combined with the distribution network data set, the grid project is evaluated to obtain evaluation results, where the evaluation dimension includes the green development dimension, which is used to evaluate the sustainability of the grid project. The green development dimension includes network loss indicators and power load change indicators. The network loss indicator is the network loss generated in the grid project, and the power load change indicator is the power load change generated in the grid project.

2. The grid project evaluation method of the distribution network according to claim 1, characterized in that: The evaluation dimension also includes at least one of a grid structure dimension, a power supply capacity dimension, an operation capacity dimension, an intelligent controllable dimension, and a grid coordination dimension; The grid project is evaluated in combination with the distribution network data set to obtain evaluation results, including: Based on the distribution network data set and grid projects, the evaluation coefficient and evaluation weight of each evaluation indicator are determined. The evaluation coefficient is the evaluation proportion of each evaluation indicator, and the evaluation weight is the importance of the evaluation indicator to the grid project. The evaluation result is determined based on the evaluation coefficient and evaluation weight.

3. The grid project evaluation method of the distribution network according to claim 2, characterized in that: Determine the evaluation coefficient of each evaluation indicator, including: Construct an evaluation matrix Y of q evaluation indicators for each p grid project mn ) p×q ,m=1,2,…,p; n=1,2,…,q,y mn is the value of the nth evaluation index of the mth grid project; The evaluation matrix is ​​standardized to obtain Determine the entropy value of each evaluation index Among them, F n is the entropy value of the nth evaluation index of the mth grid project; Give the evaluation coefficients of each evaluation index n=1,2,…,q,where W F,n is the evaluation coefficient of the nth evaluation indicator of the mth grid project.

4. The grid project evaluation method of the distribution network according to claim 2, characterized in that: The evaluation indicators of the grid structure dimension include the satisfaction of grid structure standardization and power supply radius, and satisfy the relationship RA = kY D α , where Y D is the satisfaction degree of grid structure standardization in the grid project, RA is the power supply radius of the grid project, k is the comprehensive influence coefficient, and α is the influence degree of the satisfaction degree of grid structure standardization on the power supply radius; The satisfaction degree of grid structure standardization in grid projects is specifically expressed as: Among them, Y D is the satisfaction degree of grid structure standardization in grid projects, C is the total demand for grid structure standardization, θ c is the standardized satisfaction coefficient of the grid structure c; The power supply radius of the grid project is specifically expressed as: Among them, RA is the power supply radius of the grid project, Q is the capacity of the substation in the grid project, L is the distance from the substation to the user end in the grid project, B is the farthest distance of power transmission of the substation in the grid project, q is the capacity of energy storage at the user end, ρ is the user density in the corresponding area of ​​the grid project, To round down.

5. The grid project evaluation method of the distribution network according to claim 2, characterized in that: The evaluation indicators of power supply capacity dimension include the average power outage rate of the system and the power supply balance index of the substation, and they satisfy the relationship H u =δ×(1-σ) β , where H u is the average power outage rate of the system in the grid project, S is the power supply balance index of the substation in the grid project, δ is the basic power outage rate when the power supply is completely unbalanced, and β is the influence of the power supply balance index of the substation in the grid project on the basic power outage rate; The average power outage rate of the system in the grid project is specifically expressed as: Where N is the total number of substations in the grid project, T u，i is the power outage time of the ith substation in the grid project, and T0 is the total working time of the substation in the grid project; The substation power supply balance index in the grid project is specifically expressed as: Among them, σ is the power supply balance index of substation in the grid project.

6. The grid project evaluation method of the distribution network according to claim 1, characterized in that: The network loss index and the power load change index satisfy the relationship Among them, P loss is the network loss index generated in the grid project, RE is the line resistance in the grid project, U is the line voltage in the grid project, is the power factor, ΔP is the power load change index generated in the grid project, P1 is the initial power load of the grid project, and P2 is the power load after the change of the grid project; The network loss index generated in the grid project is specifically expressed as: Among them, P i is the active power of network node i in the grid project, Q i is the reactive power of network node i in the grid project, R i is the resistance value of the branch where the network node i is located in the grid project, U i is the voltage of network node i in the grid project; The power load change index generated in the grid project is specifically expressed as: ΔP=P max -P min Among them, P max is the maximum value of the operating day load in the grid project, P min It is the minimum value of the operating day load in the grid project.

7. The grid project evaluation method of the distribution network according to claim 2, characterized in that: The evaluation indicators of the operating capacity dimension include line overload indicators and hidden danger defect indicators, and they satisfy the relationship Among them, ΔI CZZ is the line overload index of the grid project, ΔL is the hidden danger defect index of the grid project, b1 is the basic hidden danger defect level of the grid project, a1 is the influence coefficient of the line overload index on the hidden danger defect index, α1 is the relationship between the overload degree and the hidden danger defect index, and α1 is nonlinear or linear; The line overload index of the grid project is specifically expressed as follows: Among them, ΔI CZZ is the line overload index of the grid project, T j0 is the time that line j is in free flow state, T tj T is the overload time of the line j after the substation in the grid construction project within the time interval t, tj0 is the overload time of line j in front of the substation in the grid project within the time interval t, J is the total number of lines in the grid project, and T is the total working time of the substation in the grid project; The hidden danger and defect indicators of grid projects are specifically expressed as follows: Among them, ΔL is the hidden danger defect index of the grid project, α tj is the overload potential risk coefficient of line j in period t after the substation in the grid construction project, α tj0 G is the overload potential risk coefficient of the substation front line j in the construction grid project in time period t, j is the line level of line j.

8. The grid project evaluation method of the distribution network according to claim 2, characterized in that: The evaluation indicators of the intelligent controllable dimension include distribution automation coverage and smart meter coverage, and satisfy the relationship Among them, ε is the distribution automation coverage rate of the grid project, τ is the smart meter coverage rate of the grid project, b2 is the basic smart meter coverage rate of the grid project, a2 is the influence coefficient of the distribution automation coverage rate on the smart meter coverage rate, α2 is the relationship between the distribution automation coverage rate and the smart meter coverage rate, and α2 is nonlinear or linear; The distribution automation coverage index of the grid project is specifically expressed as: Among them, ε is the distribution automation coverage index of the grid project, M is the actual automation coverage number in the grid project, and M is the expected automation coverage number in the grid project; The smart meter coverage index of the grid project is specifically expressed as: Among them, τ is the smart meter coverage index of the grid project, E is the actual number of smart meters covered in the grid project, and E N is the expected number of smart meters covered in the grid project.

9. The grid project evaluation method of the distribution network according to claim 2, characterized in that: The evaluation indicators of the grid coordination dimension include overhead insulation rate and cable rate, and satisfy the relationship Where I is the overhead insulation rate in the grid project, D is the cable rate in the grid project, b3 is the basic overhead insulation rate in the grid project, a3 is the influence coefficient of the cable rate on the overhead insulation rate, α3 represents the relationship between the cable rate and the overhead insulation rate, and α3 is nonlinear or linear; The overhead insulation rate in the grid project is specifically expressed as: Where I is the overhead insulation rate in the grid project, V J For overhead lines in grid projects that have insulation requirements and meet insulation requirements, D J The total amount of overhead lines that need insulation in the grid project; The cable ratio in the grid project is specifically expressed as: Where D is the cable ratio in the grid project, V D For overhead lines that meet the cable requirements in grid projects, D D The total amount of overhead lines that require cabling in grid projects.

10. A grid project evaluation device for a distribution network, characterized in that: include: A data integration module is used to obtain a distribution network data set based on the power grid equipment data and the power grid topology map, wherein the power grid equipment data is the data of each device in the distribution network, and the power grid topology map is the connection relationship between each device in the distribution network; The project determination module is used to analyze the distribution network data set and determine the grid project; The indicator configuration module is used to provide multiple evaluation dimensions of the grid project and configure corresponding evaluation indicators for each evaluation dimension; The evaluation and analysis module is used to evaluate the grid project in combination with the distribution network data set to obtain the evaluation results; wherein, the evaluation dimension includes the green development dimension, which is used to evaluate the sustainability of the grid project. The green development dimension includes the network loss index and the power load change index. The network loss index is the network loss generated in the grid project, and the power load change index is the power load change generated in the grid project.

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