A Method and System for Selecting Load-Shedding Nodes with Distributed New Energy

Abstract

The present invention discloses a method and system for selecting load shedding nodes including distributed new energy. The method includes: determining the power supply areas corresponding to each substation within the set to be judged for the load shedding area, and calculating the proportion of distributed new energy in the total power source installed capacity within each power supply area; judging whether the end branches of the low-voltage distribution network within the power supply area are put into the subset to be judged for the load shedding nodes according to the proportion of distributed new energy in the total power source installed capacity within each power supply area; determining the load shedding risk of the end branches of the low-voltage distribution network within the set to be judged for the load shedding nodes according to a preset comprehensive load shedding risk index; reordering the corresponding end branches of the low-voltage distribution network within the subset to be judged for the load shedding nodes from small to large according to the calculation results of the comprehensive load shedding risk index, and selecting the preferred load shedding nodes according to the sorting results. The purpose of optimizing the selection range of the load shedding nodes and reducing the risk of cutting off the load shedding nodes can be achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy safety and stability control, and particularly relates to a method and system for selecting load shedding nodes containing distributed new energy. Background Art

[0002] After a large number of distributed new energy sources are scattered and connected to the power grid, the traditional single-source radial power supply structure of the distribution system has been changed. The power flow direction of the end distribution network is in an uncontrollable state due to the randomness of the output of distributed new energy sources, which increases the difficulty of the traditional pre-set stable control measure configuration strategy of the power system. At the same time, with the improvement of the research and development technology of energy storage and its equipment, the original distributed new energy units that do not have frequency modulation capabilities can also achieve self-frequency modulation control or reach a more flexible and controllable state through the configuration of an energy storage system. Therefore, when identifying the selectability of end load shedding nodes, not only the changes brought by the output of distributed new energy sources need to be considered, but also the influence of its regulation or energy storage system needs to be taken into account. In addition, due to the change of the power flow characteristics caused by the output of distributed power sources in the end distribution network, the changes of conventional electrical quantities such as power and voltage are more frequent, and the impact on the safe operation of the power grid after shedding loads should be considered more in the principle of selecting load shedding nodes.

[0003] The existing methods for selecting load shedding nodes do not consider the change of the power direction of the end line, do not consider the complication of the electrical characteristics of the end equipment, resulting in difficulty in meeting the demand for the amount of load shedding organization, and may further expand the operation risk. Summary of the Invention

[0004] The present invention provides a method and system for selecting load shedding nodes containing distributed new energy, which are used to solve the technical problems that the existing methods for selecting load shedding nodes do not consider the change of the power direction of the end line, do not consider the complication of the electrical characteristics of the end equipment, resulting in difficulty in meeting the demand for the amount of load shedding organization, and may further expand the operation risk.

[0005] In the first aspect, the present invention provides a method for selecting load shedding nodes containing distributed new energy, including:

[0006] For the receiving-end power system with DC, select the substation with the highest AC voltage level in the power grid whose direct current linear distance is not greater than the preset distance threshold and put it into the set to be judged for the load shedding area in case of DC blocking fault;

[0007] Determine the power supply areas corresponding to each substation in the set to be judged for the load shedding area, and calculate the proportion of distributed new energy in the total power source installed capacity in each power supply area;

[0008] According to the proportion of distributed new energy in the total power source installed capacity in each power supply area, judge whether the end branch of the low-voltage distribution network in the power supply area is put into the subset to be judged for load shedding nodes;

[0009] Determine the load shedding risk of the low-voltage distribution network end branches in the set of load shedding nodes to be judged according to the preset comprehensive load shedding risk index, where the comprehensive load shedding risk index includes voltage over-limit risk, power over-limit risk, and frequency support ability;

[0010] Reorder the corresponding low-voltage distribution network end branches in the sub-set of load shedding nodes to be judged in ascending order according to the calculation results of the comprehensive load shedding risk index, and select the priority load shedding nodes according to the sorting results.

[0011] In a second aspect, the present invention provides a load shedding node selection system including distributed new energy, comprising:

[0012] A selection module configured to select the grid's highest AC voltage level substation with a direct current line distance not greater than a preset distance threshold from the receiving-end power system with direct current into the set of load shedding areas to be judged for DC blocking faults;

[0013] A calculation module configured to determine the power supply areas corresponding to each substation in the set of load shedding areas to be judged, and calculate the proportion of distributed new energy in the total power supply installed capacity in each power supply area;

[0014] A judgment module configured to judge whether the low-voltage distribution network end branches in the power supply area are put into the sub-set of load shedding nodes to be judged according to the proportion of distributed new energy in the total power supply installed capacity in each power supply area;

[0015] A determination module configured to determine the load shedding risk of the low-voltage distribution network end branches in the set of load shedding nodes to be judged according to the preset comprehensive load shedding risk index, where the comprehensive load shedding risk index includes voltage over-limit risk, power over-limit risk, and frequency support ability;

[0016] A selection module configured to reorder the corresponding low-voltage distribution network end branches in the sub-set of load shedding nodes to be judged in ascending order according to the calculation results of the comprehensive load shedding risk index, and select the priority load shedding nodes according to the sorting results.

[0017] In a third aspect, an electronic device is provided, which includes: at least one processor, and a memory communicatively connected to the at least one processor, where the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the steps of the load shedding node selection method including distributed new energy according to any embodiment of the present invention.

[0018] Fourthly, the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the program instructions are executed by a processor, the processor is caused to execute the steps of the method for selecting a load-shedding node including distributed new energy according to any embodiment of the present invention.

[0019] For the method and system for selecting a load-shedding node including distributed new energy in this application, in the case of a DC blocking fault occurring in a receiving-end power system including DC, on the basis of combining the principle of selecting a load-shedding node nearby, the proportion of distributed new energy output is considered to optimize the range of node selection. In addition, considering the influence of distributed new energy on the change of electrical quantities in the end grid and the system frequency regulation control, a comprehensive risk index for load shedding is proposed to evaluate the impact of load-shedding node selection on the safe operation of the power grid, which can achieve the purpose of optimizing the range of load-shedding node selection and reducing the risk of load-shedding node removal. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 It is a flowchart of a method for selecting a load-shedding node including distributed new energy provided by an embodiment of the present invention;

[0022] Figure 2 It is a structural block diagram of a system for selecting a load-shedding node including distributed new energy provided by an embodiment of the present invention;

[0023] Figure 3 It is a schematic structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention 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 without creative efforts based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0025] Please refer to Figure 1 , which shows a flowchart of a method for selecting a load-shedding node including distributed new energy in this application.

[0026] As shown in Figure 1As shown in the figure, the method for selecting load shedding nodes with distributed new energy specifically includes the following steps:

[0027] Step S101: For the receiving-end power system with DC, select the grid's highest AC voltage level substation whose straight-line distance from the corresponding DC is not greater than the preset distance threshold and put it into the set to be judged for the load shedding area in case of DC blocking fault.

[0028] In this step, in the receiving-end power system with DC feed-in, define all DC sets in the receiving-end power system as , where is the th DC in the set;

[0029] According to the geographical location information, obtain the straight-line distance between the th highest AC voltage level substation of the grid and the th DC , and judge whether the straight-line distance is greater than the preset distance threshold;

[0030] If it is not greater than the preset distance threshold, then the th highest AC voltage level substation of the grid is put into the set to be judged for the load shedding nodes in case of blocking fault of the th DC , otherwise it is not put in.

[0031] In a specific embodiment, analyze the power system at the DC receiving end of a certain area. The DC set in this power system only includes one DC . The highest AC voltage level substation in the whole network is a 500 kV substation. According to the grid geographical location information ledger, obtain the straight-line distance between the 500 kV substations in the whole network and the DC . The corresponding 500 kV substations obtained are respectively , , . These three substations are put into the set to be judged for the load shedding nodes corresponding to the DC , then these three substations are correspondingly named , , .

[0032] Step S102: Determine the power supply areas corresponding to each substation in the set to be judged for the load shedding area, and calculate the proportion of distributed new energy in the total power generation capacity in each power supply area.

[0033] ​​In this step, for the power supply areas corresponding to the substations in the set of nodes to be judged for load shedding the th substation, according to the account information, count the installed capacity of power sources and the installed capacity of distributed new energy in the power supply area; calculate the proportion of the installed capacity of distributed new energy in the power supply area corresponding to the th substation .

[0034] In a specific embodiment, for the three substations in the set of nodes to be judged for load shedding , , , according to the account information, count the installed capacity of power sources and the installed capacity of distributed new energy in the power supply area: The installed capacity of power sources in the power supply area of the substation is 520 MW, and the installed capacity of distributed new energy is 110 MW; The installed capacity of power sources in the power supply area of the substation is 400 MW, and the installed capacity of distributed new energy is 250 MW; The installed capacity of power sources in the power supply area of the substation is 280 MW, and the installed capacity of distributed new energy is 150 MW. Then , , the proportions of the installed capacity of distributed new energy in the corresponding power supply areas are 0.212, 0.625, and 0.536 respectively.

[0035] Step S103: According to the proportion of distributed new energy in the total installed capacity of power sources in each power supply area, judge whether the end branches of the low-voltage distribution network in the power supply area are put into the subset of nodes to be judged for load shedding.

[0036] In this step, if the proportion of the installed capacity of distributed new energy in the power supply area corresponding to the th substation is not less than the preset threshold, then all the end branches of the low-voltage distribution network in the power supply area corresponding to the th substation are not put into the subset of nodes to be judged for load shedding ;

[0037] If the proportion of the installed capacity of distributed new energy in the power supply area corresponding to the th substation is less than the preset threshold, then judge that all the end branches of the low-voltage distribution network in the power supply area corresponding to the th substation are put into the subset of nodes to be judged for load shedding , where represents the th when a DC locking fault occurs The th low-voltage distribution network end branch in the power supply area corresponding to the highest AC voltage level substation.

[0038] In a specific embodiment, it is judged that , , Among the installed proportions of distributed new energy in the corresponding power supply areas, the installed proportion of distributed new energy of is less than 60%; , The installed proportions of distributed new energy are all less than 60%. Then, all the low-voltage distribution network end branches in the power supply area corresponding to the 1st substation are put into the load-shedding node to-be-judged subset .

[0039] Step S104: Determine the load-shedding risk of the low-voltage distribution network end branches in the load-shedding node to-be-judged set according to the preset comprehensive load-shedding risk index, where the comprehensive load-shedding risk index includes voltage over-limit risk, power over-limit risk, and frequency support ability.

[0040] In this step, for the in the load-shedding node to-be-judged subset, obtain the voltage value at the branch electrical measurement point , the upper voltage limit value required in the actual operation regulations , the lower voltage limit value required in the actual operation regulations , and the nominal voltage , define and calculate the voltage over-limit risk index , and the expression is:

[0041] ,

[0042] Obtain the power value at the branch electrical measurement point , the upper line power limit value required in the actual operation regulations , define and calculate the power over-limit risk index , and the expression is:

[0043] ,

[0044] Taking into account the complexity of the access of distributed new energy and its frequency modulation ability differences in the low-voltage distribution network, define and calculate the frequency support ability , and the expression is:

[0045] ,

[0046] ​Determine the load shedding risk of the end branches of the low-voltage distribution network within the set of load shedding nodes to be judged according to the preset comprehensive risk index of load shedding. The expression is:

[0047] ,

[0048] In the formula, is the comprehensive risk index of load shedding for the th end branch of the low-voltage distribution network.

[0049] In a specific embodiment, calculate the three indicators of voltage over-limit risk, power over-limit risk, and frequency support ability for each branch, and form a comprehensive risk index of load shedding: Among them, taking the first branch as an example, the nominal voltage of this branch is 10.5 kV, the upper limit value of the voltage required in the actual operation regulations is 10.7 kV, the lower limit value of the voltage is 10 kV, and the upper limit value of the power is 0.95 MW. The observable voltage value obtained from the electrical measurement point of the first branch is 10.3 kV, and the power value is 0.88 MW. According to the line ledger, this line belongs to a pure load node. To sum up, the three indicator values of voltage over-limit risk, power over-limit risk, and frequency support ability are calculated to be 0.57, 0.93, and 0.3 respectively, and the comprehensive risk index of load shedding for this branch is calculated . Calculate the comprehensive risk index values of load shedding for the corresponding branches of the remaining 2nd to 121st in the same calculation steps. For example: the value of the 2nd branch is , and the 3rd branch .

[0050] Step S105, reorder the end branches of the low-voltage distribution network corresponding to the subset of load shedding nodes to be judged from small to large according to the calculation results of the comprehensive risk index of load shedding, and select the priority load shedding nodes according to the sorting results.

[0051] In a specific embodiment, sort the comprehensive risk index values of load shedding for the corresponding branches of the 1st to 121st from small to large. For example: calculate the of the 8th branch, which is ranked 1 among all branches, then the 8th branch is used as the first priority load shedding node; the 3rd branch , which is ranked 3 among all branches, then the 3rd branch is used as the second priority load shedding node.

[0052] In summary, for the method of the present application, in the case of a DC blocking fault occurring in the receiving-end power system with DC, based on the principle of selecting nearby load-shedding nodes, the proportion of distributed new energy output is considered to optimize the range of node selection. In addition, considering the influence of distributed new energy on the changes in electrical quantities of the end grid and the system frequency regulation control, a comprehensive risk index for load shedding is proposed to evaluate the impact of the selection of load-shedding nodes on the safe operation of the power grid, which can achieve the purpose of optimizing the range of load-shedding node selection and reducing the risk of load-shedding node removal.

[0053] Please refer to Figure 2 , which shows a structural block diagram of a load-shedding node selection system with distributed new energy according to the present application.

[0054] As Figure 2 shown, the load-shedding node selection system 200 includes a selection module 210, a calculation module 220, a judgment module 230, a determination module 240, and a selection module 250.

[0055] Among them, the selection module 210 is configured to select the substation with the highest AC voltage level in the receiving-end power system with DC, whose direct current straight-line distance is not greater than the preset distance threshold, into the set to be judged of the load-shedding area for DC blocking faults; the calculation module 220 is configured to determine the power supply areas corresponding to each substation in the set to be judged of the load-shedding area, and calculate the proportion of distributed new energy in the total power installation capacity in each power supply area; the judgment module 230 is configured to judge whether the end branch of the low-voltage distribution network in the power supply area is put into the sub-set to be judged of the load-shedding node according to the proportion of distributed new energy in the total power installation capacity in each power supply area; the determination module 240 is configured to determine the load-shedding risk of the end branch of the low-voltage distribution network in the set to be judged of the load-shedding node according to the preset comprehensive risk index for load shedding, where the comprehensive risk index for load shedding includes voltage over-limit risk, power over-limit risk, and frequency support ability; the selection module 250 is configured to re-order the end branches of the low-voltage distribution network corresponding to the sub-set to be judged of the load-shedding node from small to large according to the calculation results of the comprehensive risk index for load shedding, and select the preferred load-shedding nodes according to the sorting results.

[0056] It should be understood that Figure 2 the modules described in Figure 1 correspond to the respective steps in the method described with reference to Figure 2 . Thus, the operations and features described above for the method and the corresponding technical effects also apply to

[0057] In some other embodiments, the embodiments of the present invention further provide a computer-readable storage medium, on which a computer program is stored. When the program instructions are executed by a processor, the processor is caused to execute the method for selecting a load-shedding node including distributed new energy in any of the above method embodiments;

[0058] As an implementation manner, the computer-readable storage medium of the present invention stores computer-executable instructions, and the computer-executable instructions are set as follows:

[0059] For a receiving-end power system with direct current, select the substation with the highest AC voltage level in the power grid whose straight-line distance from the corresponding direct current is not greater than a preset distance threshold and put it into the set to be judged for the load-shedding area in case of direct current blocking fault;

[0060] Determine the power supply areas corresponding to each substation in the set to be judged for the load-shedding area, and calculate the proportion of distributed new energy in the total installed power of the power supply in each power supply area;

[0061] According to the proportion of distributed new energy in the total installed power of the power supply in each power supply area, judge whether the end branch of the low-voltage distribution network in the power supply area is put into the subset to be judged for the load-shedding node;

[0062] Determine the load-shedding risk of the end branch of the low-voltage distribution network in the set to be judged for the load-shedding node according to a preset comprehensive load-shedding risk index, where the comprehensive load-shedding risk index includes voltage over-limit risk, power over-limit risk, and frequency support ability;

[0063] Reorder the corresponding end branches of the low-voltage distribution network in the subset to be judged for the load-shedding node from small to large according to the calculation results of the comprehensive load-shedding risk index, and select the preferred load-shedding nodes according to the sorting results.

[0064] The computer-readable storage medium may include a storage program area and a storage data area. Among them, the storage program area may store an operating system and application programs required for at least one function; the storage data area may store data created according to the use of the system for selecting a load-shedding node including distributed new energy, etc. In addition, the computer-readable storage medium may include a high-speed random access memory, and may also include a memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage devices. In some embodiments, the computer-readable storage medium may optionally include a memory remotely set with respect to the processor, and these remote memories may be connected to the system for selecting a load-shedding node including distributed new energy through a network. Examples of the above network include but are not limited to the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0065] Figure 3 is a schematic structural diagram of the electronic device provided by the embodiments of the present invention, as Figure 3As shown in the figure, the device includes: a processor 310 and a memory 320. The electronic device may further include: an input device 330 and an output device 340. The processor 310, the memory 320, the input device 330, and the output device 340 may be connected through a bus or other means. Figure 3 Taking the connection through the bus as an example. The memory 320 is the above-mentioned computer-readable storage medium. The processor 310 executes various functional applications and data processing of the server by running the non-volatile software programs, instructions, and modules stored in the memory 320, that is, implements the method embodiment of the load shedding node selection method for distributed new energy. The input device 330 can receive input digital or character information, and generate key signal inputs related to user settings and function controls of the load shedding node selection system for distributed new energy. The output device 340 may include display devices such as a display screen.

[0066] The above electronic device can execute the method provided by the embodiment of the present invention, and has the corresponding functional modules and beneficial effects for executing the method. For technical details not described in detail in this embodiment, reference can be made to the method provided by the embodiment of the present invention.

[0067] As an implementation, the above electronic device is applied to a load shedding node selection system for distributed new energy and is used for a client, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein, the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to:

[0068] For a receiving-end power system with direct current, select the substation with the highest AC voltage level in the power grid whose direct current linear distance is not greater than a preset distance threshold and put it into the set to be judged for the load shedding area in case of DC blocking fault;

[0069] Determine the power supply areas corresponding to each substation in the set to be judged for the load shedding area, and calculate the proportion of distributed new energy in the total power supply installed capacity in each power supply area;

[0070] According to the proportion of distributed new energy in the total power supply installed capacity in each power supply area, judge whether the end branch of the low-voltage distribution network in the power supply area is put into the subset to be judged for the load shedding node;

[0071] Determine the load shedding risk of the end branch of the low-voltage distribution network in the set to be judged for the load shedding node according to a preset comprehensive load shedding risk index, where the comprehensive load shedding risk index includes voltage over-limit risk, power over-limit risk, and frequency support ability;

[0072] Reorder the end - branch low - voltage distribution networks corresponding to the nodes to be judged in the load - shedding node subset in ascending order according to the calculation results of the comprehensive risk index of load - shedding, and select the priority load - shedding nodes according to the sorting results.

[0073] Through the description of the above - mentioned implementation manners, those skilled in the art can clearly understand that each implementation manner can be realized by means of software plus a necessary general - purpose hardware platform, and of course, it can also be realized by hardware. Based on such an understanding, the above - mentioned technical solution, in essence, or the part that contributes to the prior art can be embodied in the form of a software product. This computer software product can be stored in a computer - readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of each embodiment or some parts of the embodiments.

[0074] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of each embodiment of the present invention.

Claims

1. A method for selecting load shedding nodes containing distributed new energy, characterized in that, Including: For a receiving-end power system with direct current, select the substation with the highest AC voltage level of the power grid whose straight-line distance from the corresponding direct current is not greater than the preset distance threshold and put it into the set to be judged of the load-shedding area for DC blocking faults; Determine the power supply areas corresponding to each substation in the set to be judged of the load-shedding area, and calculate the proportion of distributed new energy in the total power source installed capacity in each power supply area; According to the proportion of distributed new energy in the total power source installed capacity in each power supply area, judge whether the end branch of the low-voltage distribution network in the power supply area is put into the subset to be judged of the load-shedding node; Determine the load-shedding risk of the end branch of the low-voltage distribution network in the subset to be judged of the load-shedding node according to the preset comprehensive load-shedding risk index, where the comprehensive load-shedding risk index includes voltage over-limit risk, power over-limit risk and frequency support ability; Sort the corresponding end branches of the low-voltage distribution network in the subset to be judged of the load-shedding node again from small to large according to the calculation results of the comprehensive load-shedding risk index, and select the priority load-shedding nodes according to the sorting results.

2. The method for selecting a load shedding node containing distributed new energy according to claim 1, wherein The step of, for a receiving-end power system with direct current, selecting the substation with the highest AC voltage level of the power grid whose straight-line distance from the corresponding direct current is not greater than the preset distance threshold and putting it into the set to be judged of the load-shedding area for DC blocking faults includes: In the receiving-end power system with DC feeding, define all DCs in the receiving-end power system as , where is the -th DC in the set; Obtain the substation with the highest AC voltage level in the power grid according to the geographical location information and the straight-line distance to the th DC line , and determine whether the straight-line distance is greater than a preset distance threshold; If it is not greater than the preset distance threshold, then for the substation with the highest AC voltage level in the power grid, put it into the set of load-shedding nodes to be judged where DC blocking faults occur for the th time, otherwise do not put it in.

3. A method for selecting a load shedding node with distributed new energy according to claim 1, characterized in that, The step of determining the power supply areas corresponding to each substation in the set to be judged of the load-shedding area and calculating the proportion of distributed new energy in the total power source installed capacity in each power supply area includes: The set of load-shedding nodes to be judged The power supply area corresponding to the substation, and the installed capacity of power sources within the power supply area is counted according to the account information and the installed capacity of distributed new energy ; Calculate the proportion of distributed new energy installed capacity in the power supply area corresponding to the th substation .

4. A method for selecting a load shedding node with distributed new energy according to claim 1, characterized in that, The step of, according to the proportion of distributed new energy in the total power source installed capacity in each power supply area, judging whether the end branch of the low-voltage distribution network in the power supply area is put into the subset to be judged of the load-shedding node includes: If the installed capacity ratio of distributed new energy in the power supply area corresponding to the th substation is not less than the preset threshold, then all the end branches of the low-voltage distribution network in the power supply area corresponding to the th substation are not put into the subset of load-shedding nodes to be judged ; If the installed capacity ratio of distributed new energy in the power supply area corresponding to the th substation is less than the preset threshold, then all the end branches of the low-voltage distribution network in the power supply area corresponding to the th substation are put into the subset of load-shedding nodes to be judged, where represents the th end branch of the low-voltage distribution network in the power supply area corresponding to the highest AC voltage level substation when the th DC has a blocking fault. th DC has a blocking fault, and represents the th highest AC voltage level substation.

5. A method for selecting a load shedding node containing distributed new energy according to claim 1, characterized in that, The step of determining the load-shedding risk of the end branch of the low-voltage distribution network in the subset to be judged of the load-shedding node according to the preset comprehensive load-shedding risk index includes: To-be-judged subset of the load-shedding nodes within , obtain the voltage value of the electrical measurement point of the branch , the upper voltage limit value required in the actual operation regulations , the lower voltage limit value required in the actual operation regulations and the nominal voltage , define and calculate the voltage over-limit risk index , and the expression is: ， Obtain the power value of the branch electrical measurement point , the upper limit of the line power required in the actual operation regulations , define and calculate the power over-limit risk index , the expression is: ， Considering the complexity of the access of distributed new energy in low-voltage distribution networks and the differences in their frequency regulation capabilities, define and calculate the frequency support capabilities , and the expression is as follows: ， Determine the load-shedding risk of the end branch of the low-voltage distribution network in the set to be judged of the load-shedding node according to the preset comprehensive load-shedding risk index, and the expression is: ， In the formula, is the comprehensive risk index of load shedding for the end branch of the \(i\)-th low-voltage distribution network.

6. A load shedding node selection system with distributed new energy, characterized in that, Including: A selection module, configured to, for a receiving-end power system with direct current, select the substation with the highest AC voltage level of the power grid whose straight-line distance from the corresponding direct current is not greater than the preset distance threshold and put it into the set to be judged of the load-shedding area for DC blocking faults; A calculation module, configured to determine the power supply areas corresponding to each substation in the set to be judged of the load-shedding area, and calculate the proportion of distributed new energy in the total power source installed capacity in each power supply area; A judgment module, configured to, according to the proportion of distributed new energy in the total power source installed capacity in each power supply area, judge whether the end branch of the low-voltage distribution network in the power supply area is put into the subset to be judged of the load-shedding node; A determination module, configured to determine the load-shedding risk of the end branch of the low-voltage distribution network in the subset to be judged of the load-shedding node according to the preset comprehensive load-shedding risk index, where the comprehensive load-shedding risk index includes voltage over-limit risk, power over-limit risk and frequency support ability; A selection module, configured to sort the corresponding end branches of the low-voltage distribution network in the subset to be judged of the load-shedding node again from small to large according to the calculation results of the comprehensive load-shedding risk index, and select the priority load-shedding nodes according to the sorting results.

7. An electronic device, characterized in that, Including: At least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

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