A power distribution network fault recovery control method and related device

Abstract

Embodiments of the present application disclose a power distribution network fault recovery control method and related device, wherein the method comprises: dividing the fault repair time of the current fault of the power distribution network according to the fault reason; obtaining the distributed power supply, load state parameters and network structure parameters corresponding to each time period under the time section, and establishing a double-layer planning model containing island division and network reconstruction; inputting the parameters corresponding to each time period into the double-layer planning model to obtain the power distribution network fault recovery scheme corresponding to each time period; finally, according to the power distribution network fault recovery scheme, the power distribution network fault is recovered and controlled. The method can realize targeted recovery control of the power distribution network fault in each time period, avoid the possibility of secondary failure caused by distributed power output fluctuation during the fault, continuously reconstruct and optimize within the power distribution network fault repair time, ensure the feasibility of the power distribution network fault recovery scheme in the entire fault duration interval, and improve the power grid resilience.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system distribution network operation control, and particularly relates to a distribution network fault recovery control method and related devices. BACKGROUND

[0002] Network reconfiguration, as an important measure for power supply recovery when the distribution network fails, is to change the combination state of sectionalizing switches and tie switches, that is, to select the power supply path of users, so as to achieve the purpose of as much load recovery as possible, as fast as possible, and as small network change as possible. At the same time, with the rapid development of distributed energy in recent years, distributed power can supply power to a certain range of loads independently in the form of island division, so as to achieve the purpose of maximum recovery of power supply in non-fault area. Therefore, according to the difference of fault point position, the research on fault recovery strategy nowadays is mainly divided into three categories: the first category is to directly use the existing tie switch after the fault occurs, and to transfer the load in the non-fault area to the safe line by using topology dynamic update, that is, network reconfiguration. The basic idea of this method is to comprehensively consider various costs during the fault period, such as network loss, switch operation cost, loss of load, etc., to find the optimal power supply recovery path under the conditions of meeting the node voltage and branch current constraints, node power balance constraints, and network structure constraints; the second category is to use various distributed power to supply power to more important loads in the region by dividing islands when part of the network is disconnected from the network side due to the lack of tie switches after the fault occurs. The basic idea of this method is to analyze the topology structure of the network first, and then find a reasonable power supply recovery path under the condition of meeting the electrical and topological constraints of the island; the third category is to comprehensively consider the first two methods, and the network reconfiguration scheme changes iteratively during the island division process, so as to obtain the globally optimal scheme.

[0003] Some researches use a comprehensive recovery method and consider the multi-period characteristics of power supply recovery, and the obtained distribution network fault recovery scheme improves the efficiency and reliability of the distribution network operation. The strategies of prioritizing network reconfiguration and prioritizing island division can comprehensively consider the common effect on power supply recovery to a certain extent, but in fact, they influence each other in the process of network reconfiguration and island division, and cannot be decoupled. It is necessary to comprehensively consider the comprehensive recovery strategy to make the final power supply recovery scheme globally optimal. The existing technology only considers the fault time, and lacks discussion on the possibility of secondary fault caused by distributed power output fluctuation during the fault period, or lacks basis for dynamic optimization reconfiguration period division during the fault period.

[0004] Therefore, how to consider continuous reconfiguration optimization within the distribution network fault repair time, ensure the feasibility of the network reconfiguration scheme in the entire fault duration interval, and achieve the goal of improving the resilience of the power grid, is a key problem that needs to be solved. SUMMARY

[0005] The main purpose of the present application is to provide a power distribution network fault recovery control method and related device, wherein the related device includes a power distribution network fault recovery control device, a computer device and a storage medium, which can solve the problem that the existing technology cannot continuously reconstruct and optimize within the fault repair time of the power distribution network.

[0006] To achieve the above-mentioned purpose, the first aspect of the present application provides a power distribution network fault recovery control method, which comprises:

[0007] When the power distribution network fails, the fault category of the current fault of the power distribution network is judged, wherein the fault category includes the fault caused by meteorological factors and the fault caused by non-meteorological factors;

[0008] According to the fault category of the current fault of the power distribution network, the fault repair time of the current fault is determined;

[0009] The fault repair time is divided into time sections, and the distributed power supply, load state parameters and network structure parameters corresponding to each time period under the time section are obtained; wherein the distributed power supply at the fault time of the power distribution network includes the current distributed power supply output condition, the load state parameters include the load power demand, and the network structure parameters include the on-grid state of the distributed power supply and the topological connection relationship of each node of the network at the current time;

[0010] A double-layer planning model is established, which takes network reconstruction as the upper model and island division as the lower model, and takes the distributed power supply, load state parameters and network structure parameters corresponding to each time period at the fault time of the power distribution network as the input of the double-layer planning model, and the power distribution network fault recovery scheme corresponding to each time period is obtained by solving; wherein the power distribution network fault recovery scheme includes the topological reconstruction scheme and the objective function value;

[0011] According to the power distribution network fault recovery scheme, operation instructions are issued to each switch device to control the recovery of the power distribution network fault.

[0012] In combination with the first aspect, in a possible implementation manner, the objective function taking island division as the lower model is:

[0013] max F DG =β1F DG1 +β2F DG2 ;

[0014] Wherein, F DGj is the island layer objective function value; F Lj is the equivalent recovery power of the distributed power supply during the fault duration; F j is the objective function value of the upper layer.The benefits of avoiding power failure of key loads in the island; β1 and β2 are weights;

[0015] The constraint conditions of the island division include:

[0016]

[0017] P DGj is the active power output of the distributed power supply of node j in the island; P Lj is the load power of node j; U j is the voltage amplitude of node j; U jmin and U jmax are the lower limit and upper limit of the voltage amplitude of node j, respectively; P k is the branch power of branch k; f j is the frequency of node j in the island; f jmin and f jmax are the lower limit and upper limit of the frequency of node j, respectively.

[0018] In combination with the first aspect, in a possible implementation manner, the objective function taking the network reconstruction as the upper model is:

[0019] max F main = β3F main1 + β4F main2

[0020] Wherein, F main is the network reconstruction layer objective function value; F main1 is the equivalent recovery power during the fault duration; F main2 is the economic loss caused by avoiding power failure of key loads during the fault duration; β3 and β4 are weights;

[0021] The constraint conditions of the network reconstruction include:

[0022]

[0023] P i and Q i are the active power and reactive power injected by node i, respectively; B ij is the conductance between node i and node j; G ij is the susceptance between node i and node j; s t is the number of switch operations in the t period; S max is the maximum number of switch operations in the period T; U i is the voltage amplitude of node i; U imin and U imax are the lower limit and upper limit of the voltage amplitude of node i, respectively; θ ij is the phase angle difference between node i and node j; λak is the failure rate of the kth line in the current situation; λ max is the maximum allowable failure rate of the line; P ij is the active power value of the branch ij; P ijmax is the maximum allowable value of the active power of the branch ij; f i is the frequency of node i; f imin and f imax are the lower limit and upper limit of the frequency of node i, respectively; g is the network topology structure obtained by the reconstruction strategy; and G is the set of all radial network structures on the outside of the island.

[0024] In combination with the first aspect, in a possible implementation manner, the distributed power supply, the load state parameter, and the network structure parameter corresponding to the fault time of the power distribution network in each time period are input into the double-layer planning model, and a power distribution network fault recovery scheme corresponding to each time period is obtained by solving the double-layer planning model, including:

[0025] The distributed power supply, the load state parameter, and the network structure parameter corresponding to the fault time of the power distribution network in each time period are input into the double-layer planning model.

[0026] The lower-layer model is solved by using a breadth-first algorithm, a first result is output, the first result is input into the upper-layer model, the upper-layer model is solved by using an improved explorer algorithm, a second result is output, the second result is input into the lower-layer model, and the step of solving the lower-layer model by using the breadth-first algorithm and outputting the first result is iterated until a maximum iteration number or a calculation precision is reached, and the power distribution network fault recovery scheme is output.

[0027] In combination with the first aspect, in a possible implementation manner, the fault repair time of the current fault is determined according to the fault category of the current fault of the power distribution network, including:

[0028] When the fault category of the current fault of the power distribution network is a fault caused by meteorological factors, the sum of the meteorological duration and the time margin is determined as the fault repair time.

[0029] When the fault category of the current fault of the power distribution network is a fault caused by non-meteorological factors, the fault repair time is determined according to worker line inspection.

[0030] In combination with the first aspect, in a possible implementation manner, a line failure rate is added to the double-layer planning model.

[0031] The calculation method of the line failure rate is as follows:

[0032]

[0033] wherein, λa (x) is the failure rate under the weather of a, times / (km·month); N axi is the number of failures of the i-th line in the x-th month in n years due to the weather of a; T ax is the duration of the weather of a in the x-th month in the historical same period; L i is the length of the i-th line, km.

[0034] To achieve the above object, the second aspect of the present application provides a power distribution network fault recovery control device, the device comprising:

[0035] a fault category judgment module: for judging the fault category of the current fault of the power distribution network when the power distribution network fails, wherein the fault category includes the fault caused by meteorological factors and the fault caused by non-meteorological factors;

[0036] a time determination module: for determining the fault repair time of the current fault according to the fault category of the current fault of the power distribution network;

[0037] a parameter acquisition module: for time sectioning the fault repair time, and acquiring the distributed power supply, load state parameter and network structure parameter corresponding to each time period under the time section; wherein the distributed power supply at the fault moment of the power distribution network includes the current distributed power supply output condition, the load state parameter includes the load power demand, and the network structure parameter includes the on-grid state of the distributed power supply and the topological connection relationship of each node of the network at the current moment;

[0038] a solution establishment module: for establishing a bi-level programming model with network reconstruction as the upper model and island division as the lower model, taking the distributed power supply, load state parameter and network structure parameter corresponding to each time period at the fault moment of the power distribution network as the input of the bi-level programming model, and solving to obtain the power distribution network fault recovery scheme corresponding to each time period; wherein the power distribution network fault recovery scheme includes the topological reconstruction scheme and the objective function value;

[0039] a recovery control module: for issuing operation instructions to each switch device according to the power distribution network fault recovery scheme to control the recovery of the power distribution network fault.

[0040] In combination with the second aspect, in a possible implementation manner, the above-mentioned time determination module comprises:

[0041] a determination module: for adding the sum of time margins to the meteorological duration to determine the fault repair time when the fault category of the current fault of the power distribution network is the fault caused by meteorological factors; and for determining the fault repair time according to the worker line inspection when the fault category of the current fault of the power distribution network is the fault caused by non-meteorological factors.

[0042] To achieve the above object, the third aspect of the present application provides a computer readable storage medium, which stores a computer program, and the computer program, when executed by a processor, causes the processor to perform the following steps:

[0043] When the power distribution network fails, the fault category of the current fault of the power distribution network is determined, wherein the fault category includes a fault caused by meteorological factors and a fault caused by non-meteorological factors;

[0044] According to the fault category of the current fault of the power distribution network, the fault repair time of the current fault is determined;

[0045] The fault repair time is divided into time sections, and the distributed power supply, load state parameters and network structure parameters corresponding to each time section under the time section are obtained, wherein the distributed power supply at the fault time of the power distribution network includes the current distributed power supply output, the load state parameters include the load power demand, and the network structure parameters include the on-grid state of the distributed power supply and the topology connection relationship of each node of the network at the current time;

[0046] A bi-level programming model is established, which takes network reconstruction as an upper model and island division as a lower model, and the distributed power supply, load state parameters and network structure parameters corresponding to each time section at the fault time of the power distribution network are input into the bi-level programming model to obtain the power distribution network fault recovery scheme corresponding to each time section, wherein the power distribution network fault recovery scheme includes a topology reconstruction scheme and an objective function value;

[0047] According to the power distribution network fault recovery scheme, operation instructions are issued to each switch device to control the recovery of the power distribution network fault.

[0048] To achieve the above object, the fourth aspect of the present application provides a computer device, which includes a memory and a processor, and the memory stores a computer program, and the computer program, when executed by the processor, causes the processor to perform the following steps:

[0049] When the power distribution network fails, the fault category of the current fault of the power distribution network is determined, wherein the fault category includes a fault caused by meteorological factors and a fault caused by non-meteorological factors;

[0050] According to the fault category of the current fault of the power distribution network, the fault repair time of the current fault is determined;

[0051] The fault repair time is time-sectionally divided, and distributed power supply, load state parameters and network structure parameters corresponding to each time period under the time section are obtained; wherein the distributed power supply at the fault time of the power distribution network includes current distributed power supply output, the load state parameters include load power demand, and the network structure parameters include in-network state of the distributed power supply and topology connection relationship of each node of the network at the current time;

[0052] A bi-level programming model with network reconstruction as an upper model and island division as a lower model is established, and distributed power supply, load state parameters and network structure parameters corresponding to each time period are input into the bi-level programming model to obtain a power distribution network fault recovery scheme corresponding to each time period; wherein the power distribution network fault recovery scheme includes a topology reconstruction scheme and an objective function value;

[0053] According to the power distribution network fault recovery scheme, operation instructions are issued to each switch device to control the recovery of the power distribution network fault.

[0054] The embodiment of the present application has the following beneficial effects:

[0055] The present application provides a power distribution network fault recovery control method, which determines the fault repair time of the current fault, time-sectionally divides the fault repair time, and obtains distributed power supply, load state parameters and network structure parameters corresponding to each time period under the time section; wherein the distributed power supply at the fault time of the power distribution network includes current distributed power supply output, the load state parameters include load power demand, and the network structure parameters include in-network state of the distributed power supply and topology connection relationship of each node of the network at the current time; the distributed power supply, load state parameters and network structure parameters corresponding to each time period are input into a bi-level programming model with network reconstruction as an upper model and island division as a lower model to obtain a power distribution network fault recovery scheme corresponding to each time period, and finally, the power distribution network fault is recovered according to the power distribution network fault recovery scheme. In the technical solution, the distributed power supply, load state parameters and network structure parameters corresponding to each time period under the time section are input into the bi-level programming model to obtain the power distribution network fault recovery scheme, which can realize the recovery control of the power distribution network fault at each time stage, avoid the re-fault caused by the fluctuation of the distributed power supply output during the fault, continuously reconstruct and optimize within the power distribution network fault repair time, ensure the feasibility of the power distribution network fault recovery scheme in the entire fault duration interval, and improve the grid resilience. BRIEF DESCRIPTION OF DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only represent some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0057] Wherein:

[0058] Figure 1 A flowchart of a power distribution network fault recovery control method in an embodiment of the present application is shown in FIG. 1.

[0059] Figure 2 A structural block diagram of a power distribution network fault recovery control device in an embodiment of the present application is shown in FIG. 2.

[0060] Figure 3 A structural block diagram of a computer device in an embodiment of the present application is shown in FIG. 3. DETAILED DESCRIPTION

[0061] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments only represent some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0062] The embodiments of the present application provide a power distribution network fault recovery control method, which is suitable for the scenario of adjusting the power distribution line switch to control the recovery of the normal operation of the power distribution network when the power distribution network fails.

[0063] Referring to Figure 1 , Figure 1 A flowchart of a power distribution network fault recovery control method provided in an embodiment of the present application is shown in FIG. 1, and the specific steps of the method are as follows: Figure 1

[0064] Step S101, when the power distribution network fails, determining the fault category of the current fault of the power distribution network.

[0065] When the power distribution network fails, first, the fault category of the current fault of the power distribution network is determined. In this embodiment, the fault category is classified according to the fault reason causing the current fault, and the fault category is specifically classified into a fault caused by meteorological factors and a fault caused by non-meteorological factors.

[0066] Step S102, determining the fault repair time of the current fault according to the fault category of the current fault of the power distribution network.

[0067] ​In the embodiment, the fault repair time of the current fault is determined according to different reasons causing the current fault of the power distribution network. Specifically, when the fault category of the current fault of the power distribution network is a fault caused by meteorological factors, since the duration of the extreme weather can be known through weather forecast when the fault is caused by meteorological disasters, the fault repair time is considered as the duration of the meteorological disasters plus a time margin, wherein the value of the time margin can be determined according to requirements, considering that it is impossible to reach the site for repair in time and fast and there is uncertainty in the output of the distributed power source in the region. When the fault category of the current fault of the power distribution network is a fault caused by non-meteorological factors, the fault repair time is determined according to the line inspection of workers, which can be preset by workers according to experience or determined according to preset rules in a possible implementation manner.

[0068] In step S103, the fault repair time is divided into time sections to obtain the distributed power source, the load state parameter and the network structure parameter corresponding to each time section under the time section; wherein the distributed power source at the fault time of the power distribution network includes the current distributed power output, the load state parameter includes the load power demand, and the network structure parameter includes the on-grid state of the distributed power source and the topological connection relationship of each node of the network at the current time.

[0069] After the fault repair time is determined, the fault repair time is divided into M time sections in the embodiment. Since the fluctuation of the distributed power output during the fault period can cause re-fault, in order to continuously reconfigure and optimize in the fault repair time of the power distribution network, ensure the feasibility of the fault recovery scheme of the power distribution network in the entire fault duration interval, and improve the feasibility of the recovery control scheme, the power distribution network is recovered and controlled for each time section in the embodiment. Specifically, for a target time section, wherein the target time section refers to any time section of the M time sections, the distributed power source at the fault time of the power distribution network, the load state parameter and the network structure parameter under the target time section are obtained, wherein the distributed power source at the fault time of the power distribution network includes the current distributed power output, the load state parameter includes the load power demand, and the network structure parameter includes the on-grid state of the distributed power source and the topological connection relationship of each node of the network at the current time.

[0070] The determination of the load power demand is mainly obtained from the historical load data of the same period through the metering data or the payment of the user electricity fee. Specifically, the relationship between the historical period x and the corresponding load data y of the historical period can be reflected by a fitting model y=f(x,c), wherein c={c1,c2,...,c n} is a pending parameter, when c appears linearly in the fitting model, then the fitting model is a linear model, otherwise it is a nonlinear model, the goodness of fit is measured by weighted least squares method, and finally the load power prediction value at a certain point in the future can be estimated through the fitted load curve. The fitting model used can include linear trend model, polynomial trend model, exponential trend model, logistic model, gompertz model, etc. At the same time, further, in order to better reflect the difference of power load between weekdays and weekends, the prediction of load power demand is carried out according to the historical same period of weekdays and weekends, and finally the output interval of distributed power and the load power demand interval in each period during the fault period can be obtained, as follows:

[0071] P DGi ∈[P DGi_min ,P DGi_max ];

[0072] P Li ∈[P Li_min ,P Li_max ];

[0073] Where, P DGi is the total output of the distributed power in the i th period; P DGi_min is the minimum output of the distributed power predicted in the i th period; P DGi_max is the maximum output of the distributed power predicted in the i th period; P Li is the total power of the load demand in the i th period; P Li_min is the minimum load power in the i th period; P Li_max is the maximum load power in the i th period.

[0074] Step S104, a bi-level programming model is established, taking network reconfiguration as the upper model and island division as the lower model, taking the distributed power, load state parameters and network structure parameters corresponding to each time period at the fault time of the distribution network as the input of the bi-level programming model, and solving to obtain the distribution network fault recovery scheme corresponding to each time period.

[0075] In the embodiment, a double-layer planning model is established in advance with network reconfiguration as an upper-layer model and island division as a lower-layer model, distributed power supply, load state parameters and network structure parameters at a fault time of the power distribution network in a target period are taken as inputs of the double-layer planning model, and a power distribution network fault recovery scheme corresponding to the target period is solved, wherein the power distribution network fault recovery scheme includes a topology reconfiguration scheme and a target function value, and the topology reconfiguration scheme includes an adjustment scheme of a power distribution network line switch. In the embodiment, the double-layer planning model can take the highest resilience of the power distribution network during the entire fault recovery period, that is, the minimum of various losses, including minimizing load loss, network loss and switch operation loss, as the target, and corresponding distributed power supply output constraint, power balance constraint, radial network structure constraint, voltage constraint, line capacity constraint and the like are established.

[0076] The target function of the island division as the lower-layer model is as follows:

[0077]

[0078] F DG1 is the equivalent recovery power of the distributed power supply during the fault duration; F DG2 is the benefit of avoiding power loss of the key load in the island; D represents a set of all nodes in the island; x j is the power-on state of the node j, x j = 0 indicates that the node loses power, x j = 1 indicates that the node recovers power; P Lj_equal is the equivalent recovery load power; t is the power loss time of the node during the fault; M j is the economic loss per unit time of the node due to power loss. The main target of the island division is to quickly recover as many important loads as possible and reduce the economic loss caused by the power loss of the key load, and the final normalized target function is as follows:

[0079] max F DG = β1F DG1 + β2F DG2 ;

[0080] F DG is the target function value of the island layer; F DG1 is the equivalent recovery power of the distributed power supply during the fault duration; F DG2 is the benefit of avoiding power loss of the key load in the island; β1 and β2 are weights. Different weights β1 and β2 can be selected according to different targets.

[0081] The constraint conditions of the island division include:

[0082]

[0083] PDGj P is the active power of distributed generation in island j; P Lj U is the load power of node j; U j U is the voltage amplitude of node j; U jmin and U jmax are the lower and upper limits of the voltage amplitude of node j, respectively; P k f is the branch power of branch k; f j f is the frequency of node j in island; f jmin and f jmax are the lower and upper limits of the frequency of node j, respectively. The island division mainly considers the constraints in the order of power constraint, node voltage constraint, branch power constraint, and radial topology constraint.

[0084] The network reconfiguration is taken as the objective function of the upper model:

[0085]

[0086] wherein, F main1 is the equivalent recovery power during the fault duration; Ω represents the set of all nodes outside the island; x j is the charging state of node j, x j = 0 indicates that the node loses power, x j = 1 indicates that the node recovers power; P Lj_equal is the equivalent recovery load power; t is the power loss time of the node during the fault duration; f DG1 is the equivalent recovery power of distributed generation during the fault duration; M j is the economic loss per unit time of the node due to power loss; F main2 is the economic loss due to avoiding key load power loss during the fault duration; C loss is the unit network loss cost; P i , Q i are the active power and reactive power injected by node i, respectively; U j is the node voltage; R l is the branch resistance.

[0087] The objective of network reconfiguration is mainly to maximize the load recovery, which includes the recovery power of the load in the island, to maximize the avoidable network loss cost and avoidable load power loss, and finally the normalized objective function is:

[0088] max F main = β3F main1 + β4F main2 ;

[0089] wherein, F main is the network reconfiguration layer objective function value, F main1 is the equivalent recovery power during the fault duration, Fmain2 To avoid the economic loss caused by the outage of critical loads during the fault duration, β3 and β4 are weights, and different weights β3 and β4 can be selected according to different targets.

[0090] The constraint conditions of network reconfiguration include:

[0091]

[0092] wherein, P i and Q i are the active power and reactive power injected by node i respectively; B ij is the conductance between node i and node j; G ij is the susceptance between node i and node j; s t is the number of switching operations within t period; S max is the maximum number of switching operations within period T; U i is the voltage amplitude of node i; U imin and U imax are the lower limit and upper limit of the voltage amplitude of node i respectively; θ ij is the phase angle difference between node i and node j; λ ak is the failure rate of the kth line under the current condition; λ max is the maximum allowable failure rate of the line; P ij is the active power value of branch ij; P ijmax is the maximum allowable active power value of branch ij; f i is the frequency of node i; f imin and f imax are the lower limit and upper limit of the frequency of node i respectively; g is the network topology structure obtained by the reconfiguration strategy; G is the set of all radial network structures on the outside of the island. The main constraints considered in network reconfiguration are in turn: power balance constraint, switching operation number constraint, line failure rate constraint, voltage constraint, branch power constraint, frequency stability constraint, and radial topology structure constraint.

[0093] Further, the line failure rate is added to the bi-level programming model, and the distribution network fault recovery scheme is determined in combination with the line failure rate programming. The line failure rate is usually obtained by statistical method, and the failure rate calculation method of distribution line is as follows:

[0094]

[0095] wherein, λ i is the failure rate of the ith line; N i is the number of failures of the line within the statistical period; L i is the length of the line; and n is the statistical years.

[0096] Wherein, under the weather conditions, the line fault rate calculation is carried out according to the historical same period month fault and statistics, and the calculation method of the line fault rate under different weather conditions is:

[0097]

[0098] Wherein, λ a (x) is the fault rate under a type of weather, times / (km·month); N axi is the number of times of faults of the ith line in the xth month in n years caused by a type of weather; T ax is the duration of a type of weather in the xth month of the historical same period; L i is the length of the ith line, km; k is the total number of lines.

[0099] In the embodiment, the distributed power supply, load state parameter and network structure parameter of the power distribution network at the target time period are taken as the input of the double-layer planning model, and the specific steps of solving the power distribution network fault recovery scheme corresponding to the target time period are as follows:

[0100] Step S201, input the distributed power supply, load state parameter and network structure parameter of the power distribution network at each time period into the double-layer planning model.

[0101] Step S202, solve the lower model by using the breadth-first algorithm, output the first result, input the first result into the upper model, solve the upper model by using the improved explorer algorithm, output the second result, input the second result into the lower model, return to execute the step of solving the lower model by using the breadth-first algorithm, output the first result, and iterate until the maximum iteration number or the calculation accuracy is reached, and output the power distribution network fault recovery scheme.

[0102] Wherein, the first result is an island power supply scheme, and the second result is a reconstruction scheme.

[0103] The distributed power supply, load state parameter and network structure parameter of the power distribution network at the target time period are input into the lower model of the double-layer planning model, the breadth-first algorithm is selected to solve the lower model, the island power supply scheme is output to the upper model of the double-layer planning model, the improved explorer algorithm is selected to solve the upper model, the reconstruction scheme is output, and then the reconstruction scheme is input into the lower model for re-solution, and the scheme is repeatedly updated until the maximum iteration number K0 or the calculation accuracy is reached, and the power distribution network fault recovery scheme is output.

[0104] Wherein, the entire power distribution network fault recovery scheme solving process is as follows:

[0105] Firstly, the distribution network fault time corresponding to the target period of distributed generation, load state parameters and network structure parameters are input, and the load is weighted according to the importance level. The equivalent load quantity calculation formula is:

[0106] P Lj_equal =ω L,j P L,j ;

[0107] Wherein, P Lj_equal is the equivalent load quantity considering the weight of node j; ω L,j is the importance degree quantization value of node j; P L,j is the load quantity of node j.

[0108] Secondly, after the fault of distribution network, the power circle search is carried out on the distributed power supply according to the capacity from small to large, and the load node with the largest equivalent load quantity is selected to be included in the island. Since the distributed power supply and the load are uncertain value sets during the fault recovery, the voltage optimization is introduced to seek the optimization scheme which is feasible under any possible value of uncertain parameters. The model is as follows:

[0109]

[0110] Wherein, F DG is the target function value; D is the selected island node set; β1 and β2 are weight coefficients, which can be adjusted; P ij is the active power value of branch ij; P ijmax is the maximum active power value allowed by branch ij; P DG is the distributed power output value; is the expected distributed power output value; μ DGj is the bias fluctuation control quantity of distributed power supply; σ DGj is the maximum bias value of distributed power output; P L is the load power; is the expected load power value; μ Lj is the bias fluctuation control quantity of load; σ Lj is the maximum bias value of power; f j is the frequency of node j; f jmin and f jmax are the lower limit and upper limit of the frequency of node j respectively; Γ is the robust control parameter, which can control the robustness of island division by setting Γ.

[0111] Then, each island divided is involved in the upper layer reconstruction model calculation as a whole, an improved explorer algorithm is adopted, that is, a mutation stage of a differential evolution algorithm is introduced into the explorer algorithm, and the distribution network is optimized and reconstructed, and in this process, the lower layer island can be possibly merged into the network side reconstruction layer.

[0112] The double layer planning model is solved in a very short time after the distribution network fault, and a fault recovery reconstruction is performed according to the finally generated distribution network fault recovery scheme, and during the fault repair time, since the distributed power output and the load value are given based on the prediction interval, the robust optimization is introduced into the island division model to ensure that the power constraint in the island can still be met in the worst case, and the lower layer model is used to re-plan the power supply recovery scheme in each time period during the fault period.

[0113] In step S105, operation instructions are issued to each switch device according to the distribution network fault recovery scheme to control the recovery of the distribution network fault.

[0114] According to the distribution network fault recovery scheme, operation instructions are issued to each switch device, and each switch device is adjusted according to the operation instructions, so that the recovery control of the distribution network fault can be realized.

[0115] Based on the above method, first, compared with the traditional fault recovery network reconstruction method, the present application considers the risk of secondary fault that can occur during the fault period after the initial network reconstruction of the distribution network, and combines fault recovery with reconstruction optimization; second, the present application takes different forms of recovery time estimation according to line faults caused by different fault reasons, and the specific division of the time period for dynamic optimization reconstruction has more theoretical basis, and can greatly improve the continuous power supply capacity of the key load; third, the present application considers the mutual correlation between island division and network reconstruction, and adopts the way of combining new energy with island division and network side reconstruction to build a distribution network fault recovery model, and the final optimization scheme has global optimality, which is helpful to improve the resilience of the power grid; fourth, the present application predicts the distributed power output interval and the load interval in different time periods during the fault recovery period, and introduces robust optimization to divide the island, which is beneficial to minimize the risk index and improve the resilience of the distribution network.

[0116] In order to better realize the above method, an embodiment of the present application provides a distribution network fault recovery control device, which can be used to realize all functions of the above method, and the device is used to realize the above method. Figure 2 , Figure 2 The structure block diagram of the distribution network fault recovery control device provided by the embodiment of the present application is shown as Figure 2 The device comprises:

[0117] The fault category judgment module 201 is configured to judge a fault category of a current fault of the power distribution network when the power distribution network has the fault, wherein the fault category includes a fault caused by a meteorological factor and a fault caused by a non-meteorological factor.

[0118] The time determination module 202 is configured to determine a fault repair time of the current fault according to the fault category of the current fault of the power distribution network.

[0119] The parameter acquisition module 203 is configured to perform time sectioning on the fault repair time, and acquire distributed power supply, load state parameter and network structure parameter corresponding to each time period under the time sectioning, wherein the distributed power supply at the fault time of the power distribution network includes a current distributed power supply output condition, the load state parameter includes a load power demand, and the network structure parameter includes an on-grid state of the distributed power supply and a topological connection relationship of each node of the network at the current time.

[0120] The establishment and solution module 204 is configured to establish a bi-level programming model with network reconstruction as an upper model and island division as a lower model, take the distributed power supply, the load state parameter and the network structure parameter corresponding to each time period as inputs of the bi-level programming model, and solve to obtain a power distribution network fault recovery scheme corresponding to each time period, wherein the power distribution network fault recovery scheme includes a topological reconstruction scheme and a target function value.

[0121] The recovery control module 205 is configured to publish operation instructions to each switch device according to the power distribution network fault recovery scheme, and perform recovery control on the power distribution network fault.

[0122] In a possible design, the time determination module 202 includes a determination module, which is configured to, when the fault category of the current fault of the power distribution network is the fault caused by the meteorological factor, determine the fault repair time by adding a meteorological duration and a sum of time margins; and when the fault category of the current fault of the power distribution network is the fault caused by the non-meteorological factor, determine the fault repair time according to worker line inspection.

[0123] In a possible design, the establishment and solution module 204 is specifically configured to: the target function of the island division as the lower model is:

[0124] max F DG =β1F DG1 +β2F DG2 ;

[0125] Wherein, F DG is a target function value of the island layer; F DG1 is an equivalent recovery electric quantity of the distributed power supply during the fault duration; and F DG2The benefits of avoiding power failure of key loads in the island; β1 and β2 are weights;

[0126] The constraint conditions of the island division include:

[0127]

[0128] P DGj is the active power of the distributed power supply of node j in the island; P Lj is the load power of node j; U j is the voltage amplitude of node j; U jmin and U jmax are the lower limit and upper limit of the voltage amplitude of node j, respectively; P k is the branch power of branch k; f j is the frequency of node j in the island; f jmin and f jmax are the lower limit and upper limit of the frequency of node j, respectively. The island division mainly considers the constraints in the order of power constraint, node voltage constraint, branch power constraint, and radial topology constraint.

[0129] In a possible design, the solving module 204 is specifically configured to: the objective function of the network reconstruction as the upper model is:

[0130] max F main = β3F main1 + β4F main2

[0131] Wherein, F main is the network reconstruction layer objective function value; F main1 is the equivalent recovery power during the fault duration; F main2 is the economic loss caused by avoiding power failure of key loads during the fault duration; β3 and β4 are weights;

[0132] The constraint conditions of the network reconstruction include:

[0133]

[0134] P i and Q i are the active power and reactive power injected by node i, respectively; B ij is the conductance between node i and node j; G ij is the susceptance between node i and node j; s t is the number of switch operations in the t period; S max is the maximum number of switch operations in the period T; U i is the voltage amplitude of node i; U imin and U imaxThese are the lower and upper limits of the voltage amplitude at node i, respectively; θ ij λ is the phase angle difference between node i and node j. ak Let λ be the failure rate of the k-th line under the current conditions; max P represents the maximum permissible fault rate of the line. ij P represents the active power value of branch ij. ijmax f is the maximum allowable active power of branch ij; i f is the frequency magnitude of node i; imin and f imax Here, represents the lower and upper limits of the frequency of node i, respectively; g represents the network topology obtained by the reconstruction strategy; and G represents the set of all radial network structures on the island's external network side. The main constraints considered in network reconstruction are, in order: power balance constraint, number of switching operations constraint, line failure rate constraint, voltage constraint, branch power constraint, frequency stability constraint, and radial topology constraint.

[0135] In one possible design, the solution module 204 is specifically used to: input the distributed power source, load state parameters, and network structure parameters corresponding to the distribution network fault time for each time period into the bi-level programming model; solve the lower-level model using a breadth-first search algorithm, output a first result, substitute the first result into the upper-level model, solve the upper-level model using an improved pathfinder algorithm, output a second result, input the second result into the lower-level model, and return to iterate the steps of solving the lower-level model using a breadth-first search algorithm and outputting the first result until the maximum number of iterations or calculation accuracy is reached, and output the distribution network fault recovery scheme.

[0136] Based on the above device, by determining the fault repair time of the current fault, the fault repair time is time-sectioned, and the distributed power supply, load state parameter and network structure parameter corresponding to each time period under the time section are obtained; wherein the distributed power supply at the fault time of the power distribution network includes the current distributed power supply output condition, the load state parameter includes the load power demand, and the network structure parameter includes the on-grid state of the distributed power supply and the topological connection relationship of each node of the network at the current time; the distributed power supply, load state parameter and network structure parameter corresponding to each time period at the fault time of the power distribution network are input into the double-layer planning model with network reconstruction as the upper model and island division as the lower model, and the power distribution network fault recovery scheme corresponding to each time period is solved, and finally, the power distribution network fault is recovered according to the power distribution network fault recovery scheme. In the technical scheme, by inputting the distributed power supply, load state parameter and network structure parameter corresponding to each time period under the time section into the double-layer planning model, the power distribution network fault recovery scheme is solved, the power distribution network fault at each time stage can be recovered and controlled in a targeted manner, the re-failure caused by the fluctuation of the distributed power supply during the fault is avoided, the optimization can be continuously reconstructed within the fault repair time of the power distribution network, the feasibility of the power distribution network fault recovery scheme in the entire fault duration interval is ensured, and the grid resilience is improved.

[0137] Figure 3 An internal structure diagram of a computer device in an embodiment is shown. The computer device can be a terminal or a server. As shown in the figure, Figure 3 The computer device includes a processor, a memory and a network interface connected through a system bus. The memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the computer device stores an operating system, and can also store a computer program, which, when executed by the processor, can enable the processor to implement all steps of the above method. The internal memory can also store a computer program, which, when executed by the processor, can enable the processor to execute all steps of the above method. Those skilled in the art can understand, Figure 3 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement.

[0138] In one embodiment, a computer device is provided, including a memory and a processor, the memory storing a computer program, the computer program being executed by the processor to enable the processor to execute each step of the above method.

[0139] In one embodiment, a computer readable storage medium is provided, which stores a computer program. The computer program is executed by a processor to make the processor perform the steps of the above method.

[0140] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a non-volatile computer readable storage medium. When the program is executed, it can include the processes of the above-mentioned embodiments. Any reference to memory, storage, database or other medium used in the embodiments provided by the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0141] The technical features of the above embodiments can be combined in any way. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not contradict, they should be considered within the scope of the present disclosure.

[0142] The above embodiments only express several implementation manners of the present application, and the description is specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the scope of protection of the patent of the present application should be subject to the appended claims.

Claims

1. A power distribution network fault restoration control method, characterized by, The method comprises: When the power distribution network fails, determining the fault category of the current fault of the power distribution network, wherein the fault category comprises a fault caused by meteorological factors and a fault caused by non-meteorological factors; According to the fault category of the current fault of the power distribution network, determining the fault repair time of the current fault; Time section division is performed on the fault repair time to obtain the distributed power supply, load state parameter and network structure parameter corresponding to each time period under the time section, wherein the distributed power supply at the fault time of the power distribution network comprises the current distributed power supply output, the load state parameter comprises the load power demand, and the network structure parameter comprises the on-grid state of the distributed power supply and the topological connection relationship of each node of the network at the current time; A bi-level programming model is established with network reconstruction as the upper model and island division as the lower model, the distributed power supply, load state parameter and network structure parameter corresponding to each time period at the fault time of the power distribution network are input into the bi-level programming model, and the fault recovery scheme corresponding to each time period of the power distribution network is solved; wherein the fault recovery scheme of the power distribution network comprises a topological reconstruction scheme and a target function value; According to the fault recovery scheme of the power distribution network, operation instructions are issued to each switch device to control the recovery of the power distribution network fault; The target function of the island division as the lower model is: ； wherein, is the island layer objective function value; is the equivalent restoration energy of the distributed power supply during the fault duration; is the benefit of avoiding power failure of the key load in the island; and is the weight; The target function of the network reconstruction as the upper model is: ； wherein, is the network reconfiguration layer objective function value; is the equivalent recovery energy during the fault duration; is the economic loss avoided by not powering down critical loads during the fault duration; and is the weight.

2. The method of claim 1, wherein, The constraint condition of the island division comprises: in, Nodes within the island j The active power output of distributed power sources; For nodes j The load power; For nodes j Voltage amplitude; and They are nodes j The lower and upper limits of voltage amplitude; branch road k The branch power; Nodes within the island j The frequency; and They are nodes j The lower and upper limits of frequency.

3. The method of claim 1, wherein, The constraint condition of the network reconstruction comprises: ； wherein, , are the injected active power and reactive power of node i ; are the conductance between node i and node j ; are the susceptance between node i and node j ; is the number of switching operations within a time period t ; is the maximum number of switching operations within a period T; is the voltage amplitude of node i ; are the lower and upper limits of the voltage amplitude of node ; i is the phase angle difference between node and node i ; j ; is the failure rate of the k th line under the current condition; is the maximum allowable failure rate of the line; is the active power value of branch The bi-level programming model is input into the bi-level programming model with the distributed power supply, load state parameter and network structure parameter corresponding to each time period at the fault time of the power distribution network as the input, and the fault recovery scheme corresponding to each time period of the power distribution network is solved, comprising: ; is the maximum allowable active power value of branch The bi-level programming model is input into the bi-level programming model with the distributed power supply, load state parameter and network structure parameter corresponding to each time period at the fault time of the power distribution network as the input; ; is the frequency of node i ; are the lower and upper limits of the frequency of node ; i g is the network topology structure obtained by the reconstruction strategy; and G is the set of all radial network structures on the outside of the island.

4. The method of claim 1, wherein, The first result is output by solving the lower model by using the breadth-first algorithm, the first result is input into the upper model, the second result is output by solving the upper model by using the improved explorer algorithm, the second result is input into the lower model, and the step of outputting the first result by solving the lower model by using the breadth-first algorithm is iterated until the maximum iteration number or the calculation accuracy is reached, and the fault recovery scheme of the power distribution network is output. The determination of the fault repair time of the current fault according to the fault category of the current fault of the power distribution network comprises: When the fault category of the current fault of the power distribution network is the fault caused by meteorological factors, the sum of the meteorological duration and the time margin is determined as the fault repair time; 5. The method of claim 1, wherein, When the fault category of the current fault of the power distribution network is the fault caused by non-meteorological factors, the fault repair time is determined according to the worker line inspection. The line fault rate is added in the bi-level programming model; The calculation method of the line fault rate is:

6. The method of claim 1, wherein, The device is used to implement the method according to any one of claims 1 to 6, and the device comprises: ​ ； wherein, is a the failure rate under the weather of the same type, times / (km·month); is n the number of failures of the line in the month due to the weather of the same type; i is x the number of failures of the line in the month due to the weather of the same type; a is the duration of the weather of the same type in the month; x is a the duration of the weather of the same type in the month; is i the length of the line, km.

7. A power distribution network fault restoration control apparatus characterized by comprising: ​ The fault category judgment module is configured to determine a fault category of a current fault of the power distribution network when the power distribution network has the fault, wherein the fault category includes a fault caused by a meteorological factor and a fault caused by a non-meteorological factor. The time determination module is configured to determine a fault repair time of the current fault according to the fault category of the current fault of the power distribution network. The parameter acquisition module is configured to perform time sectioning on the fault repair time, and acquire distributed power supply, load state parameter and network structure parameter corresponding to each time period under the time sectioning, wherein the distributed power supply at the fault time of the power distribution network includes a current distributed power supply output condition, the load state parameter includes a load power demand, and the network structure parameter includes an on-grid state of the distributed power supply and a topology connection relationship of each node of the network at the current time. The solution establishment module is configured to establish a double-layer planning model with network reconstruction as an upper model and island division as a lower model, take the distributed power supply, the load state parameter and the network structure parameter corresponding to each time period as inputs of the double-layer planning model, and solve to obtain a power distribution network fault recovery scheme corresponding to each time period, wherein the power distribution network fault recovery scheme includes a topology reconstruction scheme and a target function value. The recovery control module is configured to release operation instructions to each switch device according to the power distribution network fault recovery scheme, and perform recovery control on the power distribution network fault.

8. The apparatus of claim 7, wherein, The time determination module includes: The determination module is configured to add a sum of time margins to a meteorological duration to determine the fault repair time when the fault category of the current fault of the power distribution network is the fault caused by the meteorological factor, and determine the fault repair time according to worker line inspection when the fault category of the current fault of the power distribution network is the fault caused by the non-meteorological factor.

9. A computer readable storage medium storing a computer program, characterized in that, The computer program is executed by the processor to make the processor execute the steps of the method in any one of claims 1 to 6. 10.A computer device, comprising a memory and a processor, and characterized in that, The memory stores the computer program, and the computer program is executed by the processor to make the processor execute the steps of the method in any one of claims 1 to 6.

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