A distribution network fault recovery method and device considering the impact of waterlogging disasters

Abstract

The present invention discloses a distribution network fault recovery method and device that takes into account the impact of urban flooding disasters. The method constructs an objective function based on minimizing the loss load of the distribution system, minimizing meaningless scheduling, minimizing the number of islands, and minimizing line losses, and solves the objective function under constraint conditions. That is, the solution model fully considers the coordination between emergency resource scheduling and distribution network repair, takes minimizing load losses as the main optimization goal, avoids meaningless manpower scheduling and considers island operation costs, and minimizes line losses as much as possible, thereby outputting the optimal distribution network fault recovery strategy and achieving rapid recovery of distribution network faults.

Description

Technical Field

[0001] The present invention relates to the technical field of power system analysis, and in particular to a distribution network fault recovery method and device taking into account the impact of waterlogging disasters. Background Art

[0002] The increasing frequency of extreme disasters poses a significant challenge to the resilience of power grid systems to severe distribution network failures. To address the threat of extreme disasters like flooding, meteorological warning data is often used to predict the operating status of substations before a flood disaster strikes. Based on these predictions, substations are selected for installation of protective equipment and the deployment of mobile emergency power supplies before a disaster occurs, minimizing the impact of the disaster on the distribution network.

[0003] However, the ability to retrofit substations with protective equipment is limited, and dispatchers cannot simultaneously install protective dams for all potentially faulty substations. Furthermore, the number of backup distributed generators available to dispatchers is limited. Therefore, after a flood disaster, dispatchers must analyze the controllable and coordinated interconnection line topology and the number of repair personnel, fully leveraging the impact of dispatching decisions on network operation to ensure power supply reliability. However, current prediction models fail to produce accurate predictions, leading to meaningless dispatching and irrational allocation of repair resources during the repair process, hindering the rapid and effective recovery of distribution network failures. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: a distribution network fault recovery method and device taking into account the impact of waterlogging disasters, which realizes rapid recovery of distribution network faults by reasonably allocating distribution network repair resources.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A method for restoring a distribution network fault considering the impact of waterlogging disasters, comprising the following steps:

[0007] Obtain initial data information of the power distribution system;

[0008] According to the initial data information of the distribution system, a distribution system loss load function, a meaningless scheduling function, an island number function and a line loss function are respectively constructed, and an objective function is constructed with the distribution system having the minimum loss load, the least meaningless scheduling, the least island number and the lowest line loss;

[0009] Constraint conditions are constructed, and the objective function is solved under the constraint conditions to obtain an optimal distribution network restoration plan.

[0010] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0011] A distribution network fault recovery device that takes into account the impact of urban flooding disasters includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, each step of the above-mentioned distribution network fault recovery method that takes into account the impact of urban flooding disasters is implemented.

[0012] The beneficial effects of the present invention are as follows: by constructing an objective function with the minimum loss load of the distribution system, the minimum meaningless scheduling, the minimum number of islands and the lowest line loss, and solving the objective function under the constraint conditions, that is, the solution model fully considers the coordination between emergency resource scheduling and distribution network repair, takes minimizing load loss as the main optimization goal, avoids meaningless manpower scheduling and considers the island operation cost, and reduces line loss as much as possible, thereby outputting the best distribution network fault recovery strategy and achieving rapid recovery of distribution network faults. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a flowchart of the steps of a distribution network fault recovery method considering the impact of waterlogging disasters in an embodiment of the present invention;

[0014] Figure 2 Schematic diagram of the modified IEEE 33-node power distribution system structure in an embodiment of the present invention;

[0015] Figure 3 This is a diagram showing the resource scheduling decision effect during the restoration process of a distribution network fault restoration method considering the impact of waterlogging disasters in a moderate rainfall scenario according to an embodiment of the present invention;

[0016] Figure 4 This is a diagram showing the resource scheduling decision-making effect during the restoration process of a distribution network fault restoration method considering the impact of waterlogging disasters in a heavy rainfall scenario according to an embodiment of the present invention;

[0017] Figure 5 This is a topological diagram of the original distribution network in a moderate precipitation prediction scenario in an embodiment of the present invention;

[0018] Figure 6 This is a topological diagram of the distribution network after static emergency resources are put into use in an embodiment of the present invention;

[0019] Figure 7 This is a topological diagram of the distribution network after coordinated tie switches in an embodiment of the present invention;

[0020] Figure 8 This is a topological diagram of the distribution network after the first round of emergency repair work in an embodiment of the present invention;

[0021] Figure 9 This is a topological diagram of the distribution network after the second round of emergency repair work in an embodiment of the present invention;

[0022] Figure 10 Schematic diagram of the structure of a distribution network fault recovery device taking into account the impact of waterlogging disasters in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] To illustrate the technical content, achieved objectives and effects of the present invention in detail, the following description is given in conjunction with the embodiments and accompanying drawings.

[0024] Please refer to Figure 1 A method for restoring a distribution network fault considering the impact of waterlogging disasters comprises the following steps:

[0025] Obtain initial data information of the power distribution system;

[0026] According to the initial data information of the distribution system, a distribution system loss load function, a meaningless scheduling function, an island number function and a line loss function are respectively constructed, and an objective function is constructed with the distribution system having the minimum loss load, the least meaningless scheduling, the least island number and the lowest line loss;

[0027] Constraint conditions are constructed, and the objective function is solved under the constraint conditions to obtain an optimal distribution network restoration plan.

[0028] From the above description, it can be seen that the beneficial effects of the present invention are: by constructing an objective function with the minimum loss load of the distribution system, the minimum meaningless scheduling, the minimum number of islands and the lowest line loss, and solving the objective function under the constraints, that is, the solution model fully considers the coordination between emergency resource scheduling and distribution network repair, with minimizing load loss as the main optimization goal, while avoiding meaningless manpower scheduling and considering island operation costs, and reducing line losses as much as possible, thereby outputting the best distribution network fault recovery strategy and achieving rapid recovery of distribution network faults.

[0029] Furthermore, the distribution system loss load function, meaningless scheduling function, island number function and line loss function are respectively constructed based on the initial data information of the distribution system, and the objective function is constructed with the distribution system loss load being minimized, the meaningless scheduling being minimized, the number of islands being minimized and the line loss being minimized, including:

[0030]

[0031] Where, represents the active load demand of substation i, represents the node active load acquisition of substation i in period t, t0 represents the number of periods, and constitutes the loss load function of the distribution system; z i,trepresents the emergency repair status decision of substation i in time period t. When it is 1, it means that substation i has restored its working capacity. ξ1 is a correction parameter, which constitutes the meaningless scheduling function; Indicates the state of substation i in time period t. If substation i is an island leading node, is 1, ξ2 is a correction parameter, constituting the island number function; represents the active output of the generator at substation i, ξ3 is the correction parameter, and they constitute the line loss function.

[0032] From the above description, it can be seen that by constructing the objective function based on the distribution system loss load function, the meaningless scheduling function, the island number function and the line loss function, it is possible to solve the distribution network fault recovery plan with emergency resource scheduling and network reconstruction that minimizes the distribution system loss load, the meaningless scheduling, the number of islands and the line loss under given constraints.

[0033] Furthermore, the constructing of constraint conditions and solving the objective function under the constraint conditions to obtain the optimal distribution network restoration solution includes:

[0034] Construct reinforcement cost constraints, mobile emergency power supply quantity constraints, repair and restoration capacity constraints, line operation constraints, substation and line working capacity constraints, distribution network radiation operation constraints, and system power flow constraints;

[0035] The objective function is solved under the reinforcement cost constraint, the mobile emergency power supply quantity constraint, the emergency repair and restoration capacity constraint, the line operation constraint, the substation and line working capacity constraint, the distribution network radiation operation constraint and the system flow constraint to obtain the optimal distribution network restoration plan.

[0036] From the above description, it can be seen that by constructing multiple constraints to constrain the objective function, the objective function needs to output the optimal solution while satisfying the corresponding constraints, thereby outputting the best distribution network fault recovery plan for emergency resource scheduling and network reconstruction.

[0037] Furthermore, the construction reinforcement cost constraints include:

[0038] Obtain the total reinforcement budget;

[0039] The protection installation decision is constrained according to the total reinforcement budget to obtain the reinforcement cost constraint:

[0040]

[0041] Where s i To protect the decision variables, when s i When s is 1, it is considered that protection measures are installed for substation i before the disaster occurs; when s iWhen it is 0, no protection measures are installed in substation i; Γ i is the protection cost of substation i, B is the total reinforcement budget of the dispatcher, that is, the total reinforcement cost cannot exceed the budget B; the protection installation decision is used to decide whether to install protection measures for the substation.

[0042] From the above description, it can be seen that by establishing a reinforcement cost constraint to constrain the objective function, the number of substations that need to install protection measures is limited, avoiding excessive reinforcement costs and increasing the distribution network restoration cost.

[0043] Furthermore, the construction of the mobile emergency power supply quantity constraint includes:

[0044] Obtain the total number of dispatchable mobile emergency power sources;

[0045] The decision of the mobile emergency power supply is constrained according to the total number of the dispatchable mobile emergency power supplies to obtain the constraint on the number of mobile emergency power supplies:

[0046]

[0047] 0≤dg i ;

[0048] Among them, dg i is the decision variable for the mobile emergency power supply, which indicates the number of mobile emergency power supplies deployed in substation i. Mobile emergency power supplies can only be deployed before a disaster. c is the total number of dispatchable mobile emergency power supplies. The mobile emergency power supply decision variable is used to determine whether to deploy a mobile emergency power supply in a substation.

[0049] From the above description, it can be seen that by limiting the number of mobile emergency power supplies in the distribution network, it is avoided that a large number of mobile emergency power supplies are invested in order to quickly restore the faulty power grid, which leads to an increase in the distribution network restoration cost.

[0050] Furthermore, the construction of emergency repair and recovery capability constraints includes:

[0051] Obtain the total number of emergency repair work teams available for dispatch;

[0052] According to the total number of emergency repair work groups available for dispatch, the emergency repair and restoration decision and the number of emergency repair groups required in each period are constrained to obtain the emergency repair and restoration capacity constraint:

[0053]

[0054] 0≤z i,t ≤z i,t+1 ;

[0055] Where z i,tis the emergency repair and restoration decision, with a value of 0-1. When it is 1, it means that the substation i has completed the emergency repair at time t and will not be shut down again; D represents the total number of emergency repair work teams available for dispatch; λ t It represents the number of emergency repair teams required for the substation in time period t; the emergency repair and restoration decision is used to determine the substation that needs to be repaired in the current time period; the number of emergency repair teams required in each time period is determined by the total number of emergency repair work teams and the emergency repair and restoration decision.

[0056] From the above description, it can be seen that by limiting the total number of emergency repair work teams available for dispatch during the distribution network repair process, it is possible to maximize the use of limited emergency repair work teams to output the best emergency repair and restoration decision for the current period.

[0057] Furthermore, the construction line operation constraints include:

[0058]

[0059] Where, Indicates the line working status parameter, the value is 0-1, when it is 1, it is considered that the line is ij Normal operation during period t; when it is 0, it is considered that line l ij Disconnect during period t; i,t represents the potential working capacity of substation i in period t; when o i,t =0, the substation i is considered to have working capability;

[0060] The construction of substation and line working capacity constraints includes:

[0061] o i,t ≥(1-y i )(1-s i )(1-z i,t );

[0062] Where y i Indicates the expected working status of the node i in the substation. When it is 1, it means that the substation i is working normally. i Indicates protection installation decision; i,t Indicates emergency repair and recovery decision.

[0063] From the above description, it can be seen that by constructing line operation constraints to describe the working status of each route, and establishing substation and line working capacity constraints to describe the relationship between the lines of each substation node, the substation with the most restoration benefit in the current period can be restored first, thereby improving the distribution network restoration effect.

[0064] Furthermore, the construction of distribution network radiation operation constraints includes:

[0065]

[0066]

[0067]

[0068]

[0069]

[0070] Where, Indicates whether substation i is a distribution network node. If If it is 1, it means that substation i is a grid node; Indicates the working status of substation i, if If it is 1, it means that substation i can work normally; represents the state of substation i in time period t; g i,t represents the virtual power output provided by substation i to the power grid after it is selected as the dominant node in time period t; f ij,t represents the line l of substation i in time period t ij The virtual tidal current size; f jk,t represents the line l of substation i in time period t jk The size of the virtual current; M represents a maximum positive constant.

[0071] As can be seen from the above description, by constructing grid radiation operation constraints, based on the working status of substations in the distribution network and the virtual power output provided by the simulated substation to the grid system after being selected as the dominant node, the substation repair process can be effectively simulated and accurate repair decisions can be output.

[0072] Furthermore, the initial data information of the power distribution system includes load demand information and network topology information;

[0073] The construction of system power flow constraints includes:

[0074] Establishing an active power balance model and a reactive power balance model of the power distribution system according to the load demand information and the network topology information; and obtaining upper and lower limits of voltage, upper and lower limits of active and reactive power output, and upper and lower limits of active and reactive power supply for each substation according to the load demand information;

[0075] The system flow constraint is obtained according to the active power balance model, the reactive power balance model, the upper and lower limits of each substation voltage, the upper and lower limits of active and reactive output, and the upper and lower limits of active and reactive supply.

[0076] From the above description, it can be seen that by establishing the active power balance model and reactive power balance model of the power distribution system, and obtaining the upper and lower limits of the voltage, the upper and lower limits of the active and reactive output, and the upper and lower limits of the active and reactive supply of each substation based on the load demand information and circuit form of the distribution network, it is ensured that each substation can operate normally during the repair process.

[0077] Another embodiment of the present invention provides a distribution network fault recovery device that takes into account the impact of urban flooding disasters, including a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the computer program, it implements the various steps in the above-mentioned distribution network fault recovery method that takes into account the impact of urban flooding disasters.

[0078] The present invention relates to a distribution network fault recovery device and apparatus that takes into account the impact of waterlogging disasters. A fault recovery model is established by considering the relationship between emergency resource scheduling and distribution network reconstruction. By solving the model, a distribution network fault recovery solution is obtained that minimizes the loss of load in the distribution system, minimizes meaningless scheduling, minimizes the number of islands, and minimizes line losses. This solution achieves rapid recovery from distribution network faults. The following is an explanation of the specific implementation methods:

[0079] Example 1

[0080] Please refer to Figure 1 A method for restoring a distribution network fault considering the impact of waterlogging disasters comprises the following steps:

[0081] S1. Obtaining initial data information of the power distribution system; the initial data information of the power distribution system includes given fault information, load demand information, network topology information, mobile emergency power supply information, etc.;

[0082] S2. Based on the initial data information of the distribution system, a distribution system loss load function, a meaningless scheduling function, an island number function, and a line loss function are respectively constructed, and the objective function is constructed with the minimum loss load of the distribution system, the minimum meaningless scheduling, the minimum number of islands, and the lowest line loss to obtain:

[0083]

[0084] Where, represents the active load demand of substation i, represents the node active load acquisition of substation i in time period t, t0 represents the number of time periods, and constitutes the loss load function of the distribution system, that is, reducing the total loss of load on the total time scale is the primary optimization goal of the objective function;

[0085] z i,trepresents the emergency repair status decision of substation i in time period t. When it is 1, it means that substation i has restored its working capacity. ξ1 is a correction parameter, which constitutes the meaningless scheduling function to avoid meaningless scheduling decisions. When all substations resume normal operation, the dispatch of emergency repair personnel will have no impact on the working status of the distribution network. i,t will not change over time;

[0086] Indicates the state of substation i in time period t. If substation i is an island leading node, =1, ξ2 is a correction parameter, forming the islanding number function for reducing the number of islanding operations. Islanding is a special operating mode of a faulty distribution network, in which a distributed generator set acts as the main frequency regulating unit to provide power to the load in the network, and is affected by the dispatching capacity and the working capacity of the distributed units. Since allowing a substation to operate in the form of an island incurs higher risks and costs, it is necessary to avoid substations operating in the form of an island as much as possible.

[0087] represents the active output of the generator of substation i, ξ3 is a correction parameter, which constitutes the line loss function for reducing line loss; in an optional embodiment, the values ​​of ξ1, ξ2 and ξ3 are 0.001;

[0088] S3. Construct constraint conditions, and solve the objective function under the constraint conditions to obtain the optimal distribution network restoration solution. Specifically:

[0089] S31. Construct reinforcement cost constraints, mobile emergency power supply quantity constraints, repair and restoration capacity constraints, line operation constraints, substation and line working capacity constraints, distribution network radiation operation constraints, and system power flow constraints;

[0090] The construction of the reinforcement cost constraint includes: obtaining a total reinforcement budget; constraining the protection installation decision according to the total reinforcement budget to obtain the reinforcement cost constraint:

[0091]

[0092] Where s i To protect the decision variables, when s i When s is 1, it is considered necessary to install protection measures for substation i before the disaster occurs; when s i When it is 0, substation i does not install protection measures, and it is assumed that the substation installed with protection measures will not be shut down due to waterlogging disasters, Γ i is the protection cost of substation i, B is the total reinforcement budget of the dispatcher, that is, the total reinforcement cost cannot exceed the budget B; the protection installation decision is used to decide whether to install protection measures for the substation;

[0093] The constructing of the mobile emergency power supply quantity constraint includes: obtaining the total number of dispatchable mobile emergency power supplies; constraining the mobile emergency power supply decision according to the total number of dispatchable mobile emergency power supplies, to obtain the mobile emergency power supply quantity constraint:

[0094]

[0095] 0≤dg i ;

[0096] Where, dg i is the decision variable for mobile emergency power supply, which indicates the number of mobile emergency power supplies deployed in substation i. Mobile emergency power supplies can only be deployed before a disaster occurs and cannot be moved after a disaster occurs. c is the total number of dispatchable mobile emergency power supplies. The mobile emergency power supply decision variable is used to determine whether to deploy mobile emergency power supplies in a substation.

[0097] The construction of the emergency repair and restoration capability constraint includes: obtaining the total number of emergency repair work groups available for dispatch; constraining the emergency repair and restoration decision and the number of emergency repair work groups required for each time period according to the total number of emergency repair work groups available for dispatch, and obtaining the emergency repair and restoration capability constraint:

[0098]

[0099] 0≤z i,t ≤z i,t+1 ;

[0100] Where z i,t is the emergency repair and restoration decision, with a value of 0-1. When it is 1, it means that the substation i has been repaired at time t and will not be shut down again. i,t ≤z i,t+1 ; D represents the total number of emergency repair teams available for dispatch; λ t Indicates the number of emergency repair teams required for the substation during time period t, i.e., there is an upper limit on the number of substations that can be newly restored during time period t. The emergency repair and restoration decision is used to determine the substations that need to be repaired during the current time period. The number of emergency repair teams required for each time period is determined by the total number of emergency repair teams and the emergency repair and restoration decision.

[0101] The construction line operation constraints include:

[0102]

[0103] Where, Indicates the line working status parameter, the value is 0-1, when it is 1, it is considered that the line is ij Normal operation during period t; when it is 0, it is considered that line l ijDisconnected during period t; the working status of the line is affected by the working status of the substation connected to it on the one hand, and by the network topology on the other hand; i,t represents the potential working capacity of substation i in period t; when o i,t =0, the substation i is considered to be capable of working; when the substation i loses its working capacity due to waterlogging, the distribution lines connected to it also need to be temporarily disconnected from the network, and the substation's working capacity will constrain the lines connected to it;

[0104] The construction of substation and line working capacity constraints includes:

[0105] o i,t ≥(1-y i )(1-s i )(1-z i,t );

[0106] Where y i Indicates the expected working status of the node i in the substation. When it is 1, it means that the substation i is working normally. i Indicates protection installation decision; i,t Indicates emergency repair and restoration decision;

[0107] Among them, when the working capacity of substation i is not affected by floods i,t = 0; If substation i is expected to be shut down due to waterlogging, and the system operator has not installed protection devices before the failure, and the substation node is not able to be restored through emergency repairs in time period t, then it is considered that the substation node i has no ability to be put into system operation. At this time, o i,t =1; For a line, if any substation at one end loses its working capacity, the line needs to be cut off from the network.

[0108] Throughout the power restoration process, the distribution network must maintain radial topology constraints. A necessary and sufficient condition for radial constraints is to simultaneously satisfy connectivity and the node-edge number relationship. To ensure line connectivity, single-commodity flow constraints (SCFs) are used, and decision variables for island-leading power nodes are introduced. The number of islands is optimized while satisfying the node-edge number relationship. The Big-M method is also used to improve the SCF-radial constraint. When substations have potential operating capacity, the substation's operating status also needs to consider the network's topology. The construction of radial operation constraints for the distribution network includes:

[0109]

[0110]

[0111]

[0112]

[0113]

[0114] Where, Indicates the working status of substation i, with a value of 0-1. If it is 1, it means that substation i can work normally; Represents the state of substation i in time period t. If substation i is the island leading node, then is 1, otherwise 0; g i,t It represents the virtual power output that substation i provides to the power grid system after being selected as the leading node in time period t. When substation i is selected as the leading node, the node will be able to provide the system with a virtual power output of g. i,t ;f ij,t represents the line l of substation i in time period t ij The virtual power flow size is defined as the virtual power flow from the small-numbered node to the large-numbered node as the positive direction of the virtual power flow; M is a maximum positive constant; the substation can only participate in the work in the system when it has potential working capacity; the radial distribution network needs to meet the node-edge number relationship, and the total number of working lines cannot be more than the total number of nodes minus the number of islands; at the same time, the radial distribution network needs to meet the network connectivity, and the virtual power of the network is provided by the leading nodes of each island. Assuming that the virtual load demand of each participating substation node is 1, each substation node needs to meet the virtual power balance, and the total power injection is equal to the total power outflow, where u(j) is the front-end node set of substation node j, and v(j) is the back-end node set of substation node j; for transmission lines, they have virtual power transmission capability only when they participate in the system work in the current period; the working status of nodes and lines under the virtual power flow is the same as the working status in the actual power flow of the distribution network, that is, and It is constrained in the virtual flow and is used to represent the line l in the actual flow. ij and the working status of the substation i-node;

[0115] The system flow constraint is constructed by: establishing an active power balance model and a reactive power balance model of the power distribution system according to the load demand information and the network topology information; obtaining upper and lower limits of the voltage of each substation, upper and lower limits of the active and reactive output, and upper and lower limits of the active and reactive supply according to the load demand information; and obtaining the system flow constraint according to the active power balance model, the reactive power balance model, and the upper and lower limits of the voltage of each substation, the upper and lower limits of the active and reactive output, and the upper and lower limits of the active and reactive supply. Specifically:

[0116] The active power balance model is:

[0117]

[0118] The reactive power balance model is:

[0119]

[0120] Where, and Indicates line l ij The active and reactive power losses of the line in time period t are calculated when the energy flows into the target node; the actual power flowing into any node and the output of the generator set at that node are equal to the power flowing out of the node and the load supply at that node; Q ij,t Indicates line l ij Reactive power flows in time period t, and the reactive power flows from the smaller numbered node to the larger numbered node as the positive direction of reactive power; represents the reactive power supplied by substation i to the jurisdiction in time period t, represents the reactive power provided by substation i to the system in time period t, that is, the reactive output of the generator at this node; P ij,t Indicates line l ij Active power flows through time period i, and the active power flowing from the smaller numbered node to the larger numbered node is defined as the positive direction of active power; represents the active power supplied by substation i to the jurisdiction in time period t, represents the active power provided by substation i to the system in time period t, that is, the active output of the generator at this node; Indicates line l ij The square of the current flowing in time period t is defined as the current flowing from the smaller node to the larger node as the positive current direction;

[0121] Also includes line power constraints:

[0122]

[0123] Where, represents the square of the voltage value of substation i in time period t; the above formula is a deformation of the line power definition formula, and the relaxed constraint will be used to obtain the square of the line current;

[0124] It also includes deformation constraints based on Ohm's law and power definitions:

[0125]

[0126]

[0127] The upper and lower limit constraints of the substation voltage include:

[0128]

[0129] The upper and lower limits of the active and reactive output of the substation node include:

[0130]

[0131]

[0132] The upper and lower limits of active and reactive power supply of the substation node include:

[0133]

[0134]

[0135] It also includes the upper limit constraint of line transmission power:

[0136]

[0137] Where S max,ij Represents the power capacity of branch (i, j).

[0138] S32. Solve the objective function under the constraints of reinforcement cost, number of mobile emergency power supplies, repair and restoration capability, line operation, substation and line working capability, distribution network radiation operation, and system flow to obtain the optimal distribution network restoration plan.

[0139] Example 2

[0140] This embodiment describes the steps of the distribution network fault recovery method considering the impact of waterlogging disasters in the first embodiment in combination with specific application scenarios;

[0141] Please refer to Figure 2 This embodiment verifies the effectiveness and correctness of the above method based on a modified IEEE 33-node power distribution system. The capacity of each substation node is 5 MVA, and the system contains 32 sectionalizing branches and 5 tie-switch branches, with the sectionalizing branches represented by black solid lines and the tie-switch branches represented by black dashed lines. The network has a single power supply with a reference voltage of 12.66 kV. The time required to repair a substation is defined as a time period. This embodiment considers a total of six time periods. The disaster scenario settings are shown in Tables 1 and 2.

[0142] (1) Moderate rainfall disaster scenario:

[0143] In moderate rainfall scenarios, the distribution network failure rate is relatively lower. Assuming that the expected outage substation nodes are: 3, 4, 6, 9, 12, 14, 16, 17, and 28, a total of 9 substations; the actual outage substation nodes are: 3, 4, 6, 12, 14, 17, and 28, a total of 7 substations, with no unexpected failures.

[0144] Table 1. Workgroup requirements under moderate precipitation conditions

[0145]

[0146] (2) Heavy rainfall disaster scene:

[0147] In heavy rainfall scenarios, the distribution network failure rate is higher. Assume that the substations expected to be out of service are: 3, 4, 6, 9, 12, 14, 16, 17, 23, 28, 30, and 33, for a total of 12 substations.

[0148] Table 2. Working group requirements under heavy rainfall conditions

[0149]

[0150] Step 1: obtaining the initial data information of the power distribution system corresponding to the moderate rainfall disaster scenario according to the moderate rainfall disaster scenario, and obtaining the initial data information of the power distribution system corresponding to the heavy rainfall disaster scenario according to the heavy rainfall disaster scenario;

[0151] Step 2: Based on the initial data information of the distribution system, a distribution system loss load function, a meaningless scheduling function, an island number function, and a line loss function are respectively constructed, and an objective function is constructed with the distribution system having the minimum loss load, the minimum meaningless scheduling, the minimum number of islands, and the lowest line loss;

[0152] Step 3: Construct constraint conditions and solve the objective function under the constraint conditions to obtain the optimal distribution network restoration plan; under the expected scenario, it is assumed that the substation damage is completely consistent with the expectation; please refer to Figure 3 , which is the resource scheduling decision effect during the recovery process under the moderate precipitation scenario; please refer to Figure 4 , is the resource scheduling decision effect during the recovery process under heavy rainfall scenarios;

[0153] The recovery process of the urban distribution network under each scenario is determined by its dispatch scheme. Taking the overall dispatch solution under an accurately predicted moderate rainfall scenario as an example, the recovery process of the urban distribution network under moderate rainfall scenarios is explained.

[0154] Please refer to Figure 5 , which shows the damage situation of each substation, comparing Figure 2It can be seen that in the accurate prediction scenario, assuming that the expected working status of each substation is completely accurate, it is believed that substations numbered 3, 4, 6, 9, 12, 14, 16, 17, and 28 will definitely fail in the upcoming flood disaster. If the distribution network is affected by the disaster and no response measures are taken, only substations numbered 1, 2, 19, 20, 21, and 22 can be put into operation. Figure 5 Although other substations in the network did not fail due to the disaster, the outage of substations in key locations prevented them from receiving energy from the network and thus lost their ability to operate normally. Therefore, under the flood disaster, the number of out-of-service substations far exceeded the number of failed substations, and network operation staff urgently needed to take corresponding measures. After obtaining the optimal distribution network restoration plan through the above steps, the optimal distribution network restoration plan was implemented.

[0155] Please refer to Figure 6 , which shows the recovery of each power station after the static emergency resources are put into use; according to the solution, before the fault occurs, the operator needs to install protection facilities at substation 3 and substation 4, that is, to reinforce substation 3 and substation 4, and put mobile emergency power supplies into substations 11, 15, and 27; after the static emergency resources are put into use, the network topology is as follows Figure 6 As shown in the figure, if no emergency response measures are taken, only 6 substations can operate normally in this scenario. However, after reinforcing the substations and deploying mobile emergency power supplies, 17 substation nodes will have potential operating capabilities.

[0156] Please refer to Figure 7 , take network reconstruction measures, that is, reconstruct the distribution network topology lines, and further improve the network power supply capacity by coordinating the interconnection lines; at this time, the number of substation nodes with working capacity increases to 25;

[0157] Please refer to Figure 8 , through the dispatching agency, a repair team was dispatched to carry out emergency repair work on key substations. According to the model solution, after the disaster, substations 12 and 14 were repaired first, and the two substations were restored to normal operation. After the repairs of substations 12 and 14, the power supply of substation 13 was restored and it was able to work again due to the restoration of network connection. At this time, there were no substations in the network that were out of service due to loss of network connection. Subsequent restoration decisions will be made based on the load carried by each substation, while considering the reduction of the number of isolated islands.

[0158] Please refer to Figure 9In the second round of emergency repairs, substations 6 and 28 were selected for maintenance. After two rounds of repairs, the distribution network has basically restored its working capacity. Only substations 9, 16, and 17 in the network have not yet restored power supply, and these three faulty nodes were shut down due to direct faults caused by the disaster rather than loss of topological connection. Therefore, after the repairs of substations 9, 16, and 17, the distribution network was fully restored.

[0159] Example 3

[0160] Please refer to Figure 10 A distribution network fault recovery device that takes into account the impact of urban flooding disasters includes a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the computer program, it implements the various steps of a distribution network fault recovery method that takes into account the impact of urban flooding disasters as described in Example 1.

[0161] In summary, the present invention provides a distribution network fault recovery method and device that takes into account the impact of urban flooding disasters. The objective function is constructed by minimizing the loss load of the distribution system, minimizing meaningless scheduling, minimizing the number of islands, and minimizing line losses. The objective function is solved under the constraints of reinforcement cost constraints, mobile emergency power supply quantity constraints, emergency repair and recovery capacity constraints, line operation constraints, substation and line working capacity constraints, distribution network radiation operation constraints, and system flow constraints. That is, the solution model fully considers the coordination between emergency resource scheduling and distribution network repair, takes minimizing load loss as the main optimization goal, avoids meaningless manpower scheduling and considers island operation costs, and minimizes line losses as much as possible, thereby outputting the best distribution network fault recovery strategy and achieving rapid recovery of distribution network faults.

[0162] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's description and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A distribution network fault recovery method considering the impact of waterlogging disasters, characterized in that: Including steps: Obtain initial data information of the power distribution system; According to the initial data information of the distribution system, a distribution system loss load function, a meaningless scheduling function, an island number function and a line loss function are respectively constructed, and an objective function is constructed with the distribution system having the minimum loss load, the least meaningless scheduling, the least island number and the lowest line loss; Constructing constraint conditions, and solving the objective function under the constraint conditions to obtain an optimal distribution network restoration plan; The method comprises: constructing a distribution system loss load function, a meaningless scheduling function, an island number function, and a line loss function according to the initial data information of the distribution system, and constructing an objective function with the minimum loss load of the distribution system, the minimum meaningless scheduling, the minimum number of islands, and the lowest line loss. Where, represents the active load demand of substation i, represents the node active load acquisition of substation i in time period t, t0 represents the number of time periods, and constitutes the loss load function of the distribution system; Indicates the emergency repair status decision of substation i in time period t, with a value of 0-1. When it is 1, it means that substation i has restored its working capacity and will not be shut down again. To correct the parameters, the meaningless scheduling function is formed; Indicates the state of substation i in time period t. If substation i is an island leading node, is 1, To correct the parameters, the island number function is constructed; Indicates the active output of generator i in substation, To correct the parameters, the line loss function is formed; The constructing of constraint conditions and solving the objective function under the constraint conditions to obtain the optimal distribution network restoration solution includes: Construct reinforcement cost constraints, mobile emergency power supply quantity constraints, repair and restoration capacity constraints, line operation constraints, substation and line working capacity constraints, distribution network radiation operation constraints, and system power flow constraints; The objective function is solved under the constraints of reinforcement cost, number of mobile emergency power supplies, repair and restoration capability, line operation, substation and line working capability, distribution network radiation operation, and system flow, to obtain the optimal distribution network restoration plan.

2. A distribution network fault recovery method considering the impact of waterlogging disasters according to claim 1, characterized in that: The construction hardening cost constraints include: Obtain the total reinforcement budget; The protection installation decision is constrained according to the total reinforcement budget to obtain the reinforcement cost constraint: ； Where, To protect the decision variables, When it is 1, it is considered that protection measures are installed for substation i before the disaster occurs; when When it is 0, the substation No additional protective measures are installed; is the protection cost of substation i, B is the total reinforcement budget of the dispatcher, that is, the total reinforcement cost cannot exceed the budget B; the protection installation decision is used to decide whether to install protection measures for the substation.

3. A distribution network fault recovery method considering the impact of waterlogging disasters according to claim 1, characterized in that: The constraints on the number of portable emergency power supplies include: Obtain the total number of dispatchable mobile emergency power sources; The decision of the mobile emergency power supply is constrained according to the total number of the dispatchable mobile emergency power supplies to obtain the constraint on the number of the mobile emergency power supplies: ； ； in, is the decision variable for mobile emergency power supply, which indicates the number of mobile emergency power supplies deployed in substation i. Mobile emergency power supplies can only be deployed before a disaster. C is the total number of dispatchable mobile emergency power supplies. The mobile emergency power supply decision variable is used to determine whether to deploy mobile emergency power supplies in a substation.

4. A distribution network fault recovery method considering the impact of waterlogging disasters according to claim 1, characterized in that: Constraints for building emergency repair and recovery capabilities include: Obtain the total number of emergency repair work teams available for dispatch; According to the total number of emergency repair work groups available for dispatch, the emergency repair and restoration decision and the number of emergency repair groups required in each period are constrained to obtain the emergency repair and restoration capacity constraint: ； ； Where, represents the emergency repair status decision of substation i in time period t, with a value between 0 and 1. When it is 1, it means that substation i has restored its working capacity and will not be shut down again; D represents the total number of emergency repair work teams available for dispatch; It represents the number of emergency repair teams required for the substation in time period t; the emergency repair and restoration decision is used to determine the substation that needs to be repaired in the current time period; the number of emergency repair teams required in each time period is determined by the total number of emergency repair work teams and the emergency repair and restoration decision.

5. A distribution network fault recovery method considering the impact of waterlogging disasters according to claim 1, characterized in that: The construction line operation constraints include: ； Where, Indicates the line working status parameter, the value is 0-1, when it is 1, it is considered that the line Normal operation during the t period; when it is 0, it is considered that the line Disconnect during period t; represents the potential working capacity of substation i in period t; when When , the substation i is considered to have working capability; The construction of substation and line working capacity constraints includes: ； Where, Indicates the expected working status of the node i in the substation. When it is 1, it means that the substation i is working normally. Indicates protection installation decision; It represents the emergency repair status decision of substation i in time period t, with a value between 0 and 1. When it is 1, it means that substation i has restored its working capacity and will not be shut down again.

6. A distribution network fault recovery method considering the impact of waterlogging disasters according to claim 1, characterized in that: The construction of distribution network radiation operation constraints includes: ； ； ； ； ； Where, Indicates the line working status parameter, Indicates a line; Indicates whether substation i is a distribution network node. If If it is 1, it means that substation i is a grid node; Represents the working status of substation i, if If it is 1, it means that substation i can work normally; represents the state of substation i in time period t; represents the virtual power output provided by substation i to the power grid after it is selected as the leading node in time period t; represents the line of substation i in time period t The size of the virtual tidal current; represents the line of substation i in time period t The size of the virtual current; M represents a maximum positive constant.

7. A distribution network fault recovery method considering the impact of waterlogging disasters according to claim 1, characterized in that: The initial data information of the power distribution system includes load demand information and network topology information; Building system power flow constraints includes: Establishing an active power balance model and a reactive power balance model of the power distribution system according to the load demand information and the network topology information; and obtaining upper and lower limits of voltage, upper and lower limits of active and reactive power output, and upper and lower limits of active and reactive power supply for each substation according to the load demand information; The system flow constraint is obtained according to the active power balance model, the reactive power balance model, the upper and lower limits of each substation voltage, the upper and lower limits of active and reactive output, and the upper and lower limits of active and reactive supply.

8. A distribution network fault recovery device taking into account the impact of waterlogging disasters, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, each step of the distribution network fault recovery method considering the impact of urban flooding disasters as described in any one of claims 1 to 7 is implemented.

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