High-proportion new energy power grid viability assessment method and system

Abstract

The invention discloses a high-proportion new energy power grid survivability assessment method and system, and relates to the technical field of power grid survivability assessment, and the method comprises the steps: carrying out the network topology of a high-proportion new energy power grid, and generating a power grid topological structure parameter and a network basic characteristic parameter; simulating a natural disaster scene to obtain a power supply removal capacity and a fault scene; determining an optimal power supply cutting scheme according to the power supply cutting capacity; and evaluating the survivability of the power grid by using the fault scene, the optimal power supply removal scheme and the basic characteristic parameters of the network. The weighted power grid topology model provided by the invention not only successfully retains the local area network characteristics, but also has significant advantages in reflecting the node importance degree and the actual power system operation condition compared with an unweighted model. By introducing weighting factors such as line reactance, the model is closer to the running state of a real power grid. Meanwhile, the invention discloses the structural vulnerability of the power grid, and the structural vulnerability of the power grid with regional network characteristics is an inherent attribute of the power grid.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid viability assessment, and in particular to a method and system for assessing the viability of a power grid with a high proportion of new energy. Background Art

[0002] With the large-scale access of renewable energy power generation and flexible direct current transmission systems to the power system, the power grid is undergoing the process of power electronics from control characteristics to physical architecture. In this process, the high interconnection of the power system has increased the probability of large-scale cascading failures, which may cause large-scale power outages at any time; the further increase in the penetration rate of renewable energy has reduced the inertia of the power grid and weakened its anti-interference ability. When the power system encounters extreme events, large-scale cascading accidents may occur, and the survivability of the power grid is seriously threatened. Therefore, it is urgent to develop a survivability assessment method for a high-proportion renewable energy power grid to develop solutions.

[0003] In recent years, with the access of large-scale wind power and photovoltaic power, the power system dominated by synchronous machines is gradually transforming into a power system dominated by new energy, that is, a high-proportion new energy power system. At the same time, various extreme weather conditions are becoming more and more severe, such as typhoons, earthquakes, ice and snow weather, etc. Extreme weather can damage the basic facilities of the power system and cause power supply to be interrupted, posing a major threat to the safe operation of the power system and the basic needs of users. When a high-proportion new energy power system encounters extreme weather, it may cause the power grid to be decoupled and cause a major blackout, which seriously affects the survivability of the power system. Therefore, it is urgent to develop a survivability assessment method for a high-proportion new energy power grid to develop a solution.

[0004] At present, there are a small number of patents and papers involving the assessment of the survivability of power systems under extreme faults. Patent 201410535091.2 proposes an assessment method for the extreme survivability of a strong local power grid. This method is based on a multi-layer indicator system and classification rules, etc., and can evaluate the extreme survivability of the power grid in all aspects and covering all scenarios. However, this method can only calculate the load survival time index value and the load survival ratio value based on a certain type of extreme fault, ignoring the impact of other network topology structures on the survivability of the power grid, and is not systematic. Patent 201910960260.6 uses precipitation data in a specific area, as well as power supply, total social electricity consumption, per capita gross domestic product (GDP), high-resolution terrain and water system data, and conducts power grid disaster risk zoning based on comprehensive consideration of indicators such as disaster-causing factors. It can identify high-risk areas for heavy precipitation disasters in several power grids in a specific area, and can provide scientific meteorological information for power grid design, maintenance and decision-making services. However, it is aimed at local power grids with lower voltage levels and simpler structures, and is not suitable for more complex large power grids.

[0005] The vulnerability assessment of large power grids, relying on regional network topology models, is a research approach to deeply explore the propagation mechanism of cascading failures in power grids. This method is rooted in the theoretical framework of complex network science. By carefully analyzing the topological structure characteristics of large power grids and combining fault simulation experiments, it aims to reveal the essential laws of the development of cascading failures within the power grid. Compared with the transient and steady-state analysis method of power systems based on the principle of power flow balance, this method shows unique advantages in identifying the inherent vulnerability of power grids, and can provide guidance for the formulation of targeted reinforcement measures, thereby helping to build a more stable power grid system. However, the above-mentioned research models of power grid structural vulnerability have a common shortcoming, that is, they all use regional network models based on undirected and unweighted graphs without exception, but ignore the line reactance, a key factor that has an important influence on power flow distribution. In view of this, the present invention constructs a weighted power grid topology model and cascading failure model that incorporates line reactance factors, aiming to deeply explore the intrinsic connection between the structural vulnerability of the actual power grid and its regional network characteristics. Summary of the invention

[0006] In view of the above-mentioned problems, the present invention is proposed.

[0007] Therefore, the problem to be solved by the present invention is: how to solve the problem that the existing research models on the vulnerability of power grid structure all adopt the regional network model based on undirected and unweighted graphs, but ignore the line reactance, which is a key factor that has an important impact on the power flow distribution.

[0008] To solve the above technical problems, the present invention provides the following technical solutions: a method for evaluating the survivability of a high-proportion new energy power grid, comprising: performing network topology analysis on a high-proportion new energy power grid to generate power grid topology parameters and basic network characteristic parameters; simulating natural disaster scenarios to obtain power removal capacity and fault scenarios; determining the optimal power removal plan based on the power removal capacity; and using fault scenarios, the optimal power removal plan and basic network characteristic parameters to evaluate the survivability of the power grid.

[0009] As a preferred solution of the method for evaluating the viability of a high-proportion new energy power grid described in the present invention, the network topology includes obtaining edges, nodes, types of each node in the power grid topology structure and an association matrix describing the network structure; the basic characteristic parameters of the network include clustering coefficient, average degree, average distance, loss load percentage and power transmission efficiency reduction percentage, expressed as:

[0010]

[0011] Among them, C is the clustering coefficient, E i is the number of edges between node i and its neighbor nodes, k i is the number of neighbor nodes of node i, N is the number of all nodes, K is the average degree, pi is the degree of node i, L is the average distance, L ij is the shortest distance between node i and node j, F loss is the percentage of lost load, T1 is the set of all faulty transmission nodes, T0 is the set of all transmission nodes, F is the load of each node under the initial grid structure, η is the percentage of power transmission efficiency decline, L0 is the reciprocal sum of all transmission path lengths in the output state, and L′ is the reciprocal sum of all transmission path lengths in the new equilibrium state.

[0012] As a preferred solution of the method for evaluating the viability of a high-proportion new energy power grid described in the present invention, the evaluation of the viability of the power grid includes converting multiple indicators into a single indicator by using the superior and inferior solution distance method to comprehensively evaluate the viability of the high-proportion new energy power grid. The comprehensive indicator obtained by the superior and inferior solution distance method is expressed as:

[0013]

[0014] Among them, S is a comprehensive index, F loss_min is the minimum value of the loss load percentage, F loss_max is the maximum loss load percentage, η min is the minimum percentage decrease in power transmission efficiency, η max is the maximum value of the percentage decrease in power transmission efficiency, ω1 is the weight of the loss load percentage, and ω2 is the weight of the percentage decrease in power transmission efficiency.

[0015] Another object of the present invention is to provide a system for a method for evaluating the survivability of a high-proportion new energy power grid, which can solve the problem of evaluating the survivability of a high-proportion new energy power grid by constructing a system for evaluating the survivability of a high-proportion new energy power grid.

[0016] To solve the above technical problems, the present invention provides the following technical solutions: a high-proportion new energy power grid survivability assessment system, including, a power system regional network topology module, a power grid disaster scenario module, a power supply removal assessment module and a survivability assessment module; the power system regional network topology module will obtain the edges, nodes, the types of each node in the power grid topology structure and the association matrix module and the network basic characteristic parameter module that describe the network structure, the association matrix module acts on the power grid disaster scenario module, the power grid disaster scenario module obtains the power supply removal capacity and each fault scenario by simulating the power grid failure under natural disasters, and the optimal power supply removal plan of the system is obtained through analysis and simulation by the optimal power supply removal assessment module according to the power supply removal capacity, and finally the network basic characteristic parameter module, the optimal power supply removal plan and each fault scenario are input into the generation capacity assessment module to complete the survivability assessment of the high-proportion new energy power grid system.

[0017] As a preferred solution of a high-proportion new energy power grid survivability assessment system described in the present invention, wherein: the power system regional network topology module includes a power grid actual structure submodule, a power grid weighted topology submodule and a regional network parameter submodule; the power grid actual structure submodule is used to output power grid topology equivalent parameters, and the power grid topology equivalent parameters include converting 220kV and above transformer branches into lines to determine the edges of the topology model, merging nodes in 220kV and above high-voltage lines to determine the nodes of the topology model and renumbering them.

[0018] As a preferred solution of the high-proportion new energy power grid viability assessment system described in the present invention, the power grid weighted topology submodule accepts power grid topology equivalent parameters, and introduces line reactance into the topology map to redefine the length of the edge. Electric energy is transmitted along the path with the smallest sum of line reactance values ​​in the weighted power grid topology model. The power grid weighted topology submodule calculates the weighted association matrix of the topology map based on the power grid weighted topology equivalent parameters; the regional network parameter submodule accepts the weighted association matrix to obtain the corresponding basic characteristic parameters of the network.

[0019] As a preferred solution of the high-proportion new energy grid survivability assessment system described in the present invention, the grid disaster scenario module includes a node identification submodule, a fault mode submodule and a power balance submodule; the node identification submodule receives the grid equivalent association matrix module, determines the node category, and performs corresponding classification, which is divided into power supply nodes and non-power supply nodes, determines the terminal nodes and contact nodes in the network, and outputs the grid equivalent association matrix and the node type classification to the fault mode submodule; the fault mode submodule analyzes and calculates the node type classification of each scene to obtain the topological structure and each fault scene after the node is removed in each scene, and the logic of each fault scene includes scene 1 and scene 2. 2; Scenario 1 is based on node load. By deliberately attacking large-load nodes, the dependence of the power grid on key nodes is examined. Specifically, the node with the largest load is deliberately attacked, and then the node with the second largest load is attacked in turn; Scenario 2 is based on degree. By deliberately attacking the communication node, the dependence of the power grid on key nodes is examined. Specifically, the node with the largest degree is deliberately attacked, and then the node with the second largest degree is attacked in turn; The power balance submodule accepts the topological structure after removal of each scenario, and outputs the power removal capacity of each fault scenario according to the power balance principle. The optimal power removal evaluation module obtains the optimal power removal plan of the system according to the power removal capacity of each fault scenario and the power removal order of photovoltaic, wind power and thermal power.

[0020] As a preferred solution of the high-proportion new energy grid survivability assessment system described in the present invention, the survivability assessment module includes a post-fault topology analysis submodule, a survivability index calculation submodule and a comprehensive evaluation submodule; the post-fault topology analysis submodule accepts each fault scenario and the optimal power supply removal plan to recalculate the post-fault association matrix, and the survivability index calculation submodule calculates the survivability index loss load percentage F by accepting the post-fault association matrix and the network basic characteristic parameter module. loss The survivability index is transmitted to the comprehensive evaluation submodule, and the superior-inferior solution distance method is used to transform multiple indexes into a single index to comprehensively evaluate the survivability of the power grid with a high proportion of new energy.

[0021] A computer device includes a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the above-mentioned method for assessing the viability of a high-proportion new energy power grid are implemented.

[0022] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the above-mentioned method for assessing the survivability of a high-proportion new energy power grid.

[0023] The beneficial effects of the present invention are as follows: the weighted grid topology model proposed in the method for assessing the survivability of a high-proportion new energy grid provided by the present invention not only successfully retains the regional network characteristics, but also has significant advantages over the unweighted model in reflecting the importance of nodes and the actual operation status of the power system. By introducing weighted factors such as line reactance, the model is closer to the operation status of the real power grid. At the same time, the present invention reveals the structural fragility of the power grid. Experimental results show that the structural fragility of a power grid with regional network characteristics is an inherent attribute of the grid. By reasonably optimizing the power grid structure, the reliability level of the power grid can be effectively increased. This provides a scientific basis for power grid operation and maintenance and transformation, and helps to improve the overall stability and security of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0025] Figure 1 A flow chart of a method for evaluating the viability of a high-proportion new energy power grid provided in the first embodiment of the present invention.

[0026] Figure 2A structural diagram of a high-proportion new energy power grid survivability assessment system provided for a second embodiment of the present invention.

[0027] Figure 3 A structural diagram of a power system regional network topology module of a high-proportion new energy power grid survivability assessment system provided in a second embodiment of the present invention.

[0028] Figure 4 A structural diagram of a power grid disaster scenario module of a high-proportion new energy power grid survivability assessment system provided in accordance with a second embodiment of the present invention.

[0029] Figure 5 A structural diagram of a survivability assessment module of a high-proportion new energy power grid survivability assessment system provided in a second embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0032] Example 1, reference Figure 1 , which is the first embodiment of the present invention, and provides a method for evaluating the survivability of a high-proportion new energy power grid, including: performing network topology on a high-proportion new energy power grid to generate power grid topology structure parameters and basic network characteristic parameters; simulating natural disaster scenarios to obtain power removal capacity and fault scenarios; determining the optimal power removal plan based on the power removal capacity; and using fault scenarios, optimal power removal plans and basic network characteristic parameters to evaluate the survivability of the power grid.

[0033] S1. Carry out network topology for high-proportion new energy power grid and generate power grid topology parameters and basic network characteristic parameters.

[0034] The edges, nodes, types of nodes in the power grid topology and the association matrix describing the network structure are obtained.

[0035] Transformer branches of 220 kV and above are converted into lines to determine the edges of the topological model, and nodes in high-voltage lines of 220 kV and above are merged to determine the nodes of the topological model and renumbered.

[0036] Line reactance is introduced into the topology diagram to redefine the length of the edge. Electric energy is transmitted along the path with the smallest sum of line reactance values ​​in the weighted power grid topology model. The weighted correlation matrix of the topology diagram is calculated based on the equivalent parameters of the weighted topology of the power grid.

[0037] The basic characteristic parameters of the network include clustering coefficient, average degree, average distance, loss load percentage and power transmission efficiency reduction percentage, which are expressed as:

[0038]

[0039] Among them, C is the clustering coefficient, E i is the number of edges between node i and its neighbor nodes, k i is the number of neighbor nodes of node i, N is the number of all nodes, K is the average degree, p i is the degree of node i, L is the average distance, L ij is the shortest distance between node i and node j, F loss is the percentage of lost load, T1 is the set of all faulty transmission nodes, T0 is the set of all transmission nodes, F is the load of each node under the initial grid structure, η is the percentage of power transmission efficiency decline, L0 is the reciprocal sum of all transmission path lengths in the output state, and L′ is the reciprocal sum of all transmission path lengths in the new equilibrium state.

[0040] S2. Simulate natural disaster scenarios to obtain power removal capacity and fault scenarios.

[0041] Determine the node category and classify it into power nodes and non-power nodes, determine the terminal nodes and contact nodes in the network, and output the power grid equivalent association matrix and node type classification. Analyze and calculate the node type classification of each scenario to obtain the topological structure and fault scenarios after the node is removed. The logic of each fault scenario is as follows: Scenario 1 is based on node load. By deliberately attacking large-load nodes, the dependence of the power grid on key nodes is examined. Specifically, the node with the largest load is deliberately attacked, and the node with the second largest load is attacked in turn. Scenario 2 is based on degree. By deliberately attacking contact nodes, the dependence of the power grid on key nodes is examined. Specifically, the node with the largest degree is deliberately attacked, and the node with the second largest degree is attacked in turn.

[0042] Finally, the topological structure after the power removal of each scenario is accepted, and the power removal capacity of each fault scenario is output according to the power balance principle. According to the power removal capacity of each fault scenario, the optimal power removal plan of the system is obtained according to the power removal sequence of photovoltaic-wind power-thermal power.

[0043] S3. Determine the optimal power cut-off plan based on the power cut-off capacity.

[0044] S4. Use fault scenarios, optimal power removal plans and basic network characteristic parameters to evaluate the survivability of the power grid.

[0045] By using the superior and inferior solution distance method to transform multiple indicators into a single indicator, the viability of a high-proportion new energy power grid is comprehensively evaluated. The comprehensive indicator obtained by the superior and inferior solution distance method is expressed as:

[0046]

[0047] Among them, S is a comprehensive index, F loss_min is the minimum percentage of loss load, F loss_max is the maximum loss load percentage, η min is the minimum percentage decrease in power transmission efficiency, η max is the maximum value of the percentage decrease in power transmission efficiency, ω1 is the weight of the loss load percentage, and ω2 is the weight of the percentage decrease in power transmission efficiency.

[0048] Example 2, reference Figure 2 to Figure 5 , which is the second embodiment of the present invention, is different from the previous embodiment in that it provides a high-proportion new energy power grid survivability assessment system, including: a power system regional network topology module 100, a power grid disaster scenario module 200, a power supply removal assessment module 300 and a survivability assessment module 400. Figure 2 shown.

[0049] The power system regional network topology module 100 will obtain the edges, nodes, types of each node and the association matrix module 10 describing the network structure in the power grid topology structure, as well as the network basic characteristic parameter module 101. The association matrix module 10 acts on the power grid disaster scenario module 200. The power grid disaster scenario module 200 obtains the power supply removal capacity and various fault scenarios by simulating power grid failures under natural disasters. According to the power supply removal capacity, the optimal power supply removal plan of the system is obtained through analysis and simulation by the optimal power supply removal evaluation module 300. Finally, the network basic characteristic parameter module 101, the optimal power supply removal plan and various fault scenarios are input into the generation capacity evaluation module 400 to complete the evaluation of the survivability of the high-proportion new energy power grid system.

[0050] Figure 3 It is a structural diagram of a regional network topology module 100 of a high-proportion new energy power system, which includes a power grid actual structure submodule 102 , a power grid weighted topology submodule 103 and a regional network parameter submodule 104 .

[0051] The actual grid structure submodule 102 is used to output grid topology equivalent parameters, which include converting 220kV and above transformer branches into lines to determine the edges of the topology model, merging nodes in 220kV and above high-voltage lines to determine the nodes of the topology model and renumbering them.

[0052] The grid weighted topology submodule 103 accepts grid topology equivalent parameters and introduces line reactance into the topology map to redefine the length of the edge. Electric energy is transmitted along the path with the smallest sum of line reactance values ​​in the weighted grid topology model. The grid weighted topology submodule 103 calculates the weighted association matrix of the topology map based on the grid weighted topology equivalent parameters.

[0053] The regional network parameter submodule 104 receives the weighted association matrix and obtains the corresponding basic network characteristic parameters. The basic network characteristic parameters include clustering coefficient, average degree, average distance, loss load percentage and power transmission efficiency reduction percentage, which are expressed as:

[0054]

[0055] Among them, C is the clustering coefficient, E i is the number of edges between node i and its neighbor nodes, k i is the number of neighbor nodes of node i, N is the number of all nodes, K is the average degree, p i is the degree of node i, L is the average distance, L ij is the shortest distance between node i and node j, F loss is the percentage of lost load, T1 is the set of all faulty transmission nodes, T0 is the set of all transmission nodes, F is the load of each node under the initial grid structure, η is the percentage of power transmission efficiency decline, L0 is the reciprocal sum of all transmission path lengths in the output state, and L′ is the reciprocal sum of all transmission path lengths in the new equilibrium state.

[0056] Figure 4 It is a structural diagram of a high-proportion new energy power grid disaster scenario module 200 , which includes a node identification submodule 201 , a fault mode submodule 202 and a power balance submodule 203 .

[0057] The node identification submodule 201 receives the power grid equivalence association matrix module 10, determines the node category, and classifies it accordingly, dividing it into power supply nodes and non-power supply nodes, determines the terminal nodes and contact nodes in the network, and outputs the power grid equivalence association matrix and node type classification to the fault mode submodule 202.

[0058] The fault mode submodule 202 analyzes and calculates the node type classification of each scene to obtain the topological structure and each fault scene after the node is removed from each scene. The logic of each fault scene includes scene 1 and scene 2.

[0059] Scenario 1 is based on node load. It examines the dependence of the power grid on key nodes by deliberately attacking large-load nodes. Specifically, it deliberately attacks the nodes with the largest load, and then attacks the nodes with the second largest load in turn.

[0060] Scenario 2 examines the dependence of the power grid on key nodes based on degree by deliberately attacking the contact nodes. Specifically, the node with the largest degree is deliberately attacked, and then the nodes with the second largest degree are attacked in turn.

[0061] Finally, the power balancing submodule 203 accepts the topological structure after power removal of each scenario, and outputs the power removal capacity of each fault scenario according to the power balancing principle. The optimal power removal evaluation module 300 obtains the optimal power removal plan of the system according to the power removal capacity of each fault scenario and the power removal order of photovoltaic, wind power and thermal power.

[0062] Figure 5 4 is a structural diagram of a high-proportion new energy survivability assessment module 400 , wherein the survivability assessment module 400 includes a post-fault topology analysis submodule 401 , a survivability index calculation submodule 402 and a comprehensive evaluation submodule 403 .

[0063] The post-fault topology analysis submodule 401 receives each fault scenario and the optimal power removal solution to recalculate the post-fault correlation matrix. The survival index calculation submodule 402 receives the post-fault correlation matrix and the network basic characteristic parameter module 101 to calculate the survival index loss load percentage F. loss The survivability index is transmitted to the comprehensive evaluation submodule 403, and the multiple indexes are converted into a single index by using the superior and inferior solution distance method to comprehensively evaluate the survivability of the high-proportion new energy power grid. The comprehensive index obtained by the superior and inferior solution distance method is shown in the following formula:

[0064]

[0065] Among them, S is a comprehensive index, F loss_min is the minimum percentage of loss load, F loss_max is the maximum loss load percentage, η min is the minimum percentage decrease in power transmission efficiency, η max is the maximum value of the percentage decrease in power transmission efficiency, ω1 is the weight of the loss load percentage, and ω2 is the weight of the percentage decrease in power transmission efficiency.

[0066] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0067] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0068] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0069] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0070] Embodiment 3 is the third embodiment of the present invention. It is different from the first two embodiments in that it is used to verify the technical effects adopted in the present invention so as to verify the real effects of the method.

[0071] Based on the actual power grid in a certain area in South China, the method described in this patent is used to evaluate the survivability of the power grid. The results are shown in Table 1. It can be seen from the table that the survivability of the power grid in the region in scenario 1, i.e., load-based fault mode, is stronger than the survivability of scenario 2, i.e., degree-based fault mode.

[0072] Table 1 Evaluation index of survivability of high-proportion new energy under different faults

[0073] Scenario C K (L <![CDATA[F loss ]]> η S Scene 1 1.546 9.881 8.063 8.8％ 4％ 0.31 Scene 2 2.764 13.864 15.654 11.6％ 7％ 0.48

[0074] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for evaluating the viability of a high-proportion new energy power grid, characterized in that: include, Conduct network topology for high-proportion new energy power grids, generate power grid topology parameters and basic network characteristic parameters; Simulate natural disaster scenarios to obtain power removal capacity and fault scenarios; Determine the optimal power removal plan based on the power removal capacity; The grid survivability is assessed using fault scenarios, optimal power removal schemes and basic network characteristic parameters.

2. A method for evaluating the viability of a high-proportion new energy power grid according to claim 1, characterized in that: The network topology includes obtaining edges, nodes, types of each node in the power grid topology structure and an association matrix describing the network structure; The basic characteristic parameters of the network include clustering coefficient, average degree, average distance, loss load percentage and power transmission efficiency reduction percentage, which are expressed as, Among them, C is the clustering coefficient, E i is the number of edges between node i and its neighbor nodes, k i is the number of neighbor nodes of node i, N is the number of all nodes, K is the average degree, p i is the degree of node i, is the average distance, L ij is the shortest distance between node i and node j, F loss is the percentage of lost load, T1 is the set of all faulty transmission nodes, T0 is the set of all transmission nodes, F is the load of each node under the initial grid structure, η is the percentage of power transmission efficiency decline, L0 is the reciprocal sum of all transmission path lengths in the output state, and L′ is the reciprocal sum of all transmission path lengths in the new equilibrium state.

3. A method for evaluating the viability of a high-proportion new energy power grid as claimed in claim 2, characterized in that: The evaluation of the survivability of the power grid includes converting multiple indicators into a single indicator by using the superior and inferior solution distance method, and comprehensively evaluating the survivability of the high-proportion new energy power grid. The comprehensive indicator obtained by the superior and inferior solution distance method is expressed as: Among them, S is a comprehensive index, F loss_min is the minimum value of the loss load percentage, F loss_max is the maximum loss load percentage, η min is the minimum percentage decrease in power transmission efficiency, η max is the maximum value of the percentage decrease in power transmission efficiency, ω1 is the weight of the loss load percentage, and ω2 is the weight of the percentage decrease in power transmission efficiency.

4. A system using a high-proportion new energy grid viability assessment method as described in any one of claims 1 to 3, characterized in that: It includes a power system regional network topology module (100), a power grid disaster scenario module (200), a power supply removal assessment module (300) and a survivability assessment module (400); The power system regional network topology module (100) obtains the edges, nodes, types of each node and the association matrix module (10) describing the network structure in the power grid topology structure, and the network basic characteristic parameter module (101). The association matrix module (10) acts on the power grid disaster scenario module (200). The power grid disaster scenario module (200) obtains the power supply removal capacity and each fault scenario by simulating power grid faults under natural disasters. The optimal power supply removal plan of the system is obtained through analysis and simulation by the optimal power supply removal evaluation module (300) based on the power supply removal capacity. Finally, the network basic characteristic parameter module (101), the optimal power supply removal plan and each fault scenario are input into the generation capacity evaluation module (400) to complete the evaluation of the survivability of the high-proportion new energy power grid system.

5. A high-proportion new energy grid survivability assessment system as claimed in claim 4, characterized in that: The power system regional network topology module (100) comprises a power grid actual structure submodule (102), a power grid weighted topology submodule (103) and a regional network parameter submodule (104); The actual power grid structure submodule (102) is used to output power grid topology equivalent parameters, which include converting 220 kV and above transformer branches into lines to determine the edges of the topology model, merging nodes in 220 kV and above high-voltage lines to determine the nodes of the topology model and renumbering them.

6. A high-proportion new energy grid survivability assessment system as claimed in claim 5, characterized in that: The power grid weighted topology submodule (103) receives power grid topology equivalent parameters and introduces line reactance into the topology map to redetermine the length of the edge. Electric energy is transmitted along the path with the smallest sum of line reactance values ​​in the weighted power grid topology model. The power grid weighted topology submodule (103) calculates the weighted association matrix of the topology map according to the power grid weighted topology equivalent parameters. The regional network parameter submodule (104) receives the weighted association matrix and obtains the corresponding basic characteristic parameters of the network.

7. A high-proportion new energy grid survivability assessment system as claimed in claim 6, characterized in that: The power grid disaster scenario module (200) comprises a node identification submodule (201), a fault mode submodule (202) and a power balance submodule (203); The node identification submodule (201) receives the power grid equivalent association matrix module (10), determines the node category, and classifies it accordingly into power supply nodes and non-power supply nodes, determines the terminal nodes and contact nodes in the network, and outputs the power grid equivalent association matrix and node type classification to the fault mode submodule (202); The fault mode submodule (202) analyzes and calculates the node type classification of each scene to obtain the topological structure and each fault scene after the node is removed from each scene, and each fault scene logic includes scene 1 and scene 2; Scenario 1 is based on node load. It examines the dependence of the power grid on key nodes by deliberately attacking nodes with large loads. Specifically, it deliberately attacks the node with the largest load, and then attacks the nodes with the second largest load in turn. Scenario 2 is based on degree and examines the dependence of the power grid on key nodes by deliberately attacking the contact nodes. Specifically, the node with the largest degree is deliberately attacked, and then the nodes with the second largest degree are attacked in turn. The power balancing submodule (203) receives the topological structure after power removal of each scenario, and outputs the power removal capacity of each fault scenario according to the power balancing principle. The optimal power removal evaluation module (300) obtains the optimal power removal plan of the system according to the power removal capacity of each fault scenario and the power removal sequence of photovoltaic power, wind power and thermal power.

8. A high-proportion new energy grid survivability assessment system as claimed in claim 7, characterized in that: The survivability assessment module (400) comprises a post-fault topology analysis submodule (401), a survivability index calculation submodule (402) and a comprehensive evaluation submodule (403); The post-fault topology analysis submodule (401) receives each fault scenario and the optimal power removal solution to recalculate the post-fault correlation matrix. The survival index calculation submodule (402) receives the post-fault correlation matrix and the network basic characteristic parameter module (101) to calculate the survival index loss load percentage F. loss The survivability index is transmitted to the comprehensive evaluation submodule (403), and the superior-inferior solution distance method is used to convert multiple indexes into a single index to comprehensively evaluate the survivability of the high-proportion new energy power grid.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of a method for evaluating the viability of a high-proportion new energy power grid according to any one of claims 1 to 3 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of a method for assessing the viability of a high-proportion new energy power grid according to any one of claims 1 to 3 are implemented.

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