A power supply restoration method and system based on second-order cone programming

Abstract

The application discloses a power supply recovery method and system based on a second-order cone programming, and the method comprises the following steps: inputting the obtained switch state, line parameter and distributed power output of a power distribution network into a pre-constructed power distribution network power supply recovery model; performing cone relaxation on the power distribution network power supply recovery model based on a set relaxation variable; and solving the cone-relaxed power distribution network power supply recovery model by using a second-order cone programming algorithm to obtain the switch state and the distributed power output of the power distribution network; wherein the power distribution network power supply recovery model is constructed based on the switch state, branch node relationship and distributed power output of the power distribution network, and a virtual node is added in a branch containing a switch according to the position of the switch in the branch, virtual branches are formed based on the virtual nodes, and the model is constructed based on branch power flow. The application considers the different operating characteristics of the source and load in the power distribution system, and can quickly guarantee the maximum power supply recovery level when a user power failure accident occurs.

Description

Technical Field

[0001] This invention relates to the field of power system operation analysis technology, specifically to a power supply restoration method and system based on second-order cone programming. Background Technology

[0002] Statistics show that over 80% of power outages are caused by distribution network faults. Therefore, distribution systems need to be able to handle various complex and uncertain faults to meet users' power supply needs. Load restoration, as one of the core means to improve the reliability of distribution network power supply, is of great significance for meeting users' demand for high-quality power supply. However, when a power outage occurs, the branch power flow method can lead to inaccurate descriptions of branch states, resulting in errors in the solution results. Therefore, how to ensure the maximum power restoration level for critical loads while considering the different operating characteristics of sources and loads in the distribution system, and on the basis of safe system operation, has significant scientific and engineering value. Summary of the Invention

[0003] To address the aforementioned shortcomings in the existing technology, this invention provides a power supply restoration method based on second-order cone programming, comprising:

[0004] The obtained switch status, line parameters, and distributed generation output of the distribution network are input into the pre-built power supply recovery model of the distribution network.

[0005] The power supply recovery model of the power distribution network is subjected to cone relaxation based on the set relaxation variables;

[0006] The power supply restoration model of the distribution network after cone relaxation is solved using a second-order cone programming algorithm to obtain the switching state of the distribution network and the output of distributed generation.

[0007] The power supply restoration model for the distribution network is constructed by using the state of the distribution network switches, the relationship between branch nodes, and the output of distributed power sources as control variables. Virtual nodes are added to the branches containing switches according to the position of the switches in the branches. Virtual branches are formed based on the virtual nodes and constructed based on the power flow of the branches.

[0008] Preferably, the construction of the power distribution network power restoration model includes:

[0009] Construct an objective function with the goal of maximizing the load restoration during distribution network faults;

[0010] If the branch contains a switch, then add virtual nodes at both ends of the switch to obtain a first virtual branch composed of virtual nodes and a second virtual branch composed of branch nodes and virtual nodes.

[0011] Based on the opening and closing of the tie switch and the sectionalizing switch, the operating constraints of the first virtual branch including the switch branch are constructed.

[0012] Based on the branch power flow, construct the operating constraints for the second virtual branch and the branch without switches;

[0013] Construct network structure constraints based on the operation mode of the distribution network;

[0014] Construct operating constraints for distributed power sources based on their output.

[0015] The operating constraints including switch branches, operating constraints not including switch branches, network structure constraints, and distributed power source operating constraints are constraints constructed for the objective function.

[0016] Preferably, the operating constraints of the branch containing the switch include:

[0017] Current constraints, voltage constraints, and current amplitude constraints for branches containing switches.

[0018] Preferably, the current constraint of the branch containing the switch is as shown in the following formula:

[0019]

[0020] In the formula: I im : The current flowing from branch node i to virtual node m; I mn The current flowing from virtual node m to virtual node n; I nj The current flowing from virtual node n to branch node j;

[0021] The voltage constraint including the switch branch is shown in the following formula:

[0022]

[0023] In the formula: U max : Upper limit of voltage amplitude; U min : Lower limit of voltage amplitude; U m : Voltage amplitude of virtual node m; U n σ: Voltage amplitude of virtual node n; mn : Status of the connecting switch or sectionalizing switch;

[0024] The current amplitude constraint of the branch containing the switch is shown in the following formula:

[0025] I min σ mn ≤I mn ≤I max σ mn

[0026] In the formula: I min: Lower limit of current; I mn The current flowing from virtual node m to virtual node n; I max : Upper limit of current.

[0027] Preferably, the operating constraints that do not include switching branches include:

[0028] Branch power flow constraints, voltage drop constraints, voltage, current and power constraints, voltage constraints excluding switching branches, and current constraints excluding switching branches.

[0029] Preferably, the branch power flow constraint is as shown in the following formula:

[0030]

[0031] In the formula: p j : Injected active power at branch node j; q j : Injected reactive power at branch node j; P jk Q: Active power of branch jk with node j as the first node; jk P: Reactive power of branch jk with node j as the first end; ij Q: Active power of branch ij with node j as the terminal node; ij δ(j): Reactive power of branch ij with node j as the terminal node; δ(j): Set of terminal nodes of branch with node j as the starting node; π(j): Set of starting nodes of branch with node j as the terminal node; I ij : The current flowing from branch node i to branch node j; r ij : Resistance of branch ij; x ij : Reactance of branch ij; g j : Conductance of branch node j; b j : Susceptance of branch node j; U j : Voltage amplitude at branch node j; Ω N The set of all nodes in a power distribution network;

[0032] The voltage drop constraint is shown in the following equation:

[0033]

[0034] In the formula: U i : Voltage amplitude at branch node i; Ω sw : A collection including switch branches; Ω B / Ω sw : A collection excluding switch branches; Ω B The set of all branches in a power distribution network;

[0035] The voltage, current, and power constraints are shown in the following equation:

[0036]

[0037] The voltage constraint excluding the switching branch is shown in the following formula:

[0038]

[0039] In the formula: Lower limit of voltage amplitude at branch node j; Upper limit of voltage amplitude at branch node j;

[0040] The current constraint excluding the switching branch is shown in the following formula:

[0041]

[0042] In the formula: Lower limit of branch current ij; Upper limit of branch current ij.

[0043] Preferably, the network structure constraints are as follows:

[0044] σ ij =α ij +α ji

[0045] In the formula: σ ij The state of the distribution network switch; α ij The relationship between branch node i and branch node j; α ji The relationship between branch node j and branch node i;

[0046]

[0047] Where: Ω L Ω represents the set of nodes in a power outage branch of a distribution network. N The set of all nodes in a power distribution network.

[0048] Preferably, the operating constraints of the distributed power source are as follows:

[0049]

[0050] In the formula: This represents the minimum active power output of the k-th distributed power source. P represents the maximum active power output of the k-th distributed power source. DG,k Q represents the active power output of the k-th distributed power source; DG,k S represents the reactive power output of the k-th distributed power source; DG,k Let be the capacity of the k-th distributed power source.

[0051] Preferably, the slack variable is calculated as follows:

[0052]

[0053] In the formula: The slack variable of electric current; The slack variable of voltage amplitude; I ij : The current flowing from branch node i to branch node j; U j : Voltage amplitude at branch node j.

[0054] Based on the same inventive concept, the present invention also provides a power restoration system based on second-order cone programming, comprising:

[0055] The instantiation module is used to input the acquired switch status, line parameters and distributed power output of the distribution network into the pre-built power supply recovery model of the distribution network;

[0056] The cone relaxation module is used to perform cone relaxation on the power supply recovery model of the power distribution network based on the set relaxation variables.

[0057] The solution module is used to solve the power supply recovery model of the distribution network after cone relaxation using a second-order cone programming algorithm to obtain the switching state of the distribution network and the output of distributed power sources.

[0058] The power supply restoration model for the distribution network is constructed by using the state of the distribution network switches, the relationship between branch nodes, and the output of distributed power sources as control variables. Virtual nodes are added to the branches containing switches according to the position of the switches in the branches. Virtual branches are formed based on the virtual nodes and constructed based on the power flow of the branches.

[0059] Preferably, the system further includes a construction module for constructing a power distribution network power restoration model; the construction module includes:

[0060] Construct a target submodule to build an objective function with the objective of maximizing the load restoration during distribution network faults;

[0061] The virtual branch submodule is used to add virtual nodes at both ends of the switch if the branch contains a switch, to obtain a first virtual branch composed of virtual nodes and a second virtual branch composed of branch nodes and virtual nodes.

[0062] The first constraint condition submodule is used to construct the operation constraint conditions of the first virtual branch containing the switch branch based on the opening and closing of the tie switch and the sectionalizing switch.

[0063] The second constraint condition submodule is used to construct the operating constraints of the branch without switches based on the branch power flow for the second virtual branch and the branch without switches.

[0064] The third constraint condition submodule is used to construct network structure constraints based on the operation mode of the distribution network;

[0065] The fourth constraint condition submodule is used to construct the operating constraints of the distributed power source based on the output of the distributed power source.

[0066] The technical solution provided by this invention has the following beneficial effects:

[0067] The technical solution provided by this invention involves inputting the obtained switch states, line parameters, and distributed generation output of the distribution network into a pre-constructed distribution network power supply restoration model; performing cone relaxation on the distribution network power supply restoration model based on set relaxation variables; and solving the cone-relaxed distribution network power supply restoration model using a second-order cone programming algorithm to obtain the switch states and distributed generation output of the distribution network. The distribution network power supply restoration model uses the switch states, branch node relationships, and distributed generation output as control variables, and adds virtual nodes to branches containing switches based on the switch's location. Virtual branches are then formed based on these virtual nodes, and the model is constructed based on branch power flow. This invention can quickly ensure the maximum power supply restoration level during user power outages. Furthermore, by adding virtual nodes to branches containing switches based on their location and forming corresponding virtual branches, the invention addresses the problem of inaccurate branch state descriptions in traditional branch power flow methods. Attached Figure Description

[0068] Figure 1 This is a flowchart of the power supply restoration method based on second-order cone programming according to the present invention;

[0069] Figure 2 This is a schematic diagram of the radial behavior of branch ij in an embodiment of the present invention;

[0070] Figure 3 This is a schematic diagram of the radial distribution after adding virtual nodes and branches in branch ij in an embodiment of the present invention. Detailed Implementation

[0071] To better understand this invention, the following description, in conjunction with the accompanying drawings and examples, will further illustrate the invention.

[0072] Example 1: As Figure 1 As shown, this invention provides a power supply restoration method based on second-order cone programming, comprising:

[0073] S1. Input the obtained switch status, line parameters and distributed power output of the distribution network into the pre-built power supply recovery model of the distribution network.

[0074] S2. Perform cone relaxation on the power supply recovery model of the power distribution network based on the set relaxation variables;

[0075] S3. The power supply restoration model of the distribution network after cone relaxation is solved using the second-order cone programming algorithm to obtain the switching state of the distribution network and the output of distributed power sources.

[0076] The power supply restoration model for the distribution network is constructed by using the state of the distribution network switches, the relationship between branch nodes, and the output of distributed power sources as control variables. Virtual nodes are added to the branches containing switches according to the position of the switches in the branches. Virtual branches are formed based on the virtual nodes and constructed based on the power flow of the branches.

[0077] This invention is applicable to active distribution networks, and the distributed power sources in this invention refer to controllable distributed power sources such as micro gas turbines and diesel engines.

[0078] First, a power supply restoration model for the power distribution network is constructed, including...

[0079] Step 1: Construct the objective function for power restoration, with the objective function being to maximize the load restoration during active distribution network faults:

[0080]

[0081] Where: Ω N — A set of nodes; λ n —Power restoration flag for the nth node, 1 indicates restoration, 0 indicates no restoration; P load,n — Load of the nth section.

[0082] Step 2: Construct the operating constraints in the distribution network reconfiguration model that do not include switch branches, as shown in the following formula:

[0083]

[0084]

[0085]

[0086]

[0087]

[0088] Where: Ω B —The set of all branches; Ω sw —A set including switch branches; Ω B / Ω sw —The set of branches excluding switches; δ(j) —The set of terminal nodes of branches with j as the first terminal node; π(j) —The set of first terminal nodes of branches with j as the last terminal node; U i and U j —Voltage magnitudes at nodes i and j; P jk and Qjk —Active and reactive power of branch jk with node j as the first node; P ij and Q ij —Active and reactive power of branch ij with node j as the terminal node; p j and q j —Injected active and reactive power at node j; r ij and x ij —The resistance and reactance of branch ij; I ij —The current flowing from node i to node j; g j and b j —Conductance and susceptance of node j; Umin j —Lower limit of voltage amplitude at node j; Umax j —Upper limit of voltage amplitude at node j; Imin ij —Lower limit of current in branch ij; Imax ij —Upper limit of current in branch ij;

[0089] Step 3: Construct the operational constraints for the distribution network reconfiguration model including switch branches:

[0090] For a branch ij containing a switch, two virtual nodes m and n can be added, thus changing the original branch into three virtual branches im, mn, and nj. For example... Figure 2 and 3 The diagram shows the original distribution network radial lines and the radial lines after adding virtual nodes and branches.

[0091] (1) Branches im and nj

[0092] For branches im and nj, the operating constraints are still constructed based on the branch without switches in step 2.

[0093] (2) Branch mn

[0094] ① The relationship between voltage, current, and power is shown in the following formula:

[0095]

[0096] ② Voltage constraint

[0097] Due to the uncertainty of the switching state, the constraint on the voltage across the terminals changes from an equality to an inequality, as shown in the following equation:

[0098]

[0099] When σ mn When = 1, the line is connected and exists.

[0100] When σ mn When = 0, the line is not connected, and the relationship satisfied by the terminal voltage is redundant because it has already been reflected in the upper and lower limit constraints of a single voltage.

[0101] ③ Voltage and current amplitude constraints, as shown in the following formula:

[0102] I min σ mn ≤I mn ≤I max σ mn (9)

[0103] σ mn —The status of the connecting switch or sectionalizing switch, σ mn =1 indicates the switch is closed, σ mn =0 indicates that the switch is off.

[0104] The two formulas above constrain the current relationship under different switch states.

[0105] Step 4: Construct the network structure constraints for the power restoration model, as shown in the following equation:

[0106] σ ij =α ij +α ji (10)

[0107]

[0108]

[0109] σ ij ∈{0,1},α ij ∈{0,1},α ji ∈{0,1} (13)

[0110] Where: Ω L —The set of nodes in a power-loss branch of an active distribution network; α ij — Representing the relationship between node i and node j, when electrical energy flows from i to j, α ij When α is 1, electrical energy flows from j to i. ij The value is 0, here σ ij This characterizes a branch with a distribution network switch, indicating whether the switch is closed or open; 1 represents closed and 0 represents open. α... ij It represents a value of 1 if electrical energy flows from node i to node j, and 0 in other cases (the two nodes are not connected or electrical energy flows from j to i).

[0111] Step 5: Construct the operating constraints for the distributed power source, as shown in the following formula:

[0112]

[0113]

[0114] In the formula: PDG,k Q DG,k and S DG,k — These represent the active and reactive power output and capacity of the k-th distributed power source, respectively; Pmin DG,k and Pmax DG,k are the minimum and maximum active power output of the k-th distributed power source.

[0115] S2. Perform cone relaxation on the power supply recovery model of the power distribution network based on the set relaxation variables, including:

[0116] According to the following formula, let Perform cone relaxation:

[0117]

[0118] In the formula: —I ij Slack variables; ——U j Slack variables.

[0119] Substituting constraints (2)-(6) into... and get:

[0120]

[0121]

[0122]

[0123]

[0124]

[0125] After relaxation, formula (7) becomes:

[0126]

[0127] After relaxation, formula (8) becomes:

[0128]

[0129] After relaxation, formula (9) becomes:

[0130]

[0131] Other variables that do not require relaxation are kept unchanged.

[0132] S3. The power supply restoration model of the distribution network after cone relaxation is solved using a second-order cone programming algorithm to obtain the switching state of the distribution network and the output of distributed generation sources, including:

[0133] The power supply recovery model based on cone relaxation has good convergence and the optimal solution to the original problem can be obtained directly using algorithms such as MOSEK or CPLEX.

[0134] The technical solution provided by this invention is as follows: First, an active distribution network power restoration model based on source-load operation characteristics is established, considering the supporting role of controllable distributed power sources during power restoration, and unifying the power restoration and islanding problems into a single model; Second, addressing the issue that the original model constraints for branches containing switches cannot characterize the voltage, current, and power flow relationships in both open and closed states of the switches, a method is proposed to add virtual nodes and branches in branches containing switches, thus reconstructing the constraints for branches containing switches; Finally, to improve solution efficiency, a convex relaxation technique is used to transform the power restoration model into a second-order cone programming model, facilitating solution using existing optimization software.

[0135] This invention proposes using the active distribution network switch state σ ij Branch node relationship α ij Distributed power output P DG,k Q DG,k The power restoration model is a set of control variables. During the calculation, the initial switching state of the distribution network, line parameters, output of uncontrollable distributed power sources, output limits of controllable distributed power sources, and load power need to be input. By solving the control variables in the power restoration model, the switching state and output of controllable distributed power sources that characterize power restoration are obtained. The relationship between power loss nodes is an intermediate variable in the modeling.

[0136] The power restoration model proposed in this invention adds virtual nodes and forms corresponding virtual branches based on the actual location of the switches in the branches, thus solving the problem of inaccurate description of branch state by the branch power flow method.

[0137] Cone relaxation was performed on the power supply restoration model proposed in the invention, and it was found that the power supply restoration model can be solved by a second-order cone programming algorithm, which reduces the amount of computation.

[0138] Example 2: Based on the same inventive concept, the present invention also provides a power restoration system based on second-order cone programming, comprising:

[0139] The instantiation module is used to input the acquired switch status, line parameters and distributed power output of the distribution network into the pre-built power supply recovery model of the distribution network;

[0140] The cone relaxation module is used to perform cone relaxation on the power supply recovery model of the power distribution network based on the set relaxation variables.

[0141] The solution module is used to solve the power supply recovery model of the distribution network after cone relaxation using a second-order cone programming algorithm to obtain the switching state of the distribution network and the output of distributed power sources.

[0142] The power supply restoration model for the distribution network is constructed by using the state of the distribution network switches, the relationship between branch nodes, and the output of distributed power sources as control variables. Virtual nodes are added to the branches containing switches according to the position of the switches in the branches. Virtual branches are formed based on the virtual nodes and constructed based on the power flow of the branches.

[0143] In this embodiment, the system further includes a construction module for constructing a power distribution network power restoration model; the construction module includes:

[0144] Construct a target submodule to build an objective function with the objective of maximizing the load restoration during distribution network faults;

[0145] The virtual branch submodule is used to add virtual nodes at both ends of the switch if the branch contains a switch, to obtain a first virtual branch composed of virtual nodes and a second virtual branch composed of branch nodes and virtual nodes.

[0146] The first constraint condition submodule is used to construct the operation constraint conditions of the first virtual branch containing the switch branch based on the opening and closing of the tie switch and the sectionalizing switch.

[0147] The second constraint condition submodule is used to construct the operating constraints of the branch without switches based on the branch power flow for the second virtual branch and the branch without switches.

[0148] The third constraint condition submodule is used to construct network structure constraints based on the operation mode of the distribution network;

[0149] The fourth constraint condition submodule is used to construct the operating constraints of the distributed power source based on the output of the distributed power source.

[0150] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied 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.

[0151] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0152] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0153] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0154] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. A power supply restoration method based on second-order cone programming, characterized by, include: The obtained switch status, line parameters, and distributed generation output of the distribution network are input into the pre-built power supply recovery model of the distribution network. The power supply recovery model of the power distribution network is subjected to cone relaxation based on the set relaxation variables; The slack variable is calculated as follows: In the formula: : The slack variable of current; : The slack variable of voltage amplitude; Branch node Flow to branch nodes The current; Branch node The voltage amplitude; The power supply restoration model of the distribution network after cone relaxation is solved using a second-order cone programming algorithm to obtain the switching state of the distribution network and the output of distributed generation. The power supply restoration model for the distribution network is based on the distribution network switch status, branch node relationship and distributed power output as control variables. Virtual nodes are added in the branches containing switches according to the position of the switches in the branches. Virtual branches are formed based on each virtual node and constructed based on the power flow of the branches. The construction of the power supply restoration model for the power distribution network includes: Construct an objective function with the goal of maximizing the load restoration during distribution network faults; If the branch contains a switch, then add virtual nodes at both ends of the switch to obtain a first virtual branch composed of virtual nodes and a second virtual branch composed of branch nodes and virtual nodes. Based on the opening and closing of the tie switch and the sectionalizing switch, the operating constraints of the first virtual branch including the switch branch are constructed. Based on the branch power flow, construct the operating constraints for the second virtual branch and the branch without switches; Construct network structure constraints based on the operation mode of the distribution network; Construct operating constraints for distributed power sources based on their output. Among them, the operating constraints containing switch branches, the operating constraints not containing switch branches, the network structure constraints, and the distributed power source operating constraints are constraints constructed for the objective function; The operating constraints of the distributed power source are shown in the following formula: In the formula: For the first k The minimum active power output of a distributed power source; For the first k The maximum active power output of a distributed power source; For the first k The active power output of a distributed power source; For the first k The reactive power output of a distributed power source; For the first k The capacity of a distributed power source.

2. The method as described in claim 1, characterized in that, The operating constraints of the branch containing the switch include: Current constraints, voltage constraints, and current amplitude constraints for branches containing switches.

3. The method as described in claim 2, characterized in that, The current constraint for the branch containing the switch is shown in the following formula: In the formula: Branch node Flow to virtual nodes The current; Virtual Node Flow to virtual nodes The current; Virtual Node Flow to branch nodes The current; The voltage constraint including the switch branch is shown in the following formula: In the formula: Upper limit of voltage amplitude; Lower limit of voltage amplitude; Virtual Node The voltage amplitude; Virtual Node The voltage amplitude; : Status of the connecting switch or sectionalizing switch; The current amplitude constraint of the branch containing the switch is shown in the following formula: In the formula: Lower limit of current; Virtual Node Flow to virtual nodes The current; : Upper limit of current.

4. The method as described in claim 1, characterized in that, The operating constraints that do not include switching branches include: Branch power flow constraints, voltage drop constraints, voltage, current and power constraints, voltage constraints excluding switching branches, and current constraints excluding switching branches.

5. The method as described in claim 4, characterized in that, The branch power flow constraint is shown in the following formula: In the formula: Branch node The injected active power; Branch node Injected reactive power; :by Branches for the first node The active power; :by Branches for the first node reactive power; :by Branches for end nodes The active power; :by Branches for end nodes reactive power; :by It is the set of branch end nodes of the first node; :by The set of the starting nodes of the branches of the terminal nodes; Branch node Flow to branch nodes The current; Branch road The resistance; Branch road The reactance; Branch node The electrical conductivity; Branch node susceptance; Branch node The voltage amplitude; The set of all nodes in a power distribution network; The voltage drop constraint is shown in the following equation: In the formula: Branch node The voltage amplitude; A collection including switch branches; : A collection excluding switch branches; The set of all branches in a power distribution network; The voltage, current, and power constraints are shown in the following equation: The voltage constraint excluding the switching branch is shown in the following formula: In the formula: Branch node Lower limit of voltage amplitude; Branch node Upper limit of voltage amplitude; The current constraint excluding the switching branch is shown in the following formula: In the formula: Branch road Lower current limit; Branch road Current limit.

6. The method as described in claim 1, characterized in that, The network structure constraints are shown in the following equation: In the formula: The status of the distribution network switches; α ij branch node i and branch nodes j Relationship; branch node j and branch nodes i Relationship; In the formula: Ω L This refers to the set of nodes in a power outage branch of a distribution network. The set of all nodes in a power distribution network.

7. A power supply restoration system based on second-order cone programming, characterized in that, include: The instantiation module is used to input the acquired switch status, line parameters and distributed power output of the distribution network into the pre-built power supply recovery model of the distribution network; The cone relaxation module is used to perform cone relaxation on the power supply recovery model of the power distribution network based on the set relaxation variables. The slack variable is calculated as follows: In the formula: : The slack variable of current; : The slack variable of voltage amplitude; Branch node Flow to branch nodes The current; Branch node The voltage amplitude; The solution module is used to solve the power supply recovery model of the distribution network after cone relaxation using a second-order cone programming algorithm to obtain the switching state of the distribution network and the output of distributed power sources. The power supply restoration model for the distribution network is based on the distribution network switch status, branch node relationship and distributed power output as control variables. Virtual nodes are added in the branches containing switches according to the position of the switches in the branches. Virtual branches are formed based on each virtual node and constructed based on the power flow of the branches. The system also includes a construction module for building a power distribution network power restoration model; the construction module includes: Construct a target submodule to build an objective function with the objective of maximizing the load restoration during distribution network faults; The virtual branch submodule is used to add virtual nodes at both ends of the switch if the branch contains a switch, to obtain a first virtual branch composed of virtual nodes and a second virtual branch composed of branch nodes and virtual nodes. The first constraint condition submodule is used to construct the operation constraint conditions of the first virtual branch containing the switch branch based on the opening and closing of the tie switch and the sectionalizing switch. The second constraint condition submodule is used to construct the operating constraints of the branch without switches based on the branch power flow for the second virtual branch and the branch without switches. The third constraint condition submodule is used to construct network structure constraints based on the operation mode of the distribution network; The fourth constraint condition submodule is used to construct the operating constraints of the distributed power source based on the output of the distributed power source. The operating constraints of the distributed power source are shown in the following formula: In the formula: For the first k The minimum active power output of a distributed power source; For the first k The maximum active power output of a distributed power source; For the first k The active power output of a distributed power source; For the first k The reactive power output of a distributed power source; For the first k The capacity of a distributed power source.

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