CN116780529B - A distribution network fault recovery method, device, equipment and medium - Google Patents

Abstract

The invention belongs to the technical field of power system automation, and particularly relates to a power distribution network fault recovery method, a device, equipment and a medium, wherein the power distribution network fault recovery method is implemented by taking the maximum load recovery amount of all nodes in a target power distribution network as a target function; and solving the objective function, the distributed power supply power generation proportion model and the transferable load model based on the constraint condition to obtain a power distribution network fault recovery strategy. The power grid energy storage method has the advantages that the source network load storage is utilized to cooperate, the proportion of a fan to photovoltaic power generation is adjusted to face different extreme weather, power type energy storage is introduced to stabilize early distributed power supply power fluctuation, meanwhile, controllable loads are utilized to cut down partial loads, the partial loads are fitted with a system load curve, energy waste caused by wind abandon and light abandon is reduced, the supportability of a power grid during faults is improved, fault recovery time is shortened, and the recovery capacity of a power distribution network is improved.

Description

A distribution network fault recovery method, device, equipment and medium

Technical Field

The present invention belongs to the technical field of power system automation, and in particular relates to a distribution network fault recovery method, device, equipment and medium.

Background technique

With the frequent occurrence of disasters caused by extreme weather, large-scale power outages in power grids are becoming more and more frequent, causing huge economic losses and greatly interfering with people's normal production and life. The rapid recovery of distribution networks after a fault has great significance for people's normal life and normal production of society. Compared with traditional distribution networks, the proportion of renewable energy access in new distribution networks has increased significantly, and power supply is diversified. With the large-scale penetration of distributed power sources (DG) in distribution networks, how to make full use of distributed power sources to restore power supply to power outage areas has become a research hotspot in power grids in recent years. The transferable load demand characteristics are flexible and can be flexibly allocated during specified time periods, so that the load curve can be peak-shaving and valley-filling. When a fault occurs, part of the load is reduced and transferred to supply important node loads.

Wind power and photovoltaic power generation are now widely used as clean distributed power sources, but because the efficiency of these new energy sources is closely related to the environment, once extreme weather occurs, the output power of wind turbines and photovoltaics will be affected, and their output is uncertain. In addition, in previous fault recovery studies, in the face of sudden increases in load demand, it is generally assumed that the climbing ability of distributed power sources and energy storage is extremely strong, ignoring the difference in load following ability between distributed power sources and energy storage, resulting in weak distribution network fault recovery capabilities and failure to fully tap the potential of distributed power sources.

Summary of the invention

The purpose of the present application is to provide a distribution network fault recovery method, device, equipment and medium to solve the problem that the distribution network fault recovery strategy in the prior art ignores the difference in load following capabilities between distributed power sources and energy storage, resulting in weak distribution network fault recovery capabilities.

In order to achieve the above object, the present invention adopts the following technical solution:

In a first aspect, the present invention provides a method for power distribution network fault recovery, comprising the following steps:

Determine the load that needs to be restored after the target distribution network fails;

Constructing an objective function based on the load amount to be restored; wherein the objective function aims to maximize the load restoration amount of all nodes in the target distribution network and the utilization rate of distributed power sources;

Obtain a pre-built distributed power generation ratio model, and determine a preliminary power generation ratio of distributed power in the distributed power generation ratio model according to weather conditions;

Determine the interruptible load in the target distribution network and build a transferable load model based on the interruptible load;

Determine the constraints, including distribution network topology constraints, system flow constraints, system security constraints, and distribution network operation constraints;

Based on the constraints, the objective function, distributed generation ratio model and transferable load model are solved to obtain the distribution network fault recovery strategy.

Specifically, the objective function is as follows:

In the formula, L represents the set of all load nodes, _wi represents the importance of the load at node i, is a 0-1 variable, with values of 1 and 0 indicating load recovery and non-recovery respectively. Pi _,t represents the load recovery amount of node i in period t, and _λDG represents the utilization rate of distributed generation.

Specifically, when solving the objective function, the distributed generation ratio model and the transferable load model based on the constraints, a variance evaluation standard is also set to minimize the deviation between the load demand and the load output during the solution.

Specifically, the system safety constraints include operating voltage constraints and branch capacity constraints; the operating constraints of the distribution network include distributed energy constraints and energy storage constraints.

Specifically, an island is formed after a distribution network failure. After the step of obtaining a distribution network failure recovery strategy, the distribution network failure recovery is performed, and each restored island is sequentially connected to the main network according to a preset island priority.

Specifically, in the step of connecting the restored islands to the main network in sequence according to the preset island priorities, the preset island priorities include:

The first score of the island is determined based on the distance between the island and the main network;

Determine the second score of the island based on the failures inside and outside the island;

The third score of the island is determined based on the energy storage and distributed energy capacity within the island;

A fourth score for the island is determined based on the amount of controllable load within the island;

Determine the total score of the island according to the first score, the second score, the third score, and the fourth score;

Prioritize silos based on their total score.

Specifically, the objective function, the distributed generation ratio model and the transferable load model are solved based on the constraints, including:

Firstly, the big M method is used to relax the operation constraints and topological constraints of the distribution network, so that the active power, reactive power and line current of the disconnected branch are zero, and there are no constraints on the closed branch; then the solution tool is called to solve the problem.

In a second aspect, the present invention provides a distribution network fault recovery device, comprising:

The first determination module is used to determine the load that needs to be restored after a target distribution network failure;

An objective function construction module is used to construct an objective function based on the load amount to be restored; wherein the objective function takes the load restoration amount of all nodes in the target distribution network and the maximum utilization rate of distributed power sources as the target;

The second determination module is used to obtain a pre-built distributed power generation ratio model and determine the preliminary power generation ratio of the distributed power generation in the distributed power generation ratio model according to weather conditions;

A third determination module is used to determine the interruptible load in the target distribution network and to construct a transferable load quantity model based on the interruptible load;

A fourth determination module is used to determine constraint conditions, including distribution network topology constraints, system flow constraints and system security constraints, as well as distribution network operation constraints;

The solution module is used to solve the objective function, the distributed generation ratio model and the transferable load model based on the constraint conditions to obtain the distribution network fault recovery strategy.

In a third aspect, the present invention provides an electronic device, comprising a processor and a memory, wherein the processor is configured to execute a computer program stored in the memory to implement the distribution network fault recovery method as described above.

In a fourth aspect, the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores at least one instruction, and when the at least one instruction is executed by a processor, the distribution network fault recovery method as described above is implemented.

Compared with the prior art, the beneficial effects of the present invention are as follows:

The present invention provides a distribution network fault recovery method, which utilizes the coordination of source, grid, load and storage to adjust the ratio of wind turbine and photovoltaic power generation to face different extreme weather conditions, introduces power-type energy storage to smooth out early distributed power fluctuations, and simultaneously utilizes controllable loads to reduce part of the load to fit the system load curve, thereby reducing energy waste caused by wind and solar abandonment, improving the support of the power grid during faults, shortening the fault recovery time, and improving the recovery capability of the distribution network.

The present invention takes into account the power supply, distribution network, load and energy storage together by utilizing the synergistic effect of source, grid, load and storage, considers the proportion of distributed power generation according to extreme weather conditions, divides the island level into different levels according to faults and other conditions, adjusts the controllable load according to the output of distributed power supply and the predicted load curve, and adjusts the output of power storage according to the climbing limit of distributed power supply and energy storage. The four parts are interconnected and coordinated with each other.

In the face of extreme disaster weather, the present invention establishes a distributed power generation model by formulating the power generation ratio of wind turbines and photovoltaics in distributed power sources in advance, which not only ensures the maximum power generation capacity of distributed power sources, but also reduces the possibility of wind turbines and photovoltaics being dragged in the face of extreme disaster weather;

The present invention divides isolated islands into different levels, focuses on the recovery of isolated islands with lower levels during fault recovery, and connects isolated islands to the main network in order according to their levels after fault recovery is completed, thereby ensuring that more loads are restored during the fault recovery process and that the orderliness of access to the main network is ensured, thereby reducing the time required to access the main network after fault recovery.

The present invention utilizes the rapid power support of power-type energy storage and is invested when the output demand of distributed power sources increases. It can not only smooth out part of the power fluctuations, but also shorten the fault recovery time. At the same time, the adjustment of the controllable load allows the output of the power source to fit the load demand curve as much as possible, thereby improving the recovery efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

FIG1 is a flow chart of a method for recovering from a power distribution network failure according to an embodiment of the present invention;

FIG2 is an IEEE33 node diagram provided by an embodiment of the present invention;

FIG3 is a diagram of island classification provided by an embodiment of the present invention;

FIG4 is a comparison diagram of distributed power generation between strategies 1 and 2 provided in an embodiment of the present invention;

FIG5 is a comparison diagram of load recovery amounts of strategies 1 and 2 provided in an embodiment of the present invention;

FIG6 is a structural block diagram of a distribution network fault recovery device according to an embodiment of the present invention;

FIG. 7 is a structural block diagram of an electronic device according to an embodiment of the present invention.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit exemplary embodiments according to the present invention.

Example 1

As shown in FIG1 , a distribution network fault recovery method includes the following steps:

S1. Determine the load that needs to be restored after the target distribution network fails.

S2. Constructing an objective function based on the load amount to be restored; wherein the objective function aims to maximize the load restoration amount of all nodes in the target distribution network and the utilization rate of distributed power sources.

Specifically, the objective function constructed is as follows:

In the formula, L represents the set of all load nodes, _wi represents the importance of the load at node i, is a 0-1 variable, with values of 1 and 0 indicating load recovery and non-recovery respectively. Pi _,t represents the load recovery amount of node i in period t, and _λDG represents the utilization rate of distributed generation.

S3. Obtain a pre-built distributed power generation ratio model, and determine a preliminary power generation ratio of the distributed power generation in the distributed power generation ratio model according to weather conditions.

Specifically, the established distributed power generation ratio model is as follows:

_PtDG ^＝ _λ1PtWT ⁺ _{λ2PtPV ​ ​} ^​

^{Where PtDG} _represents the power generation of distributed generation in period t, _λ1 and _λ2 are the power generation ratios of wind turbine and photovoltaic respectively, and _λ1 + _λ2 ＝1, _PtWT represents the power generation of wind turbine in period t, _{and PtPV} ^represents the power generation of ^photovoltaic power in period t.

Initial power generation:

_Pt ^＝ _{PtDG +} ^Ptsc

In the formula, _PtDG represents the distributed generation power ⁱⁿ period t, ^and _Ptsc represents the power generation power of power-type energy storage in period t.

S4. Determine the interruptible load in the target distribution network, and build a transferable load model based on the interruptible load.

Specifically, the transferable load model is constructed as follows:

In the formula, represents the maximum power of the interruptible load, η represents the transferable load factor, Ω _ch represents the transferable load node set, μ∈(0,1),/> Represents the load recovery amount required during period t.

S5. Determine the constraints, including distribution network topology constraints, system flow constraints, system security constraints, and distribution network operation constraints.

Specifically, the system safety constraints include operating voltage constraints and branch capacity constraints; the operating constraints of the distribution network include distributed energy constraints and energy storage constraints.

In some optional embodiments, the distribution network topology constraints are as follows:

In the formula, _bij,t and bji _,t represent the child-parent relationship between node i and node j in time period t. If node j is the parent node of node i, then _bij = 1, _bji = 0, otherwise _bji = 1, _bij = 0. If node i and node j are not connected, then _bij = _bji = 0. Ω represents the set of all nodes, Ω _G represents the set of faulty nodes, and _aij,t represents the power-on status of line ij in time period t. If it is powered on, it is 1, otherwise it is 0.

In some optional embodiments, the system power flow constraints are as follows:

Where I _ij,t represents the current amplitude flowing through branch ij during period t, U _t,i represents the voltage amplitude at node i during period t, r _ki represents the resistance of branch ki, x _ki represents the reactance of branch ki, P _ij,t and Q _ij,t represent the active power and reactive power transmitted by line ij during period t, respectively. Respectively represent the active power and reactive power of the distributed generation injected into node i during time period t;/> Respectively represent the active power and reactive power released by the energy storage at node i during time period t;/> They represent the active power and reactive power consumed by the load on node i during period t respectively.

In some optional embodiments, the system safety constraint includes an operating voltage constraint and a branch capacity constraint, wherein:

Operating voltage constraints:

in, and/> They represent the minimum and maximum voltages that node i can withstand respectively;

The branch capacity constraint is:

in, Represents the maximum current that branch ij can pass.

In some optional embodiments, the operation constraints of the distribution network include:

Distributed energy constraints:

In the formula, Respectively represent the active power and reactive power generated by the power supply at node i during time period t; Represents the upper and lower limits of the active output of the power source at node i during time period t;/> The capacity of the power supply connected to the i-node.

Energy storage constraints:

Ptbs＝Ptbs,d-Ptbs,c

Ptbs,d,min≤Ptbs,d≤Ptbs,d,max

Ptbs,c,min≤Ptbs,c≤Ptbs,c,max

Ptsc,min≤Ptsc≤Ptre

^Ptsc ₊ ^Ptbs _{＝ PtESS} ^​

In the formula, P _t ^bs represents the power injected into the grid by the battery energy storage system in period t, P _t ^bs,c and P _t ^bs,d represent the charging and discharging power of the battery energy storage system in period t, P _t ^bs,d,min and P _t ^bs,d,max represent the upper and lower limits of the discharge power, P _t ^bs,c,min and P _t ^bs,c,max represent the upper and lower limits of the charging power, and P _t ^sc,min represents the lower limit of the discharge of power-type energy storage. is the energy storage charging and discharging power at node i in time period t, the charging power is positive and the discharging power is negative,/> is the energy storage capacity at node i.

S6. Based on the constraints, the objective function, the distributed generation ratio model and the transferable load model are solved to obtain the distribution network fault recovery strategy.

The specific solution steps include: first, using the big M method to relax the operation constraints and topology constraints of the distribution network, so that the active power, reactive power and line current of the disconnected branch are zero, and there are no constraints on the closed branch; then calling the solution tool to solve.

To be more specific, we introduce and/> Instead of/> and/> The large M method is used to relax the operation constraints and topological constraints of the distribution network, so that the active power, reactive power and line current of the disconnected branch are zero, and there are no constraints on the closed branch:

It is understandable that an island is formed after a distribution network failure. In order to ensure the integrity of the main network, the scope of the island is determined by searching for the existence of distributed power sources near the fault. While considering the output of distributed energy and energy storage, the load side demand and controllable load characteristics are considered, and the controllable load is distributed to the island as evenly as possible to improve the internal regulation capacity of the island.

In some optional embodiments, isolated islands are classified into different levels, and isolated islands with higher output of distributed energy and energy storage, fewer surrounding faults, and which meet their own load requirements and have spare capacity are given higher priority.

In some optional embodiments, after the step of obtaining the distribution network fault recovery strategy, distribution network fault recovery is performed, and each restored island is sequentially connected to the main network according to a preset island priority.

Specifically, the preset methods for determining the priority of an island include: determining a first score of the island based on the distance between the island and the main grid; determining a second score of the island based on faults inside and outside the island; determining a third score of the island based on the energy storage and distributed energy capacity within the island; determining a fourth score of the island based on the controllable load within the island; determining a total score of the island based on the first score, the second score, the third score, and the fourth score; and determining the priority of the island based on the total score of the island.

It is understandable that when designing the standards for the first score to the fourth score, a scoring interval may be established, for example, different levels of distance standards may be set, and corresponding scores may be obtained when different levels of distance standards are met.

In some optional embodiments, when solving the objective function, the distributed generation ratio model and the transferable load model based on the constraints, a variance evaluation standard is also set to minimize the deviation between the load demand and the load output during the solution.

It is understandable that the purpose of establishing the variance standard is to achieve the absorption of distributed power sources, fit the expected load curve, and introduce variance to represent the deviation between load demand and load output:

Where n represents the fault recovery time, Represents load demand.

Another embodiment of the present solution provides a distribution network fault recovery method, which effectively improves the load recovery amount and reduces the power fluctuation of the distributed power source in the early stage of recovery by studying the synergy between the distributed power source, energy storage, and transferable load, analyzing the output capacity of the distributed power source, and the adjustable range of the transferable load, including the following steps:

Step 10: Obtain fault information of the target distribution network to establish an objective function, a distributed generation ratio model, and a transferable load model.

Specifically, fault information may include data such as extreme weather conditions, load that needs to be restored, distributed generation capacity, transferable load, and power that can be generated by energy storage.

The objective function established in this scheme is as follows:

In the formula, L represents the set of all load nodes, w _i represents the importance of the load at node i, is a 0-1 variable, with values of 1 and 0 indicating load recovery and non-recovery respectively. Pi _,t represents the load recovery amount of node i in period t, and _λDG represents the utilization rate of distributed generation.

Step 20. Based on extreme weather conditions, preliminarily determine the power generation ratio of wind turbines and photovoltaics in distributed power sources.

It should be noted that the initial power generation ratio is formulated based on extreme weather conditions. For example, in windy and rainy weather, the photovoltaic power generation ratio is reduced, and in windless and sunny days, the photovoltaic power generation ratio is increased.

Specifically, the distributed power generation ratio model is established as follows:

_PtDG ^＝ _λ1PtWT ⁺ _{λ2PtPV ​ ​} ^​

^{Where PtDG} _represents the power generation of distributed generation in period t, _λ1 and _λ2 are the power generation ratios of wind turbine and photovoltaic respectively, and _λ1 + _λ2 ＝1, _PtWT represents the power generation of wind turbine in period t, _{and PtPV} ^represents the power generation of ^photovoltaic power in period t.

Step 30) Utilize the synergy of source, grid, load and storage to formulate a fault recovery strategy.

According to the load recovery amount, power type energy storage is added to the distributed power source to adjust the transferable load amount, including:

Faced with the initial surge in load recovery, the load demand cannot be met in time due to the power limitation of distributed energy climbing. At this time, the properties of power-type energy storage supercapacitors are used to quickly smooth out power fluctuations and increase initial power generation.

The power generation during period t is:

_Pt ^＝ _{PtDG +} ^Ptsc

In the formula, _Pt represents the power generation during period t, _PtDG represents the power generation of distributed generation during period t, ^and _Ptsc represents the power generation of power-type energy storage ^during period t.

During the recovery process, loads are divided into first-, second-, and third-level loads according to their importance. First-level loads are restored first, and load recovery sets are established based on their importance:

In the formula, represents the load recovery set, w _i,t represents the load importance, and P _i,t represents the load recovery amount of node i in period t.

The transferable load model is established as follows:

In the formula, represents the load transfer amount during period t,/> represents the load transfer amount of node i in period t,/> represents the maximum power of the interruptible load, η represents the transferable load factor, Ω _ch represents the transferable load node set, μ∈(0,1), represents the load recovery required in period t, and _Pt represents the initial power generation.

At the same time, in order to realize the consumption of distributed power sources and fit the expected load curve, the variance is introduced to represent the deviation between load demand and load output:

In the formula, k represents the deviation, n represents the fault recovery time, represents the load demand, ^PESS represents the total load of all energy storage, and _Pt represents the power generation power in period t.

Step 40) Solve the objective function, the distributed generation ratio model, and the transferable load model to obtain a distribution network fault recovery method.

The distribution network topology constraints, system flow constraints and system security constraints are established as follows:

Distribution network topology constraints:

In the formula, _bij,t and bji _,t represent the child-parent relationship between node i and node j in time period t. If node j is the parent node of node i, then _bij = 1, _bji = 0, otherwise _bji = 1, _bij = 0. If node i and node j are not connected, then _bij = _bji = 0. Ω represents the set of all nodes, Ω _G represents the set of faulty nodes, and _aij,t represents the power-on status of line ij in time period t. If it is powered on, it is 1, otherwise it is 0.

System power flow constraints:

Wherein, P _ki,t represents the active power transmitted by line ki during period t, P _t,i represents the active power of node i during period t, Q _ki,t represents the reactive power transmitted by line ki during period t, Q _t,i represents the reactive power of node i during period t, a _t,i represents the load disconnection relationship of node i during period t, U _t,j represents the voltage of node j during period t, P _t,ij represents the active power transmitted by line ij during period t, r _ij represents the resistance of branch ij, x _ij represents the reactance of branch ij, Q _t,ij represents the reactive power transmitted by line ij during period t, represents the square of the current flowing through branch ij during period t, a _ij,t represents the energized state of line ij during period t, r _ki represents the resistance of branch ki, I _ij,t represents the current amplitude flowing through branch ij during period t, P _ij,t and Q _ij,t represent the active power and reactive power transmitted by line ij during period t, respectively, and x _ki represents the reactance of branch ki./> Respectively represent the active power and reactive power of the distributed generation injected into node i during period t,/> Respectively represent the active power and reactive power released by the energy storage at node i during time period t,/> They represent the active power and reactive power consumed by the load on node i during period t, respectively; U _t,i represents the voltage amplitude at node i during period t;

System safety constraints include operating voltage constraints and branch capacity constraints, where:

Operating voltage constraints:

in, and/> They represent the minimum and maximum voltages that node i can withstand respectively;

The branch capacity constraint is:

in, Represents the maximum current that branch ij can pass.

The operation constraints of the distribution network include distributed energy constraints, energy storage constraints, and transferable load constraints, as follows: Distributed energy constraints:

In the formula, Respectively represent the active power and reactive power generated by the power supply at node i during time period t; Represents the upper and lower limits of the active output of the power source at node i during time period t;/> The capacity of the power supply connected to the i-node.

Energy storage constraints:

P _t ^bs =P _t ^bs,d -P _t ^bs,c

P _t ^bs,d,min ≤P _t ^bs,d ≤P _t ^bs,d,max

P _t ^bs,c,min ≤P _t ^bs,c ≤P _t ^bs,c,max

P _t ^sc,min ≤P _t ^sc ≤P _t ^re

^Ptsc ₊ ^Ptbs _{＝ PtESS} ^​

In the formula, P _t ^bs represents the power injected into the grid by the battery energy storage system in period t, P _t ^bs,c and P _t ^bs,d represent the charging and discharging power of the battery energy storage system in period t, P _t ^bs,d,min and P _t ^bs,d,max represent the upper and lower limits of the discharge power, P _t ^bs,c,min and P _t ^bs,c,max represent the upper and lower limits of the charging power, and P _t ^sc,min represents the lower limit of the discharge of power-type energy storage. is the energy storage charging and discharging power at node i in time period t, the charging power is positive and the discharging power is negative,/> is the energy storage capacity at node i,/> Indicates the amount of transferable load, /> represents the active power of energy storage,/> Represents the reactive power of energy storage.

Solve the objective function, distributed generation ratio model, and transferable load model:

Introducing variables and/> Instead of/> and/> The large M method is used to relax the operation constraints and topological constraints of the distribution network, so that the active power, reactive power and line current of the disconnected branch are zero, and there are no constraints on the closed branch:

In the formula, and/> They represent the square of the voltage at node i and the square of the current flowing through branch ij during period t, M represents an infinite number, a _ij represents the power-on state of line ij during period t, /> represents the square of the voltage at node j during period t, _Qij,t and Qt _,ij represent the reactive power transmitted by line ij during period t,

When solving the problem, you can use YAMIP programming, CPLEX, MOSEK and other software to solve it.

In order to verify the effectiveness of the distribution network fault recovery method, this scheme provides a specific example: using the improved ieee33 node distribution network as shown in Figure 2, assuming that extreme weather such as heavy rain occurs, the distribution network lines 6-7, 19-20, and 31-32 fail and are disconnected from the main grid. The expected power outage time is four hours.

Strategy 1: Using the fault recovery method proposed in the present invention, after receiving the rainstorm disaster message, adjust the power generation ratio of photovoltaic and wind turbines, invest in power-type energy storage at the initial stage of fault recovery, adjust the controllable load, divide the island level according to the divided islands, and close the relevant contact lines. After the fault recovery is completed, access the main grid in the order of island level.

Strategy 2: After receiving the disaster message, the power generation ratio is not adjusted, and power generation is still carried out according to the original output. Power-type energy storage is not considered, only energy-type energy storage is released, and controllable loads are not considered. Normal island division is carried out and the main grid is connected after recovery.

Analyze the example graph: According to Figure 4, compared with Strategy 2, the addition of power storage in Strategy 1 makes up for the climbing limitation of distributed power sources when a larger power output is needed in the early stage, and improves the early load recovery amount; According to Figure 5, without considering controllable load regulation and power storage, the load recovery amount of Strategy 2 is lower than that of Strategy 1, and the load recovery curve of Strategy 1 is more in line with the expected load recovery amount. It can be concluded that the fault recovery scheme considering the coordination of source, grid, load and storage improves the early load recovery amount, ensures the power supply of important loads in the early stage, and improves the load recovery efficiency.

Example 2

As shown in FIG6 , based on the same inventive concept as the above embodiment, the present invention further provides a distribution network fault recovery device, comprising:

The first determination module is used to determine the load that needs to be restored after a target distribution network failure;

An objective function construction module is used to construct an objective function based on the load amount to be restored; wherein the objective function takes the load restoration amount of all nodes in the target distribution network and the maximum utilization rate of distributed power sources as the target;

The second determination module is used to obtain a pre-built distributed power generation ratio model and determine the preliminary power generation ratio of the distributed power generation in the distributed power generation ratio model according to weather conditions;

A third determination module is used to determine the interruptible load in the target distribution network and to construct a transferable load quantity model based on the interruptible load;

A fourth determination module is used to determine constraint conditions, including distribution network topology constraints, system flow constraints and system security constraints, as well as distribution network operation constraints;

The solution module is used to solve the objective function, the distributed generation ratio model and the transferable load model based on the constraint conditions to obtain the distribution network fault recovery strategy.

Example 3

As shown in FIG. 7 , the present invention also provides an electronic device 100 for implementing a distribution network fault recovery method in Example 1; the electronic device 100 includes a memory 101, at least one processor 102, a computer program 103 stored in the memory 101 and executable on at least one processor 102, and at least one communication bus 104.

The memory 101 may be used to store a computer program 103 , and the processor 102 implements the steps of a distribution network fault recovery method in Example 1 by running or executing the computer program stored in the memory 101 and calling the data stored in the memory 101 .

The memory 101 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area may store data (such as audio data) created according to the use of the electronic device 100, etc. In addition, the memory 101 may include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other non-volatile solid-state storage devices.

At least one processor 102 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The processor 102 may be a microprocessor or any conventional processor, etc. The processor 102 is the control center of the electronic device 100, and uses various interfaces and lines to connect various parts of the entire electronic device 100.

The memory 101 in the electronic device 100 stores a plurality of instructions to implement a distribution network fault recovery method, and the processor 102 can execute the plurality of instructions to implement:

Determine the load that needs to be restored after the target distribution network fails.

An objective function is constructed based on the load amount to be restored; wherein the objective function aims to maximize the load restoration amount of all nodes in the target distribution network and the utilization rate of distributed power sources.

A pre-built distributed generation power generation proportion model is obtained, and a preliminary power generation proportion of distributed generation in the distributed generation power generation proportion model is determined according to weather conditions.

Determine the interruptible load in the target distribution network and build a transferable load model based on the interruptible load.

Determine the constraints, including distribution network topology constraints, system flow constraints, system security constraints, and distribution network operation constraints.

Based on the constraints, the objective function, distributed generation ratio model and transferable load model are solved to obtain the distribution network fault recovery strategy.

Example 4

If the module/unit integrated in the electronic device 100 is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. Computer-readable media may include: any entity or device that can carry computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory and read-only memory (ROM, Read-Only Memory).

Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

The present invention is described with reference to the flowchart and/or block diagram of the method, device (system), and computer program product according to the embodiment of the present invention. It should be understood that each process and/or box in the flowchart and/or block diagram, as well as the combination of the process and/or box in the flowchart and/or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.

These computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.

In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims (8)

1. The power distribution network fault recovery method is characterized by comprising the following steps of:

determining the load quantity to be recovered after the fault of the target power distribution network;

Constructing an objective function based on the load quantity to be recovered; the objective function aims at the maximum load recovery quantity and the maximum distributed power supply utilization rate of all nodes in the target power distribution network;

acquiring a pre-constructed distributed power supply power generation proportion model, and determining the primary power generation proportion of a distributed power supply in the distributed power supply power generation proportion model according to weather conditions;

determining an interruptible load in a target power distribution network, and constructing a transferable load quantity model based on the interruptible load;

determining constraint conditions, including topology constraint of a power distribution network, system power flow constraint and system safety constraint, and operation constraint of the power distribution network;

Solving an objective function, a distributed power supply power generation proportion model and a transferable load model based on constraint conditions to obtain a power distribution network fault recovery strategy;

Forming islands after the power distribution network fails, recovering the power distribution network failure after the step of obtaining a power distribution network failure recovery strategy, and sequentially accessing each recovered island into a main network according to a preset island priority; the preset island priority comprises the following steps:

Determining a first score of the island according to the distance between the island and the main network;

determining a second score of the island according to faults inside and outside the island;

Determining a third score of the island according to the energy storage and the distributed energy capacity in the island;

determining a fourth score for the island according to the controllable load amount within the island;

Determining the total score of the island according to the first score, the second score, the third score and the fourth score;

and determining the priority of the island according to the total score of the island.

2. The power distribution network fault recovery method according to claim 1, wherein the objective function is as follows:

Where L represents the set of all load nodes, w _i represents the importance of the load at node i, And the variable is 0-1, the values are 1 and 0, the load recovery and the non-recovery are respectively represented, P _i,t represents the load recovery amount of the i-node in the t period, and lambda _DG represents the utilization rate of the distributed power supply.

3. The power distribution network fault recovery method according to claim 1, wherein when solving the objective function, the distributed power generation ratio model and the transferable load quantity model based on the constraint condition, a variance evaluation criterion is further set, and when solving, the deviation degree of the load demand and the load output is minimized.

4. The power distribution network fault recovery method of claim 1, wherein the system security constraints include an operating voltage constraint and a branch capacity constraint; the operation constraints of the power distribution network comprise distributed energy constraints and energy storage constraints.

5. The power distribution network fault recovery method according to claim 1, wherein solving the objective function, the distributed power generation ratio model and the transferable load model based on the constraint condition specifically comprises:

Firstly, loosening the operation constraint of a power distribution network and the topology constraint of the power distribution network by using a large M method to ensure that the active power, reactive power and line current of an open branch are zero and the closed branch is not constrained; and then calling a solving tool to solve.

6. A power distribution network fault recovery apparatus, comprising:

The first determining module is used for determining the load quantity to be recovered after the fault of the target power distribution network;

The objective function construction module is used for constructing an objective function based on the load quantity to be recovered; the objective function aims at the maximum load recovery quantity and the maximum distributed power supply utilization rate of all nodes in the target power distribution network;

The second determining module is used for obtaining a pre-built distributed power supply power generation proportion model and determining the preliminary power generation proportion of the distributed power supply in the distributed power supply power generation proportion model according to weather conditions;

The third determining module is used for determining the interruptible load in the target power distribution network and constructing a transferable load quantity model based on the interruptible load;

the fourth determining module is used for determining constraint conditions, including topology constraint of the power distribution network, system power flow constraint and system safety constraint, and operation constraint of the power distribution network;

the solving module is used for solving the objective function, the distributed power supply power generation proportion model and the transferable load model based on the constraint condition to obtain a power distribution network fault recovery strategy;

Forming islands after the power distribution network fails, recovering the power distribution network failure after the step of obtaining a power distribution network failure recovery strategy, and sequentially accessing each recovered island into a main network according to a preset island priority; the preset island priority comprises the following steps:

Determining a first score of the island according to the distance between the island and the main network;

determining a second score of the island according to faults inside and outside the island;

Determining a third score of the island according to the energy storage and the distributed energy capacity in the island;

determining a fourth score for the island according to the controllable load amount within the island;

Determining the total score of the island according to the first score, the second score, the third score and the fourth score;

and determining the priority of the island according to the total score of the island.

7. An electronic device comprising a processor and a memory, the processor being configured to execute a computer program stored in the memory to implement the power distribution network fault recovery method of any one of claims 1 to 5.

8. A computer readable storage medium storing at least one instruction that when executed by a processor implements a power distribution network fault recovery method according to any one of claims 1 to 5.