A method and system for setting disturbance of cascading faults and sequential interruption considering the impact of new energy grid connection

Abstract

The present invention discloses a method and system for setting a cascading fault sequential disconnection disturbance that takes into account the impact of renewable energy grid connection, wherein the method comprises: constructing a boundary condition vector of a power grid severe fault simulation calculation method based on the stringency requirements of operating conditions; constructing a power grid sequential disconnection initial component set vector based on the grid-connected renewable energy correlation requirements; constructing a sequential disconnection component trigger condition set vector that takes into account the fault ride-through characteristics of renewable energy power sources; designing a cascading fault sequential disconnection disturbance setting process that takes into account the impact of renewable energy grid connection based on the boundary condition vector of the power grid severe fault simulation calculation method, the power grid sequential disconnection initial component set vector and the sequential disconnection component trigger condition set vector; and obtaining a final severe fault set of cascading fault sequential disconnection disturbance that takes into account the impact of renewable energy grid connection based on the cascading fault sequential disconnection disturbance setting process.

Description

Technical Field

[0001] The present invention relates to the technical field of power system simulation analysis, and more specifically, to a method and system for setting cascading fault sequential interruption disturbances taking into account the impact of renewable energy grid connection. Background Art

[0002] my country's primary power system is currently undergoing a profound transformation. Electromagnetic conversion equipment such as generators, transformers, and motors in the power generation, transmission, and load stages of the system are gradually being replaced by power electronic conversion equipment. On the power generation side, my country has made the large-scale development of renewable energy, primarily wind and solar power, a key strategic deployment for energy development. It is foreseeable that even more centralized and distributed renewable energy will be integrated into the power system in the future.

[0003] The electronicization of power across the source-grid-load chain, especially on the generation side, will pose significant challenges to the safe and stable operation of power grids. In recent years, both domestically and internationally, systems incorporating large-scale renewable energy have experienced cascading failures and outages. For example, the 2006 "November 4" blackout in Western Europe saw a large number of wind turbines disconnected from the grid, leading to a significant imbalance in active power and ultimately causing prolonged frequency deviations in the Western European power grid. In 2011, multiple wind turbine disconnections occurred near wind farms in Jiuquan, Northwest my country, and Zhangjiakou, Hebei.

[0004] Domestic and international scholars have conducted extensive research on cascading failures in power grids, focusing primarily on the following two areas: First, the study of the development mechanism of cascading failures, using three research methods: ① Pattern search methods, including analytical methods, stochastic simulation methods, and state-space analysis methods; ② Complex system theory methods, with commonly used models including the OPA model, CASCADE model, and hidden fault model; and ③ Complex network theory methods, with commonly used models including the small-world model, Watts construction model, and Holme and Kim center-separated model. Second, the study of cascading failure prevention and control measures, with common methods including active node removal strategy, load distribution equalization strategy, load transfer strategy, active flow removal strategy, and active islanding strategy. However, existing technologies have not considered the impact of renewable energy grid integration on the development of cascading failures in power grids. Summary of the Invention

[0005] The technical solution of the present invention provides a method and system for setting a cascading fault sequential breaking disturbance taking into account the influence of renewable energy grid connection, so as to solve the problem of how to set a cascading fault sequential breaking disturbance taking into account the influence of renewable energy grid connection.

[0006] In order to solve the above problems, the present invention provides a method for setting a cascading fault sequential interruption disturbance taking into account the impact of renewable energy grid connection, the method comprising:

[0007] Construct boundary condition vectors for power grid severe fault simulation calculation based on the stringency of operating conditions;

[0008] Construct the initial component set vector for grid sequential disconnection based on the correlation requirements of grid-connected new energy;

[0009] Construct a set of triggering condition vectors for sequential disconnection elements taking into account the fault ride-through characteristics of new energy power sources;

[0010] Design a cascading fault sequential disconnection disturbance setting process taking into account the impact of new energy grid connection based on the boundary condition vector of the power grid severe fault simulation calculation method, the initial element set vector of the power grid sequential disconnection, and the trigger condition set vector of the sequential disconnection element;

[0011] Based on the cascading fault sequential interruption disturbance setting process, a final severe fault set of the cascading fault sequential interruption disturbance taking into account the impact of the new energy grid connection is obtained.

[0012] Preferably, the step of constructing a boundary condition vector for a power grid severe fault simulation calculation method based on the stringency requirements of operating conditions includes:

[0013] Define the boundary condition vector K of the power grid severe fault simulation calculation method and the inherent related problem set vector P in the original system Risk , the severe operating condition set vector P in various operating conditions of the power grid SeriousMode The output situation set vector p of wind power and photovoltaic power with the greatest impact on the system Wind-Sola ;

[0014] The element k of the boundary condition vector of the power grid severe fault simulation calculation method i , the element p of the inherent related problem set vector in the original system Risk , the element p of the severe operating condition set vector in various operating conditions of the power grid SeriousMode The element p of the set vector of the output conditions of wind power and photovoltaic power that have the greatest impact on the system Wind-Sola , there is the following functional relationship:

[0015] k i =f(p Risk ,p seriousmode ,p wind-solar )

[0016] Among them, k i ∈K,p Risk ∈P Risk , p SeriousMode ∈P SeriousMode , p Wind-Solar ∈P Wind-Solar , where i≤max-k, max-k is the maximum number of elements in the K vector.

[0017] Preferably, the constructing of the grid sequential disconnection initial element set vector based on the grid-connected new energy correlation requirement includes:

[0018] Define the line set vector L of all lines in the power grid sorted by load rate from large to small HeavyLoad , the line set vector L of all power grid lines sorted from large to small according to the scale of new energy grid connection in the region Max-Wind-Solar , the line set vector L of all power grid lines is sorted from largest to smallest according to the severity of grid structure damage caused by line failure Structure , the line set vector L of all lines in the power grid is ranked from largest to smallest according to the serious imbalance of power grid operation after the fault. Operation ;

[0019] For a network of business lines, the line set vector L is HeavyLoad , the line set vector L Max-Wind-Solar , the line set vector L Structure and the line set vector L Operation The subscript algebra and sorting in the grid are used to obtain the initial element set vector X of the grid disconnection sequence, including:

[0020] Let a, b, c, and d be any line x in the power grid. r In Line Set Vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation The subscript values ​​of the sort are:

[0021] X=[x min(a+b+c+d) , x [min(a+b+c+d)+1] ,……,x [min(a+b+c+d)+r] ,……],

[0022] Where 1≤r≤m, m is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation The number of elements of x min(a+b+c+d) is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the order is calculated, the line with the smallest subscript value after the order is calculated; [min(a+b+c+d)+1] is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structureand line set vector L Operation After the algebraic sum of the subscript values ​​in the order is calculated, the line with the next smallest subscript value after the order is calculated; [min(a+b+c+d)+r] is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the sorting, the line with the smallest subscript value after sorting is r; that is, 1≤r≤m, m is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation Preferably, the construction of the trigger condition set vector of the successive disconnection elements taking into account the fault ride-through characteristics of the new energy power supply includes:

[0023] Assume that the trigger condition set vector Y of the successive disconnection components is:

[0024] Y=[y overload-1 ,……,y overload-j ,……,y wind-Solar-H-V-1 ,y wind-Solar-L-V-1 ,y wind-Solar-H-F-1 ,y wind-Solar-L-F-1 ,……,y wind-Solar-H-V-t ,y wind-Solar-L-V-t ,y wind-Solar-H-F-t ,y wind-Solar-L-F-t ,……], where y overload-j represents the overcurrent protection setting value of the jth line in the network, 1≤j≤m, m is the number of elements in the trigger condition set vector Y of the successive disconnection elements, y wind-Solar-H-V-t 、y wind-Solar-L-V-t 、y wind-Solar-H-F-t They represent the high voltage ride-through capability, low voltage ride-through capability, high frequency ride-through capability, and low frequency ride-through capability of the t-th wind power or photovoltaic power source in the grid, respectively. 1≤t≤t max , t max Indicates the total amount of wind power and photovoltaic power sources in the power grid.

[0025] Preferably, the step of obtaining a final severe fault set of cascading failures and sequential interruption disturbances taking into account the impact of new energy grid connection based on the cascading failures and sequential interruption disturbance setting process includes:

[0026] The element k of the boundary condition vector of the simulation calculation method for severe power grid faults i When i is less than or equal to the maximum number of elements max-k of the boundary condition vector of the power grid serious fault simulation calculation method, the elements X in the initial component set vector X of the power grid are disconnected successively. rWhen r is less than or equal to the number of elements m of the initial set of components of the power grid that are disconnected successively, the element X in the initial set of components of the power grid that are disconnected successively is traversed. r In k i Carry out fault simulation in advance mode and obtain simulation results;

[0027] When the simulation result is within the action constant value range of any element of the sequential disconnection element trigger condition set vector Y, the elements within the constant value range are disconnected, and the fault simulation is continued.

[0028] According to another aspect of the present invention, a system for setting a cascading fault sequential interruption disturbance taking into account the impact of renewable energy grid connection is provided, the system comprising:

[0029] The first construction unit is used to construct a boundary condition vector of a power grid severe fault simulation calculation method based on the stringency requirement of the operating conditions;

[0030] The second construction unit is used to construct an initial component set vector for successive disconnection of the power grid based on the correlation requirements of the grid-connected new energy;

[0031] The third construction unit is used to construct a set of triggering conditions for successive disconnection elements taking into account the fault ride-through characteristics of the new energy power supply;

[0032] A design unit is configured to design a cascading fault sequential disconnection disturbance setting process taking into account the impact of new energy grid connection based on the boundary condition vector of the power grid severe fault simulation calculation method, the power grid sequential disconnection initial element set vector, and the sequential disconnection element triggering condition set vector;

[0033] The result unit is used to obtain a final serious fault set of cascading faults and sequential interruption disturbances taking into account the impact of new energy grid connection based on the cascading faults and sequential interruption disturbance setting process.

[0034] Preferably, the first construction unit is used to construct a boundary condition vector of a power grid severe fault simulation calculation method based on the stringency requirement of the operating conditions, including:

[0035] Define the boundary condition vector K of the power grid severe fault simulation calculation method and the inherent related problem set vector P in the original system Risk , the severe operating condition set vector P in various operating conditions of the power grid SeriousMode The output situation set vector p of wind power and photovoltaic power with the greatest impact on the system Wind-Sola ;

[0036] The element k of the boundary condition vector of the power grid severe fault simulation calculation method i , the element p of the inherent related problem set vector in the original system Risk , the element p of the severe operating condition set vector in various operating conditions of the power gridSeriousMode The element p of the set vector of the output conditions of wind power and photovoltaic power that have the greatest impact on the system Wind-Sola , there is the following functional relationship:

[0037] k i =f(p Risk ,p seriousmode ,p wind-solar )

[0038] Among them, k i ∈K,p Risk ∈P Risk , p SeriousMode ∈P SeriousMode , p Wind-Solar ∈P Wind-Solar , where i≤max-k, max-k is the maximum number of elements in the K vector.

[0039] Preferably, the second construction unit is configured to construct a grid sequential disconnection initial element set vector based on grid-connected new energy correlation requirements, including:

[0040] Define the line set vector L of all lines in the power grid sorted by load rate from large to small HeavyLoad , the line set vector L of all power grid lines sorted from large to small according to the scale of new energy grid connection in the region Max-Wind-Solar , the line set vector L of all power grid lines is sorted from largest to smallest according to the severity of grid structure damage caused by line failure Structure , the line set vector L of all lines in the power grid is ranked from largest to smallest according to the serious imbalance of power grid operation after the fault. Operation ;

[0041] For a network of business lines, the line set vector L is HeavyLoad , the line set vector L Max-Wind-Solar , the line set vector L Structure and the line set vector L Operation The subscript algebra and sorting in the grid are used to obtain the initial element set vector X of the grid disconnection sequence, including:

[0042] Let a, b, c, and d be any line x in the power grid. r In Line Set Vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation The subscript values ​​of the sort are:

[0043] X=[x min(a+b+c+d) , x [min(a+b+c+d)+1] ,……,x [min(a+b+c+d)+r] ,……],

[0044] Where 1≤r≤m, m is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation The number of elements of x min(a+b+c+d) is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the order is calculated, the line with the smallest subscript value after the order is calculated; [min(a+b+c+d)+1] is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the order is calculated, the line with the next smallest subscript value after the order is calculated; [min(a+b+c+d)+r] is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the sorting, the line with the smallest subscript value after sorting is r; that is, 1≤r≤m, m is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation Preferably, the third construction unit is used to construct a set of triggering conditions for successive disconnection elements taking into account the fault ride-through characteristics of the new energy power supply, including:

[0045] Assume that the trigger condition set vector Y of the successive disconnection components is:

[0046] Y=[y overload-1 ,……,y overload-j ,……,y wind-Solar-H-V-1 ,y wind-Solar-L-V-1 ,y wind-Solar-H-F-1 ,y wind-Solar-L-F-1 ,……,y wind-Solar-H-V-t ,y wind-Solar-L-V-t ,y wind-Solar-H-F-t ,y wind-Solar-L-F-t ,……], where y overload-j represents the overcurrent protection setting value of the jth line in the network, 1≤j≤m, m is the number of elements in the trigger condition set vector Y of the successive disconnection elements, y wind-Solar-H-V-t 、y wind-Solar-L-V-t 、y wind-Solar-H-F-tThey represent the high voltage ride-through capability, low voltage ride-through capability, high frequency ride-through capability, and low frequency ride-through capability of the t-th wind power or photovoltaic power source in the grid, respectively. 1≤t≤t max , t max Indicates the total amount of wind power and photovoltaic power sources in the power grid.

[0047] Preferably, the result unit is configured to obtain a final severe fault set of cascading failures and sequential interruption disturbances taking into account the impact of new energy grid connection based on the cascading failures and sequential interruption disturbance setting process, including:

[0048] The element k of the boundary condition vector of the simulation calculation method for severe power grid faults i When i is less than or equal to the maximum number of elements max-k of the boundary condition vector of the power grid serious fault simulation calculation method, the elements X in the initial component set vector X of the power grid are disconnected successively. r When r is less than or equal to the number of elements m of the initial set of components of the power grid that are disconnected successively, the element X in the initial set of components of the power grid that are disconnected successively is traversed. r In k i Carry out fault simulation in advance mode and obtain simulation results;

[0049] When the simulation result is within the action constant value range of any element of the sequential disconnection element trigger condition set vector Y, the elements within the constant value range are disconnected, and the fault simulation is continued.

[0050] The technical solution of the present invention provides a method for setting a cascading fault sequential disconnection disturbance that takes into account the impact of renewable energy grid connection, the method comprising: constructing a boundary condition vector of a power grid severe fault simulation calculation method based on the stringency requirements of operating conditions; constructing a power grid sequential disconnection initial component set vector based on the grid-connected renewable energy correlation requirements; constructing a sequential disconnection component triggering condition set vector that takes into account the fault ride-through characteristics of renewable energy power supplies; designing a cascading fault sequential disconnection disturbance setting process that takes into account the impact of renewable energy grid connection based on the boundary condition vector of the power grid severe fault simulation calculation method, the power grid sequential disconnection initial component set vector and the sequential disconnection component triggering condition set vector; and obtaining a final severe fault set of the cascading fault sequential disconnection disturbance that takes into account the impact of renewable energy grid connection based on the cascading fault sequential disconnection disturbance setting process. The technical solution of the present invention is based on an investigation of the relevant technical research progress in the field of domestic renewable energy grid connection and cascading failure blackouts, combined with the characteristics and actual situation of large-scale renewable energy grid connection, and taking into account the volatility characteristics of renewable energy output, proposes a boundary condition vector of a power grid severe fault simulation calculation method based on the stringency of operating conditions and a grid successive disconnection initial component set vector construction principle based on the grid-connected renewable energy correlation requirements. On the basis of the conventional initial fault causing the adjacent line overload to trigger the successive disconnection fault process, a successive disconnection component trigger condition set vector construction method taking into account the fault ride-through characteristics of renewable energy power supply is proposed, and a cascading failure successive disconnection disturbance setting process taking into account the impact of renewable energy grid connection is given, forming a cascading failure successive disconnection disturbance setting method that can effectively take into account the impact of renewable energy grid connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0052] Figure 1 This is a flow chart of a method for setting a cascading fault sequential interruption disturbance taking into account the impact of new energy grid connection according to a preferred embodiment of the present invention;

[0053] Figure 2 A low voltage ride-through capability curve system structure diagram according to a preferred embodiment of the present invention;

[0054] Figure 3 The low voltage ride-through capability requirement of the photovoltaic power station according to the preferred embodiment of the present invention;

[0055] Figure 4 A flow chart is provided for a cascading fault sequential interruption disturbance setting taking into account the impact of new energy grid connection according to a preferred embodiment of the present invention; and

[0056] Figure 5 The present invention is a structural diagram of a system for sequentially interrupting disturbances caused by cascading faults taking into account the impact of new energy grid connection according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0057] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to provide a thorough and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments shown in the accompanying drawings is not intended to limit the present invention. In the accompanying drawings, identical elements are denoted by the same reference numerals.

[0058] Unless otherwise specified, the terms used herein (including technical terms) have the meanings commonly understood by those skilled in the art. In addition, it is understood that terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0059] Figure 1 The present invention is a flowchart of a method for setting disturbances for sequential interruption of cascading faults that takes into account the impact of new energy grid connection according to a preferred embodiment of the present invention. Due to the rapid development of new energy power generation such as wind power and photovoltaic power in my country in recent years, it is expected that a large number of wind power and photovoltaic power stations will be connected to the grid in the future. As intermittent power sources, wind power and solar photovoltaic power generation will have an impact on system currents, reactive voltage, system stability, power quality, etc. during grid connection. At the same time, the fault ride-through characteristics of wind power and photovoltaic power sources, including high and low voltage protection, high and low frequency protection, will also affect the development of the fault during the grid fault. The traditional method for setting disturbances for sequential interruption of cascading faults cannot take into account the above-mentioned impact after the new energy power source is connected to the grid. The goal of the method for setting the disturbance of sequential disconnection due to cascading failures taking into account the influence of the grid connection of new energy sources is to provide a method for constructing a new scenario of cascading failures that can effectively reflect the process of large-scale wind power, photovoltaic power and other new energy sources being disconnected from the grid due to their fault ride-through characteristics after large-scale new energy sources are connected to the grid, and then interweave and couple the process of sequential disconnection due to line overload and exiting operation after conventional disturbances, thereby providing a reasonable and effective technical analysis method for accurately grasping the new characteristics and new problems that may arise in the grid cascading failures after the grid connection of new energy sources. In order to carry out research on the method for setting the disturbance of sequential disconnection due to cascading failures taking into account the influence of the grid connection of new energy sources, so as to ensure the reliable operation of the grid after the grid connection of new energy sources, the present invention provides a method for setting the disturbance of sequential disconnection due to cascading failures taking into account the influence of the grid connection of new energy sources, and the method includes:

[0060] Preferably, in step 101 : constructing a boundary condition vector of a power grid severe fault simulation calculation method based on the stringency requirement of the operating conditions.

[0061] Preferably, constructing a boundary condition vector of a power grid severe fault simulation calculation method based on the stringency requirements of operating conditions includes:

[0062] Define the boundary condition vector K of the power grid severe fault simulation calculation method and the inherent related problem set vector P in the original system Risk , the severe operating condition set vector P in various operating conditions of the power grid SeriousMode The output situation set vector p of wind power and photovoltaic power with the greatest impact on the system Wind-Sola ;

[0063] Element k of the boundary condition vector for power grid severe fault simulation calculation method i , the element p of the inherent related problem set vector in the original system Risk , the element p of the severe operating condition set vector in various operating conditions of the power grid SeriousMode The element p of the set vector of the output conditions of wind power and photovoltaic power that have the greatest impact on the system Wind-Sola , there is the following functional relationship:

[0064] k i =f(p Risk ,p seriousmode ,p wind-solar )

[0065] Among them, k i ∈K,p Risk ∈P Risk , p SeriousMode ∈P SeriousMode , p Wind-Solar ∈P Wind-Solar , where i≤max-k, max-k is the maximum number of elements in the K vector.

[0066] The present invention constructs boundary condition vectors of a power grid severe fault simulation calculation method based on the stringent requirements of operating conditions.

[0067] To enhance the guiding significance of severe fault analysis for actual power grids, not only must the fault disturbance form be targeted, but the selected calculation method must also be able to specifically reflect the inherent relevant issues of the actual power grid and must be the most severe among the various operating conditions of the grid. Considering the output fluctuations of renewable energy sources after grid integration, the most severe output conditions of renewable energy sources must also be effectively accounted for.

[0068] Define the boundary condition vector K of the power grid severe fault simulation calculation method, with vector P Risk , P SeriousMode and P Wind-Solar They represent the set of inherent related problems in the original system, the set of severe operating conditions in various operating conditions of the power grid, and the set of output conditions where wind power and photovoltaic power connected to the grid have the greatest impact on the system. Then the elements k in the above four vectors are i 、p Risk , pSeriousMode and p Wind-Sola , there is the following functional relationship:

[0069] k i =f(p Risk ,p seriousmode ,p wind-solar )

[0070] Among them, k i ∈K,p Risk ∈P Risk , p SeriousMode ∈P SeriousMode , p Wind-Solar ∈P Wind-Solar , where i≤max-k, max-k is the maximum number of elements in the K vector.

[0071] Based on the relevant operating element vector P in the above functional relationship Risk , P SeriousMode and P Wind-Solar By taking different element values ​​of , we can obtain a specific value k of the boundary condition vector for severe fault analysis.

[0072] Preferably, in step 102: constructing a grid sequential disconnection initial element set vector based on the grid-connected new energy correlation requirement.

[0073] Preferably, constructing a grid sequential disconnection initial component set vector based on the grid-connected new energy correlation requirement includes:

[0074] Define the line set vector L of all lines in the power grid sorted by load rate from large to small HeavyLoad , the line set vector L of all power grid lines sorted from large to small according to the scale of new energy grid connection in the region Max-Wind-Solar , the line set vector L of all power grid lines is sorted from largest to smallest according to the severity of grid structure damage caused by line failure Structure , the line set vector L of all lines in the power grid is ranked from largest to smallest according to the serious imbalance of power grid operation after the fault. Operation ;

[0075] Do business on a network line by its on line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation The subscript algebra and sorting in the grid are used to obtain the initial component set vector X for successive disconnection of the power grid, including:

[0076] Let a, b, c, and d be any line x in the power grid. r In Line Set Vector L HeavyLoad , line set vector LMax-Wind-Solar , line set vector L Structure and line set vector L Operation The subscript values ​​of the sort are:

[0077] X=[x min(a+b+c+d) , x [min(a+b+c+d)+1] ,……,x [min(a+b+c+d)+r] ,……],

[0078] Where 1≤r≤m, m is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation The number of elements of x min(a+b+c+d) is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the order is calculated, the line with the smallest subscript value after the order is calculated; [min(a+b+c+d)+1] is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the order is calculated, the line with the next smallest subscript value after the order is calculated; [min(a+b+c+d)+r] is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the sorting, the line with the smallest subscript value after sorting is r; that is, 1≤r≤m, m is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation The number of elements. The present invention constructs the initial component set vector for successive disconnection of the power grid based on the correlation requirements of the grid-connected new energy. For the offline analysis of serious faults, the initial component set vector for successive disconnection of the power grid can be selected from the traversal idea based on the fault component in the conventional N-1 analysis, but considering that the traversal should generally start from the line with the most serious consequences of the fault, related problems can be found in advance and the subsequent workload can be reduced. Specifically, the initial fault line set can be selected according to the following criteria: 1. The initial flow load rate of the line is high; 2. The scale of new energy grid connection in the area where the line is located is large; 3. The grid structure is seriously damaged after the line fault; 4. The grid operation amount (active power, reactive power) is seriously unbalanced after the line fault.

[0079] With vector L HeavyLoad , L Max-Wind-Solar , L Structure , L Operation These represent, respectively, the set of lines ranked from high to low in terms of initial power flow load rate, the set of lines ranked from large to small in terms of the scale of new energy grid integration in their respective regions, the set of lines ranked from large to small in terms of the severity of grid structural damage caused by line failures, and the set of lines ranked from large to small in terms of the severity of imbalance in grid operating quantities (active and reactive) after line failures. It can be seen that the vectors corresponding to these sets all have the same number of elements, m, where m is the number of lines in the studied grid. By summing the subscript values ​​of the same line in each of these line types and arranging them in ascending order, we can obtain the initial set of elements X for the grid's sequential disconnection based on the requirements for grid-connected new energy relevance. This is done by setting the order of the line elements representing the initial disturbance as the initial element, thus generating all the line elements in X.

[0080] Let a, b, c, and d be any line x in the power grid. r In vector L HeavyLoad , L Max-Wind-Solar , L Structure , L Operation The subscript values ​​of the sort are

[0081] X=[x min(a+b+c+d) , x [min(a+b+c+d)+1] ,……,x [min(a+b+c+d)+r] ,……], where 1≤r≤m.

[0082] In actual engineering, in order to reduce the amount of calculation, not all lines will be traversed. That is, a threshold value m of the number of engineering analyses can be set. R , usually this value is much smaller than m, and i only needs to satisfy 1≤i≤m R The specific m R The choice of value can be determined based on the actual power grid situation that needs to be analyzed and combined with existing engineering experience.

[0083] Preferably, in step 103: a set of triggering conditions for successive disconnection elements taking into account the fault ride-through characteristics of the new energy power source is constructed.

[0084] Preferably, constructing a set of triggering condition vectors for successive disconnection elements taking into account the fault ride-through characteristics of the new energy power supply includes:

[0085] Assume that the trigger condition set vector Y of the successive disconnection components is:

[0086] Y=[y overload-1 ,……,y overload-j ,……,y wind-Solar-H-V-1 ,y wind-Solar-L-V-1 ,y wind-Solar-H-F-1 ,ywind-Solar-L-F-1 ,……,y wind-Solar-H-V-t ,y wind-Solar-L-V-t ,y wind-Solar-H-F-t ,y wind-Solar-L-F-t ,……], where y overload-j represents the overcurrent protection setting value of the jth line in the network, 1≤j≤m, m is the number of elements in the trigger condition set vector Y of the successive disconnection elements, y wind-Solar-H-V-t 、y wind-Solar-L-V-t 、y wind-Solar-H-F-t They represent the high voltage ride-through capability, low voltage ride-through capability, high frequency ride-through capability, and low frequency ride-through capability of the t-th wind power or photovoltaic power source in the grid, respectively. 1≤t≤t max , t max Indicates the total amount of wind power and photovoltaic power sources in the power grid.

[0087] The present invention constructs a set of trigger condition vectors of successive disconnecting elements taking into account the fault ride-through characteristics of a new energy power supply.

[0088] The grid fault ride-through (GFRT) requirement for wind turbines and photovoltaic power sources is widely recognized as one of the most challenging and important technical requirements. The fundamental concept of GFRT for renewable energy power sources can be summarized as follows: when a power system accident or disturbance causes the voltage or frequency at the grid connection point to exceed the normal operating range permitted by standards, the wind turbine or photovoltaic power source must be able to maintain continuous operation without disconnection and smoothly transition to normal operation within a certain voltage or frequency range and duration.

[0089] 1) Wind turbine low voltage ride-through

[0090] The Technical Regulations for Wind Farm Integration into the Power System (GB / T19963-2011) puts forward specific requirements for low voltage ride-through of wind farms:

[0091] a) When the voltage at the wind farm grid connection point drops to 20% of the nominal voltage, the wind turbines in the wind farm should remain connected to the grid and operate continuously for 625ms;

[0092] b) When the voltage at the wind farm grid connection point can recover to 90% of the rated voltage within 2 seconds after a drop, the wind turbines in the wind farm remain connected to the grid and operate continuously.

[0093] The detailed description of low voltage ride-through capability is shown in the attached Figure 2 .

[0094] 2) Wind turbine high voltage ride-through

[0095] my country's State Grid Corporation of China's corporate standard Q / GDW 1878-2013, "Technical Standard for Reactive Power Configuration and Voltage Control in Wind Farms," ​​requires wind farms and wind turbines to possess certain high voltage ride-through capabilities. This standard references the high voltage ride-through technical indicators proposed by developed countries in the wind power sector and, based on research on overvoltages during several large-scale wind power outages in my country, proposes the high voltage ride-through technical indicators for wind turbines, as shown in the table below. This standard requires that when the power frequency positive sequence voltage at the grid connection point reaches 1.2 pu, wind turbines must be able to operate continuously for at least 200 milliseconds without disconnecting from the grid.

[0096] Table 1 High voltage ride-through technical indicators proposed in Q / GDW1878-2013

[0097] Power frequency positive sequence voltage value at the grid connection point (pu) Runtime <![CDATA[1.10≤U T ≤1.15]]> Capable of running for 2 seconds each time <![CDATA[1.15<U T ≤1.20]]> Capable of running in 200ms per run <![CDATA[1.20<U T ]]> Exit

[0098] 3) Fan frequency ride-through

[0099] In addition to voltage ride-through, fault ride-through capability should also include frequency ride-through (FRT). Currently, research in this area is relatively rare, and there's no consensus on the relevant content. However, wind turbines generally have frequency over-limit protection, which is used to promptly disconnect the wind turbine when the frequency fluctuates significantly. Grid frequency fluctuations can affect the normal operation of wind turbines. When the grid frequency exceeds the upper or lower set points set for the wind turbine, the frequency over-limit protection activates, disconnecting the wind turbine from the system and shutting it down. For example, the general technical specifications for the Vestas V90-1.8 / 2.0MW 50Hz VCS wind turbine specify the following frequency operating range for wind turbine grid connection: If the frequency exceeds 53Hz for 0.2 seconds or falls below 47Hz for 0.2 seconds, the generator and inverter will disconnect.

[0100] my country's "Technical Regulations for Wind Farm Connection to Power Systems" (GB / T19963-2011) also gives the frequency operating range of wind turbines, as shown in the following table.

[0101] Table 2 Operation regulations of wind farms in different power system frequency ranges

[0102]

[0103] 4) Photovoltaic power supply low voltage ride-through

[0104] The Technical Regulations for the Integration of Photovoltaic Power Stations into Power Systems (GB / T19964-2012) specifies the low voltage ride-through requirements that photovoltaic power stations should meet:

[0105] 1) When the voltage at the grid connection point of the photovoltaic power station drops to 0, the photovoltaic power station should be able to operate continuously for 0.15s without being disconnected from the grid.

[0106] 2) The voltage at the grid connection point of the photovoltaic power station drops to the following Figure 3 When the value is below curve 1, the photovoltaic power station can be disconnected from the grid.

[0107] 5) Photovoltaic power supply high voltage ride through

[0108] The Technical Regulations for the Connection of Photovoltaic Power Stations to the Power System (GB / T19964-2012) also provides the voltage operating range of photovoltaic power stations, as shown in the following table.

[0109] Table 3 Operation regulations of photovoltaic power stations in different grid connection point voltage ranges

[0110]

[0111] 6) Photovoltaic power frequency ride-through

[0112] The Technical Regulations for the Connection of Photovoltaic Power Stations to the Power System (GB / T19964-2012) also provides the frequency operating range of photovoltaic power stations, as shown in the following table.

[0113] Table 4 Operation regulations of photovoltaic power stations in different power system frequency ranges

[0114]

[0115] 3.2 Triggering condition set vector of sequential disconnection elements considering fault ride-through characteristics of new energy power supply

[0116] Usually, the disturbance is disconnected successively. The starting condition for the subsequent disturbance is that the initial fault line or the previous fault line triggers a flow transfer. If the transferred flow value exceeds the overcurrent protection setting of the line for other lines still in operation in the power grid, the line will continue to exit operation, and this cycle will be repeated, forming a successive disconnection. At the same time, considering that after the new energy is connected to the grid, wind turbines and photovoltaic power sources have four types of fault ride-through capabilities: high power ride-through, low voltage ride-through, high frequency ride-through, and low frequency ride-through. When the initial fault line or the previous fault line triggers a flow transfer, or the grid structure is damaged, the voltage and frequency of the wind turbine or photovoltaic power grid connection point change significantly, exceeding the range of the new energy power voltage and frequency fault ride-through capability, causing the new energy power unit to exit operation, this can also be regarded as triggering the successive disconnection of the grid elements, that is, the continued development of the successive disconnection process occurs. For this reason, the vector Y is set to represent the trigger condition set of the successive disconnection elements taking into account the fault ride-through characteristics of the new energy power source. Then there is

[0117] Y=[y overload-1 ,……,y overload-j ,……,y wind-Solar-H-V-1 ,y wind-Solar-L-V-1 ,y wind-Solar-H-F-1 ,y wind-Solar-L-F-1 ,……,y wind-Solar-H-V-t ,ywind-Solar-L-V-t ,y wind-Solar-H-F-t ,y wind-Solar-L-F-t ,……], where y overload-j represents the overcurrent protection setting value of the jth line in the network, 1≤j≤m; and y wind-Solar-H-V-t 、y wind-Solar-L-V-t 、y wind-Solar-H-F-t They represent the high voltage ride-through capability, low voltage ride-through capability, high frequency ride-through capability, and low frequency ride-through capability of the t-th wind power or photovoltaic power source in the grid, respectively. 1≤t≤t max , t max Indicates the total amount of wind power and photovoltaic power sources in the power grid.

[0118] Preferably, in step 104: based on the boundary condition vector of the power grid severe fault simulation calculation mode, the power grid sequential disconnection initial element set vector and the sequential disconnection element triggering condition set vector, a cascading fault sequential disconnection disturbance setting process is designed taking into account the impact of new energy grid connection.

[0119] Preferably, in step 105 : based on the cascading failure sequential interruption disturbance setting process, a final severe fault set of the cascading failure sequential interruption disturbance taking into account the impact of the new energy grid connection is obtained.

[0120] Preferably, obtaining a final severe fault set of cascading faults and sequential interruption disturbances taking into account the impact of new energy grid connection based on the cascading faults and sequential interruption disturbance setting process includes:

[0121] The element k of the boundary condition vector of the simulation calculation method for severe power grid faults i When i is less than or equal to the maximum number of elements max-k of the boundary condition vector of the power grid serious fault simulation calculation method, the elements X in the initial component set vector X of the power grid are disconnected successively. r When r is less than or equal to the number of elements m of the initial set of components of the power grid that are disconnected successively, the element X in the initial set of components of the power grid that are disconnected successively is traversed. r In k i Carry out fault simulation in advance mode and obtain simulation results;

[0122] When the simulation result is within the action constant range of any element of the trigger condition set vector Y of the successive disconnection elements, the elements that fall within the constant range are disconnected and the fault simulation is continued.

[0123] The present invention proposes a process for setting disturbances for cascading faults and sequential disconnection that takes into account the impact of renewable energy grid connection. Based on the boundary condition vector K of the grid severe fault simulation calculation method with strict operating conditions, the vector X of the initial set of sequential disconnection components, and the vector Y of the triggering condition of the sequential disconnection components, the present invention designs and proposes a process for setting disturbances for cascading faults and sequential disconnection that takes into account the impact of renewable energy grid connection. Based on this process, the final severe fault set F of the cascading faults and sequential disconnection disturbance that takes into account the impact of renewable energy grid connection can be obtained. Cascading Specific content is as attached. Figure 4 shown.

[0124] The present invention's method for setting disturbances for cascading failures and sequential disconnections, which takes into account the impact of renewable energy grid integration, effectively accounts for the potential for disorderly disconnections of wind and photovoltaic power sources caused by cascading failures and sequential disconnections after large-scale renewable energy grid integration. It constructs a new cascading failure scenario, intertwined with the sequential disconnections of renewable energy sources due to fault ride-through issues and the sequential disconnections of line overloads. This provides a more comprehensive and effective disturbance setting method for analyzing cascading failures in large power grids, thereby providing strong technical support for analyzing serious grid faults under renewable energy grid integration.

[0125] Figure 5 This is a structural diagram of a system for sequential interruption of cascading faults taking into account the impact of new energy grid connection according to a preferred embodiment of the present invention. Figure 5 As shown, the present invention provides a cascading fault sequential interruption disturbance setting system taking into account the impact of new energy grid connection, the system comprising:

[0126] The first construction unit 501 is used to construct a boundary condition vector of a power grid severe fault simulation calculation method based on the stringency requirements of the operating conditions. Preferably, the first construction unit 501 is used to construct a boundary condition vector of a power grid severe fault simulation calculation method based on the stringency requirements of the operating conditions, including:

[0127] Define the boundary condition vector K of the power grid severe fault simulation calculation method and the inherent related problem set vector P in the original system Risk , the severe operating condition set vector P in various operating conditions of the power grid SeriousMode The output situation set vector p of wind power and photovoltaic power with the greatest impact on the system Wind-Sola ;

[0128] Element k of the boundary condition vector for power grid severe fault simulation calculation method i , the element p of the inherent related problem set vector in the original system Risk , the element p of the severe operating condition set vector in various operating conditions of the power grid SeriousMode The element p of the set vector of the output conditions of wind power and photovoltaic power that have the greatest impact on the system Wind-Sola , there is the following functional relationship:

[0129] k i =f(p Risk ,p seriousmode ,p wind-solar )

[0130] Among them, k i ∈K,p Risk ∈P Risk , p SeriousMode ∈P SeriousMode , p Wind-Solar ∈P Wind-Solar , where i≤max-k, max-k is the maximum number of elements in the K vector.

[0131] The second construction unit 502 is used to construct an initial component set vector for successive disconnection of the power grid based on the correlation requirements of the grid-connected new energy. Preferably, the second construction unit 502 is used to construct an initial component set vector for successive disconnection of the power grid based on the correlation requirements of the grid-connected new energy, including:

[0132] Define the line set vector L of all lines in the power grid sorted by load rate from large to small HeavyLoad , the line set vector L of all power grid lines sorted from large to small according to the scale of new energy grid connection in the region Max-Wind-Solar , the line set vector L of all power grid lines is sorted from largest to smallest according to the severity of grid structure damage caused by line failure Structure , the line set vector L of all lines in the power grid is ranked from largest to smallest according to the serious imbalance of power grid operation after the fault. Operation ;

[0133] Do business on a network line by its on line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation The subscript algebra and sorting in the grid are used to obtain the initial component set vector X for successive disconnection of the power grid, including:

[0134] Let a, b, c, and d be any line x in the power grid. r In Line Set Vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation The subscript values ​​of the sort are:

[0135] X=[x min(a+b+c+d) , x [min(a+b+c+d)+1] ,……,x [min(a+b+c+d)+r] ,……],

[0136] Where 1≤r≤m, m is the line set vector LHeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation The number of elements of x min(a+b+c+d) is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the order is calculated, the line with the smallest subscript value after the order is calculated; [min(a+b+c+d)+1] is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the order is calculated, the line with the next smallest subscript value after the order is calculated; [min(a+b+c+d)+r] is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the sorting, the line with the smallest subscript value after sorting is r; that is, 1≤r≤m, m is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation The third construction unit 503 is used to construct a set of triggering conditions for successive disconnection elements taking into account the fault ride-through characteristics of the new energy power supply. Preferably, the third construction unit 503 is used to construct a set of triggering conditions for successive disconnection elements taking into account the fault ride-through characteristics of the new energy power supply, including:

[0137] Assume that the trigger condition set vector Y of the successive disconnection components is:

[0138] Y=[y overload-1 ,……,y overload-j ,……,y wind-Solar-H-V-1 ,y wind-Solar-L-V-1 ,y wind-Solar-H-F-1 ,y wind-Solar-L-F-1 ,……,y wind-Solar-H-V-t ,y wind-Solar-L-V-t ,y wind-Solar-H-F-t ,y wind-Solar-L-F-t ,……], where y overload-j represents the overcurrent protection setting value of the jth line in the network, 1≤j≤m, m is the number of elements in the trigger condition set vector Y of the successive disconnection elements, y wind-Solar-H-V-t 、y wind-Solar-L-V-t 、y wind-Solar-H-F-tThey represent the high voltage ride-through capability, low voltage ride-through capability, high frequency ride-through capability, and low frequency ride-through capability of the t-th wind power or photovoltaic power source in the grid, respectively. 1≤t≤t max , t max Indicates the total amount of wind power and photovoltaic power sources in the power grid.

[0139] The design unit 504 is used to design a cascading fault sequential disconnection disturbance setting process taking into account the impact of new energy grid connection based on the boundary condition vector of the power grid severe fault simulation calculation method, the power grid sequential disconnection initial element set vector and the sequential disconnection element triggering condition set vector.

[0140] The result unit 505 is used to obtain a final severe fault set of cascading faults cascading interruption disturbances taking into account the impact of new energy grid connection based on the cascading faults cascading interruption disturbance setting process.

[0141] Preferably, the result unit 505 is configured to obtain a final severe fault set of cascading faults and sequential interruption disturbances taking into account the impact of new energy grid connection based on the cascading faults and sequential interruption disturbance setting process, including:

[0142] The element k of the boundary condition vector of the simulation calculation method for severe power grid faults i When i is less than or equal to the maximum number of elements max-k of the boundary condition vector of the power grid serious fault simulation calculation method, the elements X in the initial component set vector X of the power grid are disconnected successively. r When r is less than or equal to the number of elements m of the initial set of components of the power grid that are disconnected successively, the element X in the initial set of components of the power grid that are disconnected successively is traversed. r In k i Carry out fault simulation in advance mode and obtain simulation results;

[0143] When the simulation result is within the action constant range of any element of the trigger condition set vector Y of the successive disconnection elements, the elements that fall within the constant range are disconnected and the fault simulation is continued.

[0144] A cascading fault sequential interruption disturbance setting system 500 taking into account the impact of new energy grid connection in a preferred embodiment of the present invention corresponds to a cascading fault sequential interruption disturbance setting method 100 taking into account the impact of new energy grid connection in a preferred embodiment of the present invention, and will not be described in detail here.

[0145] The invention has been described above with reference to a few embodiments. However, it is readily apparent to a person skilled in the art that other embodiments than the ones disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

[0146] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / the [means, component, etc.]" are to be interpreted openly as referring to at least one instance of the means, component, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not necessarily need to be performed in the exact order disclosed, unless explicitly stated otherwise.

Claims

1. A method for setting a cascading fault sequential interruption disturbance taking into account the impact of new energy grid connection, the method comprising: Construct boundary condition vectors for power grid severe fault simulation calculation methods based on the stringency requirements of operating conditions; Construct the initial component set vector of grid sequential disconnection based on the correlation requirements of grid-connected renewable energy, including: Define the line set vector L of all lines in the power grid sorted from large to small according to load rate HeavyLoad , the line set vector L of all power grid lines sorted from large to small according to the scale of new energy grid connection in the region Max-Wind-Solar , the line set vector L of all power grid lines is sorted from largest to smallest according to the severity of grid structure damage caused by line failure Structure , the line set vector L of all lines in the power grid is from large to small according to the serious imbalance of power grid operation after the fault Operation ; For any line, according to its line set vector L HeavyLoad , the line set vector L Max-Wind-Solar , the line set vector L Structure and the line set vector L Operation The subscript algebra and sorting in the grid are used to obtain the initial component set vector X for the grid to be disconnected successively, including: Let a, b, c, d be any line x in the power grid. r In Line Set Vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation The subscript values ​​sorted in , then: X=[x min(a+b+c+d) ,x [min(a+b+c+d)+1] ,……,x [min(a+b+c+d)+r] ,……], Where 1≤r≤m, m is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation The number of elements of x min(a+b+c+d) is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the order is calculated, the line with the smallest subscript value after the order is calculated; x [min(a+b+c+d)+1] is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the order is calculated, the line with the next smallest subscript value after the order is calculated; x [min(a+b+c+d)+r] is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the sorting, the line with the rth smallest subscript value after sorting; Construct a set of triggering condition vectors of successive disconnection elements taking into account the fault ride-through characteristics of renewable energy power sources, including: Assume that the trigger condition set vector Y of the successive disconnection components is: Y=[y overload-1 , ..., y overload-j , ..., y wind-Solar-H-V-1 ,y wind-Solar-L-V-1 ,y wind-Solar-H-F-1 ,y wind-Solar-L-F-1 ,……,y wind-Solar-H-V-t ,y wind-Solar-L-V-t ,y wind-Solar-H-F-t ,y wind-Solar-L-F-t ,……], where y overload-j represents the overcurrent protection setting of the jth line in the network, 1≤j≤m, m is the number of elements of the trigger condition set vector Y of the successive disconnection elements, y wind-Solar-H-V-t ,y wind-Solar-L-V-t ,y wind-Solar-H-F-t ,y wind-Solar-L-F-t They represent the high voltage ride-through capability, low voltage ride-through capability, high frequency ride-through capability, and low frequency ride-through capability of the t-th wind power or photovoltaic power source in the power grid, respectively. 1≤t≤t max , t max Indicates the total number of wind power and photovoltaic power sources in the grid; Design a cascading fault sequential disconnection disturbance setting process taking into account the impact of new energy grid connection based on the boundary condition vector of the power grid severe fault simulation calculation method, the initial element set vector of the power grid sequential disconnection and the trigger condition set vector of the sequential disconnection element; Based on the cascading fault sequential interruption disturbance setting process, a final severe fault set of cascading fault sequential interruption disturbance taking into account the impact of new energy grid connection is obtained, including: The element k of the boundary condition vector for the simulation calculation method of severe power grid faults i When i is less than or equal to the maximum number of elements max-k of the boundary condition vector of the power grid severe fault simulation calculation method, the element X in the initial component set vector X of the power grid is disconnected successively. r When r is less than or equal to the number of elements m of the initial component set vector of the power grid successive disconnection, the element X in the initial component set vector X of the power grid successive disconnection is traversed. r In k i Carry out fault simulation in this way and obtain simulation results; When the simulation result is within the action constant range of any element of the trigger condition set vector Y of the successive disconnection elements, the elements within the constant range are disconnected, and the fault simulation is continued.

2. The method according to claim 1, wherein the step of constructing a boundary condition vector of a power grid severe fault simulation calculation method based on the severity requirements of operating conditions comprises: Define the boundary condition vector K of the power grid severe fault simulation calculation method and the inherent related problem set vector P in the original system Risk , the severe operating condition set vector P in various operating conditions of the power grid SeriousMode The output situation set vector P of wind power and photovoltaic power with the greatest impact on the system Wind-Sola ; The element k of the boundary condition vector of the power grid severe fault simulation calculation method i , the element p of the inherent relevant problem set vector in the original system Risk , the element p of the severe condition set vector in various operating conditions of the power grid SeriousMode The element p of the set vector of the output conditions of wind power and photovoltaic power that have the greatest impact on the system Wind-Sola , there is the following functional relationship: k i =f(p Risk, p seriousmode ,p wind-solar ) Among them, k i ∈K,p Risk ∈P Risk , p SeriousMode ∈P SeriousMode , p Wind-Solar ∈P Wind-Solar , where i≤max-k, max-k is the maximum number of elements in the K vector.

3. A cascading fault sequential interruption disturbance setting system taking into account the impact of new energy grid connection, the system comprising: A first construction unit is used to construct a boundary condition vector of a power grid severe fault simulation calculation method based on the stringency requirements of the operating conditions; The second construction unit is used to construct an initial component set vector for sequential disconnection of the power grid based on the correlation requirements of the grid-connected new energy, including: Define the line set vector L of all lines in the power grid sorted from large to small according to load rate HeavyLoad , the line set vector L of all power grid lines sorted from large to small according to the scale of new energy grid connection in the region Max-Wind-Solar , the line set vector L of all power grid lines is sorted from largest to smallest according to the severity of grid structure damage caused by line failure Structure , the line set vector L of all lines in the power grid is from large to small according to the serious imbalance of power grid operation after the fault Operation ; For any line, according to its line set vector L HeavyLoad , the line set vector L Max-Wind-Solar , the line set vector L Structure and the line set vector L Operation The subscript algebra and sorting in the grid are used to obtain the initial component set vector X for the grid to be disconnected successively, including: Let a, b, c, d be any line x in the power grid. r In Line Set Vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation The subscript values ​​sorted in , then: X=[x min(a+b+c+d) ,x [min(a+b+c+d)+1] ,……,x [min(a+b+c+d)+r] ,……], Where 1≤r≤m, m is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation The number of elements of x min(a+b+c+d) is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the order is calculated, the line with the smallest subscript value after the order is calculated; x [min(a+b+c+d)+1] is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the order is calculated, the line with the next smallest subscript value after the order is calculated; x [min(a+b+c+d)+r] is the line set vector L HeavyLoad , line set vector L Max-Wind-Solar , line set vector L Structure and line set vector L Operation After the algebraic sum of the subscript values ​​in the sorting, the line with the rth smallest subscript value after sorting; The third construction unit is used to construct a set of triggering conditions for successive disconnection elements taking into account the fault ride-through characteristics of the new energy power supply, including: Assume that the trigger condition set vector Y of the successive disconnection components is: Y=[y overload-1 , ..., y overload-j , ..., y wind-Solar-H-V-1 ,y wind-Solar-L-V-1 ,y wind-Solar-H-F-1 ,y wind-Solar-L-F-1 ,……,y wind-Solar-H-V-t ,y wind-Solar-L-V-t ,y wind-Solar-H-F-t ,y wind-Solar-L-F-t ,……], where y overload-j represents the overcurrent protection setting of the jth line in the network, 1≤j≤m, m is the number of elements of the trigger condition set vector Y of the successive disconnection elements, y wind-Solar-H-V-t ,y wind-Solar-L-V-t ,y wind-Solar-H-F-t ,y wind-Solar-L-F-t They represent the high voltage ride-through capability, low voltage ride-through capability, high frequency ride-through capability, and low frequency ride-through capability of the t-th wind power or photovoltaic power source in the power grid, respectively. 1≤t≤t max , t max Indicates the total number of wind power and photovoltaic power sources in the grid; A design unit is used to design a cascading fault sequential disconnection disturbance setting process taking into account the influence of new energy grid connection based on the boundary condition vector of the power grid severe fault simulation calculation mode, the initial element set vector of the power grid sequential disconnection and the trigger condition set vector of the sequential disconnection element; The result unit is used to obtain the final serious fault set of cascading faults and successive interruption disturbances taking into account the impact of new energy grid connection based on the cascading faults and successive interruption disturbance setting process, including: The element k of the boundary condition vector for the simulation calculation method of severe power grid faults i When i is less than or equal to the maximum number of elements max-k of the boundary condition vector of the power grid severe fault simulation calculation method, the element X in the initial component set vector X of the power grid is disconnected successively. r When r is less than or equal to the number of elements m of the initial component set vector of the power grid successive disconnection, the element X in the initial component set vector X of the power grid successive disconnection is traversed. r In k i Carry out fault simulation in this way and obtain simulation results; When the simulation result is within the action constant range of any element of the trigger condition set vector Y of the successive disconnection elements, the elements within the constant range are disconnected, and the fault simulation is continued.

4. The system according to claim 3, wherein the first construction unit is used to construct a boundary condition vector of a power grid severe fault simulation calculation method based on the severity requirements of operating conditions, comprising: Define the boundary condition vector K of the power grid severe fault simulation calculation method and the inherent related problem set vector P in the original system Risk , the severe operating condition set vector P in various operating conditions of the power grid SeriousMode The output situation set vector P of wind power and photovoltaic power with the greatest impact on the system Wind-Sola ; The element k of the boundary condition vector of the power grid severe fault simulation calculation method i , the element p of the inherent relevant problem set vector in the original system Risk , the element p of the severe condition set vector in various operating conditions of the power grid SeriousMode The element p of the set vector of the output conditions of wind power and photovoltaic power that have the greatest impact on the system Wind-Sola , there is the following functional relationship: k i =f(p Risk ,p seriousmode ,p wind-solar ) Among them, k i ∈K,p Risk ∈P Risk , p SeriousMode ∈P SeriousMode , p Wind-Solar ∈P Wind-Solar , where i≤max-k, max-k is the maximum number of elements in the K vector.

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