Method and device for identifying weak links in power grid in area with access of new energy cluster

Abstract

The present invention relates to the technical field of new energy power generation, and specifically provides a method and device for identifying weak links in the power grid in areas with new energy cluster access, including: determining the weighted new energy multi-station short-circuit ratio of each new energy power station in the power grid to be evaluated based on the multi-station short-circuit ratio of each new energy power station in the power grid to be evaluated; determining the sensitivity of each new energy power station in the power grid to be evaluated to the strength of the cluster-accessed power grid based on the weighted new energy multi-station short-circuit ratio of each new energy power station in the power grid to be evaluated; and identifying weak links in the power grid to be evaluated based on the sensitivity of each new energy power station in the power grid to be evaluated to the strength of the cluster-accessed power grid. The technical solution provided by the present invention can provide guiding suggestions for strengthening power grid construction and guiding the stable operation of the power grid.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy power generation, and particularly to a method and device for identifying weak links in the power grid in areas with new energy cluster access. Background Art

[0002] At present, the newly installed capacity of new energy such as wind power and solar energy accounts for an increasing proportion. Renewable energy power generation has gradually become the main power source. The access scale of new energy is gradually increasing, and the grid strength is gradually weakening. It is an inevitable trend for the new energy development that the weak power grid with new energy as the main power source.

[0003] For areas with new energy cluster development, new energy is often connected to the end of the power grid, there is no local load to consume new energy locally, and there is no conventional power source support. It is necessary to send out through AC-DC interconnection channels. Therefore, the grid strength in the cluster access area has a crucial impact on the access scale and consumption capacity of new energy to the power grid. At the DC sending end of the cluster access area, due to the new energy transient overvoltage problem, the overvoltage tolerance ability of new energy is continuously required; for example, there are operation risks such as transient overvoltage problems and non-power frequency oscillation problems in the wind power and photovoltaic clusters at the direct sending end of the cluster access area. Previously, when local power grids encountered specific problems, only the specific problems were solved, and there was little analysis of the strength constraints and maximum consumption capacity of new energy clusters accessing the power grid from the perspective of grid strength. Summary of the Invention

[0004] In order to overcome the above defects, the present invention provides a method and device for identifying weak links in the power grid in areas with new energy cluster access.

[0005] In a first aspect, a method for identifying weak links in the power grid in areas with new energy cluster access is provided. The method for identifying weak links in the power grid in areas with new energy cluster access includes:

[0006] Based on the multi-station short-circuit ratio of each new energy power station in the power grid to be evaluated, determine the weighted new energy multi-station short-circuit ratio of each new energy power station in the power grid to be evaluated;

[0007] Based on the weighted new energy multi-station short-circuit ratio of each new energy power station in the power grid to be evaluated, determine the sensitivity of each new energy power station in the power grid to be evaluated to the grid strength of the cluster access;

[0008] Based on the sensitivity of each new energy power station in the power grid to be evaluated to the grid strength of the cluster access, identify the weak links in the power grid to be evaluated.

[0009] Preferably, the operation mode of the power grid to be evaluated includes at least one of the following: conventional power source startup mode, new energy startup and output mode, DC operation mode, and load mode.

[0010] Preferably, the calculation formula for the multi-station short-circuit ratio of each new energy station in the power grid to be evaluated is as follows:

[0011]

[0012] In the above formula, MRSCR j is the multi-station short-circuit ratio of new energy station j, S kj is the short-circuit capacity at the connection point of new energy station j, P m and Q m are the active power and reactive power of new energy station m respectively, z is the imaginary symbol, is the self-impedance of new energy station j connected to the power grid, is the mutual impedance between new energy station j and new energy station m, n is the total number of stations in the new energy cluster, and m and n are positive integers.

[0013] Preferably, the calculation formula for the weighted new energy multi-station short-circuit ratio of each new energy station in the power grid to be evaluated is as follows:

[0014]

[0015]

[0016] In the above formula, WSCR i is the weighted new energy multi-station short-circuit ratio of new energy station i, WSCR′ i is the weighted new energy multi-station short-circuit ratio of new energy station i after the apparent power increases by ΔS i , MRSCR i and MRSCR j are the multi-station short-circuit ratios of new energy stations i and j respectively, S i and S j are the apparent powers of new energy stations i and j respectively, MRSCR′ i is the weighted new energy multi-station short-circuit ratio of new energy station i after the apparent power increases by ΔS i , MRSCR′ j are the weighted new energy multi-station short-circuit ratios of new energy station j after the apparent power increases by ΔS j respectively, S i and S j are the apparent powers of new energy stations i and j respectively, n is the total number of stations in the new energy cluster, ΔS i and ΔS j are the apparent power increments of new energy stations i and j respectively, and n, j, and i are positive integers.

[0017] Furthermore, the value ranges of ΔS i and ΔS j are both 5%Sn +z5% S n , where z is the imaginary symbol and S n is the rated capacity of the new energy power station.

[0018] Preferably, the calculation formula for the sensitivity of each new energy power station in the evaluated power grid to the strength of the cluster connected to the power grid is as follows:

[0019]

[0020] In the above formula, M i is the sensitivity of the new energy power station i to the strength of the cluster connected to the power grid, ΔS i is the apparent power increment of the new energy power station i, S b is the base capacity of the power grid, WSCR i is the weighted new energy multi-power station short circuit ratio of the new energy power station i, WSCR' i is the apparent power increased by ΔS i and WSCR' is the weighted new energy multi-power station short circuit ratio of the new energy power station i after the increase, where b and i are positive integers.

[0021] Preferably, identifying the weak link in the power grid in the evaluated power grid based on the sensitivity of each new energy power station in the evaluated power grid to the strength of the cluster connected to the power grid includes:

[0022] Regarding the new energy power station with the greatest sensitivity to the strength of the cluster connected to the power grid in the evaluated power grid as the weak link in the power grid of the evaluated power grid.

[0023] In a second aspect, a device for identifying weak links in a power grid in a region where a new energy cluster is connected is provided. The device for identifying weak links in a power grid in a region where a new energy cluster is connected includes:

[0024] A first determination module, configured to determine the weighted new energy multi-power station short circuit ratio of each new energy power station in the evaluated power grid based on the multi-power station short circuit ratio of each new energy power station in the evaluated power grid;

[0025] A second determination module, configured to determine the sensitivity of each new energy power station in the evaluated power grid to the strength of the cluster connected to the power grid based on the weighted new energy multi-power station short circuit ratio of each new energy power station in the evaluated power grid;

[0026] An identification module, configured to identify the weak link in the power grid in the evaluated power grid based on the sensitivity of each new energy power station in the evaluated power grid to the strength of the cluster connected to the power grid.

[0027] Preferably, the operation mode of the evaluated power grid includes at least one of the following: conventional power source startup mode, new energy startup and output mode, DC operation mode, and load mode.

[0028] Preferably, the calculation formula for the multi-station short-circuit ratio of each new energy power station in the power grid to be evaluated is as follows:

[0029]

[0030] In the above formula, MRSCR j is the multi-station short-circuit ratio of new energy power station j, S kj is the short-circuit capacity of the access point of new energy power station j, P m and Q m are the active power and reactive power of new energy power station m respectively, z is the imaginary symbol, is the self-impedance of new energy power station j connected to the power grid, is the mutual impedance between new energy power station j and new energy power station m, n is the total number of power stations in the new energy cluster, and m and n are positive integers.

[0031] Preferably, the calculation formula for the weighted new energy multi-station short-circuit ratio of each new energy power station in the power grid to be evaluated is as follows:

[0032]

[0033]

[0034] In the above formula, WSCR i is the weighted new energy multi-station short-circuit ratio of new energy power station i, WSCR′ i is the weighted new energy multi-station short-circuit ratio of new energy power station i after the apparent power increases by ΔS i , MRSCR i and MRSCR j are the multi-station short-circuit ratios of new energy power stations i and j respectively, S i and S j are the apparent powers of new energy power stations i and j respectively, MRSCR′ i is the weighted new energy multi-station short-circuit ratio of new energy power station i after the apparent power increases by ΔS i , MRSCR′ j are the weighted new energy multi-station short-circuit ratios of new energy power station j after the apparent power increases by ΔS j respectively, S i and S j are the apparent powers of new energy power stations i and j respectively, n is the total number of power stations in the new energy cluster, ΔS i and ΔS j are the apparent power increments of new energy power stations i and j respectively, and n, j, and i are positive integers.

[0035] Furthermore, the value ranges of ΔS i and ΔS j are both 5%Sn +z5%S n , where z is the imaginary symbol and S n is the rated capacity of the new energy power station

[0036] Preferably, the calculation formula for the sensitivity of each new energy power station in the evaluated power grid to the strength of the cluster connected to the power grid is as follows:

[0037]

[0038] In the above formula, M i is the sensitivity of the new energy power station i to the strength of the cluster connected to the power grid, ΔS i is the apparent power increment of the new energy power station i, S b is the power grid benchmark capacity, WSCR i is the weighted new energy multi-power station short circuit ratio of the new energy power station i, WSCR' i is the weighted new energy multi-power station short circuit ratio of the new energy power station i after the apparent power increases by ΔS i , where b and i are positive integers

[0039] Preferably, the recognition module is specifically configured to:

[0040] Regard the new energy power station with the greatest sensitivity to the strength of the cluster connected to the power grid in the evaluated power grid as the weak link of the power grid in the evaluated power grid

[0041] In a third aspect, a computer device is provided, including: one or more processors;

[0042] The processor is used to store one or more programs;

[0043] When the one or more programs are executed by the one or more processors, the method for identifying the weak link of the power grid in the area where the new energy cluster is connected is implemented

[0044] In a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed, the method for identifying the weak link of the power grid in the area where the new energy cluster is connected is implemented

[0045] One or more of the above technical solutions of the present invention have at least one or more of the following beneficial effects:

[0046] The present invention provides a method and device for identifying weak links in the power grid in areas with new energy cluster access, including: determining the weighted new energy multi-station short-circuit ratio of each new energy power station in the power grid to be evaluated based on the multi-station short-circuit ratio of each new energy power station in the power grid to be evaluated; determining the sensitivity of each new energy power station in the power grid to be evaluated to the strength of the cluster-connected power grid based on the weighted new energy multi-station short-circuit ratio of each new energy power station in the power grid to be evaluated; and identifying the weak links in the power grid in the power grid to be evaluated based on the sensitivity of each new energy power station in the power grid to be evaluated to the strength of the cluster-connected power grid. The technical solution provided by the present invention, for areas with new energy cluster access, based on the strength requirements for the stable operation of new energy power generation connected to the power grid, proposes a method for identifying weak points in the power grid for new energy cluster access. Based on the weighted multi-station short-circuit ratio of the new energy cluster connected to the power grid, the sensitivity analysis method is used to obtain the weak points of the power grid strength under the current power grid mode, so as to provide theoretical guidance for the construction and large-scale development of new energy bases. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a schematic flowchart of the main steps of the method for identifying weak links in the power grid in areas with new energy cluster access according to an embodiment of the present invention;

[0048] Figure 2 is a structural diagram of the grid framework of the new energy cluster grid connection calculation example system according to an embodiment of the present invention;

[0049] Figure 3 is a main structural block diagram of the device for identifying weak links in the power grid in areas with new energy cluster access according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0050] The following further details the specific embodiments of the present invention with reference to the accompanying drawings.

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0052] As disclosed in the background art, currently, the newly installed capacity of new energy such as wind power and solar energy accounts for an increasing proportion. Renewable energy power generation is gradually becoming the main power source. The access scale of new energy is gradually increasing, and the power grid strength is gradually weakening. The weak power grid with new energy as the main power source is an inevitable trend of new energy development.

[0053] For new energy cluster development areas, new energy is often connected to the end of the power grid. There is no local load to consume the new energy locally, and there is no conventional power source to support it. It is necessary to send it out through AC / DC interconnected channels. Therefore, the grid strength of the cluster access area has a crucial impact on the scale and consumption capacity of new energy connected to the grid. At the DC sending end of the cluster access area, due to the transient overvoltage problem of new energy, continuous requirements for the overvoltage tolerance ability of new energy are put forward; for example, there are operation risks such as transient overvoltage problems and non-power frequency oscillation problems in the wind power and photovoltaic clusters at the direct sending end of the cluster access area. Previously, specific problems were often solved when local grids encountered them, and there was little analysis of the strength constraints and maximum consumption capacity of new energy clusters connected to the grid from the perspective of grid strength.

[0054] In order to improve the above problems, the present invention provides a method and device for identifying weak grid links in areas with new energy cluster access, including: determining the weighted new energy multi-station short-circuit ratio of each new energy station in the evaluated power grid based on the multi-station short-circuit ratio of each new energy station in the evaluated power grid; determining the sensitivity of each new energy station in the evaluated power grid to the grid strength of cluster access based on the weighted new energy multi-station short-circuit ratio of each new energy station in the evaluated power grid; and identifying weak grid links in the evaluated power grid based on the sensitivity of each new energy station in the evaluated power grid to the grid strength of cluster access. The technical solution provided by the present invention aims at areas with new energy cluster access, and based on the strength requirements for the stable operation of new energy power generation connected to the grid, proposes a method for identifying weak points in the grid for new energy cluster access. Based on the weighted multi-station short-circuit ratio of new energy clusters connected to the grid, the sensitivity analysis method is used to obtain the weak points of grid strength under the current grid mode, so as to provide theoretical guidance for the construction and large-scale development of new energy bases.

[0055] The above solution will be elaborated in detail below.

[0056] Embodiment 1

[0057] Refer to the appendix Figure 1 , Figure 1 which is a schematic diagram of the main step flow of the method for identifying weak grid links in areas with new energy cluster access according to an embodiment of the present invention. As Figure 1 shown, the method for identifying weak grid links in areas with new energy cluster access in the embodiment of the present invention mainly includes the following steps:

[0058] Step S101: Determine the weighted new energy multi-station short-circuit ratio of each new energy station in the evaluated power grid based on the multi-station short-circuit ratio of each new energy station in the evaluated power grid;

[0059] Step S102: Determine the sensitivity of each new energy station in the power grid to be evaluated to the grid connection strength of the cluster based on the weighted new energy multi-station short-circuit ratio of each new energy station in the power grid to be evaluated;

[0060] Step S103: Identify the weak grid links in the power grid to be evaluated based on the sensitivity of each new energy station in the power grid to be evaluated to the grid connection strength of the cluster.

[0061] Among them, the operation mode of the power grid to be evaluated includes at least one of the following: conventional power generation unit starting mode, new energy starting and output mode, DC operation mode, and load mode.

[0062] In this embodiment, the calculation formula for the multi-station short-circuit ratio of each new energy station in the power grid to be evaluated is as follows:

[0063]

[0064] In the above formula, MRSCR j is the multi-station short-circuit ratio of new energy station j, S kj is the short-circuit capacity at the connection point of new energy station j, P m and Q m are the active power and reactive power of new energy station m respectively, z is the imaginary symbol, is the self-impedance of new energy station j connected to the power grid, is the mutual impedance between new energy station j and new energy station m, n is the total number of stations in the new energy cluster, and m and n are positive integers.

[0065] In this embodiment, the calculation formula for the weighted new energy multi-station short-circuit ratio of each new energy station in the power grid to be evaluated is as follows:

[0066]

[0067]

[0068] In the above formula, WSCR i is the weighted new energy multi-station short-circuit ratio of new energy station i, WSCR′ i is the weighted new energy multi-station short-circuit ratio of new energy station i after the apparent power increases by ΔS i , MRSCR i and MRSCR j are the multi-station short-circuit ratios of new energy stations i and j respectively, S i and S j are the apparent powers of new energy stations i and j respectively, MRSCR′ i is the weighted new energy multi-station short-circuit ratio of new energy station i after the apparent power increases by ΔS i , MRSCR′j The apparent power increases by ΔS respectively j The weighted new - energy multi - power - station short - circuit ratio of new - energy power station j after that, S i and S j The apparent powers of new - energy power stations i and j are S_i and S_j respectively, n is the total number of power stations in the new - energy cluster, ΔS i and ΔS j The increments of the apparent powers of new - energy power stations i and j are ΔS_i and ΔS_j respectively, where n, j, and i are positive integers.

[0069] Among them, the ΔS i and ΔS j Both take values in the range of 5%S n +z5%S n , where z is the imaginary symbol, and S n is the rated capacity of the new - energy power station.

[0070] In this embodiment, the calculation formula for the sensitivity of each new - energy power station in the evaluated power grid to the grid connection strength of the cluster is as follows:

[0071]

[0072] In the above formula, M i is the sensitivity of new - energy power station i to the grid connection strength of the cluster, ΔS i is the increment of the apparent power of new - energy power station i, S b is the grid base capacity, WSCR i is the weighted new - energy multi - power - station short - circuit ratio of new - energy power station i, WSCR′ i is the weighted new - energy multi - power - station short - circuit ratio of new - energy power station i after the apparent power increases by ΔS i , where b and i are positive integers.

[0073] In this embodiment, identifying the weak grid links in the evaluated power grid based on the sensitivity of each new - energy power station in the evaluated power grid to the grid connection strength of the cluster includes:

[0074] Regarding the new - energy power station with the maximum sensitivity to the grid connection strength of the cluster in the evaluated power grid as the weak grid link in the evaluated power grid.

[0075] In an application scenario, as Figure 2 shown, Figure 2 In [the scenario], 7 hydropower units are started, with a total installed capacity of 4.62 million kilowatts, the installed capacity of new - energy is 7.2 million kilowatts, the photovoltaic output is 70%, the wind - power output is 30%, the total network load is 11 million kilowatts, and the DC external transmission is 6 million kilowatts.

[0076] The calculation results are shown in Table 1 in the appendix, and it is determined that new - energy power station D - 2 is the weak grid - strength link in the evaluated mode.

[0077] Table 1

[0078]

[0079]

[0080]

[0081] Example 2

[0082] Based on the same inventive concept, the present invention also provides a device for identifying weak links in the power grid in the area where a new energy cluster is connected, as Figure 3 shown. The device for identifying weak links in the power grid in the area where a new energy cluster is connected includes:

[0083] A first determination module, configured to determine the weighted new energy multi-station short-circuit ratio of each new energy station in the power grid to be evaluated based on the multi-station short-circuit ratio of each new energy station in the power grid to be evaluated;

[0084] A second determination module, configured to determine the sensitivity of each new energy station in the power grid to be evaluated to the strength of the cluster-connected power grid based on the weighted new energy multi-station short-circuit ratio of each new energy station in the power grid to be evaluated;

[0085] An identification module, configured to identify weak links in the power grid to be evaluated based on the sensitivity of each new energy station in the power grid to be evaluated to the strength of the cluster-connected power grid.

[0086] Preferably, the operation mode of the power grid to be evaluated includes at least one of the following: conventional power source starting mode, new energy starting and output mode, DC operation mode, load mode.

[0087] Preferably, the calculation formula for the multi-station short-circuit ratio of each new energy station in the power grid to be evaluated is as follows:

[0088]

[0089] In the above formula, MRSCR j is the multi-station short-circuit ratio of new energy station j, S kj is the short-circuit capacity at the access point of new energy station j, P m and Q m are the active power and reactive power of new energy station m respectively, z is the imaginary symbol, is the self-impedance of new energy station j connected to the power grid, is the mutual impedance between new energy station j and new energy station m, n is the total number of stations in the new energy cluster, and m and n are positive integers.

[0090] Preferably, the calculation formula for the weighted new - energy multi - station short - circuit ratio of each new - energy station in the evaluated power grid is as follows:

[0091]

[0092]

[0093] In the above formula, WSCR i is the weighted new - energy multi - station short - circuit ratio of new - energy station i, WSCR′ i is the weighted new - energy multi - station short - circuit ratio of new - energy station i after the apparent power increases by ΔS i MRSCR i and MRSCR j are the multi - station short - circuit ratios of new - energy stations i and j respectively, S i and S j are the apparent powers of new - energy stations i and j respectively, MRSCR′ i is the weighted new - energy multi - station short - circuit ratio of new - energy station i after the apparent power increases by ΔS i MRSCR′ j are the weighted new - energy multi - station short - circuit ratios of new - energy station j after the apparent power increases by ΔS j S i and S j are the apparent powers of new - energy stations i and j respectively, n is the total number of stations in the new - energy cluster, ΔS i and ΔS j are the apparent - power increments of new - energy stations i and j respectively, n, j, i are positive integers.

[0094] Furthermore, the value ranges of ΔS i and ΔS j are both 5%S n +z5%S n where z is the imaginary symbol, and S n is the rated capacity of the new - energy station.

[0095] Preferably, the calculation formula for the sensitivity of each new - energy station in the evaluated power grid to the grid - connection strength of the cluster is as follows:

[0096]

[0097] In the above formula, M i is the sensitivity of new - energy station i to the grid - connection strength of the cluster, ΔS i is the apparent - power increment of new - energy station i, S b is the grid - reference capacity, WSCR i is the weighted new - energy multi - station short - circuit ratio of new - energy station i, WSCR′i For the apparent power to increase by ΔS i The weighted new - energy multi - power - station short - circuit ratio of the new - energy power station i after that, where b and i are positive integers.

[0098] Preferably, the recognition module is specifically configured to:

[0099] Regard the new - energy power station with the greatest sensitivity to the grid - connection strength of the cluster in the to - be - evaluated power grid as the weak link of the power grid in the to - be - evaluated power grid.

[0100] Embodiment 3

[0101] Based on the same inventive concept, the present invention also provides a computer device, which includes a processor and a memory. The memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or may also be other general - purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field - Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function, so as to implement the steps of a method for identifying weak links in the power grid of a new - energy cluster access area in the above - mentioned embodiment.

[0102] Embodiment 4

[0103] Based on the same inventive concept, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory). The computer-readable storage medium is a memory device in a computer device, used to store programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and, of course, the extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, and this storage space stores the operating system of the terminal. Moreover, in this storage space, one or more instructions suitable for being loaded and executed by the processor are also stored. These instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. One or more instructions stored in the computer-readable storage medium can be loaded and executed by the processor to implement the steps of the method for identifying weak links in the power grid in a new energy cluster access area in the above-mentioned embodiments.

[0104] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0105] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the function specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0106] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements the function in Figure 1 one flow or multiple flows and / or blocksFigure 1 The functions specified in one or more boxes.

[0107] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide for implementing steps of Figure 1 one process or more processes and / or boxes Figure 1 the functions specified in one box or more boxes.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the specific implementation manners of the present invention. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A method for identifying weak links in the power grid in areas with new energy cluster access, characterized in that The method includes: Determining the weighted new - energy multi - substation short - circuit ratio of each new - energy substation in the to - be - evaluated power grid based on the multi - substation short - circuit ratio of each new - energy substation in the to - be - evaluated power grid; Determining the sensitivity of each new - energy substation in the to - be - evaluated power grid to the grid connection strength of the cluster based on the weighted new - energy multi - substation short - circuit ratio of each new - energy substation in the to - be - evaluated power grid; Identifying the weak grid links in the to - be - evaluated power grid based on the sensitivity of each new - energy substation in the to - be - evaluated power grid to the grid connection strength of the cluster; The calculation formula for the sensitivity of each new - energy substation in the to - be - evaluated power grid to the grid connection strength of the cluster is as follows: In the above formula, M i is the sensitivity of the new energy station i to the grid connection strength of the cluster, ΔS i is the apparent power increment of the new energy station i, S b is the grid base capacity, WSCR i is the weighted new energy multi-station short-circuit ratio of the new energy station i, WSCR′ i is the weighted new energy multi-station short-circuit ratio of the new energy station i after the apparent power increases by ΔS i , where b and i are positive integers; The identifying the weak grid links in the to - be - evaluated power grid based on the sensitivity of each new - energy substation in the to - be - evaluated power grid to the grid connection strength of the cluster includes: Taking the new - energy substation with the maximum sensitivity to the grid connection strength of the cluster in the to - be - evaluated power grid as the weak grid link in the to - be - evaluated power grid; The calculation formula for the weighted new - energy multi - substation short - circuit ratio of each new - energy substation in the to - be - evaluated power grid is as follows: In the above formula, WSCR i is the weighted new energy multi - substation short - circuit ratio of new energy substation i, WSCR′ i is the weighted new energy multi - substation short - circuit ratio of new energy substation i after the apparent power increases by ΔS i , MRSCR i and MRSCR j are the multi - substation short - circuit ratios of new energy substations i and j respectively, S i and S j are the apparent powers of new energy substations i and j respectively, MRSCR′ i is the weighted new energy multi - substation short - circuit ratio of new energy substation i after the apparent power increases by ΔS i , MRSCR′ j are the weighted new energy multi - substation short - circuit ratios of new energy substation j after the apparent power increases by ΔS j respectively, n is the total number of substations in the new energy cluster, ΔS i and ΔS j are the apparent power increments of new energy substations i and j respectively, and n, j, i are positive integers.

2. The method according to claim 1, characterized in that, The operating mode of the to - be - evaluated power grid includes at least one of the following: conventional power source starting mode, new - energy starting and output mode, DC operation mode, load mode.

3. The method according to claim 1, characterized in that The calculation formula for the multi - substation short - circuit ratio of each new - energy substation in the to - be - evaluated power grid is as follows: In the above formula, MRSCR j is the multi-station short-circuit ratio of new energy station j, S kj is the short-circuit capacity of the connection point of new energy station j, P m and Q m are the active power and reactive power of new energy station m respectively, z is the imaginary symbol, is the self-impedance of new energy station j connected to the power grid, is the mutual impedance between new energy station j and new energy station m, n is the total number of stations in the new energy cluster, and m and n are positive integers.

4. The method according to claim 1, characterized in that, The said ΔS i and ΔS j both have a value range of 5%S n +z5%S n , where z is the imaginary symbol and S n is the rated capacity of the new energy power station.

5. A device for identifying weak links in the power grid in an area with new energy cluster access, characterized in that, The device includes: A first determination module, configured to determine the weighted new - energy multi - substation short - circuit ratio of each new - energy substation in the to - be - evaluated power grid based on the multi - substation short - circuit ratio of each new - energy substation in the to - be - evaluated power grid; A second determination module, configured to determine the sensitivity of each new - energy substation in the to - be - evaluated power grid to the grid connection strength of the cluster based on the weighted new - energy multi - substation short - circuit ratio of each new - energy substation in the to - be - evaluated power grid; An identification module, configured to identify the weak grid links in the to - be - evaluated power grid based on the sensitivity of each new - energy substation in the to - be - evaluated power grid to the grid connection strength of the cluster; The calculation formula for the sensitivity of each new - energy substation in the to - be - evaluated power grid to the grid connection strength of the cluster is as follows: In the above formula, M i is the sensitivity of the new energy power station i to the grid connection strength of the cluster, and ΔS i is the apparent power increment of the new energy power station i, S b is the grid base capacity, WSCR i is the weighted new energy multi-power station short-circuit ratio of the new energy power station i, WSCR′ i is the weighted new energy multi-power station short-circuit ratio of the new energy power station i after the apparent power increases by ΔS i where b and i are positive integers; The identification module is specifically configured to: Take the new - energy substation with the maximum sensitivity to the grid connection strength of the cluster in the to - be - evaluated power grid as the weak grid link in the to - be - evaluated power grid; The calculation formula for the weighted new - energy multi - substation short - circuit ratio of each new - energy substation in the to - be - evaluated power grid is as follows: In the above formula, WSCR i is the weighted new - energy multi - substation short - circuit ratio of new - energy substation i, WSCR′ i is the weighted new - energy multi - substation short - circuit ratio of new - energy substation i after the apparent power increases by ΔS i , MRSCR i and MRSCR j are the multi - substation short - circuit ratios of new - energy substations i and j respectively, S i and S j are the apparent powers of new - energy substations i and j respectively, MRSCR′ i is the weighted new - energy multi - substation short - circuit ratio of new - energy substation i after the apparent power increases by ΔS i , MRSCR′ j are the weighted new - energy multi - substation short - circuit ratios of new - energy substation j after the apparent power increases by ΔS j respectively, n is the total number of substations in the new - energy cluster, ΔS i and ΔS j are the apparent - power increments of new - energy substations i and j respectively, and n, j, i are positive integers.

6. The device according to claim 5, characterized in that The operating mode of the to - be - evaluated power grid includes at least one of the following: conventional power source starting mode, new - energy starting and output mode, DC operation mode, load mode.

7. The device according to claim 5, characterized in that The calculation formula for the multi - substation short - circuit ratio of each new - energy substation in the to - be - evaluated power grid is as follows: In the above formula, MRSCR j is the multi - substation short - circuit ratio of new - energy substation j, S kj is the short - circuit capacity at the connection point of new - energy substation j, P m and Q m are the active power and reactive power of new - energy substation m respectively, z is the imaginary symbol, is the self - impedance of new - energy substation j connected to the power grid, is the mutual impedance between new - energy substation j and new - energy substation m, n is the total number of substations in the new - energy cluster, and m and n are positive integers.

8. The device according to claim 5, characterized in that, The said ΔS i and ΔS j both have a value range of 5%S n +z5%S n , where z is the imaginary symbol and S n is the rated capacity of the new energy power station.

9. A computer device, characterized in that, It includes: One or more processors and a memory; The memory is used to store one or more programs; When the one or more programs are executed by the one or more processors, the method for identifying weak grid links in the power grid of the new - energy cluster access area as described in any one of claims 1 to 4 is implemented.

10. A computer-readable storage medium, characterized in that, There is a computer program stored thereon, and when the computer program is executed, the method for identifying weak grid links in the power grid of the new - energy cluster access area as described in any one of claims 1 to 4 is implemented.

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