Power grid partitioning method, device and equipment based on frequency drop rate and medium

Abstract

The invention relates to the technical field of power system frequency modulation, in particular to a power grid partitioning method, device and equipment based on a frequency drop rate and a medium, and the method comprises the steps: obtaining the distribution of disturbance power among different generators at a 0 + moment according to a power grid power disturbance site and a synchronous torque coefficient of a synchronous generator node; according to the rotor motion equation of the generator, the initial decline rate of the rotor frequency of each generator is obtained by combining the inertia distribution of the generator; solving a time derivative by combining a frequency divider formula for estimating the frequency distribution of the whole network to obtain the frequency drop rate distribution of nodes of the whole network, and calculating the frequency drop rate of each node by taking the nodes of the synchronous generator as boundaries; and performing clustering calculation by taking the frequency drop rate of each node as a characteristic to obtain a power grid partition based on the frequency drop rate. According to the method, partitioning is carried out according to the initial frequency drop rate of the nodes, and the method has certain guiding significance on frequency distribution calculation of the power grid and partition frequency adjustment.

Description

Technical Field

[0001] The present invention relates to the technical field of power system frequency regulation, and in particular to a method, device, equipment and medium for power grid partitioning based on frequency drop rate. Background Art

[0002] In recent years, the power generation of renewable energy in the power grid has grown rapidly, the power of DC transmission outside the region has continued to increase, the proportion of wind and solar new energy and inter-regional DC and other inertia-free power sources has gradually increased, the proportion of a large number of conventional units has decreased, the startup mode has become smaller, the maximum inertia and real-time inertia levels of the power system have shown a continuous downward trend, the frequency response characteristics have gradually changed, and the system's anti-disturbance ability has rapidly decreased.

[0003] How to accurately characterize the inertia distribution and frequency response characteristics of new power systems, accurately identify the virtual inertia level of new equipment such as new energy / energy storage, evaluate the inertia demand and safety risks of the power grid, and achieve comprehensive defense of power grid frequency security has become an important issue that the current power grid needs to solve urgently.

[0004] The frequency dynamic process of the dual-high system is quite different from that of the traditional power system, and the frequency distribution phenomenon cannot be ignored. Taking the frequency distribution into account, in order to facilitate the calculation and frequency regulation operation, the frequency partitioning of the power grid has become a further research content. Based on the principle that the frequency characteristics within the partition are basically consistent and the frequency characteristics between the partitions are different, the method of power grid partitioning is studied, and reasonable power grid partitioning is carried out to reflect the differences in frequency characteristics in different regions, providing a basis for the evaluation of power grid partition equivalence and safety domain.

[0005] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Summary of the invention

[0006] The present invention provides a method, device, equipment and medium for power grid partitioning based on frequency drop rate, thereby effectively solving the problems in the background technology.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is: a power grid partitioning method based on frequency drop rate, comprising the following steps:

[0008] According to the power disturbance location of the power grid and the synchronous torque coefficient of the synchronous generator node, the distribution of the disturbance power among different generators at time 0+ is obtained;

[0009] According to the rotor motion equation of the generator, combined with the inertia distribution of the generator and the distribution of the disturbance power, the initial drop rate of the rotor frequency of each generator is obtained;

[0010] Combined with the frequency divider formula for estimating the frequency distribution of the entire network, the time derivative is calculated, and the frequency reduction rate distribution of the nodes of the entire network is obtained according to the initial reduction rate of the rotor frequency of each generator. The frequency reduction rate of each node is calculated with the synchronous generator node as the boundary.

[0011] The frequency drop rate of each node is used as a feature, and clustering calculation is performed to obtain the power grid partition based on the frequency drop rate.

[0012] Furthermore, the method of obtaining the distribution of the disturbance power among different generators at time 0+ includes:

[0013] At the 0+ moment, due to the rotor inertia of the generator, its power angle will not change instantaneously, then:

[0014] δ ikΔ =δ iΔ -δ kΔ =-δ kΔ (0 + );

[0015] δ ikΔ is the phase angle difference between generator node i and disturbance point k, δ iΔ is the phase angle of generator node i, δ kΔ is the phase angle of the disturbance point k, δ kΔ (0 + ) is the phase angle mutation of the disturbance point k at time 0+;

[0016] For the disturbance point k, the electromagnetic power increment P borne by each generator at time 0+ iΔ (0 + ) and load power mutation P LΔ (0 + ) is:

[0017]

[0018] Furthermore, the initial drop rate of the rotor frequency of each generator is obtained according to the rotor motion equation of the generator in combination with the inertia distribution and the disturbance power distribution of the generator, including:

[0019]

[0020] Where P iΔ (0 + ) is the change in electromagnetic power borne by the i-th generator node at the moment of disturbance 0+, δ ikΔ (0 + ), δ ijΔ (0 + ) are the phase angle difference between generator node i and disturbance point k, and the phase angle difference between generator node i and generator node j at time 0+, n is the number of generators; ksik , k sij They are the synchronous torque coefficients of generator node i and disturbance point k, and the synchronous torque coefficients of generator node i and generator node j, respectively. Their expressions are:

[0021]

[0022] Where U k , E i is the voltage of node k and the internal potential of generator i, B ik , B ij is the susceptance between nodes i and j, and between i and k;

[0023] The phase angle of the disturbance point k changes suddenly to:

[0024]

[0025] The relationship between the power allocated to each generator and the synchronous torque coefficient is:

[0026]

[0027] According to the rotor motion equation of the generator:

[0028]

[0029] In the formula, ω i is the generator angular frequency, T Ji is the generator inertia, P mi ,P ei is the mechanical power and electromagnetic power of the generator, D i for generator damping;

[0030] At the beginning of the disturbance, the mechanical power and speed of the engine did not change suddenly. The difference between the mechanical power and electromagnetic power terms in the rotor motion equation is the change in electromagnetic power, and the damping term is zero, so:

[0031]

[0032] Furthermore, the frequency divider formula for estimating the frequency distribution of the entire network is combined, and its time derivative is calculated to obtain the frequency drop rate distribution of the nodes in the entire network, including:

[0033] According to the divider formula, the relationship between the frequency distribution of the nodes in the entire network and the generator frequency is:

[0034] Δω B =DΔω G ;

[0035] In the formula, ω B is the node voltage frequency in the system, ω SGis the synchronous machine rotor frequency, and the matrix D is determined by the admittance matrix of the network, and its derivative is:

[0036]

[0037] Combined with the formula for the initial frequency drop rate of the generator, we can get:

[0038]

[0039] In the formula, is the initial frequency drop rate of the node, H is a column vector of length n, P LΔ (0 + ) is the load power mutation amount at time 0+.

[0040] Furthermore, the frequency drop rate of each node is obtained by calculation, including:

[0041] For a column vector H of length n, its i-th item is:

[0042]

[0043] The initial frequency drop rate of the mth node is:

[0044]

[0045] In the formula, is the initial frequency drop rate of the mth node, k sik is the synchronous torque coefficient between generator node i and disturbance point k, T Ji is the generator inertia.

[0046] Furthermore, the clustering calculation is performed based on the frequency drop rate of each node, including:

[0047] Step 1: Set the number of clusters K and initially select K centroids;

[0048] Step 2: Calculate the distance between each node and the centroid based on the Euclidean distance, and assign the node to the cluster corresponding to the nearest centroid;

[0049] Step 3: Recalculate the centroid position of each cluster, that is, the average of the frequency drop rates of all nodes in the cluster;

[0050] Step 4: Repeat steps 2 and 3 until the centroid position no longer changes or convergence conditions are reached, and output the partitions of each node in the power grid.

[0051] The present invention also includes a power grid partitioning device based on the frequency drop rate, using the above method, the partitioning device includes:

[0052] The disturbance power distribution calculation unit is used to obtain the distribution of the disturbance power among different generators at time 0+ according to the power grid power disturbance location and the synchronous torque coefficient of the synchronous generator node;

[0053] An initial descent rate calculation unit is used to obtain the initial descent rate of each generator rotor frequency according to the rotor motion equation of the generator, combined with the inertia distribution of the generator and the distribution of the disturbance power;

[0054] A frequency drop rate calculation unit is used to combine the frequency divider formula for estimating the frequency distribution of the whole network, calculate the time derivative thereof, obtain the frequency drop rate distribution of the nodes of the whole network according to the initial drop rate of each generator rotor frequency, and calculate the frequency drop rate of each node with the synchronous generator node as the boundary;

[0055] The partition unit is used to perform clustering calculation based on the frequency drop rate of each node to obtain the power grid partition based on the frequency drop rate.

[0056] The present invention also includes a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method described above is implemented.

[0057] The present invention also includes a storage medium on which a computer program is stored. When the computer program is executed by a processor, the method described above is implemented.

[0058] The beneficial effects of the present invention are as follows: the present invention partitions the system according to the initial frequency drop rate of the node based on the principle that the frequency within the partition is consistent and the frequency between the partitions is different. First, the rotor frequency drop rate is determined by distributing the disturbance power among the synchronous machines in combination with the inertia distribution of the synchronous machines. Secondly, the initial frequency drop rate distribution of the nodes in the system is obtained by the frequency divider method, and then clustering calculation is performed to obtain the partitioning scheme of the power grid. The present invention has certain guiding significance for the frequency distribution calculation of the power grid and the frequency adjustment of the partitions. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] 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 recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0060] Figure 1 is a flow chart of the method in Example 1;

[0061] Figure 2 It is a structural schematic diagram of the device in Example 1;

[0062] Figure 3 This is a schematic diagram of power grid partitioning in Example 2;

[0063] Figure 4 A schematic diagram of the structure of a computer device. DETAILED DESCRIPTION

[0064] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0065] Embodiment 1:

[0066] like Figure 1 As shown: A power grid partitioning method based on frequency drop rate includes the following steps:

[0067] According to the power disturbance location of the power grid and the synchronous torque coefficient of the synchronous generator node, the distribution of the disturbance power among different generators at time 0+ is obtained;

[0068] According to the rotor motion equation of the generator, combined with the inertia distribution of the generator and the distribution of the disturbance power, the initial drop rate of the rotor frequency of each generator is obtained;

[0069] Combined with the frequency divider formula for estimating the frequency distribution of the entire network, the time derivative is calculated, and the frequency reduction rate distribution of the nodes of the entire network is obtained according to the initial reduction rate of the rotor frequency of each generator. The frequency reduction rate of each node is calculated with the synchronous generator node as the boundary.

[0070] The frequency drop rate of each node is used as a feature, and clustering calculation is performed to obtain the power grid partition based on the frequency drop rate.

[0071] Based on the principle that the frequency within the partition is consistent and the frequency between the partitions is different, the partition is performed according to the initial frequency drop rate of the node. First, the rotor frequency drop rate is determined by the distribution of the disturbance power among the synchronous machines and the inertia distribution of the synchronous machines. Secondly, the initial frequency drop rate distribution of the nodes in the system is obtained by the frequency divider method, and then clustering calculation is performed to obtain the partition scheme of the power grid. This embodiment has certain guiding significance for the frequency distribution calculation of the power grid and the frequency adjustment of the partition.

[0072] In this embodiment, the distribution of disturbance power among different generators at time 0+ is obtained, including:

[0073] At the 0+ moment, due to the rotor inertia of the generator, its power angle will not change instantaneously, then:

[0074] δ ikΔ =δ iΔ -δ kΔ =-δkΔ (0 + );

[0075] δ ikΔ is the phase angle difference between generator node i and disturbance point k, δ iΔ is the phase angle of generator node i, δ kΔ is the phase angle of the disturbance point k, δ kΔ (0 + ) is the phase angle mutation of the disturbance point k at time 0+;

[0076] For the disturbance point k, the electromagnetic power increment P borne by each generator at time 0+ iΔ (0 + ) and load power mutation P LΔ (0 + ) is:

[0077]

[0078] According to the rotor motion equation of the generator, combined with the inertia distribution of the generator and the distribution of the disturbance power, the initial drop rate of the rotor frequency of each generator is obtained, including:

[0079]

[0080] Where P iΔ (0 + ) is the change in electromagnetic power borne by the i-th generator node at the moment of disturbance 0+, δ ikΔ (0 + ), δ ijΔ (0 + ) are the phase angle difference between generator node i and disturbance point k, and the phase angle difference between generator node i and generator node j at time 0+, n is the number of generators; k sik , k sij They are the synchronous torque coefficients of generator node i and disturbance point k, and the synchronous torque coefficients of generator node i and generator node j, respectively. Their expressions are:

[0081]

[0082] Where U k , E i is the voltage of node k and the internal potential of generator i, B ik , B ij is the susceptance between nodes i and j, and between i and k;

[0083] The phase angle of the disturbance point k changes suddenly to:

[0084]

[0085] The relationship between the power allocated to each generator and the synchronous torque coefficient is:

[0086]

[0087] According to the rotor motion equation of the generator:

[0088]

[0089] In the formula, ω i is the generator angular frequency, T Ji is the generator inertia, P mi ,P ei is the mechanical power and electromagnetic power of the generator, D i for generator damping;

[0090] At the beginning of the disturbance, the mechanical power and speed of the engine did not change suddenly. The difference between the mechanical power and electromagnetic power terms in the rotor motion equation is the change in electromagnetic power, and the damping term is zero, so:

[0091]

[0092] Among them, combined with the frequency divider formula for estimating the frequency distribution of the entire network, the time derivative is calculated to obtain the frequency drop rate distribution of the nodes in the entire network, including:

[0093] According to the divider formula, the relationship between the frequency distribution of the nodes in the entire network and the generator frequency is:

[0094] Δω B =DΔω G ;

[0095] In the formula, ω B is the node voltage frequency in the system, ω SG is the synchronous machine rotor frequency, and the matrix D is determined by the admittance matrix of the network, and its derivative is:

[0096]

[0097] Combined with the formula for the initial frequency drop rate of the generator, we can get:

[0098]

[0099] In the formula, is the initial frequency drop rate of the node, H is a column vector of length n, P LΔ (0 + ) is the load power mutation amount at time 0+.

[0100] As a preferred embodiment of the above, the frequency drop rate of each node is calculated, including:

[0101] For a column vector H of length n, its i-th item is:

[0102]

[0103] The initial frequency drop rate of the mth node is:

[0104]

[0105] In the formula, is the initial frequency drop rate of the mth node, k sik is the synchronous torque coefficient between generator node i and disturbance point k, T Ji is the generator inertia.

[0106] In this embodiment, clustering calculation is performed based on the frequency drop rate of each node, including:

[0107] Step 1: Set the number of clusters K and initially select K centroids;

[0108] Step 2: Calculate the distance between each node and the centroid based on the Euclidean distance, and assign the node to the cluster corresponding to the nearest centroid;

[0109] Step 3: Recalculate the centroid position of each cluster, that is, the average of the frequency drop rates of all nodes in the cluster;

[0110] Step 4: Repeat steps 2 and 3 until the centroid position no longer changes or convergence conditions are reached, and output the partitions of each node in the power grid.

[0111] like Figure 2 As shown, this embodiment also includes a power grid partitioning device based on the frequency drop rate. Using the above method, the partitioning device includes:

[0112] The disturbance power distribution calculation unit is used to obtain the distribution of the disturbance power among different generators at time 0+ according to the power grid power disturbance location and the synchronous torque coefficient of the synchronous generator node;

[0113] An initial descent rate calculation unit is used to obtain the initial descent rate of each generator rotor frequency according to the rotor motion equation of the generator, combined with the inertia distribution of the generator and the distribution of the disturbance power;

[0114] A frequency drop rate calculation unit is used to combine the frequency divider formula for estimating the frequency distribution of the whole network, calculate the time derivative thereof, obtain the frequency drop rate distribution of the nodes of the whole network according to the initial drop rate of each generator rotor frequency, and calculate the frequency drop rate of each node with the synchronous generator node as the boundary;

[0115] The partition unit is used to perform clustering calculation based on the frequency drop rate of each node to obtain the power grid partition based on the frequency drop rate.

[0116] Embodiment 2:

[0117] This embodiment provides a power grid partitioning method based on frequency drop rate, including:

[0118] (1) According to the location of the power disturbance in the power grid and the synchronous torque coefficient of the synchronous generator node, the distribution of the disturbance power among different generators at time 0+ is obtained; further, according to the rotor motion equation of the generator, combined with the inertia distribution of the generator and the distribution of the disturbance power, the initial decrease rate of the rotor frequency of each generator is obtained.

[0119] Assume that there are n generators in the system. When a power disturbance occurs at node k, the electromagnetic power change P borne by the i-th generator node at the moment of disturbance is 0+ iΔ (0 + )for:

[0120]

[0121] Among them, δ ikΔ (0 + ), δ ijΔ (0 + ) are the phase angle difference between generator node i and disturbance point k, and the phase angle difference between generator node i and generator node j at time 0+, k sik , k sij They are the synchronous torque coefficients of generator node i and disturbance point k, and the synchronous torque coefficients of generator node i and generator node j, respectively. Their expressions are:

[0122]

[0123] Among them, U k , E i is the voltage of node k and the internal potential of generator i, B ik , B ij is the susceptance between nodes i and j, and between i and k. At time 0+, due to the rotor inertia of the generator, its power angle will not change instantaneously:

[0124] δ iΔ =0,δ ijΔ =0;

[0125] Therefore, there are:

[0126] δ ikΔ =δ iΔ -δ kΔ =-δ kΔ (0 + );

[0127] For the disturbance point k, the power P borne by each generator iΔ (0 + ) and load power mutation P LΔ (0 + ) is:

[0128]

[0129] The phase angle mutation of the k-node is obtained as follows:

[0130]

[0131] Combining the two equations, we get the relationship between the power allocated to each generator and the synchronous torque coefficient:

[0132]

[0133] From the above formula, it can be obtained that the closer the electrical distance between the generator and the disturbance point, the smaller the initial angle difference, and the greater the sharing of the disturbance power.

[0134] The rotor motion equation of the generator is:

[0135]

[0136] Among them, ω i is the generator angular frequency, T Ji is the generator inertia, P mi ,P ei is the mechanical power and electromagnetic power of the generator, D i is the generator damping. At the beginning of the disturbance, the mechanical power and speed of the engine do not change suddenly. The difference between the mechanical power and electromagnetic power terms in the rotor motion equation is the change in electromagnetic power, and the damping term is zero, so:

[0137]

[0138] (2) Combined with the frequency divider formula for estimating the frequency distribution of the entire network, the time derivative is calculated to obtain the frequency drop rate distribution of the nodes in the entire network. Taking the synchronous machine as the boundary, the frequency drop rate expression of each node is calculated.

[0139] According to the divider formula, the relationship between the frequency distribution of the nodes in the entire network and the generator frequency is:

[0140] Δω B =DΔω G ;

[0141] ω B is the node voltage frequency in the system, ω SGis the synchronous machine rotor frequency, and the matrix D is determined by the admittance matrix of the network. Derivative:

[0142]

[0143] Combined with the formula for the initial frequency drop rate of the generator, we can get:

[0144]

[0145] Where H is a column vector of length n, and its i-th item is:

[0146]

[0147] Thus, the initial frequency drop rate of the mth node is:

[0148]

[0149] (3) According to the characteristic of frequency drop rate, cluster calculation is performed to obtain a power grid partitioning scheme based on frequency drop rate.

[0150] Figure 3 It is a schematic diagram of the power grid partition in the present invention. It can be seen that in the partition scheme obtained according to this method, the three areas are:

[0151] Region 1: nodes 1, 2, 3, 9, 17, 18, 25, 26, 27, 30, 37, 39;

[0152] Region 2: nodes 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16, 19, 20, 21, 22, 23, 24, 31, 32, 33, 34, 35, 36;

[0153] Region 3: Nodes 28, 29, 38.

[0154] This embodiment provides a method for power grid partitioning based on frequency drop rate. The method includes: partitioning according to the initial frequency drop rate (RoCof) of the node based on the characteristics of the frequency curve after the disturbance, with the principle that the frequency within the partition is consistent and the frequency between the partitions is different. First, the rotor frequency drop rate is determined by distributing the disturbance power among the synchronous machines in combination with the inertia distribution of the synchronous machines. Secondly, the initial frequency drop rate distribution of the nodes in the system is obtained by the divider method, and then clustering calculation is performed to obtain the partitioning scheme of the power grid. The present invention has certain guiding significance for the frequency distribution calculation of the power grid and the frequency regulation of the partitions.

[0155] See also Figure 4A computer device 400 provided in an embodiment of the present application includes: a processor 410 and a memory 420, wherein the memory 420 stores a computer program executable by the processor 410, and when the computer program is executed by the processor 410, the above method is executed.

[0156] The embodiment of the present application further provides a storage medium 430 on which a computer program is stored. When the computer program is run by the processor 410, the above method is executed.

[0157] Among them, the storage medium 430 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable red-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, disk or optical disk.

[0158] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0159] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0160] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0161] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0162] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0163] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0164] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0165] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for power grid partitioning based on frequency drop rate, characterized in that: The steps include: According to the power disturbance location of the power grid and the synchronous torque coefficient of the synchronous generator node, the distribution of the disturbance power among different generators at time 0+ is obtained; According to the rotor motion equation of the generator, combined with the inertia distribution of the generator and the distribution of the disturbance power, the initial drop rate of the rotor frequency of each generator is obtained; Combined with the frequency divider formula for estimating the frequency distribution of the entire network, the time derivative is calculated, and the frequency reduction rate distribution of the nodes of the entire network is obtained according to the initial reduction rate of the rotor frequency of each generator. The frequency reduction rate of each node is calculated with the synchronous generator node as the boundary. The frequency drop rate of each node is used as a feature, and clustering calculation is performed to obtain the power grid partition based on the frequency drop rate.

2. The method for power grid partitioning based on frequency drop rate according to claim 1, characterized in that: The method of obtaining the distribution of the disturbance power among different generators at time 0+ includes: At the 0+ moment, due to the rotor inertia of the generator, its power angle will not change instantaneously, then: d ikΔ =d iΔ -d kΔ =-d kΔ (0 + ); δ ikΔ is the phase angle difference between generator node i and disturbance point k, δ iΔ is the phase angle of generator node i, δ kΔ is the phase angle of the disturbance point k, δ kΔ (0 + ) is the phase angle mutation of the disturbance point k at time 0+; For the disturbance point k, the electromagnetic power increment P borne by each generator at time 0+ iΔ (0 + ) and load power mutation P LΔ (0 + ) is:

3. The method for power grid partitioning based on frequency drop rate according to claim 2, characterized in that: The initial drop rate of each generator rotor frequency is obtained according to the rotor motion equation of the generator, combined with the inertia distribution of the generator and the distribution of the disturbance power, including: Where P iΔ (0 + ) is the change in electromagnetic power borne by the i-th generator node at the moment of disturbance 0+, δ ikΔ (0 + ), δ ijΔ (0 + ) are the phase angle difference between generator node i and disturbance point k at time 0+, and the phase angle difference between generator node i and generator node j, n is the number of generators; k sik , k sij They are the synchronous torque coefficients of generator node i and disturbance point k, and the synchronous torque coefficients of generator node i and generator node j, respectively, and their expressions are: k sik =U k E i B ik cosδ ik0 k sij =And i AND j B ij what is it? ij0 ; Where U k , E i is the voltage of node k and the internal potential of generator i, B ik , B ij is the susceptance between nodes i and j, and between i and k; Phase angle mutation at disturbance point k -δ kΔ (0 + )for: The relationship between the power allocated to each generator and the synchronous torque coefficient is: According to the rotor motion equation of the generator: In the formula, ω i is the generator angular frequency, T Ji is the generator inertia, P mi ,P ei is the mechanical power and electromagnetic power of the generator, D i for generator damping; At the beginning of the disturbance, the mechanical power and speed of the engine did not change suddenly. The difference between the mechanical power and electromagnetic power terms in the rotor motion equation is the change in electromagnetic power, and the damping term is zero, so:

4. The method for power grid partitioning based on frequency drop rate according to claim 1, characterized in that: The frequency divider formula for estimating the frequency distribution of the entire network is combined, and the time derivative is calculated to obtain the frequency drop rate distribution of the nodes in the entire network, including: According to the divider formula, the relationship between the frequency distribution of the nodes in the entire network and the generator frequency is: Give B =Dれ G ; In the formula, ω B is the node voltage frequency in the system, ω SG is the synchronous machine rotor frequency, and the matrix D is determined by the admittance matrix of the network, and its derivative is: Combined with the formula for the initial frequency drop rate of the generator, we can get: In the formula, is the initial frequency drop rate of the node, H is a column vector of length n, P LΔ (0 + ) is the load power mutation amount at time 0+.

5. The method for power grid partitioning based on frequency drop rate according to claim 4, characterized in that: The frequency drop rate of each node is obtained by calculation, including: For a column vector H of length n, its i-th item is: The initial frequency drop rate of the mth node is: In the formula, is the initial frequency drop rate of the mth node, k sik is the synchronous torque coefficient between generator node i and disturbance point k, T Ji is the generator inertia.

6. The method for power grid partitioning based on frequency drop rate according to claim 1, characterized in that: The clustering calculation is performed based on the frequency drop rate of each node, including: Step 1: Set the number of clusters K and initially select K centroids; Step 2: Calculate the distance between each node and the centroid based on the Euclidean distance, and assign the node to the cluster corresponding to the nearest centroid; Step 3: Recalculate the centroid position of each cluster, that is, the average of the frequency drop rates of all nodes in the cluster; Step 4: Repeat steps 2 and 3 until the centroid position no longer changes or convergence conditions are reached, and output the partitions of each node in the power grid.

7. A power grid partitioning device based on frequency drop rate, characterized in that: Using the method according to any one of claims 1 to 6, the partitioning device comprises: The disturbance power distribution calculation unit is used to obtain the distribution of the disturbance power among different generators at time 0+ according to the power grid power disturbance location and the synchronous torque coefficient of the synchronous generator node; An initial descent rate calculation unit is used to obtain the initial descent rate of each generator rotor frequency according to the rotor motion equation of the generator, combined with the inertia distribution of the generator and the distribution of the disturbance power; A frequency drop rate calculation unit is used to combine the frequency divider formula for estimating the frequency distribution of the whole network, calculate the time derivative thereof, obtain the frequency drop rate distribution of the nodes of the whole network according to the initial drop rate of each generator rotor frequency, and calculate the frequency drop rate of each node with the synchronous generator node as the boundary; The partition unit is used to perform clustering calculation based on the frequency drop rate of each node to obtain the power grid partition based on the frequency drop rate.

8. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 6 is implemented.

9. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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