A method, device and equipment for distinguishing asynchronous partitions of AC / DC synchronous power grid

Abstract

The invention relates to an asynchronous partition determination method, device and equipment for an AC / DC synchronous power grid. The AC / DC synchronous power grid comprises a first power grid area and a second power grid area. The method is used to determine whether the AC / DC synchronous power grid can be asynchronously partitioned. The method comprehensively considers the degree of strong DC and weak AC, synchronization power and frequency constraints. The AC transmission power, DC transmission power and the state of the AC / DC synchronous power grid in the two power grid areas are used to determine the total DC transmission power, the critical value of the AC transmission total power and the maximum power angle difference of the two power grid areas. The AC / DC ratio index is determined according to the critical value of the DC transmission total power and the AC transmission total power. Whether the AC / DC synchronous power grid needs to be asynchronously partitioned is determined by judging the AC / DC ratio index and the maximum power angle difference. Whether the AC / DC synchronous power grid can be asynchronously partitioned is then determined based on first operating data, second operating data and frequency constraints. The method can provide a reference basis for the planning and construction of the power grid.

Description

Technical Field

[0001] The present invention relates to the technical field of power grids, and in particular to a method, a device and equipment for distinguishing asynchronous partitions of an AC / DC synchronous power grid. Background Art

[0002] The development of large power grids has two basic characteristics: one is the improvement of the voltage level of the backbone network, and the other is the strengthening of regional power grid interconnection. The interconnection of regional power grids can give full play to the scale benefits of the power grid, realize the sharing of backup in the whole region, and enhance the ability of regional power grids to withstand impact loads and resist accidents; the power between regions supports each other to improve the safety of the power grid; it can achieve peak shaving and valley filling, water and fire mutual assistance, and cross-basin compensation; the selection of new units is flexible and the unit power generation cost is reduced; the optimization of regional resources is achieved, which is conducive to the consumption of large-scale new energy. However, the excessive scale of large power grids will also bring a series of problems, such as: serious mutual influence between AC and DC, insufficient risk prevention ability of large power outages, large-scale over-limit of short-circuit current, disordered and uncontrollable power flow caused by the randomness of new energy output, etc.

[0003] It is very important to determine whether the synchronous power grid needs asynchronous partitioning and whether it can be asynchronously partitioned for the planning and construction of large power grids. Existing research on large power grids mainly focuses on the single stability characteristics of the power grid, and a series of studies have been carried out to determine the stability characteristics of the power grid from the aspects of frequency, voltage, power angle, strong direct current and weak alternating current, etc. Summary of the invention

[0004] The embodiments of the present invention provide a method, device and equipment for distinguishing asynchronous partitions of an AC / DC synchronous power grid, which are applied to an AC / DC synchronous power grid to solve the technical problem that there is no existing method for distinguishing asynchronous partitions of a large power grid.

[0005] In order to achieve the above purpose, the embodiment of the present invention provides the following technical solutions:

[0006] A method for distinguishing asynchronous partitions of an AC / DC synchronous power grid is applied to an AC / DC synchronous power grid, wherein the AC / DC synchronous power grid includes a first power grid area and a second power grid area. The method for distinguishing asynchronous partitions of an AC / DC synchronous power grid includes the following steps:

[0007] The first power grid area and the second power grid area are in a rated power operation state, obtaining a DC transmission power and an AC transmission power transmitted n times between the first power grid area and the second power grid area, and determining a total DC transmission power and a total AC transmission power between the first power grid area and the second power grid area according to the n DC transmission powers and the AC transmission powers;

[0008] Screening out the maximum DC transmission power from the n DC transmission powers, controlling the AC / DC synchronous power grid to perform unipolar or bipolar blocking according to the maximum DC transmission power, and if the AC / DC synchronous power grid is in a critical stable state after a DC unipolar or bipolar blocking failure, obtaining the total AC transmission power at this time as the critical value of the total AC transmission power and the maximum power angle difference of all units in the first power grid area and the second power grid area;

[0009] Determine an AC-DC ratio index of the AC-DC synchronous power grid according to the AC transmission total power critical value and the DC transmission total power;

[0010] If the AC-DC ratio index is less than the first index threshold, the AC-DC synchronous power grid enters the asynchronous partition judgment; or if the AC-DC ratio index is between the first index threshold and the second index threshold, and the maximum power angle difference is greater than the power angle difference threshold, the AC-DC synchronous power grid enters the asynchronous partition judgment;

[0011] Wherein, the judgment that the AC / DC synchronous power grid enters an asynchronous partition includes:

[0012] Acquiring first operating data of the first power grid area and acquiring second operating data of the second power grid area;

[0013] If the first operating data and the second operating data satisfy the constraint condition, asynchronously partitioning the AC / DC synchronous power grid;

[0014] The first operating data and the second operating data both include: the maximum power loss of a single component, the total capacity of the unit at startup, the unit primary frequency regulation capability data, the load primary frequency regulation capability data and the DC FLC regulation capability data.

[0015] Preferably, the constraint condition includes four discrimination conditions, including a first discrimination condition, a second discrimination condition, a third discrimination condition and a fourth discrimination condition; the first discrimination condition is that the maximum power loss of a single element in the first power grid area is less than 0.2 times the total capacity of the units in the first power grid area that are turned on; the second discrimination condition is that the maximum power loss of a single element in the first power grid area is less than the first total capacity data; the third discrimination condition is that the maximum power loss of a single element in the second power grid area is less than 0.2 times the total capacity of the units in the second power grid area that are turned on; the fourth discrimination condition is that the maximum power loss of a single element in the second power grid area is less than the second total capacity data;

[0016] Among them, the first total capacity data is obtained by summing up the primary frequency regulation capability data of the units, the primary frequency regulation capability data of the loads and the DC FLC regulation capability data of the first power grid area; the second total capacity data is obtained by summing up the primary frequency regulation capability data of the units, the primary frequency regulation capability data of the loads and the DC FLC regulation capability data of the second power grid area.

[0017] Preferably, the method for distinguishing asynchronous partitions of an AC / DC synchronous power grid includes: if the first operating data and the second operating data do not satisfy any one of the discrimination conditions in the constraints, increasing the total capacity or total capability data of the first power grid area and / or the second power grid area until the modified first operating data and the second operating data satisfy the constraints.

[0018] Preferably, the method for determining asynchronous partitioning of an AC / DC synchronous power grid comprises: if the AC / DC ratio index is greater than a first index threshold, then the AC / DC synchronous power grid is not asynchronously partitioned; or

[0019] If the AC-DC ratio index is between the first index threshold and the second index threshold, and the maximum power angle difference is not greater than the power angle difference threshold, the AC-DC synchronous power grid does not perform asynchronous partitioning.

[0020] Preferably, controlling the AC / DC synchronous power grid to perform unipolar or bipolar locking according to the maximum DC transmission power includes: determining whether there are stabilization measures for bipolar locking of the AC / DC synchronous power grid, and if so, determining that the AC / DC synchronous power grid performs unipolar locking; otherwise, determining that the AC / DC synchronous power grid performs bipolar locking.

[0021] Preferably, after a DC unipolar or bipolar blocking fault occurs in the AC / DC synchronous power grid, the AC / DC synchronous power grid is in a critical stable state, including:

[0022] After a DC unipolar or bipolar blocking fault occurs in the AC / DC synchronous grid, if the AC / DC synchronous grid is stable, increasing the output of the units in the first grid area and reducing the output of the units in the second grid area until the AC / DC synchronous grid is in a critical stable state; or

[0023] After a DC unipolar or bipolar blocking fault occurs in the AC / DC synchronous power grid, if the AC / DC synchronous power grid is unstable, the output of the units in the first power grid area is reduced, and the output of the units in the second power grid area is increased until the AC / DC synchronous power grid is in a critical stable state.

[0024] The present invention also provides an AC / DC synchronous power grid asynchronous partition determination device, which is applied to an AC / DC synchronous power grid, wherein the AC / DC synchronous power grid includes a first power grid area and a second power grid area, and the AC / DC synchronous power grid asynchronous partition determination device includes a first data module, a second data module, a third data module and a determination module;

[0025] The first data module is used for obtaining the DC transmission power and AC transmission power transmitted n times between the first grid area and the second grid area when the first grid area and the second grid area are in a rated power operation state, and determining the total DC transmission power and the total AC transmission power between the first grid area and the second grid area according to the n DC transmission powers and the AC transmission powers;

[0026] The second data module is used to filter out the maximum DC transmission power from the n DC transmission powers, control the AC / DC synchronous power grid to perform unipolar or bipolar blocking according to the maximum DC transmission power, and if the AC / DC synchronous power grid is in a critical stable state after a DC unipolar or bipolar blocking failure, obtain the AC transmission total power at this time as the AC transmission total power critical value and the maximum power angle difference of all units in the first power grid area and the second power grid area;

[0027] The third data module is used to determine the AC-DC ratio index of the AC-DC synchronous power grid according to the AC transmission total power critical value and the DC transmission total power;

[0028] The judgment module is used to judge whether the AC / DC synchronous power grid enters an asynchronous partition according to the AC / DC ratio index being less than the first index threshold; or whether the AC / DC synchronous power grid enters an asynchronous partition according to the AC / DC ratio index being between the first index threshold and the second index threshold, and the maximum power angle difference being greater than the power angle difference threshold;

[0029] Wherein, the judgment that the AC / DC synchronous power grid enters an asynchronous partition includes:

[0030] Acquiring first operating data of the first power grid area and acquiring second operating data of the second power grid area;

[0031] If the first operating data and the second operating data satisfy the constraint condition, asynchronously partitioning the AC / DC synchronous power grid;

[0032] The first operating data and the second operating data both include: the maximum power loss of a single component, the total capacity of the unit at startup, the unit primary frequency regulation capability data, the load primary frequency regulation capability data and the DC FLC regulation capability data.

[0033] Preferably, the constraint condition includes four discrimination conditions, including the first discrimination condition, the second discrimination condition, the third discrimination condition and the fourth discrimination condition; the first discrimination condition is that the maximum power loss of a single element in the first power grid area is less than 0.2 times the total capacity of the units in the first power grid area; the second discrimination condition is that the maximum power loss of a single element in the first power grid area is less than the first total capacity data; the third discrimination condition is that the maximum power loss of a single element in the second power grid area is less than 0.2 times the total capacity of the units in the second power grid area; the fourth discrimination condition is that the maximum power loss of a single element in the second power grid area is less than the second total capacity data. Among them, the first total capacity data is obtained by summing up the primary frequency regulation capacity data of the units in the first power grid area, the primary frequency regulation capacity data of the loads and the DC FLC regulation capacity data; the second total capacity data is obtained by summing up the primary frequency regulation capacity data of the units in the second power grid area, the primary frequency regulation capacity data of the loads and the DC FLC regulation capacity data.

[0034] Preferably, after a DC unipolar or bipolar blocking fault occurs in the AC / DC synchronous power grid, the second data module includes a system stability processing submodule and a system instability processing submodule;

[0035] The system stability processing submodule is used to increase the output of the units in the first grid area and reduce the output of the units in the second grid area according to the AC / DC synchronous grid being stable, until the AC / DC synchronous grid is in a critical stable state;

[0036] The system instability processing submodule is used to reduce the unit output in the first grid area and increase the unit output in the second grid area according to the AC / DC synchronous grid being unstable, until the AC / DC synchronous grid is in a critical stable state.

[0037] The present invention also provides a terminal device, comprising a processor and a memory;

[0038] The memory is used to store program codes and transmit the program codes to the processor;

[0039] The processor is used to execute the above-mentioned method for determining asynchronous partitions of AC / DC synchronous power grids according to the instructions in the program code.

[0040] It can be seen from the above technical scheme that the embodiments of the present invention have the following advantages: the method, device and equipment for distinguishing asynchronous partitions of an AC / DC synchronous power grid are applied to an AC / DC synchronous power grid, the AC / DC synchronous power grid includes a first power grid area and a second power grid area, the method includes: when the first power grid area and the second power grid area are in a rated power operation state, obtaining the DC transmission power and the AC transmission power of n transmissions between the first power grid area and the second power grid area, and determining the total DC transmission power and the total AC transmission power between the first power grid area and the second power grid area according to the n DC transmission powers and the AC transmission powers; screening out the maximum DC transmission power from the n DC transmission powers, and controlling the AC / DC synchronous power grid to perform unipolar or bipolar locking according to the maximum DC transmission power; if the AC / DC synchronous power grid is in a critical stable state after a DC unipolar or bipolar locking fault, the total AC transmission power at this time is obtained as the critical value of the total AC transmission power. value and the maximum power angle difference of all units in the first power grid area and the second power grid area; determine the AC-DC ratio index of the AC-DC synchronous power grid according to the AC total power transmission critical value and the DC total power transmission total power; if the AC-DC ratio index is less than the first index threshold, the AC-DC synchronous power grid enters the asynchronous partition judgment; or if the AC-DC ratio index is between the first index threshold and the second index threshold, and the maximum power angle difference is greater than the power angle difference threshold, the AC-DC synchronous power grid enters the asynchronous partition judgment; wherein, the AC-DC synchronous power grid enters the asynchronous partition judgment including: obtaining the first operating data of the first power grid area and obtaining the second operating data of the second power grid area; if the first operating data and the second operating data meet the constraint conditions, the AC-DC synchronous power grid is asynchronously partitioned; the first operating data and the second operating data both include: the maximum loss power of a single component, the total capacity of the unit startup, the unit primary frequency regulation capability data, the load primary frequency regulation capability data and the DC FLC regulation capability data. The method for distinguishing asynchronous partitions of an AC / DC synchronous power grid can be used to judge whether an AC / DC synchronous power grid needs asynchronous partitioning and whether it can be asynchronously partitioned, thereby providing a reference basis for planning and construction of a power grid; the method realizes the judgment on whether an AC / DC synchronous power grid can be asynchronously partitioned, and the method comprehensively considers the degree of strong direct current and weak alternating current; the AC transmission power, the DC transmission power and the state of the AC / DC synchronous power grid in two power grid areas are used to determine the total DC transmission power, the critical value of the AC transmission total power and the maximum power angle difference of the two power grid areas, the AC / DC ratio index is determined according to the critical value of the DC transmission total power and the AC transmission total power, and the AC / DC ratio index and the maximum power angle difference are judged to determine whether the AC / DC synchronous power grid needs to be asynchronously partitioned by judging the AC / DC ratio index and the maximum power angle difference, and then based on the first operating data, the second operating data and the constraint conditions, it is judged whether the AC / DC synchronous power grid can be asynchronously partitioned, thereby providing a reference basis for planning and construction of a power grid, and solving the technical problem that there is no existing judgment on asynchronous partitioning of a large power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0042] Figure 1 A flowchart of the steps of the method for determining asynchronous partitions of an AC / DC synchronous power grid according to an embodiment of the present invention;

[0043] Figure 2 A schematic diagram of the structure of an AC / DC synchronous power grid in the method for distinguishing asynchronous partitions of an AC / DC synchronous power grid according to an embodiment of the present invention;

[0044] Figure 3 A flowchart of the steps of a method for determining asynchronous partitions of an AC / DC synchronous power grid according to another embodiment of the present invention;

[0045] Figure 4 It is a framework diagram of the device for distinguishing asynchronous partitions of an AC / DC synchronous power grid according to an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] In an embodiment of the present application, corrugated paper trademark detection can adopt a special case of general object detection in computer vision. Corrugated paper trademark detection is challenging in the following aspects, such as unique appearance, instance diversity, large-scale object detection, scalable network and brand similarity.

[0048] The embodiments of the present application provide a method, device and equipment for determining asynchronous partitions of an AC / DC synchronous power grid, which are applied to an AC / DC synchronous power grid to solve the technical problem that there is no existing method for determining asynchronous partitions of a large power grid.

[0049] Embodiment 1:

[0050] Figure 1 This is a flowchart of the steps of the method for determining asynchronous partitions of an AC / DC synchronous power grid according to an embodiment of the present invention. Figure 2 It is a structural schematic diagram of an AC / DC synchronous power grid in the method for distinguishing asynchronous partitions of an AC / DC synchronous power grid according to an embodiment of the present invention.

[0051] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides an AC / DC synchronous power grid asynchronous partition determination method, which is applied to an AC / DC synchronous power grid, wherein the AC / DC synchronous power grid includes a first power grid area and a second power grid area, and the AC / DC synchronous power grid asynchronous partition determination method includes the following steps:

[0052] S1. When the first power grid area and the second power grid area are operating at rated power, the DC transmission power and the AC transmission power of n transmissions between the first power grid area and the second power grid area are obtained, and the total DC transmission power and the total AC transmission power between the first power grid area and the second power grid area are determined based on the n DC transmission powers and AC transmission powers.

[0053] In the embodiment of the present invention, both the first power grid area A and the second power grid area B are provided with generators, and the generators may be synchronous generators.

[0054] It should be noted that if Figure 2 As shown, in step S1, the DC power of the first power grid area A and the second power grid area B are controlled to operate at rated power, and all DC transmission powers of the DC channels of the first power grid area A and the second power grid area B are obtained, which are P and dc1n , P dc2n ,…,P dcnn ; Obtain all AC transmission powers of the AC channels of the first power grid area A and the second power grid area B at this time, which are P ac1 , P ac2 ,…,P acm The power transmission from the first power grid area A to the second power grid area B is set as the positive direction.

[0055] In the embodiment of the present invention, the total DC transmission power between the first power grid area and the second power grid area is calculated based on n DC transmission powers: , the total AC transmission power between the first power grid area and the second power grid area is calculated based on n AC transmission powers: .

[0056] S2. Filter out the maximum DC transmission power from n DC transmission powers, and control the AC / DC synchronous power grid to perform unipolar or bipolar interlocking according to the maximum DC transmission power. If the AC / DC synchronous power grid is in a critical stable state after a DC unipolar or bipolar interlocking failure, the total AC transmission power at this time is obtained as the critical value of the total AC transmission power and the maximum power angle difference of all units in the first grid area and the second grid area.

[0057] It should be noted that in step S2, the AC / DC synchronous power grid may be controlled to perform unipolar or bipolar blocking according to the maximum DC transmission power, and the AC / DC synchronous power grid is in a critical stable state again after the DC unipolar or bipolar blocking failure, and the AC / DC synchronous power grid is in a critical stable state again, and the AC / DC synchronous power grid is in a critical stable state again. The critical value of the total AC transmission power and the maximum power angle difference corresponding to the AC / DC synchronous power grid being in a critical stable state are obtained to provide data for subsequent steps. The AC / DC synchronous power grid is in a critical stable state when the power grid is disturbed by external forces, and the state of the power grid is in a stable state and an unstable state. At this time, the state is called a critical state.

[0058] S3. According to the critical value of total AC transmission power P accritical And the total DC transmission power P dcsum Determine the AC-DC ratio index of the AC-DC synchronous power grid.

[0059] It should be noted that in step S3, the AC-DC ratio index is calculated based on the AC transmission total power critical value and the DC transmission total power. acdc The expression is: .

[0060] S4. If the AC-DC ratio index is less than the first index threshold, the AC-DC synchronous power grid enters the asynchronous partition judgment; or if the AC-DC ratio index is between the first index threshold and the second index threshold, and the maximum power angle difference is greater than the power angle difference threshold, the AC-DC synchronous power grid enters the asynchronous partition judgment.

[0061] It should be noted that the AC / DC ratio index can be compared with the first index threshold and the second index threshold, and the maximum power angle difference can be compared with the power angle difference threshold to determine whether the AC / DC synchronous power grid needs to enter the asynchronous partition judgment. In step S4, it is defined that the AC / DC ratio index is within a certain numerical range and the maximum power angle difference is within a certain numerical range, and the AC / DC synchronous power grid enters the asynchronous partition judgment, which means that the AC / DC synchronous power grid needs asynchronous partitioning. In this embodiment, the first index threshold, the second index threshold and the power angle difference threshold can all be set according to demand. Preferably, the first index threshold can be selected as 0.5, the second index threshold can be selected as 1, and the power angle difference threshold can be 90°.

[0062] In the embodiment of the present invention, the determination of whether the AC / DC synchronous power grid enters an asynchronous partition includes:

[0063] S41. Obtaining first operating data of the first power grid area and obtaining second operating data of the second power grid area;

[0064] S42. If the first operation data and the second operation data satisfy the constraint condition, the AC / DC synchronous power grid is asynchronously partitioned;

[0065] The first operation data and the second operation data both include: the maximum power loss of a single component, the total capacity of the unit startup, the unit primary frequency regulation capability data, the load primary frequency regulation capability data and the DC FLC regulation capability data. Among them, the single component in the AC / DC synchronous power grid can be a generator or a DC power component.

[0066] It should be noted that, in the judgment content of the AC / DC synchronous power grid entering the asynchronous partition, the AC / DC synchronous power grid can only be asynchronously partitioned if the first operating data of the first power grid area and the second operating data of the second power grid area both meet the constraint conditions. A , the total startup capacity of the units in the first grid area A is S A , the primary frequency regulation capability data P of the units in the first power grid area A gA , the load primary frequency regulation capability data P of the first power grid area A LA , DC FLC regulation capability data P of the first power grid area A FLCA ; The maximum power loss P of a single element in the second grid area B B , the total startup capacity of the units in the second grid area B is S B , the primary frequency regulation capability data P of the units in the second power grid area B gB , the load primary frequency regulation capability data P of the second power grid area B LB , DC FLC regulation capability data P of the second power grid area B FLCB .

[0067] In the embodiment of the present invention, the method for distinguishing asynchronous partitions of an AC / DC synchronous power grid can determine whether the AC / DC synchronous power grid needs asynchronous partitions and whether it can be asynchronously partitioned, thereby providing a reference for planning and construction of the power grid.

[0068] A method for distinguishing asynchronous partitions of an AC / DC synchronous power grid provided by the present invention is applied to an AC / DC synchronous power grid, wherein the AC / DC synchronous power grid includes a first power grid area and a second power grid area, and the method includes: when the first power grid area and the second power grid area are in a rated power operation state, obtaining a DC transmission power and an AC transmission power transmitted n times between the first power grid area and the second power grid area, and determining a total DC transmission power and a total AC transmission power between the first power grid area and the second power grid area according to the n DC transmission powers and the AC transmission powers; screening out a maximum DC transmission power from the n DC transmission powers, and controlling the AC / DC synchronous power grid to perform unipolar or bipolar blocking according to the maximum DC transmission power; if the AC / DC synchronous power grid is in a critical stable state after a DC unipolar or bipolar blocking fault, the total AC transmission power at this time is obtained as a critical value of the total AC transmission power and the total AC transmission power of the first power grid area and the second power grid area. The maximum power angle difference of all units in the power grid area; determine the AC-DC ratio index of the AC-DC synchronous power grid according to the AC total power critical value and the DC total power; if the AC-DC ratio index is less than the first index threshold, the AC-DC synchronous power grid enters the asynchronous partition judgment; or if the AC-DC ratio index is between the first index threshold and the second index threshold, and the maximum power angle difference is greater than the power angle difference threshold, the AC-DC synchronous power grid enters the asynchronous partition judgment; wherein, the AC-DC synchronous power grid enters the asynchronous partition judgment including: obtaining the first operating data of the first power grid area and obtaining the second operating data of the second power grid area; if the first operating data and the second operating data meet the constraint conditions, the AC-DC synchronous power grid is asynchronously partitioned; the first operating data and the second operating data both include: the maximum loss power of a single component, the total capacity of the unit startup, the unit primary frequency regulation capability data, the load primary frequency regulation capability data and the DC FLC regulation capability data. The method for distinguishing asynchronous partitions of an AC / DC synchronous power grid can be used to judge whether an AC / DC synchronous power grid needs asynchronous partitioning and whether it can be asynchronously partitioned, thereby providing a reference basis for planning and construction of a power grid; the method realizes the judgment on whether an AC / DC synchronous power grid can be asynchronously partitioned, and comprehensively considers the degree of strong DC and weak AC; the AC transmission power, DC transmission power and the state of the AC / DC synchronous power grid in two power grid areas are used to determine the total DC transmission power, the critical value of the AC transmission total power and the maximum power angle difference of the two power grid areas, the AC / DC ratio index is determined according to the critical value of the DC transmission total power and the AC transmission total power, and the AC / DC ratio index and the maximum power angle difference are judged to determine whether the AC / DC synchronous power grid needs to be asynchronously partitioned by judging the AC / DC ratio index and the maximum power angle difference, and then based on the first operating data, the second operating data and the constraint conditions, it is judged whether the AC / DC synchronous power grid can be asynchronously partitioned, thereby providing a reference basis for planning and construction of a power grid, and solving the technical problem that there is no existing judgment on asynchronous partitioning of a large power grid.

[0069] In one embodiment of the present invention, the constraint conditions include four discrimination conditions, including a first discrimination condition, a second discrimination condition, a third discrimination condition and a fourth discrimination condition; the first discrimination condition is that the maximum power loss of a single component in the first power grid area is less than 0.2 times the total capacity of the units in the first power grid area, that is, The second judgment condition is that the maximum power loss of a single element in the first power grid area is less than the first total capacity data, that is, P A <P gA +P LA +P FLCA The third judgment condition is that the maximum power loss of a single component in the second power grid area is less than 0.2 times the total capacity of the units in the second power grid area. The fourth judgment condition is that the maximum power loss of a single element in the second power grid area is less than the second total capacity data, that is, P B <P gB +P LB +P FLCB Among them, according to the primary frequency regulation capability data P of the units in the first power grid area gA , Load primary frequency regulation capability data P LA and DC FLC regulation capability data P FLCA The summation is calculated to obtain the first total capacity data; according to the primary frequency regulation capacity data P of the units in the second power grid area gB , Load primary frequency regulation capability data P LB and DC FLC regulation capability data P FLCB The second total capability data is obtained by summing up and calculating.

[0070] It should be noted that, in the judgment of the AC / DC synchronous power grid entering the asynchronous partition, if the first power grid area A and the second power grid area B both meet Four judgment conditions are met, then the first power grid area A and the second power grid area B after asynchronous partitioning meet the requirements that the frequency change rate after the single element is locked is less than 1Hz / s, and its recovery frequency deviation is less than 0.2Hz, and the AC / DC synchronous power grid can be asynchronously partitioned. In this embodiment, , To meet the frequency change rate index requirements of the asynchronous power grid partition; A <P gA +P LA +P FLCA , P B <P gB +P LB +P FLCB To meet the steady-state frequency requirements of the asynchronous partition of the power grid.

[0071] Figure 3This is a flowchart of the steps of a method for identifying asynchronous partitions of an AC / DC synchronous power grid according to another embodiment of the present invention.

[0072] like Figure 3 As shown, in one embodiment of the present invention, the method for distinguishing asynchronous partitions of the AC / DC synchronous power grid includes: if the first operating data and the second operating data do not meet any one of the constraints, then increasing the total capacity or total capability data of the first power grid area and / or the second power grid area until the modified first operating data and the second operating data meet the constraints.

[0073] It should be noted that if one of the four judgment conditions of step S5 is not satisfied, it is necessary to increase the total capacity or total capability data of the first power grid area and / or the second power grid area until the modified first operation data and the second operation data meet the constraint conditions, and then the AC / DC synchronous power grid is asynchronously partitioned. In this embodiment, the method for distinguishing asynchronous partitions of the AC / DC synchronous power grid determines whether the AC / DC synchronous power grid needs to be asynchronously partitioned by the AC / DC ratio index and the maximum power angle difference of the units between the first power grid area and the second power grid area, and determines whether the AC / DC synchronous power grid can be asynchronously partitioned by the frequency change rate and the recovery frequency deviation index, and proposes improvement measures for the AC / DC synchronous power grid that needs but cannot be asynchronously partitioned. The method for distinguishing asynchronous partitions of the AC / DC synchronous power grid can determine whether the AC / DC synchronous power grid needs asynchronous partitioning and whether it can be asynchronously partitioned, and provide a reference basis for the planning and construction of the power grid.

[0074] like Figure 3 As shown, in one embodiment of the present invention, the method for determining asynchronous partitions of an AC / DC synchronous power grid includes:

[0075] If the AC-DC ratio index is greater than the first index threshold, the AC-DC synchronous power grid does not perform asynchronous partitioning; or

[0076] If the AC-DC ratio index is between the first index threshold and the second index threshold, and the maximum power angle difference is not greater than the power angle difference threshold, the AC-DC synchronous power grid does not perform asynchronous partitioning.

[0077] It should be noted that, based on the above judgment content, it is judged that the AC / DC synchronous power grid does not need to be asynchronously partitioned.

[0078] In one embodiment of the present invention, controlling the AC / DC synchronous power grid to perform unipolar or bipolar locking according to the maximum DC transmission power includes: determining whether there are stabilization measures for the bipolar locking of the AC / DC synchronous power grid, and if so, determining that the AC / DC synchronous power grid performs unipolar locking; otherwise, determining that the AC / DC synchronous power grid performs bipolar locking.

[0079] It should be noted that the above content is based on the fact that if there are stabilization measures for bipolar interlocking, unipolar interlocking will be performed, and if there are no stabilization measures for bipolar interlocking, bipolar interlocking will be performed.

[0080] In one embodiment of the present invention, after a DC unipolar or bipolar blocking fault occurs in the AC / DC synchronous power grid, the AC / DC synchronous power grid is in a critical stable state, including:

[0081] After a DC unipolar or bipolar blocking fault occurs in the AC / DC synchronous grid, if the AC / DC synchronous grid is stable, the output of the units in the first grid area is increased and the output of the units in the second grid area is reduced until the AC / DC synchronous grid is in a critical stable state; or

[0082] After a DC unipolar or bipolar blocking fault occurs in the AC / DC synchronous grid, if the AC / DC synchronous grid is unstable, the output of the units in the first grid area is reduced, and the output of the units in the second grid area is increased until the AC / DC synchronous grid is in a critical stable state.

[0083] It should be noted that if the AC / DC synchronous grid is stable after a DC unipolar or bipolar blocking fault, the output of the units in the first grid area A is increased and the output of the units in the second grid area B is reduced, so that the total AC transmission power P acsum Increase; if the AC / DC synchronous grid loses stability after a DC unipolar or bipolar blocking fault, the output of the units in the first grid area A is reduced, and the output of the units in the second grid area B is increased, so that the total AC transmission power P acsum Reduce until the AC / DC synchronous power grid is critically stable after DC blocking, and the total AC transmission power P at this time acsum Denoted as P accritical , and at the same time obtain the maximum power angle difference of all units in the first power grid area A and the second power grid area B at this time.

[0084] Embodiment 2:

[0085] Figure 4 It is a framework diagram of an AC / DC synchronous power grid asynchronous partition identification device according to an embodiment of the present invention.

[0086] like Figure 4 As shown, an embodiment of the present invention further provides an AC / DC synchronous power grid asynchronous partition determination device, which is applied to an AC / DC synchronous power grid, the AC / DC synchronous power grid includes a first power grid area and a second power grid area, and the AC / DC synchronous power grid asynchronous partition determination device includes a first data module 10, a second data module 20, a third data module 30 and a determination module 40;

[0087] The first data module 10 is used for obtaining the DC transmission power and AC transmission power of n transmissions between the first power grid area and the second power grid area when the first power grid area and the second power grid area are in a rated power operation state, and determining the total DC transmission power and the total AC transmission power between the first power grid area and the second power grid area according to the n DC transmission powers and AC transmission powers;

[0088] The second data module 20 is used to screen out the maximum DC transmission power from the n DC transmission powers, and control the AC / DC synchronous power grid to perform unipolar or bipolar blocking according to the maximum DC transmission power. If the AC / DC synchronous power grid is in a critical stable state after a DC unipolar or bipolar blocking fault, the AC / DC synchronous power grid is obtained as the AC transmission total power critical value and the maximum power angle difference of all units in the first power grid area and the second power grid area.

[0089] The third data module 30 is used to determine the AC-DC ratio index of the AC-DC synchronous power grid according to the AC transmission total power critical value and the DC transmission total power;

[0090] The judgment module 40 is used to judge whether the AC / DC synchronous power grid enters an asynchronous partition when the AC / DC ratio index is less than the first index threshold; or whether the AC / DC synchronous power grid enters an asynchronous partition when the AC / DC ratio index is between the first index threshold and the second index threshold and the maximum power angle difference is greater than the power angle difference threshold;

[0091] The judgment of AC / DC synchronous power grid entering asynchronous partition includes:

[0092] Acquiring first operating data of a first power grid area and acquiring second operating data of a second power grid area;

[0093] If the first operation data and the second operation data satisfy the constraint condition, asynchronously partitioning the AC / DC synchronous power grid;

[0094] Both the first operating data and the second operating data include: the maximum power loss of a single component, the total capacity of the unit at startup, the unit's primary frequency regulation capability data, the load's primary frequency regulation capability data and the DC FLC regulation capability data.

[0095] In the embodiment of the present application, the constraint conditions include four discrimination conditions, including the first discrimination condition, the second discrimination condition, the third discrimination condition and the fourth discrimination condition; the first discrimination condition is that the maximum power loss of a single element in the first power grid area is less than 0.2 times the total capacity of the units in the first power grid area; the second discrimination condition is that the maximum power loss of a single element in the first power grid area is less than the first total capacity data; the third discrimination condition is that the maximum power loss of a single element in the second power grid area is less than 0.2 times the total capacity of the units in the second power grid area; the fourth discrimination condition is that the maximum power loss of a single element in the second power grid area is less than the second total capacity data. Among them, the first total capacity data is obtained by summing up the primary frequency regulation capacity data of the units in the first power grid area, the primary frequency regulation capacity data of the loads and the DC FLC regulation capacity data; the second total capacity data is obtained by summing up the primary frequency regulation capacity data of the units in the second power grid area, the primary frequency regulation capacity data of the loads and the DC FLC regulation capacity data.

[0096] In the embodiment of the present application, after a DC unipolar or bipolar blocking fault occurs in the AC / DC synchronous power grid, the second data module 20 includes a system stability processing submodule and a system instability processing submodule;

[0097] The system stability processing submodule is used to increase the output of the units in the first grid area and reduce the output of the units in the second grid area according to the AC / DC synchronous grid being stable, until the AC / DC synchronous grid is in a critical stable state;

[0098] The system instability processing submodule is used to reduce the output of the units in the first grid area and increase the output of the units in the second grid area according to the instability of the AC / DC synchronous grid, until the AC / DC synchronous grid is in a critical stable state.

[0099] It should be noted that the modules in the device of Example 2 correspond to the steps in the method of Example 1. The content of the method for determining asynchronous partitions of AC / DC synchronous power grids has been described in detail in Example 1, and the content of the modules in the device will not be described in detail in this Example 2.

[0100] Embodiment three:

[0101] An embodiment of the present invention provides a terminal device, including a processor and a memory;

[0102] A memory, used for storing program codes and transmitting the program codes to a processor;

[0103] The processor is used to execute the above-mentioned method for distinguishing asynchronous partitions of AC and DC synchronous power grids according to instructions in the program code.

[0104] It should be noted that the processor is used to execute the steps in the above-mentioned embodiment of the method for distinguishing asynchronous partitions of an AC / DC synchronous power grid according to the instructions in the program code. Alternatively, the processor implements the functions of each module / unit in the above-mentioned system / device embodiments when executing the computer program.

[0105] Exemplarily, the computer program may be divided into one or more modules / units, one or more modules / units are stored in a memory and executed by a processor to complete the present application. One or more modules / units may be a series of computer program instruction segments capable of completing a specific function, and the instruction segments are used to describe the execution process of the computer program in a terminal device.

[0106] The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The terminal device may include, but is not limited to, a processor and a memory. Those skilled in the art will appreciate that this does not constitute a limitation on the terminal device, and may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal device may also include input and output devices, network access devices, buses, etc.

[0107] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0108] The memory can be an internal storage unit of the terminal device, such as a hard disk or memory of the terminal device. The memory can also be an external storage device of the terminal device, such as a plug-in hard disk equipped on the terminal device, a SmartMedia Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. Furthermore, the memory can also include both the internal storage unit of the terminal device and the external storage device. The memory is used to store computer programs and other programs and data required by the terminal device. The memory can also be used to temporarily store data that has been output or is to be output.

[0109] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0110] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0111] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0112] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0113] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0114] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for distinguishing asynchronous partitions of an AC / DC synchronous power grid, applied to an AC / DC synchronous power grid, wherein the AC / DC synchronous power grid includes a first power grid area and a second power grid area, and is characterized in that: The method for determining asynchronous partitions of an AC / DC synchronous power grid comprises the following steps: The first power grid area and the second power grid area are in a rated power operation state, obtaining a DC transmission power and an AC transmission power transmitted n times between the first power grid area and the second power grid area, and determining a total DC transmission power and a total AC transmission power between the first power grid area and the second power grid area according to the n DC transmission powers and the AC transmission powers; Screening out the maximum DC transmission power from the n DC transmission powers, controlling the AC / DC synchronous power grid to perform unipolar or bipolar blocking according to the maximum DC transmission power, and if the AC / DC synchronous power grid is in a critical stable state after a DC unipolar or bipolar blocking failure, obtaining the total AC transmission power at this time as the critical value of the total AC transmission power and the maximum power angle difference of all units in the first power grid area and the second power grid area; Determine an AC-DC ratio index of the AC-DC synchronous power grid according to the AC transmission total power critical value and the DC transmission total power; If the AC-DC ratio index is less than the first index threshold, the AC-DC synchronous power grid enters the asynchronous partition judgment; or if the AC-DC ratio index is between the first index threshold and the second index threshold, and the maximum power angle difference is greater than the power angle difference threshold, the AC-DC synchronous power grid enters the asynchronous partition judgment; Wherein, the judgment that the AC / DC synchronous power grid enters an asynchronous partition includes: Acquiring first operating data of the first power grid area and acquiring second operating data of the second power grid area; If the first operating data and the second operating data satisfy the constraint condition, asynchronously partitioning the AC / DC synchronous power grid; The first operation data and the second operation data both include: the maximum power loss of a single component, the total capacity of the unit at startup, the unit primary frequency regulation capability data, the load primary frequency regulation capability data and the DC FLC regulation capability data; The constraint condition includes four discrimination conditions, including a first discrimination condition, a second discrimination condition, a third discrimination condition and a fourth discrimination condition; the first discrimination condition is that the maximum power loss of a single element in the first power grid area is less than 0.2 times the total capacity of the units in the first power grid area that are turned on; the second discrimination condition is that the maximum power loss of a single element in the first power grid area is less than the first total capacity data; the third discrimination condition is that the maximum power loss of a single element in the second power grid area is less than 0.2 times the total capacity of the units in the second power grid area that are turned on; the fourth discrimination condition is that the maximum power loss of a single element in the second power grid area is less than the second total capacity data; Among them, the first total capacity data is obtained by summing up the primary frequency regulation capability data of the units, the primary frequency regulation capability data of the loads and the DC FLC regulation capability data of the first power grid area; the second total capacity data is obtained by summing up the primary frequency regulation capability data of the units, the primary frequency regulation capability data of the loads and the DC FLC regulation capability data of the second power grid area.

2. The method for determining asynchronous partitions of an AC / DC synchronous power grid according to claim 1, characterized in that: include: If the first operating data and the second operating data do not meet any of the judgment conditions in the constraints, the total capacity or total capability data of the first power grid area and / or the second power grid area is increased until the modified first operating data and the second operating data meet the constraints.

3. The method for determining asynchronous partitions of an AC / DC synchronous power grid according to claim 1, characterized in that: include: If the AC-DC ratio index is greater than the first index threshold, the AC-DC synchronous power grid does not perform asynchronous partitioning; or If the AC-DC ratio index is between the first index threshold and the second index threshold, and the maximum power angle difference is not greater than the power angle difference threshold, the AC-DC synchronous power grid does not perform asynchronous partitioning.

4. The method for determining asynchronous partitions of an AC / DC synchronous power grid according to claim 1, characterized in that: Controlling the AC / DC synchronous power grid to perform unipolar or bipolar locking according to the maximum DC transmission power includes: determining whether there are stabilization measures for the bipolar locking of the AC / DC synchronous power grid, and if so, determining that the AC / DC synchronous power grid performs unipolar locking; otherwise, determining that the AC / DC synchronous power grid performs bipolar locking.

5. The method for distinguishing asynchronous partitions of an AC / DC synchronous power grid according to claim 1, characterized in that: After a DC unipolar or bipolar blocking fault occurs in the AC / DC synchronous power grid, the AC / DC synchronous power grid is in a critical stable state, including: After a DC unipolar or bipolar blocking fault occurs in the AC / DC synchronous grid, if the AC / DC synchronous grid is stable, increasing the output of the units in the first grid area and reducing the output of the units in the second grid area until the AC / DC synchronous grid is in a critical stable state; or After a DC unipolar or bipolar blocking fault occurs in the AC / DC synchronous power grid, if the AC / DC synchronous power grid is unstable, the output of the units in the first power grid area is reduced, and the output of the units in the second power grid area is increased until the AC / DC synchronous power grid is in a critical stable state.

6. An AC / DC synchronous power grid asynchronous partition identification device, applied to an AC / DC synchronous power grid, the AC / DC synchronous power grid comprising a first power grid area and a second power grid area, characterized in that: The AC / DC synchronous power grid asynchronous partition determination device comprises a first data module, a second data module, a third data module and a determination module; The first data module is used for obtaining the DC transmission power and AC transmission power transmitted n times between the first grid area and the second grid area when the first grid area and the second grid area are in a rated power operation state, and determining the total DC transmission power and the total AC transmission power between the first grid area and the second grid area according to the n DC transmission powers and the AC transmission powers; The second data module is used to filter out the maximum DC transmission power from the n DC transmission powers, control the AC / DC synchronous power grid to perform unipolar or bipolar blocking according to the maximum DC transmission power, and if the AC / DC synchronous power grid is in a critical stable state after a DC unipolar or bipolar blocking failure, obtain the AC transmission total power at this time as the AC transmission total power critical value and the maximum power angle difference of all units in the first power grid area and the second power grid area; The third data module is used to determine the AC-DC ratio index of the AC-DC synchronous power grid according to the AC transmission total power critical value and the DC transmission total power; The judgment module is used to judge whether the AC / DC synchronous power grid enters an asynchronous partition according to the AC / DC ratio index being less than the first index threshold; or whether the AC / DC synchronous power grid enters an asynchronous partition according to the AC / DC ratio index being between the first index threshold and the second index threshold, and the maximum power angle difference being greater than the power angle difference threshold; Wherein, the judgment that the AC / DC synchronous power grid enters an asynchronous partition includes: Acquiring first operating data of the first power grid area and acquiring second operating data of the second power grid area; If the first operating data and the second operating data satisfy the constraint condition, asynchronously partitioning the AC / DC synchronous power grid; The first operation data and the second operation data both include: the maximum power loss of a single component, the total capacity of the unit at startup, the unit primary frequency regulation capability data, the load primary frequency regulation capability data and the DC FLC regulation capability data; The constraint condition includes four discrimination conditions, including a first discrimination condition, a second discrimination condition, a third discrimination condition and a fourth discrimination condition; the first discrimination condition is that the maximum power loss of a single element in the first power grid area is less than 0.2 times the total capacity of the units in the first power grid area that are turned on; the second discrimination condition is that the maximum power loss of a single element in the first power grid area is less than the first total capacity data; the third discrimination condition is that the maximum power loss of a single element in the second power grid area is less than 0.2 times the total capacity of the units in the second power grid area that are turned on; the fourth discrimination condition is that the maximum power loss of a single element in the second power grid area is less than the second total capacity data; Among them, the first total capacity data is obtained by summing up the primary frequency regulation capability data of the units, the primary frequency regulation capability data of the loads and the DC FLC regulation capability data of the first power grid area; the second total capacity data is obtained by summing up the primary frequency regulation capability data of the units, the primary frequency regulation capability data of the loads and the DC FLC regulation capability data of the second power grid area.

7. The device for distinguishing asynchronous partitions of an AC / DC synchronous power grid according to claim 6, characterized in that: After a DC unipolar or bipolar blocking fault occurs in the AC / DC synchronous power grid, the second data module includes a system stability processing submodule and a system instability processing submodule; The system stability processing submodule is used to increase the output of the units in the first grid area and reduce the output of the units in the second grid area according to the AC / DC synchronous grid being stable, until the AC / DC synchronous grid is in a critical stable state; The system instability processing submodule is used to reduce the unit output in the first grid area and increase the unit output in the second grid area according to the AC / DC synchronous grid being unstable, until the AC / DC synchronous grid is in a critical stable state.

8. A terminal device, characterized in that: including a processor and a memory; The memory is used to store program codes and transmit the program codes to the processor; The processor is used to execute the method for determining asynchronous partitions of an AC / DC synchronous power grid according to any one of claims 1 to 5 according to the instructions in the program code.

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