Distributed control method and device oriented to integration of source network load and storage

Abstract

The invention provides a distributed control method and device oriented to source network load storage integration, and the method comprises the steps: firstly obtaining the admittance information of a power system and a preset disconnection function, and calculating the node voltage of each node when any branch is disconnected according to the admittance information and the preset disconnection function, and taking the node voltage as a first calculation result; equivalently calculating the power flow distribution when one line is disconnected according to the first calculation result, and taking the power flow distribution as a second calculation result; calculating power flow distribution when the power supply is interrupted according to the second calculation result, and taking the power flow distribution as a third calculation result; and finally, according to the first calculation result, the second calculation result and the third calculation result, determining an N-k static security verification result of the power system, and according to the N-k static security verification result, performing prevention and control on the power system. By setting a corresponding disconnection function, deeply analyzing three interruption conditions of branches, lines and power supplies, and expanding to N-k static safety verification, the disconnection problem of the power system is accurately analyzed, and prevention and control are effectively carried out.

Description

Technical Field

[0001] The present invention belongs to the technical field of power grids, and in particular relates to a distributed control method and device for source-grid-load-storage integration. Background Art

[0002] As the scale of the power grid continues to expand, the probability of power grid failure also increases. In order to ensure the safe operation of the power grid and reduce the impact of power grid failures on the operation of the power system, it is particularly important to find a method that can perform static safety analysis online. N-1 safety verification is one of the most common static safety assessment methods, which aims to predict the consequences after an accident and sort them according to the degree of voltage limit violation or transmission power overload. Therefore, a set of serious accidents can be found to help with subsequent preventive control, which is essentially a problem of system circuit breaker flow calculation.

[0003] At present, the traditional power flow algorithms used for N-1 safety verification of power systems include DC power flow method, compensation method, sensitivity method, etc. The above methods use approximate disconnection power flow algorithm to calculate the disconnection problem of power systems, and use linear calculation to solve nonlinear problems to improve the speed. However, there are still large errors in accuracy, and the calculation results can only be used to screen serious faults and expected accident severity. Therefore, it is inevitable to perform secondary accurate calculations on serious faults, and there may be masking phenomena, resulting in confusion in the sorting of expected accidents. Summary of the invention

[0004] In view of this, the present invention provides a distributed control method and device for source-grid-load-storage integration, aiming to solve the problem that the safety verification accuracy of the prior art still has large errors.

[0005] A first aspect of an embodiment of the present invention provides a distributed control method for source-grid-load-storage integration, including:

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

[0007] According to the first calculation result, equivalently calculating the power flow distribution when one line is disconnected as the second calculation result;

[0008] Calculate the power flow distribution when the power supply is interrupted according to the second calculation result as the third calculation result;

[0009] According to the first calculation result, the second calculation result and the third calculation result, the static safety verification result of Nk of the power system is determined, and preventive control is performed on the power system according to the static safety verification result of Nk.

[0010] In a possible implementation, the node voltage of each node when any branch is disconnected is calculated according to the admittance information and the disconnection function as a first calculation result, including:

[0011] 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-order derivative is performed to express the node voltage as the third-order Taylor series expansion of the disconnected branch admittance to obtain the first calculation result.

[0012] In a possible implementation, based on the first calculation result, equivalently calculating the power flow distribution when one line is disconnected as the second calculation result includes:

[0013] According to the first calculation result, calculating 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, and the power flow distribution is calculated according to the power flow Jacobian matrix as the second calculation result.

[0015] In a possible implementation, calculating, according to the second calculation result, a power flow distribution when a power outage occurs as a third calculation result, includes:

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

[0017] In a possible implementation, determining a static safety verification result of Nk of the power system according to the first calculation result, the second calculation result, and the third calculation result includes:

[0018] According to 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 loops are disconnected is determined to obtain a static safety verification result of Nk.

[0019] In a possible implementation, preventive control is performed on the power system according to the static safety verification result of Nk:

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

[0021] According to the severe accident set, the fault control logic of the power system is determined.

[0022] In a possible implementation, the method further includes:

[0023] When the topology of the power system changes, the disconnection function is reselected and the process jumps to the step of obtaining the admittance information of the power system and the preset disconnection function.

[0024] In a possible implementation manner, the disconnection function is a linear disconnection function or a nonlinear disconnection 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 an embodiment of the present invention provides a distributed control device for source-grid-load-storage integration, including:

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

[0030] A line analysis module, used for equivalently calculating the power flow distribution when a line is disconnected according to the first calculation result as the second calculation result;

[0031] A power supply analysis module, used to calculate the power flow distribution when the power supply is interrupted according to the second calculation result as a third calculation result;

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

[0033] The distributed control method and device for source-grid-load-storage integration provided by the embodiment of the present invention first obtains the admittance information and preset disconnection function of the power system, and calculates the node voltage of each node when any branch is disconnected according to the admittance information and the disconnection function as the first calculation result; then, according to the first calculation result, the flow distribution when a line is disconnected is equivalently calculated as the second calculation result; then, according to the second calculation result, the flow distribution when the power supply is interrupted is calculated as the third calculation result; finally, according to the first calculation result, the second calculation result, and the third calculation result, the static safety verification result of Nk of the power system is determined, and the power system is preventively controlled according to the static safety verification result of Nk. By setting the corresponding disconnection function, the three interruption situations of branches, lines, and power supplies are deeply analyzed, and then extended to the static safety verification of Nk, so as to accurately analyze the disconnection problem of the power system and effectively perform preventive control. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, 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.

[0035] Figure 1 It is a flow chart for implementing a distributed control method for source-grid-load-storage integration provided by an embodiment of the present invention;

[0036] Figure 2 It is the variation curve of the continuous disconnection function;

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

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

[0039] Figure 5 It is a schematic diagram of the IEEE14 node system structure of the present invention;

[0040] Figure 6 It is a structural schematic diagram of a distributed control device for source-grid-load-storage integration provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0041] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0042] Figure 1 1 is a flow chart of the implementation of the distributed control method for source-grid-load-storage integration provided by the embodiment of the present invention. Figure 1 As shown, in some embodiments, a distributed control method for source-grid-load-storage integration includes:

[0043] S110, acquiring admittance information and a preset disconnection function of the power system, and calculating, according to the admittance information and the disconnection function, the node voltage of each node when any branch is disconnected, as a first calculation result;

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

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

[0046] Figure 2 is the changing curve of the continuous disconnection function. Figure 2 As shown, the continuous disconnection function can be set as follows:

[0047] n(λ)=1-λ (1)

[0048] n(λ)=(1-λ) / (1+λ) (2)

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

[0050] The (1-λ) / (1+λ) in formula (4) is a nonlinear disconnection function, wherein the linear function conforms to the nonlinear relationship of cos(πλ / 2).

[0051] It can be seen that the change rules of different disconnection functions are different, but their initial and final values ​​are consistent; although continuous disconnection can be achieved, it is actually meaningless and is only used for curve comparison; the power equation can be listed from the circuit:

[0052] PLD=(10-U)[0.5+0.5η(λ)]U (5)

[0053] Formula (6) can be organized into the following form:

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

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

[0056] Figure 3 Schematic diagram of branch disconnection power flow circuit in the DC circuit of the present invention. Figure 3 The first disconnected branch in ; assume negative; the power is constant, expand the 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, formula (4) is second-order differentiated with respect to λ, and the result is:

[0057]

[0058] exist Figure 1 In the equation, when λ = 0, the initial state of the system is: PLD = 9 and U0 = 9, which can be solved by the following formula:

[0059]

[0060] In addition, according to the above analogy, the third-order Taylor series coefficient a3 can be obtained;

[0061] Then, the third-order Taylor series about U is:

[0062]

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

[0064]

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

[0068]

[0069]

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

[0071] In some embodiments, S110 includes: when 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 a second-order derivative to express the node voltage as a third-order Taylor series expansion of the disconnected branch admittance to obtain a first calculation result.

[0072] In the embodiment of the present invention, the branch parameter is the admittance, and η(λ) is the disconnection function; let λ be a parameter of the branch circuit disconnection process, and the admittance of one branch is multiplied by the disconnection function η(λ), then 0.5η(λ) indicates that the branch is about to be disconnected; if the branch admittance is zero, the corresponding branch state is disconnected; the continuous variation interval of λ is [0,1].

[0073] S120, based on the first calculation result, equivalently calculating the power flow distribution when one line is disconnected as the second calculation result;

[0074] In some embodiments, S120 includes: calculating the node voltage of each node when the three branches are disconnected according to the first calculation result; equating 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 according to the power flow Jacobian matrix as the second calculation result.

[0075] Figure 4 Schematic diagram of km-type equivalent circuit of disconnected power grid line of the present invention. Figure 4 As shown, in the embodiment of the present invention, assuming that the continuous disconnection function is η(λ)=(1-λ) / (1+λ), 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 equation also contains the parameter λ, which is expressed 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 elements of the power flow Jacobian matrix J have both voltage variables and disconnection functions η(λ), which are expressed as follows:

[0079]

[0080] The Jacobian matrix J' can be equivalently decomposed into two matrices, and we can get:

[0081] J′=J1η(λ)+J2 (18)

[0082] Among them, J1 and J2 are:

[0083]

[0084] It should be noted that

[0085] When λ=0 and η(0)=1, J′=J1+J2.

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

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

[0088] The power flow equation of the power system is 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, so the derivative of row λ in formula (23) can be solved:

[0094]

[0095] In formula (25),

[0096] When λ=0 and η(0)=1, J'=J1+J2, where J is the power flow Jacobian matrix obtained before the line is disconnected and does not need to be recalculated;

[0097] therefore:

[0098]

[0099] It can be seen that since J is the Jacobian matrix of the converged power flow calculation before the line interruption, its inverse matrix already exists, and various interruption power flow calculations all use the same inverse matrix of the Jacobian matrix, so the amount of calculation is equivalent to the load flow calculation performed by traditional interruption methods, such as the DC method or the compensation method.

[0100] S130, calculating the power flow distribution when the power supply is interrupted according to the second calculation result as a third calculation result;

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

[0102] In the embodiment of the present 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), the interrupted power flow results with higher accuracy can also be obtained by fitting the third-order Taylor series;

[0105] This is because power outages do not affect the system network structure but only change the initial value of the power flow equation.

[0106] S140, determining a static safety verification result of Nk of the power system according to the first calculation result, the second calculation result, and the third calculation result, and performing preventive control on the power system according to the static safety verification result of Nk.

[0107] In some embodiments, the static safety verification result of Nk of the power system is determined based on the first calculation result, the second calculation result, and the third calculation result, including: 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, to obtain the static safety verification result of Nk.

[0108] In an embodiment of the present invention, after considering the three fault conditions of branch disconnection, line disconnection and power interruption, the Nk fault combinations that need to be analyzed can be selected (each fault combination is composed of different branch disconnections, line disconnections and power interruptions), and any fault combination can be applied to the simulated / emulated power system. The power flow distribution of the circuit system in this process is calculated, and it is checked whether the loads of all lines are within the safety limit, whether the voltages of all nodes are within the allowable range, and the transient stability of the system is evaluated to complete the static safety check.

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

[0110] In an embodiment of the present invention, each fault combination corresponds to a fault control scheme, and priorities need to be set between these fault control schemes. Therefore, they are sorted according to the voltage limitation or overload degree as the severity. The more serious the fault combination is in the serious accident concentration, the higher the priority of the corresponding fault control scheme.

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

[0112] Figure 5Schematic diagram of the IEEE 14 node system structure of the present invention. Figure 5 As shown in the figure, taking the IEEE 14-bus system as an example, the voltage value of each node after the line is disconnected is calculated. The results show that the proposed method has high accuracy and accelerates the analysis and calculation speed. The details are shown in the following table.

[0113] Table 2 Voltage results of IEEE14-bus system after disconnecting branch 3-4

[0114]

[0115] Table 3 Power results before and after disconnection of branch 3-4 in IEEE14-bus system

[0116]

[0117] According to Tables 2 and 3, it can be observed that compared with the NR power flow method, the disconnection power flow calculation method based on Taylor series fitting proposed in this paper has little difference in the voltage value and phase angle of each node after the system line is disconnected. The voltage value difference is 0–0.005pu, the phase angle difference is 0–1.5°, and the active and reactive values ​​are the same, which proves that the method proposed in this paper has high accuracy in calculating the power flow distribution after the system is disconnected. In addition, the method in this paper does not require the correction of the calculation process of the precise matrix elements, which greatly speeds up the analysis and calculation speed, and its theoretical significance and application value are very significant;

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

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

[0120] Table 4 Comparison of branch disconnection power flow calculation results between Newton-Raphson method and this method

[0121]

[0122] From the results in Table 4, it can be found that the error between the disconnection flow calculated by the proposed method and the calculation result of the NR method is very small, and the node voltage amplitude error and voltage phase angle error are in the range of 0–0.01 and 0–0.0095, respectively. Such calculation errors will not affect the evaluation of the system operation status. In addition, the NR method takes 2.9607 seconds to calculate the flow of all branch disconnections, while the proposed method takes a total of 0.3312 seconds, and the total analysis and calculation time is only 11.2% of the traditional method. It can be seen that the calculation speed of the proposed method is greatly accelerated. Therefore, this method is more suitable for fast fault scanning to determine the degree of impact of the fault on the system stability.

[0123] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean 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 embodiment of the present invention.

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

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

[0126] A line analysis module 620 is used to calculate the power flow distribution when a line is disconnected according to the first calculation result, as a second calculation result;

[0127] A power analysis module 630, configured to calculate, based on the second calculation result, a power flow distribution when a power outage occurs, as a third calculation result;

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

[0129] Optionally, the branch analysis module 610 is used to: when the admittance of any branch satisfies the disconnection function, expand the node voltage into a Taylor series of the disconnection parameter in the disconnection function, and perform a second-order derivative to express the node voltage as a third-order Taylor series expansion of the disconnected branch admittance to obtain a 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 according to the first calculation result; equate 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 according to the power flow Jacobian matrix as the second calculation result.

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

[0132] Optionally, the preventive 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 a static safety verification result of Nk.

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

[0134] Optionally, the distributed control device 6 for source-grid-load-storage integration 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 admittance information of the power system and the preset disconnection function.

[0135] Optionally, the disconnection function is a linear disconnection function or a nonlinear disconnection function.

[0136] Optionally, 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 source-grid-load-storage integration provided in this embodiment can be used to execute the above method embodiments. Its implementation principles and technical effects are similar, and this embodiment will not be repeated here.

[0140] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0141] Those skilled in the art will appreciate that the units and algorithm steps of each example 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 performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0142] In the embodiments provided by the present 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 only schematic, for example, the division of modules or units is only a logical function division, and 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 through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0143] 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.

[0144] 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.

[0145] If the integrated module / 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 present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. Computer-readable media may include: any entity or device capable of carrying computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal and software distribution medium, etc.

[0146] 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 may be replaced by equivalents. Such 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, and should be included in the protection scope of the present invention.

Claims

1. A distributed control method for source-grid-load-storage integration, characterized in that: include: Acquire the admittance information and the preset disconnection function of the power system, and calculate the node voltage of each node when any branch is disconnected according to the admittance information and the disconnection function as a first calculation result; According to the first calculation result, equivalently calculating the power flow distribution when one line is disconnected as the second calculation result; According to the second calculation result, calculating the power flow distribution when the power supply is interrupted as a third calculation result; A static safety verification result of Nk of the power system is determined according to the first calculation result, the second calculation result, and the third calculation result, and preventive control is performed on the power system according to the static safety verification result of Nk.

2. The distributed control method for source-grid-load-storage integration according to claim 1 is characterized in that: Calculating, according to the admittance information and the disconnection function, the node voltage of each node when any branch is disconnected as a first calculation result, including: When 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 a second-order derivative is performed to express the node voltage as a third-order Taylor series expansion of the disconnected branch admittance to obtain a first calculation result.

3. The distributed control method for source-grid-load-storage integration according to claim 2 is characterized in that: According to the first calculation result, the power flow distribution when one line is disconnected is equivalently calculated as the second calculation result, including: According to the first calculation result, calculating 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, and the power flow distribution is calculated according to the power flow Jacobian matrix as the second calculation result.

4. The distributed control method for source-grid-load-storage integration according to claim 3 is characterized in that: According to the second calculation result, calculating the power flow distribution when the power supply is interrupted as a third calculation result, including: According to the interruption of the power supply, the initial value of the power flow Jacobian matrix is ​​changed, and the power flow distribution is recalculated to obtain a third calculation result.

5. The distributed control method for source-grid-load-storage integration according to claim 1 is characterized in that: Determining a static safety verification result of Nk of the power system according to the first calculation result, the second calculation result, and the third calculation result includes: According to 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 to obtain a static safety verification result of Nk.

6. The distributed control method for source-grid-load-storage integration according to claim 1 is characterized in that: Preventive control is performed on the power system according to the Nk static safety verification result, including: Sorting the static safety verification results of the Nk according to the voltage limit violation or the transmission power overload degree to obtain a serious accident set; According to the severe accident set, a fault control logic of the power system is determined.

7. The distributed control method for source-grid-load-storage integration according to claim 1 is characterized in that: The method further comprises: When the topology of the power system changes, the disconnection function is reselected and the process jumps to the step of obtaining the admittance information of the power system and the preset disconnection function.

8. The distributed control method for source-grid-load-storage integration according to claim 1 is characterized in that: The disconnection function is a linear disconnection function or a nonlinear disconnection function.

9. The distributed control method for source-grid-load-storage integration according to claim 8 is characterized in that: The disconnect function is: n(λ)=(1-λ) / (1+λ) Where n(λ) is the nonlinear disconnection function and λ is the disconnection parameter.

10. A distributed control device for source-grid-load-storage integration, characterized in that: include: A branch analysis module, used to obtain the admittance information of the power system and a preset disconnection function, and calculate the node voltage of each node when any branch is disconnected according to the admittance information and the disconnection function as a first calculation result; A line analysis module, configured to calculate, based on the first calculation result, a power flow distribution when a line is disconnected, as a second calculation result; A power supply analysis module, configured to calculate, based on the second calculation result, a power flow distribution when a power interruption occurs, as a third calculation result; A preventive control module is used to determine a static safety verification result of Nk of the power system according to the first calculation result, the second calculation result, and the third calculation result, and to perform preventive control on the power system according to the static safety verification result of Nk.

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