Source network load storage integrated distributed control method and device

Abstract

This invention provides a distributed control method and device for integrated power generation, grid, load, and storage. First, it acquires the admittance information and a preset disconnection function of the power system, and uses this to calculate the node voltage of each node when any branch is disconnected, as the first calculation result. Then, based on the first calculation result, it calculates the power flow distribution when a line is disconnected, as the second calculation result. Next, based on the second calculation result, it calculates the power flow distribution when the power supply is interrupted, as the third calculation result. Finally, based on the first, second, and third calculation results, it determines the N-k static security check result of the power system, and performs preventative control of the power system based on the N-k static security check result. By setting corresponding disconnection functions, it deeply analyzes three types of interruption scenarios: branch, line, and power supply, and then extends this to N-k static security check, thereby accurately analyzing the power system's line disconnection problem and effectively implementing preventative control.

Description

Technical Field

[0001] This invention belongs to the field of power grid technology, and in particular relates to a distributed control method and device for the integration of power generation, grid, load and storage. Background Technology

[0002] As the power grid continues to expand, the probability of grid failures also increases. To ensure the safe operation of the power grid and reduce the impact of grid failures on power system operation, finding a method for online static security analysis is crucial. N-1 security checks are one of the most common static security assessment methods, aiming to predict the consequences of accidents by ranking them according to voltage limit violations or transmission power overload levels. Therefore, a set of severe accidents can be identified, aiding subsequent preventative control; essentially, it is a problem of calculating system out-of-circuit power flow.

[0003] Traditional power flow algorithms used for N-1 safety verification in power systems include DC power flow methods, compensation methods, and sensitivity methods. These methods use approximate disconnection power flow algorithms to calculate power system disconnection problems, and using linear calculations to solve nonlinear problems can improve speed. However, significant errors remain in accuracy, and the calculation results can only be used to filter severe faults and the severity of anticipated accidents. Therefore, a secondary, precise calculation is inevitably required for severe faults, and there may be masking phenomena, leading to disordered ranking of anticipated accidents. Summary of the Invention

[0004] In view of this, the present invention provides a distributed control method and device for integrated source-grid-load-storage systems, aiming to solve the problem that the accuracy of safety verification in the existing technology still has a large error.

[0005] A first aspect of this invention provides a distributed control method for integrated source-grid-load-storage systems, comprising:

[0006] Obtain the admittance information and preset disconnection function of the power system, and calculate the node voltage of each node when any branch is disconnected based on the admittance information and disconnection function, as the first calculation result;

[0007] Based on the first calculation result, the power flow distribution when one line is disconnected is calculated equivalently and used as the second calculation result.

[0008] Based on the second calculation result, the power flow distribution when the power is interrupted is calculated as the third calculation result;

[0009] Based on the first calculation result, the second calculation result, and the third calculation result, the static security verification result of Nk of the power system is determined, and preventive control of the power system is carried out based on the static security verification result of Nk.

[0010] In one possible implementation, based on admittance information and a disconnection function, the node voltages of each node when any branch is disconnected are calculated as a first calculation result, including:

[0011] If the admittance of any branch satisfies the disconnect function, the node voltage is expanded into a Taylor series of the disconnect parameter in the disconnect function, and the second derivative is performed to express the node voltage as a third-order Taylor series expansion of the disconnect branch admittance, thus obtaining the first calculation result.

[0012] In one possible implementation, based on the first calculation result, the power flow distribution when one line is disconnected is equivalently calculated and used as the second calculation result, including:

[0013] Based on the first calculation result, calculate the node voltage of each node when the three branches are disconnected;

[0014] The node voltage of each node when the three branches are disconnected is equivalent to the node voltage when one line is disconnected. The power flow distribution is calculated based on the power flow Jacobian matrix and used as the second calculation result.

[0015] In one possible implementation, based on the second calculation result, the power flow distribution during a power outage is calculated as a third calculation result, including:

[0016] Based on the power interruption situation, the initial value of the power flow Jacobian matrix is ​​changed, and the power flow distribution is recalculated to obtain the third calculation result.

[0017] In one possible implementation, the static security verification result of the power system Nk is determined based on the first calculation result, the second calculation result, and the third calculation result, including:

[0018] Based on the first calculation result, the second calculation result, and the third calculation result, the power flow distribution of the power system when any one or more circuits are disconnected is determined, and the static security verification result of Nk is obtained.

[0019] In one possible implementation, preventative control of the power system is performed based on the Nk static security check result:

[0020] The static safety verification results of Nk are sorted according to the degree of voltage limit violation or transmission power overload to obtain the severe incident set;

[0021] Based on the severe incident set, determine the fault control logic of the power system.

[0022] In one possible implementation, the method also includes:

[0023] When the topology of the power system changes, a new disconnect function is selected and the process jumps to the steps of obtaining the power system's admittance information and the preset disconnect function.

[0024] In one possible implementation, the disconnect function is either a linear disconnect function or a nonlinear disconnect function.

[0025] In one possible implementation, the disconnect function is:

[0026] n(λ) = (1-λ) / (1+λ)

[0027] Where n(λ) is the nonlinear disconnection function and λ is the disconnection parameter.

[0028] A second aspect of the present invention provides a distributed control device for integrated source-grid-load-storage systems, comprising:

[0029] The branch analysis module is used to obtain the admittance information and preset disconnection function of the power system, and calculate the node voltage of each node when any branch is disconnected based on the admittance information and disconnection function, as the first calculation result;

[0030] The line analysis module is used to calculate the power flow distribution when a line is disconnected based on the first calculation result, and use it as the second calculation result.

[0031] The power analysis module is used to calculate the power flow distribution when the power is interrupted based on the second calculation result, and use it as the third calculation result;

[0032] The prevention and control module is used to determine the static security verification result of the power system Nk based on the first calculation result, the second calculation result, and the third calculation result, and to perform prevention and control on the power system based on the static security verification result of Nk.

[0033] The distributed control method and apparatus for integrated power generation, grid, load, and storage provided in this invention first acquires the admittance information and preset disconnection functions of the power system. Based on the admittance information and disconnection functions, it calculates the node voltage of each node when any branch is disconnected, as the first calculation result. Then, based on the first calculation result, it calculates the power flow distribution when a line is disconnected, as the second calculation result. Next, based on the second calculation result, it calculates the power flow distribution when the power supply is interrupted, as the third calculation result. Finally, based on the first, second, and third calculation results, it determines the static security verification result Nk of the power system and performs preventative control on the power system based on the Nk static security verification result. By setting corresponding disconnection functions, it deeply analyzes three types of interruption scenarios: branch, line, and power supply, and then extends this analysis to the Nk static security verification, thereby accurately analyzing the power system's line disconnection problem and effectively performing preventative control. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a flowchart illustrating the implementation of a distributed control method for integrated source-grid-load-storage systems provided in an embodiment of the present invention.

[0036] Figure 2 It is the curve of the continuously discontinuous function;

[0037] Figure 3 This is a schematic diagram of a branch disconnected power flow circuit in the DC circuit of the present invention;

[0038] Figure 4 This is a schematic diagram of the km-type equivalent circuit of the power grid disconnection line of the present invention;

[0039] Figure 5 This is a schematic diagram of the IEEE 14-node system architecture of the present invention;

[0040] Figure 6 This is a schematic diagram of the structure of a distributed control device for integrated source-grid-load-storage provided in an embodiment of the present invention. Detailed Implementation

[0041] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0042] Figure 1 This is a flowchart illustrating the implementation of a distributed control method for integrated source-grid-load-storage systems provided in an embodiment of the present invention. Figure 1 As shown, in some embodiments, a distributed control method for integrated source-grid-load-storage systems includes:

[0043] S110: Obtain the admittance information and preset disconnection function of the power system, and calculate the node voltage of each node when any branch is disconnected based on the admittance information and disconnection function, and use it as the first calculation result;

[0044] In this embodiment of the invention, the physical meaning of the disconnection function is the transition method of a branch from normal operation to disconnection, and its function value describes the degree of progress of this process.

[0045] In some embodiments, the disconnect function is a linear disconnect function or a non-linear disconnect function.

[0046] Figure 2 It is the curve of the continuously discontinuous function. For example... Figure 2 As shown, the continuous disconnection function can be set in the following form:

[0047] n(λ)=1-λ (1)

[0048] n(λ)=(1-λ) / (1+λ) (2)

[0049] Obviously, when λ = 0, η(0) = 1, which corresponds to the normal state of the system; when λ = 1, η(1) = 0, which corresponds to the branch being disconnected; using (1-λ) in formula (3), it is a linear disconnection function;

[0050] In formula (4), (1-λ) / (1+λ) is a nonlinear disconnect function; the linear function conforms to the nonlinear relationship of cos(πλ / 2).

[0051] It can be seen that the rules of change for different disconnection functions are different, but their initial and final values ​​are the same; although continuous disconnection can be achieved, it has no practical significance and is only used for curve comparison; the power equation can be derived from the circuit:

[0052] PLD=(10-U)[0.5+0.5η(λ)]U (5)

[0053] Equation (6) can be rearranged into the following form:

[0054] P LD =f(U,λ)=(5U-0.5U) 2 [1+η(λ)] (7)

[0055] As can be seen from formula (8), when λ = 0 to 1, U is a composite function of parameter λ, that is, U = U(η(λ));

[0056] Figure 3 This is a schematic diagram of the branch disconnection power flow circuit in the DC circuit of the present invention. Next, we will analyze... Figure 3 The first branch to be disconnected; assume negative; power is constant, expand voltage U into a Taylor series of parameter λ, and combine it with the nonlinear disconnection function η(λ); taking the second-order Taylor series as an example, take the second derivative of formula (4) with respect to λ, and get:

[0057]

[0058] exist Figure 1 In the case where λ = 0, assuming the initial state of the system is PLD = 9 and U0 = 9, the solution can be obtained using the following formula:

[0059]

[0060] Furthermore, by analogy above, the coefficients a3 of the third-order Taylor series can be obtained;

[0061] Then, the third Taylor series of U is:

[0062]

[0063] In formula (13), if λ = 1, then the disconnect voltage can be obtained immediately:

[0064]

[0065] Specifically, the choice of different disconnection functions η(λ) has a significant impact on the convergence speed of Taylor series;

[0066] Specifically, the impact analysis of the disconnection voltage calculation results under different disconnection functions is shown in Table 1.

[0067] Table 1. The Influence of Two Breakdown Functions on the Convergence Accuracy of Taylor Series

[0068]

[0069]

[0070] It can be seen that when the linear disconnect function (1-λ) is applied, the voltage calculation error reaches 3.73%, which is clearly far from meeting the requirements for accurate calculation. However, after using the nonlinear disconnect function (1-λ) / (1+λ), the voltage accuracy is improved by more than an order of magnitude, and the third-order calculation error is only |Δ|=0.35%. This proves that the choice of disconnect function has a great influence on the accuracy of the calculation results. Therefore, this paper adopts the nonlinear disconnect function in formula (15), which is also the important significance of the nonlinear disconnect function proposed in this paper. In practical systems, especially in large-scale power systems with stronger nonlinear characteristics, there are different requirements for the selection of disconnect function. Subsequent research will focus on how to select a better disconnect function.

[0071] In some embodiments, S110 includes: if the admittance of any branch satisfies the disconnection function, expanding the node voltage into a Taylor series of the disconnection parameter in the disconnection function, and performing second-order differentiation to express the node voltage as a third-order Taylor series expansion of the disconnection branch admittance, thereby obtaining a first calculation result.

[0072] In this embodiment of the invention, the branch parameter is the admittance, and η(λ) is the disconnection function; let λ be the parameter of the branch circuit disconnection process, and the admittance of one branch multiplied by the disconnection function η(λ) means that the branch is about to disconnect; if the branch admittance is zero, the corresponding branch state is disconnected; the continuous variation range of λ is [0,1].

[0073] S120, Based on the first calculation result, the power flow distribution when a line is disconnected is calculated equivalently and used as the second calculation result;

[0074] In some embodiments, S120 includes: calculating the node voltage of each node when the three branches are disconnected based on the first calculation result; converting the node voltage of each node when the three branches are disconnected to the node voltage when one line is disconnected, and calculating the power flow distribution based on the power flow Jacobian matrix as the second calculation result.

[0075] Figure 4 This is a schematic diagram of the km-type equivalent circuit for the power grid disconnection line of the present invention. Figure 4 As shown, in this embodiment of the invention, let the continuous disconnection function be η(λ)=(1-λ) / (1+λ), then the disconnected line is Lk-m; at this time, the π-type equivalent circuit of the disconnected line; disconnecting one line is equivalent to disconnecting three branches at the same time, and the admittance of each branch is a function of the disconnection parameter λ.

[0076] During the line disconnection process, since the four elements in the admittance matrix Y are functions of λ, the power flow equations also include the parameter λ, as follows:

[0077]

[0078] Since the four elements in the network admittance matrix Y are functions of λ, the four elements at the corresponding positions in the power flow Jacobian matrix J contain both voltage variables and disconnection functions η(λ), as shown below:

[0079]

[0080] The Jacobian matrix J' can be equivalently decomposed into two matrices, from which we can obtain:

[0081] J′=J1η(λ)+J2 (18)

[0082] Wherein, J1 and J2 are respectively:

[0083]

[0084] It is important to note that

[0085] When λ = 0 and η(0) = 1, J' = J1 + J2.

[0086] For ease of description, this paper uses the power flow equation in polar coordinates to derive the calculation of disconnected power flow;

[0087] Similarly, the power flow equations in rectangular coordinates can be used for derivation;

[0088] The power flow equations of the power system are as follows:

[0089] W=F(X,λ) (20)

[0090] In formula (21):

[0091]

[0092] X = [δ1 δ2 … δ n-1 U1 U2…U m ] T (twenty two)

[0093] It can be seen that the phase angle δ and voltage U of each node in the system are functions of the parameter λ, therefore the derivative of λ in equation (23) can be solved:

[0094]

[0095] In formula (25),

[0096] When λ=0 and η(0)=1, J'=J1+J2, J is the power flow Jacobian matrix obtained before the line is disconnected, and there is no need to recalculate it;

[0097] therefore:

[0098]

[0099] As can be seen, since J is the Jacobian matrix that converges in the power flow calculation before the line interruption, its inverse matrix already exists. All interruption power flow calculations use the same inverse matrix of the Jacobian matrix, so its computational workload is equivalent to that of traditional interruption methods, such as the DC method or the compensation method for load power flow calculation.

[0100] S130, Based on the second calculation result, calculate the power flow distribution when the power supply is interrupted, and use it as the third calculation result;

[0101] In some embodiments, S130 includes: changing the initial value of the power flow Jacobian matrix according to the power interruption situation, and recalculating the power flow distribution to obtain a third calculation result.

[0102] In this embodiment of the invention, during the disconnection of the power branch, the node admittance matrix of the power system remains unchanged, but the injected power of the node changes.

[0103] The analysis results show that the calculation accuracy of the Taylor series method is not strongly dependent on the interruption power function η(λ);

[0104] When η(λ)=(1-λ) / (1+λ), high-precision results of interrupted power flow can also be obtained by fitting a third-order Taylor series;

[0105] This is because a power outage does not affect the system network structure; it only changes the initial values ​​of the power flow equations.

[0106] S140, based on the first calculation result, the second calculation result, and the third calculation result, determine the static security verification result of Nk of the power system, and perform preventive control on the power system based on the static security verification result of Nk.

[0107] In some embodiments, determining the static security verification result of the power system Nk based on the first calculation result, the second calculation result, and the third calculation result includes: determining the power flow distribution of the power system when any one or more circuits are disconnected based on the first calculation result, the second calculation result, and the third calculation result, and obtaining the static security verification result of Nk.

[0108] In this embodiment of the invention, after considering three fault conditions—branch disconnection, line disconnection, and power interruption—the Nk fault combination to be analyzed can be selected (each fault combination consists of different branch disconnection, line disconnection, and power interruption). Any fault combination is applied to the simulated power system, the power flow distribution of the circuit system is calculated during this process, the load of all lines is checked to see if it is within the safety limit, the voltage of all nodes is confirmed to be within the allowable range, and the transient stability of the system is evaluated to complete the static safety verification.

[0109] In some embodiments, preventive control of the power system is performed based on the static security verification results of Nk: the static security verification results of Nk are sorted according to the degree of voltage limit violation or transmission power overload to obtain a set of serious incidents; the fault control logic of the power system is determined based on the set of serious incidents.

[0110] In this embodiment of the invention, each fault combination corresponds to a fault control scheme. These fault control schemes need to be prioritized. Therefore, they are sorted according to the severity of voltage limitation or overload. The fault combination that appears earlier in the severe accident set has a higher priority for its corresponding fault control scheme.

[0111] In some embodiments, the method further includes the step of: when the topology of the power system changes, reselecting a disconnection function and jumping to the step of obtaining the admittance information of the power system and a preset disconnection function.

[0112] Figure 5This is a schematic diagram of the IEEE 14-node system architecture of the present invention. Figure 5 As shown, taking the IEEE 14-node system as an example, the voltage values ​​of each node after the line is disconnected are calculated. The results show that the method presented in this paper has high accuracy and speeds up the analysis and calculation. Details are shown in the table below.

[0113] Table 2 Voltage results after disconnecting branch 3-4 in the IEEE 14-node system

[0114]

[0115] Table 3 Power results before and after disconnecting branch 3-4 in the IEEE 14-node system

[0116]

[0117] As can be observed from Tables 2 and 3, compared with the NR power flow method, the proposed Taylor series fitting-based disconnection power flow calculation method shows very small differences in voltage values ​​and phase angles at each node after the line is disconnected. The voltage value difference is 0–0.005 pu, and the phase angle difference is 0–1.5°. The active and reactive power values ​​are the same, proving that the proposed method has high accuracy in calculating the power flow distribution after the line is disconnected. Furthermore, the proposed method does not require correction of the calculation process for precise matrix elements, which greatly accelerates the analysis and calculation speed, demonstrating significant theoretical and practical value.

[0118] The results are based on the Taylor expansion disconnect power flow method proposed in this paper and are compared with the actual values ​​calculated by the Newton-Raphson method.

[0119] In step S2, the method in S2.2 can be easily extended to the case of line k being disconnected, enabling rapid static security analysis of the power system Nk.

[0120] Table 4 Comparison of branch-disconnect power flow calculation results between the Newton-Raphson method and the method presented in this paper.

[0121]

[0122] The results in Table 4 show that the error between the power flow calculation results obtained by the proposed method and those obtained by the NR method is very small. The node voltage magnitude error and voltage phase angle error are within the ranges of 0–0.01 and 0–0.0095, respectively. Such calculation errors will not affect the assessment of the system's operating status. Furthermore, the NR method takes 2.9607 seconds to calculate the power flow with all branches disconnected, while the proposed method takes only 0.3312 seconds, representing only 11.2% of the total analysis and calculation time of the traditional method. This demonstrates that the proposed method significantly accelerates the calculation speed. Therefore, this method is more suitable for rapid fault scanning to determine the extent to which faults affect system stability.

[0123] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0124] Figure 6 This is a schematic diagram of the structure of a distributed control device for integrated source-grid-load-storage systems provided in an embodiment of the present invention. Figure 6 As shown, in some embodiments, the distributed control device 6 for integrated source-grid-load-storage systems includes:

[0125] The branch analysis module 610 is used to acquire the admittance information and preset disconnection function of the power system, and calculate the node voltage of each node when any branch is disconnected based on the admittance information and disconnection function, as the first calculation result;

[0126] The line analysis module 620 is used to calculate the power flow distribution when a line is disconnected based on the first calculation result, and use it as the second calculation result.

[0127] The power analysis module 630 is used to calculate the power flow distribution when the power is interrupted based on the second calculation result, and use it as the third calculation result.

[0128] The prevention and control module 640 is used to determine the static security verification result of Nk of the power system based on the first calculation result, the second calculation result, and the third calculation result, and to perform prevention and control on the power system based on the static security verification result of Nk.

[0129] Optionally, the branch analysis module 610 is used to: expand the node voltage into a Taylor series of the disconnection parameter in the disconnection function when the admittance of any branch satisfies the disconnection function, and perform second-order differentiation to express the node voltage as a third-order Taylor series expansion of the disconnection branch admittance, thereby obtaining the first calculation result.

[0130] Optionally, the line analysis module 620 is used to: calculate the node voltage of each node when the three branches are disconnected based on the first calculation result; convert the node voltage of each node when the three branches are disconnected to the node voltage when one line is disconnected, and calculate the power flow distribution based on the power flow Jacobian matrix as the second calculation result.

[0131] Optionally, the power analysis module 630 is used to: change the initial value of the power flow Jacobian matrix according to the power interruption situation, and recalculate the power flow distribution to obtain a third calculation result.

[0132] Optionally, the prevention and control module 640 is used to: determine the power flow distribution of the power system when any one or more circuits are disconnected based on the first calculation result, the second calculation result, and the third calculation result, and obtain the static security verification result of Nk.

[0133] Optionally, the prevention and control module 640 is used to: sort the static safety verification results of Nk according to the degree of voltage limit violation or transmission power overload to obtain a set of serious incidents; and determine the fault control logic of the power system based on the set of serious incidents.

[0134] Optionally, the distributed control device 6 for the integrated source-grid-load-storage system also includes an adjustment module for: when the topology of the power system changes, reselecting the disconnection function and jumping to the step of obtaining the power system's admittance information and the preset disconnection function.

[0135] Optionally, the disconnect function can be a linear disconnect function or a non-linear disconnect function.

[0136] Optional, the disconnect function is:

[0137] n(λ) = (1-λ) / (1+λ)

[0138] Where n(λ) is the nonlinear disconnection function and λ is the disconnection parameter.

[0139] The distributed control device for integrated source-grid-load-storage provided in this embodiment can be used to execute the above method embodiment. Its implementation principle and technical effect are similar, and will not be described again here.

[0140] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0141] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0142] In the embodiments provided by this invention, it should be understood that the disclosed devices / controllers and methods can be implemented in other ways. For example, the device / controller embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0143] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0144] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0145] If an integrated module / unit is implemented as 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, all or part of the processes in the methods of the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0146] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A distributed control method for integrated source-grid-load-storage systems, characterized in that, include: Obtain the admittance information and preset disconnection function of the power system, and calculate the node voltage of each node when any branch is disconnected based on the admittance information and the disconnection function, as the first calculation result; Based on the first calculation result, the power flow distribution when one line is disconnected is calculated equivalently and used as the second calculation result. Based on the second calculation result, the power flow distribution when the power is interrupted is calculated as the third calculation result; Based on the first calculation result, the second calculation result, and the third calculation result, the static security verification result of Nk of the power system is determined, and preventive control is carried out on the power system based on the static security verification result of Nk. Based on the admittance information and the disconnection function, calculate the node voltage of each node when any branch is disconnected, as the first calculation result, including: If the admittance of any branch satisfies the disconnection function, the node voltage is expanded into a Taylor series of the disconnection parameter in the disconnection function, and the second derivative is performed to express the node voltage as a third-order Taylor series expansion of the disconnection branch admittance, thus obtaining the first calculation result.

2. The distributed control method for integrated source-grid-load-storage system according to claim 1, characterized in that, Based on the first calculation result, the power flow distribution when one line is disconnected is calculated equivalently, and this is used as the second calculation result, including: Based on the first calculation result, calculate the node voltage of each node when the three branches are disconnected; The node voltage of each node when the three branches are disconnected is equivalent to the node voltage when one line is disconnected. The power flow distribution is calculated based on the power flow Jacobian matrix and used as the second calculation result.

3. The distributed control method for integrated source-grid-load-storage system according to claim 2, characterized in that, Based on the second calculation result, the power flow distribution during a power outage is calculated as the third calculation result, including: Based on the power interruption situation, the initial value of the power flow Jacobian matrix is ​​changed, and the power flow distribution is recalculated to obtain a third calculation result.

4. The distributed control method for integrated source-grid-load-storage system according to claim 1, characterized in that, Based on the first calculation result, the second calculation result, and the third calculation result, the static security verification result of Nk of the power system is determined, including: Based on the first calculation result, the second calculation result, and the third calculation result, the power flow distribution of the power system when any one or more circuits are disconnected is determined, and the static security verification result of Nk is obtained.

5. The distributed control method for integrated source-grid-load-storage system according to claim 1, characterized in that, Based on the Nk static security verification result, preventive control is performed on the power system, including: The static security verification results of Nk are sorted according to the degree of voltage limit violation or transmission power overload to obtain the severe incident set; Based on the set of severe incidents, determine the fault control logic for the power system.

6. The distributed control method for integrated source-grid-load-storage system according to claim 1, characterized in that, The method further includes: When the topology of the power system changes, a new disconnect function is selected and the process jumps to the steps of obtaining the power system's admittance information and the preset disconnect function.

7. The distributed control method for integrated source-grid-load-storage system according to claim 1, characterized in that, The disconnection function can be a linear disconnection function or a nonlinear disconnection function.

8. The distributed control method for integrated source-grid-load-storage system according to claim 7, characterized in that, The disconnect function is: in, n ( λ ) is a non-linear disconnection function. λ To disconnect parameters.

9. A distributed control device for integrated source-grid-load-storage systems, characterized in that, include: The branch analysis module is used to obtain the admittance information of the power system and the preset disconnection function. When the admittance of any branch satisfies the disconnection function, the node voltage is expanded into the Taylor series of the disconnection parameter in the disconnection function, and the second derivative is performed to express the node voltage as the third-order Taylor series expansion of the disconnection branch admittance, thus obtaining the first calculation result. The line analysis module is used to calculate the power flow distribution when a line is disconnected based on the first calculation result, and use it as the second calculation result. The power analysis module is used to calculate the power flow distribution when the power is interrupted based on the second calculation result, as the third calculation result; The prevention and control module is used to determine the static security verification result of the power system Nk based on the first calculation result, the second calculation result, and the third calculation result, and to perform prevention and control on the power system based on the static security verification result of Nk.

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