Island power supply recovery method and system considering active support operation mode

Abstract

The invention discloses an island power supply recovery method and system considering an active support operation mode, and the method comprises the steps: collecting actual geographic position data, and determining an interconnectable node set of ESV-SOP in a power distribution network; and according to the positions and the number of the fault lines, constructing a power distribution network post-disaster island model, and identifying whether the distributed resources have voltage support or not. And constructing an ESV-SOP and artificial rush repair team mathematical model. And solving all the models to obtain an ESV-SOP scheduling path, an ESV-SOP working mode switching sequence, a line first-aid repair sequence and a power distribution network load support level. According to the island power supply recovery method and system considering the active support operation mode provided by the invention, the working mode of the VF is expanded based on the defects of the ESV-SOP provided by the existing research institute, and the capability of participating in island power supply recovery is improved. And the power supply reliability is effectively improved, and the method has great significance for island power supply and recovery and island support in an emergency period.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid control, and in particular to an island power supply recovery method and system considering an active support operation mode. Background Art

[0002] Electricity is one of the most basic energy sources supporting the national economy. With the development of the economy, the country has also put forward new requirements for the reliability of the power system. However, many major power outages in recent years have shown that distribution networks are prone to line failures when facing extreme natural disasters, thus being forced to form power-off island networks. Therefore, the current distribution network is difficult to meet the needs of social production and life "all the time", and it is urgent to improve its power supply reliability and resilience.

[0003] To this end, domestic and foreign scholars have conducted a lot of research on post-disaster island power supply in distribution networks. The main idea is to use remote control devices such as line switches to actively divide the scope of the island and regulate the resources in the system (such as energy storage, photovoltaics, wind power, emergency vehicles, etc.) to support the load. However, existing studies mostly focus on photovoltaics and wind power to actively divide single-source islands or form a preset number of island groups, and rarely consider whether resources can actively support the grid voltage and the rationality of the island division method. For example, in actual projects, due to the intermittent and uncertain nature of time and space, photovoltaics and wind power are difficult to match load demand in real time when there is no voltage support, and often cannot independently bear the island load; in addition, most transmission lines are not equipped with circuit breakers and line switches, and cannot realize the breaking action and strictly divide the islands with distributed resources as the center. Therefore, the island power supply strategy proposed by existing studies is not applicable enough, and it is difficult to achieve reliable power supply and rapid recovery of islands in random fault scenarios. Summary of the invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the technical problem solved by the present invention is that the existing technology rarely considers whether resources can actively support the grid voltage and the rationality of the island division method. In addition, most transmission lines are not equipped with circuit breakers and line switches, which cannot realize the breaking action and strictly divide the islands around distributed resources. Therefore, the island power supply strategy proposed by the existing research is not applicable enough, and it is difficult to achieve reliable power supply and rapid recovery of the island in the case of random faults.

[0006] To solve the above technical problems, the present invention provides the following technical solutions: a method for island power supply restoration considering an active support operation mode, comprising: collecting actual geographic location data and determining a set of interconnectable nodes of an ESV-SOP in a distribution network.

[0007] According to the location and number of faulty lines, a post-disaster island model of the distribution network is constructed to identify whether the distributed resources have voltage support.

[0008] Construct mathematical models of ESV-SOP and manual repair team.

[0009] All models are solved to obtain the dispatch path of ESV-SOP, the switching sequence of ESV-SOP working modes, the line repair sequence and the load support level of the distribution network.

[0010] As a preferred solution of the island power supply restoration method considering the active support operation mode described in the present invention, wherein: the actual geographic location data is collected to determine the interconnectable node set of ESV-SOP in the distribution network, including introducing an N×N ESV-SOP scheduling feasible domain matrix R, N represents the number of distribution network nodes, and R is expressed as:

[0011]

[0012] Among them, R ij An identifier variable indicating whether node i and node j are interconnected. When the value is 1, it means they are interconnected, otherwise the value is 0.

[0013] Search for elements with a value of 1 in the matrix R, record their horizontal and vertical coordinates, and form a horizontal coordinate sequence A and a vertical coordinate sequence B, with the elements of the two corresponding to each other.

[0014] As a preferred solution of the island power supply restoration method considering the active support operation mode described in the present invention, wherein: the construction of the distribution network post-disaster island model according to the location and number of faulty lines includes obtaining the location and number of faulty lines and numbering them, and the obtained faulty line set is represented by F. Using the binary variable z ij Indicates the open / closed state of the line connecting node i and node j, with closed as 1 and open as 0. F =0.

[0015] According to graph theory, we can judge whether the distribution network forms an island. When the N-node radial distribution network is operating normally, N-1 lines are put into operation. Assuming that after f lines fail, the distribution network still has h lines in operation. If there is no tie switch in the distribution network, f+1 islands will be formed. If there is a tie switch, the relationship is expressed as:

[0016] h≥N-1-f

[0017] Determine whether the distributed resources on the island have voltage support and establish a mathematical model of distributed resources based on the prediction curve.

[0018] Introducing distributed resource support voltage identification variable ζ m,t , it is defined that when the distributed power source has working conditions, the value is 1, otherwise it is 0. It is expressed as:

[0019]

[0020] Among them, ε ij,t The identification variable indicating whether ESV-SOP interconnects node i and node j. The value is 1 when interconnection is defined, otherwise it is 0. I represents the main network, I m Indicates the island where the distributed resource m is located.

[0021] The output constraint of distributed resources is expressed as:

[0022]

[0023] Among them, P m,t represents the output power of distributed resource m, P m,t max Indicates the maximum power output by distributed resource m.

[0024] As a preferred scheme of the island power supply restoration method considering the active support operation mode described in the present invention, wherein: the construction of the distribution network post-disaster island model includes, when the distribution network is operating normally, including a branch flow model for power flow calculation, when a line fault occurs and an island operation is formed, introducing network reconstruction constraints and modifying the voltage balance equation in the branch flow model.

[0025] The branch flow model includes power flow equation constraints, safety condition constraints and second-order cone relaxation constraints.

[0026] The power flow equation constraint requires that any node in the distribution network must satisfy the power balance constraint expressed as:

[0027]

[0028] Among them, P i,dis Indicates the active power output of the distributed power supply at the node, Q i,dis Represents the reactive power output by the distributed power supply at the node, P i,l Indicates the active load output by the distributed power supply at this node, Q i,l Indicates the active (reactive) load output by the distributed power supply at this node. i,net Indicates the active power output from the upper power grid to the node, Q i,net Indicates the reactive power output from the upper power grid to the node. Ω ki represents the set of branches flowing into node i, Ω ij represents the set of branches out of node i. ij Represents the active power flowing through the branch, Q ij Represents the reactive power flowing through the branch. i,e Indicates the active power input to the ESV-SOP of this node, Q i,e Indicates the reactive power input to the ESV-SOP of this node.ij Represents the square of the branch current. ij Represents the resistance of the line, x ij Indicates the reactance of the line.

[0029] The safety condition constraint requires that any node and any branch of the distribution network should meet the safety standard, which can be expressed as:

[0030]

[0031] Among them, V i represents the square of the voltage at node i, P ij represents the active power of the branch connecting node i and node j, Q ij Represents the reactive power of the branch connecting node i and node j.

[0032] Introduce the second-order cone relaxation constraint, expressed as:

[0033]

[0034] The voltage balance equation constraint that needs to be modified for network reconstruction is expressed as:

[0035]

[0036] Wherein, M represents an arbitrarily large positive number.

[0037] As a preferred solution of the island power supply restoration method considering the active support operation mode described in the present invention, wherein: the construction of the ESV-SOP and the manual repair team mathematical model includes establishing an ESV-SOP working mode characterization model, introducing and defining a 0-1 identification variable to characterize the working mode of the ESV-SOP: μ c,t , μ α c,t and μ β c,t .

[0038] At time t, the cth ESV-SOP is connected to the distribution network, then μ c,t =1. Otherwise μ c,t =0.

[0039] μ α c,t A value of 1 indicates that the mode is VF at time t, otherwise it is 0.

[0040] μ β c,t A value of 1 indicates that the mode is PQ at time t, otherwise it is 0.

[0041] The working mode is expressed as:

[0042]

[0043] Each ESV-SOP can only access one fault location at any time, so the constraint is expressed as:

[0044]

[0045] Among them, ξ k,m,t The access position of the cth ESV-SOP at t0 is represented by a 0-1 variable. When its value is 1, it means that the ESV-SOP is connected to R at t ij .

[0046] Set the working constraints of ESV-SOP. After ESV-SOP is connected to the fault location, it transmits power. Then the working state constraints are expressed as:

[0047]

[0048] Among them, P n,sop Indicates the active power output by the nth port of ESV-SOP, Q n,sop Indicates the reactive power output by the nth port of ESV-SOP. N n,sop Indicates the rated apparent power of the nth port. bat Indicates the output power of the energy storage battery. Z indicates the set of all ports of a single ESV-SOP. dc Represents the set of DC-DC ports of ESV-SOP, Z ac Represents the set of AC-AC ports of ESV-SOP.

[0049] The energy storage battery meets the charge and discharge constraints, which can be expressed as:

[0050]

[0051] Among them, P max bat Indicates the upper limit of the charging and discharging power of the energy storage battery, P min bat Indicates the lower limit of the charging and discharging power of the energy storage battery, C c bat Indicates the charge capacity at time t.

[0052] As a preferred solution of the island power supply restoration method considering the active support operation mode described in the present invention, the mathematical model of the artificial repair team includes, for the fault line set F, introducing a one-dimensional variable matrix Ft to characterize its maintenance status, expressed as:

[0053] F t =[z 1,t ,z 2,t ,…,z f,t],f∈X

[0054] Among them, z f,t represents the closed state of the fault line, and the matrix elements are related to z ij,t Correspondingly, assuming that c manual repair teams can repair h lines in a unit time, it can be expressed as:

[0055]

[0056] Among them, i,t Represents the dispatch identification variable matrix of the i-th manual repair team at time t.

[0057] As a preferred solution of the island power supply restoration method considering the active support operation mode described in the present invention, wherein: the solving of all models to obtain the ESV-SOP dispatch path, the ESV-SOP working mode switching sequence, the line repair sequence and the distribution network load support level includes adopting the objective function of minimizing load reduction, which is expressed as:

[0058]

[0059] Where L represents the actual load borne by the distribution network in the emergency scenario, L v Indicates the load amount of the load forecast curve.

[0060] A commercial solver is used to solve the problem, and the dispatch path of ESV-SOP, the switching sequence of ESV-SOP working modes, the line repair sequence, and the load support level of the distribution network are obtained.

[0061] An island power supply restoration system considering an active support operation mode, characterized in that: it includes:

[0062] Determine the node set module, collect actual geographic location data, and determine the interconnectable node set of ESV-SOP in the distribution network.

[0063] Construct an island model module, build a post-disaster island model of the distribution network according to the location and number of faulty lines, and identify whether distributed resources have voltage support.

[0064] Construct the manual repair team model module and build the ESV-SOP and manual repair team mathematical models.

[0065] The solution module solves all models and obtains the dispatch path of ESV-SOP, the switching sequence of ESV-SOP working modes, the line repair sequence and the load support level of the distribution network.

[0066] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0067] A computer-readable storage medium stores a computer program, which implements the steps of the method described above when executed by a processor.

[0068] The beneficial effects of the present invention are as follows: based on the deficiencies of the ESV-SOP proposed by the existing research, the working mode of its VF is expanded, and its ability to participate in the restoration of power supply to isolated islands is improved. Based on this, based on the impact of line failures caused by extreme natural disasters on the division of isolated islands in practice, the working conditions of whether distributed resources can actively support the operation of isolated islands are considered, and an isolated island power supply restoration strategy supported by ESV-SOP taking into account multiple modes is given. The optimization result of the entire time period is obtained with the goal of maximizing the overall system supply load, which effectively improves the reliability of power supply, which is of great significance to the power supply and restoration of isolated islands and the support of isolated islands during emergency periods. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0070] Figure 1 An overall flow chart of an island power supply restoration method and system considering an active support operation mode is provided for the first embodiment of the present invention.

[0071] Figure 2 A method and system for island power supply restoration considering an active support operation mode is provided as a first embodiment of the present invention, which is an emergency scenario diagram in which the system is forced to divide into island operation due to the disconnection of three lines.

[0072] Figure 3 A photovoltaic predicted output curve and a total load predicted curve diagram of an island power supply restoration method and system considering an active support operation mode are provided in the first embodiment of the present invention.

[0073] Figure 4 A detailed flow chart of an island power supply restoration method and system considering an active support operation mode is provided for the first embodiment of the present invention.

[0074] Figure 5 A second embodiment of the present invention provides an island power supply restoration method taking into account an active support operation mode and a diagram of active loads that can be supported by the system under two scenarios. DETAILED DESCRIPTION

[0075] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0076] Example 1

[0077] Reference Figure 1 to Figure 4 , as an embodiment of the present invention, provides a method, comprising:

[0078] S1: Collect actual geographic location data to determine the set of interconnectable nodes of ESV-SOP in the distribution network.

[0079] The N×N ESV-SOP scheduling feasible region matrix R is introduced, where N represents the number of distribution network nodes and R is expressed as:

[0080]

[0081] Among them, R ij An identifier variable indicating whether node i and node j are interconnected. When the value is 1, it means they are interconnected, otherwise the value is 0.

[0082] It should be noted that "interconnectable" in this article means that different nodes are actually close to each other, have the necessary equipment (such as high-voltage interfaces), can be connected by cables of a certain length and exchange power through SOP.

[0083] Search for elements with a value of 1 in the matrix R, record their horizontal and vertical coordinates, and form a horizontal coordinate sequence A and a vertical coordinate sequence B, with the elements of the two corresponding to each other.

[0084] S2: Based on the location and number of faulty lines, a post-disaster island model of the distribution network is constructed to identify whether the distributed resources have voltage support.

[0085] It should be noted that the fault line set is represented by F, then F = {4-5, 6-26, 12-13}, that is, the branches connecting nodes 4 and 5, nodes 6 and 26, and nodes 12 and 13. Using the binary variable z ij Indicates the open / closed state of the line connecting node i and node j, defining "closed" as 1 and "open" as 0. It is easy to know that z F =0, that is, z 45 =0, z 626 =0, z 1213 =0.

[0086] The location and number of faulty lines are obtained and numbered, and the resulting faulty line set is represented by F. Using the binary variable z ij Indicates the open / closed state of the line connecting node i and node j, with closed being defined as 1 and open being defined as 0.

[0087] According to graph theory, it is determined whether the distribution network forms an island. That is, when the N = 33 node radial distribution network is operating normally, N-1 = 32 lines should be put into operation. Assuming that after f = 3 lines fail, the distribution network still has h = 29 lines in operation, and there is no tie switch action in the distribution network, it is divided into f + 1 = 4 islands. If there is a tie switch action, the relationship is expressed as:

[0088] h≥N-1-f

[0089] Determine whether the distributed resources on the island have voltage support and establish a mathematical model of distributed resources based on the prediction curve.

[0090] It should be noted that since the ESV-SOP in this paper can adopt the VF control mode and has the voltage support capability, the support voltage required for the distributed resources can be supplied by the upper power grid or ESV-SOP. Therefore, there is a coupling between the voltage support effect of the artificial repair team and the ESV-SOP on the distributed resources. For this reason, the distributed resource support voltage identification variable ζ is introduced m,t , it is defined that when the distributed power source has working conditions, the value is 1, otherwise it is 0. It is expressed as:

[0091]

[0092] Among them, ε ij,t The identification variable indicating whether ESV-SOP interconnects node i and node j. The value is 1 when interconnection is defined, otherwise it is 0. I represents the main network, I m Indicates the island where the distributed resource m is located.

[0093] Furthermore, the distributed resources mentioned in this article specifically refer to power sources with volatility and intermittent characteristics, such as photovoltaic and wind power.

[0094] The output constraint of distributed resources is expressed as:

[0095]

[0096] Among them, P m,t represents the output power of distributed resource m, P m,t max Indicates the maximum power output by distributed resource m.

[0097] Establish an island operation model for the distribution network. When the distribution network is operating normally, it includes a branch flow model for power flow calculation. When a line fault occurs and an island operation occurs, it is necessary to introduce network reconstruction constraints and modify the voltage balance equation in the branch flow model.

[0098] The branch flow model includes power flow equation constraints, safety condition constraints and second-order cone relaxation constraints.

[0099] The power flow equation constraint requires that any node in the distribution network must satisfy the power balance constraint, which can be expressed as:

[0100]

[0101] Among them, P i,dis Indicates the active power output of the distributed power supply at the node, Q i,dis Represents the reactive power output by the distributed power supply at the node, P i,l Indicates the active load output by the distributed power supply at this node, Q i,l Indicates the active (reactive) load output by the distributed power supply at this node. i,net Indicates the active power output from the upper power grid to the node, Q i,net Indicates the reactive power output from the upper power grid to the node. Ω ki represents the set of branches flowing into node i, Ω ij represents the set of branches out of node i. ij Represents the active power flowing through the branch, Q ij Represents the reactive power flowing through the branch. i,e Indicates the active power input to the ESV-SOP of this node, Q i,e Indicates the reactive power input to the ESV-SOP of this node. ij Represents the square of the branch current. ij Represents the resistance of the line, x ij Indicates the reactance of the line.

[0102] The safety condition constraint requires that any node and any branch of the distribution network should meet the safety standard, which can be expressed as:

[0103]

[0104] Among them, V i represents the square of the voltage at node i, P ij represents the active power of the branch connecting node i and node j, Q ij Represents the reactive power of the branch connecting node i and node j.

[0105] The introduction of second-order cone relaxation constraints reduces the difficulty of solving the branch flow model in the computer, which can be expressed as:

[0106]

[0107] The voltage balance equation constraint that needs to be modified for network reconstruction is expressed as:

[0108]

[0109] Wherein, M represents an arbitrarily large positive number.

[0110] It should be noted that M is not an infinite positive number, and is taken as 100 in the present invention.

[0111] S3: Construct mathematical models of ESV-SOP and manual repair team.

[0112] Establish the ESV-SOP working mode characterization model, introduce and define 0-1 identification variables to characterize the ESV-SOP working mode: μ c,t , μ α c,t and μ β c,t .

[0113] At time t, the cth ESV-SOP is connected to the distribution network, then μ c,t =1. Otherwise μ c,t =0.

[0114] μ α c,t A value of 1 indicates that the mode is VF at time t, otherwise it is 0.

[0115] μ β c,t A value of 1 indicates that the mode is PQ at time t, otherwise it is 0.

[0116] The working mode is expressed as:

[0117]

[0118] Each ESV-SOP can only access one fault location at any time, so the constraint is expressed as:

[0119]

[0120] Among them, ξ k,m,t The access position of the cth ESV-SOP at t0 is represented by a 0-1 variable. When its value is 1, it means that the ESV-SOP is connected to R at t ij .

[0121] Set the working constraints of ESV-SOP. After ESV-SOP is connected to the fault location, it transmits power. Then the working state constraints are expressed as:

[0122]

[0123] Among them, P n,sop Indicates the active power output by the nth port of ESV-SOP, Q n,sop Indicates the reactive power output by the nth port of ESV-SOP. N n,sop Indicates the rated apparent power of the nth port. bat Indicates the output power of the energy storage battery. Z indicates the set of all ports of a single ESV-SOP. dc Represents the set of DC-DC ports of ESV-SOP, Z ac Represents the set of AC-AC ports of ESV-SOP.

[0124] The energy storage battery meets the charge and discharge constraints, which can be expressed as:

[0125]

[0126] Among them, P max bat Indicates the upper limit of the charging and discharging power of the energy storage battery, P min bat Indicates the lower limit of the charging and discharging power of the energy storage battery, C c bat Indicates the charge capacity at time t.

[0127] It should be noted that this paper takes P max bat It is 150KW.

[0128] For the fault line set F, a one-dimensional variable matrix Ft is introduced to characterize its maintenance status, which is expressed as:

[0129] F t =[z 1,t ,z 2,t ,…,z f,t ],f∈X

[0130] Among them, z f,t represents the closed state of the fault line, and the matrix elements are related to z ij,t Correspondingly, assuming that c manual repair teams can repair h lines in a unit time, it can be expressed as:

[0131]

[0132] Among them, i,t Represents the dispatch identification variable matrix of the i-th manual repair team at time t.

[0133] S4: Solve all models to obtain the dispatch path of ESV-SOP, the switching sequence of ESV-SOP working modes, the line repair sequence and the load support level of the distribution network.

[0134] The objective function of minimizing load reduction is adopted, which is expressed as:

[0135]

[0136] Where L represents the actual load borne by the distribution network in the emergency scenario, L v Indicates the load amount of the load forecast curve.

[0137] A commercial solver is used to solve the problem, and the dispatch path of ESV-SOP, the switching sequence of ESV-SOP working modes, the line repair sequence, and the load support level of the distribution network are obtained.

[0138] The above embodiments also include an island power supply restoration system considering an active support operation mode, specifically:

[0139] Determine the node set module, collect actual geographic location data, and determine the interconnectable node set of ESV-SOP in the distribution network.

[0140] Construct an island model module, build a post-disaster island model of the distribution network according to the location and number of faulty lines, and identify whether distributed resources have voltage support.

[0141] Construct the manual repair team model module and build the ESV-SOP and manual repair team mathematical models.

[0142] The solution module solves all models and obtains the dispatch path of ESV-SOP, the switching sequence of ESV-SOP working modes, the line repair sequence and the load support level of the distribution network.

[0143] The computer device may be a server. The computer device includes a processor, a memory, an input / output interface (I / O for short) and a communication interface. The processor, the memory and the input / output interface are connected via a system bus, and the communication interface is connected to the system bus via the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data cluster data of a power monitoring system. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, a method is implemented.

[0144] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0145] Example 2

[0146] Reference Figure 5 , which is an embodiment of the present invention, provides an island power supply restoration method and system considering the active support operation mode. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through simulation experiments.

[0147] In order to verify the effectiveness and superiority of the method involved in the present invention, the following three scenarios are set up in this implementation mode and verified on an IEEE33 node network containing a tie switch.

[0148] Scenario 1: Using the strategy proposed in this paper, three multi-mode ESV-SOPs are configured for island support power supply, denoted as ESV-SOP (VF+PQ).

[0149] Scenario 2: Three ESV-SOPs are configured for island support power supply, with only PQ working mode, denoted as ESV-SOP(PQ).

[0150] Figure 5 It is a comparison of the effect of the distribution network supporting the load under the two scenarios in this implementation method. The optimization results of the two scenarios can be compared, and the main features are as follows: After the line fault occurs, scenario one can provide voltage support for the distributed resources in the island through the VF working mode of ESV-SOP, and the distributed resources can work normally to support the island load. However, the ESV-SOP of scenario two can only transfer the supply flow through the PQ working mode, and the voltage required for the operation of the distributed resources can only be provided by the main network into which the island is incorporated after the faulty line is repaired. Therefore, compared with scenario two, scenario one has multiple working modes, which can adapt to the emergency scenario of the system passively dividing the island after the line failure, which can significantly reduce the load loss and improve the power supply reliability and resilience of the distribution network, verifying the effectiveness and superiority of the method proposed in this article.

[0151] 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 preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for island power supply restoration considering active support operation mode, It is characterized in that include: Collect actual geographic location data to determine the set of interconnectable nodes of ESV-SOP in the distribution network; According to the location and number of faulty lines, a distribution network post-disaster island model is constructed to identify whether distributed resources have voltage support; Construct mathematical models of ESV-SOP and manual repair team; All models are solved to obtain the dispatch path of ESV-SOP, the switching sequence of ESV-SOP working modes, the line repair sequence and the load support level of the distribution network.

2. The island power supply restoration method considering the active support operation mode as claimed in claim 1, Features: The collecting of actual geographic location data and determining the set of interconnectable nodes of ESV-SOP in the distribution network includes introducing an N×N ESV-SOP scheduling feasible domain matrix R, where N represents the number of nodes in the distribution network and R is expressed as: Among them, R ij An identifier variable indicating whether nodes i and j are interconnected. If the value is 1, it indicates that they are interconnected, otherwise the value is 0. Search for elements with a value of 1 in the matrix R, record their horizontal and vertical coordinates, and form a horizontal coordinate sequence A and a vertical coordinate sequence B, with the elements of the two corresponding to each other.

3. The island power supply restoration method considering the active support operation mode as claimed in claim 2, Features: The construction of the distribution network post-disaster island model according to the location and number of faulty lines includes obtaining the location and number of the faulty lines and numbering them, and the obtained faulty line set is represented by F; Using the binary variable z ij Indicates the open / closed state of the line connecting node i and node j, with closed as 1 and open as 0. F =0; According to graph theory, we can judge whether the distribution network forms an island. When the N-node radial distribution network is operating normally, N-1 lines are put into operation. Assuming that after f lines fail, the distribution network still has h lines in operation. If there is no tie switch action in the distribution network, f+1 islands will be formed. If there is a tie switch action, the relationship is expressed as: h≥N-1-f Determine whether the distributed resources on the island have voltage support and establish a mathematical model of distributed resources based on the prediction curve; Introducing distributed resource support voltage identification variable ζ m,t , it is defined that when the distributed power source has working conditions, the value is 1, otherwise it is 0; it is expressed as: Among them, ε ij,t An identifier variable indicating whether ESV-SOP interconnects nodes i and j. The value is 1 when interconnection is defined, otherwise it is 0. I represents the main network, I m represents the island where the distributed resource m is located; The output constraint of distributed resources is expressed as: Among them, P m,t represents the output power of distributed resource m, P m,t max Indicates the maximum power output by distributed resource m.

4. The island power supply restoration method considering the active support operation mode as claimed in claim 3, Features: The construction of the distribution network post-disaster island model includes: when the distribution network is operating normally, including a branch flow model for power flow calculation, when a line fault occurs and an island operation is formed, introducing a network reconstruction constraint and modifying the voltage balance equation in the branch flow model; The branch flow model includes power flow equation constraints, safety condition constraints and second-order cone relaxation constraints; The power flow equation constraint requires that any node in the distribution network must satisfy the power balance constraint expressed as: Among them, P i,dis Indicates the active power output of the distributed power supply at the node, Q i,dis Represents the reactive power output by the distributed power supply at the node, P i,l Indicates the active load output by the distributed power supply at this node, Q i,l Represents the active (reactive) load output by the distributed power supply at this node; P i,net Indicates the active power output from the upper power grid to the node, Q i,net Indicates the reactive power output from the upper power grid to the node; Ω ki represents the set of branches flowing into node i, Ω ij represents the branch set out of node i; P ij Represents the active power flowing through the branch, Q ij Represents the reactive power flowing through the branch; P i,e Indicates the active power input to the ESV-SOP of this node, Q i,e Represents the reactive power input to the ESV-SOP of this node; I ij Represents the square of branch current; r ij Represents the resistance of the line, x ij Indicates the reactance of the line; The safety condition constraint requires that any node and any branch of the distribution network should meet the safety standard, which can be expressed as: Among them, V i represents the square of the voltage at node i, P ij represents the active power of the branch connecting node i and node j, Q ij represents the reactive power of the branch connecting node i and node j; Introduce the second-order cone relaxation constraint, expressed as: The voltage balance equation constraint that needs to be modified for network reconstruction is expressed as: Wherein, M represents an arbitrarily large positive number.

5. The island power supply restoration method considering the active support operation mode as claimed in claim 4, Features: The construction of the mathematical model of ESV-SOP and manual repair team includes establishing an ESV-SOP working mode characterization model, introducing and defining a 0-1 identification variable to characterize the working mode of ESV-SOP: μ c,t , μ α c,t and μ β c,t ; At time t, the cth ESV-SOP is connected to the distribution network, then μ c,t =1; otherwise μ c,t =0; μ α c,t When the value is 1, it means that it is in VF mode at time t, otherwise it is 0; μ β c,t When the value is 1, it means that it is in PQ mode at time t, otherwise it is 0; The working mode is expressed as: Each ESV-SOP can only access one fault location at any time, so the constraint is expressed as: Among them, ξ k,m,t Indicates t 0 The access position of the cth ESV-SOP at time t is a 0-1 variable. When its value is 1, it means that the ESV-SOP accesses R at time t. ij ; Set the working constraints of ESV-SOP. After ESV-SOP is connected to the fault location, it transmits power. Then the working state constraints are expressed as: Among them, P n,sop Indicates the active power output by the nth port of ESV-SOP, Q n,sop Indicates the reactive power output by the nth port of ESV-SOP; S N n,sop Indicates the rated apparent power of the nth port; P bat Represents the output power of the energy storage battery; Z represents the set of all ports of a single ESV-SOP; Z dc Represents the set of DC-DC ports of ESV-SOP, Z ac Represents the set of AC-AC ports of ESV-SOP; The energy storage battery meets the charge and discharge constraints, which can be expressed as: Among them, P max bat Indicates the upper limit of the charging and discharging power of the energy storage battery, P min bat Indicates the lower limit of the charging and discharging power of the energy storage battery, C c bat Indicates the charge capacity at time t.

6. The island power supply restoration method considering the active support operation mode as claimed in claim 5, Features: The mathematical model of the artificial repair team includes, for the fault line set F, introducing a one-dimensional variable matrix Ft to characterize its maintenance status, which is expressed as: F t =[of 1,t ,With 2,t ,...,With f,t ],f∈X Among them, z f,t represents the closed state of the fault line, and the matrix elements are related to z ij,t Correspondingly, assuming that c manual repair teams can repair h lines in a unit time, it can be expressed as: Among them, i,t Represents the dispatch identification variable matrix of the i-th manual repair team at time t.

7. The island power supply restoration method considering the active support operation mode as claimed in claim 6, Features: The solution of all models to obtain the dispatch path of ESV-SOP, the switching order of ESV-SOP working mode, the line repair order and the load support level of the distribution network includes adopting the objective function of minimizing load reduction, which is expressed as: Where L represents the actual load borne by the distribution network in the emergency scenario, L v Indicates the load amount of the load forecast curve; A commercial solver is used to solve the problem, and the dispatch path of ESV-SOP, the switching sequence of ESV-SOP working modes, the line repair sequence, and the load support level of the distribution network are obtained.

8. An island power supply restoration system taking into account an active support operation mode using the method according to any one of claims 1 to 7, Features: Determine the node set module, collect actual geographic location data, and determine the interconnectable node set of ESV-SOP in the distribution network; Construct an island model module to build a post-disaster island model of the distribution network based on the location and number of faulty lines, and identify whether distributed resources have voltage support; Construct the manual repair team model module and build the ESV-SOP and manual repair team mathematical models; The solution module solves all models and obtains the dispatch path of ESV-SOP, the switching sequence of ESV-SOP working modes, the line repair sequence and the load support level of the distribution network.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program. It is characterized in that When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, It is characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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