A method and device for active power distribution network fault restoration considering sop

Abstract

The application relates to the technical field of power distribution network fault recovery, and particularly provides an active power distribution network fault recovery method and device considering SOP, which comprises the following steps: determining an SOP transfer capacity based on a preset SOP transfer capacity constraint condition; substituting the SOP transfer capacity into a pre-constructed active power distribution network fault recovery model, and solving the pre-constructed active power distribution network fault recovery model to obtain a power distribution network branch on-off adjustment vector for fault recovery; wherein the pre-constructed active power distribution network fault recovery model comprises a target function, model optimization variables and constraint conditions configured for the pre-constructed active power distribution network fault recovery model. The technical scheme provided by the application considers the limitation of the SOP transfer capacity in the active power distribution network, realizes power supply recovery of the power distribution network, and reduces line loss generated in the fault recovery process.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power distribution network fault recovery, and particularly relates to a method and device for active power distribution network fault recovery considering SOP. BACKGROUND

[0002] In order to meet the needs of energy transformation and energy conservation and environmental protection, it is an inevitable trend for power grids to widely access distributed renewable energy. Due to the time-varying nature of renewable energy, after a large number of distributed power sources are connected to the distribution network, the power flow in the system presents time-varying and multidirectional characteristics, and power exchange is more frequent, which may, to some extent, lead to problems such as voltage and current out-of-limit, and therefore higher requirements are put forward for the fault recovery capability of the distribution network.

[0003] SOP is a power electronic device installed at a traditional tie switch, which can accurately control the active and reactive power of the two sides of the tie switch. Replacing part of the traditional tie switch with SOP in the distribution network helps to improve the accommodation capacity of the distribution network for distributed power sources, thereby solving a series of new problems brought by large-scale access of distributed power sources. In the event of a fault, SOP can effectively prevent fault current from passing through due to the effect of DC isolation, and can provide effective voltage support for the fault side during power supply recovery, thereby expanding the power supply recovery range. At present, the research on the application of SOP to distribution network fault recovery is still in its infancy. One existing solution proposes a recovery strategy for passive distribution network trunk faults considering SOP, and uses the interior point method for solution, but it does not consider the transfer capacity of SOP, and only takes reducing the amount of lost load as the optimization objective. Another existing solution also studies the active distribution network fault recovery method with SOP, but it does not make a detailed analysis of the volatility of distributed power sources and loads. SUMMARY

[0004] In order to overcome the above-mentioned defects, the present application provides a method and device for active power distribution network fault recovery considering SOP.

[0005] In a first aspect, a method for active power distribution network fault recovery considering SOP is provided, which comprises:

[0006] determining the transfer capacity of SOP based on a predetermined SOP transfer capacity constraint condition;

[0007] substituting the SOP transfer capacity into a pre-constructed active power distribution network fault recovery model, and solving the pre-constructed active power distribution network fault recovery model to obtain a distribution network branch on-off adjustment vector for fault recovery;

[0008] The pre-constructed active power distribution network fault recovery model comprises a target function, model optimization variables and constraint conditions configured for the pre-constructed active power distribution network fault recovery model.

[0009] Preferably, before the determination of the SOP transfer capacity based on the preset SOP transfer capacity constraint condition, the method comprises:

[0010] When both ends of the SOP are the networking side subnets, the control mode of the normal side of the SOP is U dc Q control mode, and the control mode of the fault side is a PQ control mode.

[0011] When one end of the SOP is the networking side subnet and the other end is the disconnection side subnet, the control mode of the normal side of the SOP is U dc Q control mode, and the control mode of the fault side is V f control mode.

[0012] Preferably, the determination of the SOP transfer capacity based on the preset SOP transfer capacity constraint condition comprises:

[0013] The maximum active power output by the SOP fault side when the power distribution network meets the preset SOP transfer capacity constraint condition is taken as the SOP transfer capacity.

[0014] The preset SOP transfer capacity constraint condition comprises at least one of the following: a node voltage constraint, a branch current constraint, a power distribution network power flow constraint, an SOP two-end active power balance constraint and an SOP two-end capacity constraint.

[0015] Further, the mathematical expression of the SOP two-end active power balance constraint is as follows:

[0016] P1+P2=0

[0017] The mathematical expression of the SOP two-end capacity constraint is as follows:

[0018]

[0019] In the above formula, P1 and P2 are respectively the active power input by the normal side of the SOP and the active power output by the fault side of the SOP, Q1 and Q2 are respectively the reactive power on both sides of the SOP, and S1 and S2 are respectively the access capacities on both sides of the SOP.

[0020] Preferably, the calculation formula of the target function is as follows:

[0021]

[0022] In the above formula, f is the target value of the target function, a k is the weight coefficient of node k, P kis the loss of load for node k, N is the total number of loss of load nodes except island nodes, L is the total number of lines, P x is the active power loss on line x.

[0023] Further, when node k is a first-level load, α k = 2, when node k is a second-level load, α k = 1.5, when node k is a third-level load, α k = 1.

[0024] Further, the model optimization variable is a distribution network branch on-off adjustment vector for fault recovery, and the mathematical expression is as follows:

[0025] A = {A1, A2, A3…A n}

[0026] In the above formula, A is the distribution network branch on-off adjustment vector for fault recovery, A n is the switch state of branch n, A n = 0 indicates off, and A n = 1 indicates on.

[0027] Further, the constraint condition configured for the pre-constructed active power distribution network fault recovery model comprises at least one of the following: a SOP active power balance constraint, a SOP capacity constraint, a SOP transfer capacity constraint, a node voltage constraint, a branch current constraint, a distribution network power flow constraint, a radial distribution network constraint, and an island internal power constraint.

[0028] Further, the mathematical expression of the SOP transfer capacity constraint is as follows:

[0029] P2≤ P max

[0030] In the above formula, P max is the SOP transfer capacity, and P2 is the active power output on the fault side of the SOP.

[0031] In a second aspect, an active power distribution network fault recovery device considering a SOP is provided, and the active power distribution network fault recovery device considering the SOP comprises:

[0032] A determination module is configured to determine a SOP transfer capacity based on a preset SOP transfer capacity constraint condition;

[0033] A solution module is configured to substitute the SOP transfer capacity into a pre-constructed active power distribution network fault recovery model, and solve the pre-constructed active power distribution network fault recovery model to obtain a distribution network branch on-off adjustment vector for fault recovery;

[0034] The pre-constructed active power distribution network fault recovery model comprises a target function, model optimization variables and constraint conditions configured for the pre-constructed active power distribution network fault recovery model.

[0035] Preferably, the determination module is specifically configured to:

[0036] The maximum active power output on the fault side of the SOP when the power distribution network meets the preset SOP transfer capacity constraint condition is taken as the SOP transfer capacity.

[0037] The preset SOP transfer capacity constraint condition comprises at least one of the following: a node voltage constraint, a branch current constraint, a power distribution network power flow constraint, an SOP two-end active power balance constraint and an SOP two-end capacity constraint.

[0038] Preferably, the calculation formula of the target function is as follows:

[0039]

[0040] In the above formula, f is a target value of the target function, a is a weight coefficient of the node k, P is a load of the node k, N is a total number of load loss nodes except island nodes, L is a total number of lines, P is an active power loss on the line x, and N is a total number of load loss nodes except island nodes. k k x

[0041] Further, the model optimization variable is a power distribution network branch on-off adjustment vector for fault recovery, and a mathematical expression thereof is as follows:

[0042] A = {A1, A2, A3…A n}

[0043] In the above formula, A is the power distribution network branch on-off adjustment vector for fault recovery, A is a switch state of the branch n, A = 0 indicates disconnection, and A = 1 indicates connection. n n n

[0044] Further, the constraint condition configured for the pre-constructed active power distribution network fault recovery model comprises at least one of the following: an SOP two-end active power balance constraint, an SOP two-end capacity constraint, an SOP transfer capacity constraint, a node voltage constraint, a branch current constraint, a power distribution network power flow constraint, a radial power distribution network constraint and an island internal power constraint.

[0045] In a third aspect, a computer device is provided, comprising: one or more processors;

[0046] The processor is configured to store one or more programs.

[0047] ​​​​​​When the one or more programs are executed by the one or more processors, the method for active power distribution network fault recovery considering SOP is implemented.

[0048] In a fourth aspect, a computer readable storage medium is provided, and a computer program is stored on the computer readable storage medium, and the computer program is executed to implement the method for active power distribution network fault recovery considering SOP.

[0049] The one or more technical solutions of the present application have at least one or more of the following advantages:

[0050] The present application provides a method and device for active power distribution network fault recovery considering SOP, comprising: determining the SOP transfer capacity based on the preset SOP transfer capacity constraint condition; substituting the SOP transfer capacity into the pre-constructed active power distribution network fault recovery model, and solving the pre-constructed active power distribution network fault recovery model to obtain a power distribution network branch on-off adjustment vector for fault recovery; wherein the pre-constructed active power distribution network fault recovery model comprises a target function, model optimization variables and constraint conditions configured for the pre-constructed active power distribution network fault recovery model. The present application formulates a corresponding fault recovery scheme by using SOP, considers the limitation of SOP transfer capacity in active power distribution network, improves the power supply recovery capability of power distribution network, and reduces the line loss generated in the fault recovery process. Compared with various recovery strategies, the effectiveness and flexibility of the proposed fault recovery scheme are embodied. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 is the main step flow diagram of the method for active power distribution network fault recovery considering SOP of the embodiment of the present application;

[0052] Figure 2 is the IEEE33 node system topology graph containing SOP of the embodiment of the present application;

[0053] Figure 3 is the main structure block diagram of the device for active power distribution network fault recovery considering SOP of the embodiment of the present application. DETAILED DESCRIPTION

[0054] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0055] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0056] Embodiment 1

[0057] Refer to the drawings Figure 1 , Figure 1 is the main step flowchart of the active power distribution network fault recovery method considering SOP of an embodiment of the present application. As shown in the figure, the active power distribution network fault recovery method considering SOP in the embodiment of the present application mainly includes the following steps: Figure 1

[0058] Step S101: determining the SOP transfer capacity based on a preset SOP transfer capacity constraint condition;

[0059] Step S102: substituting the SOP transfer capacity into a pre-constructed active power distribution network fault recovery model, and solving the pre-constructed active power distribution network fault recovery model to obtain a power distribution network branch on-off adjustment vector for fault recovery;

[0060] The pre-constructed active power distribution network fault recovery model includes a target function, model optimization variables and constraint conditions configured for the pre-constructed active power distribution network fault recovery model.

[0061] In the embodiment, before the SOP transfer capacity is determined based on the preset SOP transfer capacity constraint condition, the following is included:

[0062] When both ends of the SOP are networking side subnets, the control mode of the normal side of the SOP is U dc Q control mode, and the control mode of the fault side is PQ control mode, so as to realize real-time and accurate adjustment of power flow between connected feeder lines;

[0063] When one end of the SOP is a networking side subnet and the other end is a lost connection side subnet, the control mode of the normal side of the SOP is U dc Q control mode, and the control mode of the fault side is V f control mode, providing voltage and frequency support for the lost connection side subnet. At this time, the SOP is equivalent to a power supply of the lost connection side subnet.

[0064] In the embodiment, the SOP transfer capacity is determined based on the preset SOP transfer capacity constraint condition, including:

[0065] The maximum active power output by the SOP fault side when the power distribution network meets the preset SOP transfer capacity constraint condition is taken as the SOP transfer capacity;

[0066] The preset SOP transfer capacity constraint condition includes at least one of the following: node voltage constraint, branch current constraint, power distribution network power flow constraint, SOP two-end active power balance constraint, and SOP two-end capacity constraint. ​

[0067] Specifically, the node voltage constraint is:

[0068] V i.min ≤V i ≤V i.max

[0069] The branch current constraint is:

[0070]

[0071] wherein V i is the node voltage, I ji is the branch current flowing from node j to node i.

[0072] The power flow constraint of the distribution network is:

[0073]

[0074]

[0075]

[0076] Node v is directly connected to the SOP fault side outlet, wherein ψ v is the set of branch end nodes of which node v is the head end, φ v is the set of branch head end nodes of which node v is the end node; P jv , Q jv are the active power and the reactive power transmitted from node j to node v, R jv , X jv are the resistance and the reactance of branch jv, P v , Q v are the active power and the reactive power flowing into node v except for branch jv; Z vj is the branch impedance, S vj is the branch v j head end capacity.

[0077]

[0078] wherein P v，SOP , Q v，SOP are the active power and the reactive power provided by the SOP to node v, P v，DG , Q v，DG are the active power and the reactive power transmitted by the optical storage system connected to node v to node v, P v，LOAD , Q v，LOAD are the active power and the reactive power consumed by the load on node v.

[0079] The mathematical expression of the active power balance constraint at both ends of the SOP is as follows:

[0080] P1+P2=0

[0081] The mathematical expression of the capacity constraint at both ends of the SOP is as follows:

[0082]

[0083] In the above formula, P1 and P2 are active power input on the normal side and active power output on the fault side of the SOP respectively, Q1 and Q2 are reactive power on both sides of the SOP respectively, and S1 and S2 are the access capacity on both sides of the SOP.

[0084] In the embodiment, the calculation formula of the target function is as follows:

[0085]

[0086] In the above formula, f is the target value of the target function, α k is the weight coefficient of node k, P k is the loss of load of node k, N is the total number of loss-of-power load nodes except the island node, L is the total number of lines, and P x is the active power loss on line x.

[0087] When node k is a first-level load, α k = 2, when node k is a second-level load, α k = 1.5, and when node k is a third-level load, α k = 1.

[0088] In one embodiment, the model optimization variable is a distribution network branch on-off adjustment vector for fault recovery, and the mathematical expression is as follows:

[0089] A = {A1, A2, A3…A n}

[0090] In the above formula, A is the distribution network branch on-off adjustment vector for fault recovery, A n is the switch state of branch n, A n = 0 indicates off, and A n = 1 indicates on.

[0091] The constraint condition configured for the pre-constructed active power distribution network fault recovery model includes at least one of the following: SOP active power balance constraint at both ends, SOP capacity constraint at both ends, SOP transfer capacity constraint, node voltage constraint, branch current constraint, distribution network power flow constraint, radial distribution network constraint, and island internal power constraint.

[0092] Specifically, the active power balance constraint at both ends of the SOP, the capacity constraint at both ends of the SOP, the SOP transfer capacity constraint, the node voltage constraint, the branch current constraint, the power flow constraint of the distribution network, and the preset SOP transfer capacity constraint condition are the same, in addition, the mathematical expression of the SOP transfer capacity constraint is as follows:

[0093] P2≤P max

[0094] In the above formula, P max is the SOP transfer capacity, and P2 is the active power output on the fault side of the SOP.

[0095] Radial distribution network constraint:

[0096] g∈G

[0097] Island power constraint:

[0098]

[0099] In the formula, g is the reconstructed network topology, G is the set of radial network topology, P eq,T is the total output of the islanded optical storage system in period T, b is the node in the island, D is the set of nodes in the island, and P b is the size of the load in the island in period T.

[0100] In one embodiment, due to the limited power supply capacity of the main network and the SOP transfer capacity limitation, the nodes far away cannot be guaranteed to be restored, so it is necessary to consider the time-varying nature of the distributed power and the load, according to the fault occurrence time and duration of the distribution network, to divide the island of the nodes with optical storage system.

[0101] Further, the main network line needs to be reconstructed to realize fault recovery, considering the time-varying nature of the distributed power and the load, according to the fault occurrence time and duration of the distribution network, the binary particle swarm optimization algorithm is used to optimize and solve the main network reconstruction scheme, including the following steps:

[0102] 1. Determine the fault occurrence time and recovery time, and then determine the power supply of the optical storage system in the main network and the power demand of the load;

[0103] 2. Solve the reconstructed network by using the binary particle swarm optimization algorithm, set the number of particles, the number of iterations, and the population dimension, initialize the particle velocity and the initial particle velocity;

[0104] In the binary particle swarm optimization algorithm, the velocity vector iteration formula of the particle is the same as that of the particle swarm optimization algorithm, and the position vector is determined by using the Sigmoid function and the piecewise comparison method.

[0105] Sigmoid function:

[0106]

[0107] Segment comparison:

[0108]

[0109] The velocity vector iteration process is still:

[0110]

[0111] In the formula, The position of the i-th particle in the t+1 generation is, The velocity of the i-th particle in the t+1 generation is rand is a random number with a value between 0 and 1, ω is the particle inertia coefficient, which is 0.6, c1 and c2 are particle learning coefficients, which are 2.0, The individual optimal solution and the global optimal solution in the current iteration process are respectively.

[0112] 3. Taking the switch state of the out-of-service subnetwork line of the distribution network as the optimization variable, the optimal topological structure of fault recovery is searched, and the objective function value is solved. It is checked whether the node voltage is out of limit, if the node voltage is below the lower limit, the main network load is further reduced on this basis, if the node voltage is above the upper limit, or the SOP operation constraint is not met, the topological scheme is discarded under the premise of the current outlet voltage, and the search is restarted.

[0113] 4. The particle swarm is iterated multiple times, and after the iteration number is reached, the optimal solution and the corresponding objective function value are output.

[0114] 5. The island division scheme and the main network reconstruction scheme are combined to form a fault recovery scheme corresponding to a specific fault occurrence time and recovery time.

[0115] The present application relates to the active distribution network fault recovery strategy containing SOP, considering the limitation of the transfer supply capacity of SOP in the active distribution network, the power supply recovery capability of the distribution network is improved, and the line loss generated in the fault recovery process is reduced. Compared with various recovery strategies, the effectiveness and flexibility of the proposed fault recovery scheme are embodied.

[0116] In an optimal embodiment, as shown in Figure 2 Taking IEEE-33 nodes as an example, the total line load is (3715+j2300)kVA, the SOP is installed at the tie switch 24-28, the VSC capacity at both ends of the SOP is 1550kVA, the optical storage system is installed at nodes 14, 19, 26 and 29, the fault occurs at 11:00-12:00, the recovery conditions of 1 hour and 2 hours of fault duration are verified, and the scheme of the present application is used for solving:

[0117] First, determine the control mode of SOP under different operating conditions, the criteria are as follows:

[0118] (1) SOP both ends are networking side subnets

[0119] That is, the outage area can be directly connected with the superior power supply through the tie switch, and the fault is quickly isolated by the circuit breaker, then the tie switch is closed, and the SOP normal side remains U dc Q control mode, and the fault side is set as PQ control mode to realize real-time and accurate adjustment of power flow between connected feeders.

[0120] (2) SOP one end is a networking side subnet and the other end is a loss of connection side subnet

[0121] That is, the outage area cannot be directly connected with the superior power supply through the tie switch, and SOP is used instead of the traditional tie switch, and the SOP normal side remains U dc Q control mode, and the SOP fault side control mode is set as V f control mode, providing voltage and frequency support for the loss of connection side subnet. At this time, SOP is equivalent to the power supply of the loss of connection side subnet.

[0122] The control mode of SOP under different operating conditions is shown in Table 1.

[0123] Table 1

[0124]

[0125] Suppose the fault occurs in branch 19-20 and branch 2-3, according to the above criteria, the SOP control mode is set as: fault side V f control mode, normal side U dc Q control mode.

[0126] Second, calculate the transfer capacity of SOP in the active distribution network, and the VSC capacity of both ends of SOP is 1550 kVA.

[0127] Solve the transfer capacity based on the step S101.

[0128] Third, establish a fault recovery model of the active distribution network, including the following steps:

[0129] 1. Establish a fault recovery model of the active distribution network:

[0130] The objective function of the fault recovery model includes:

[0131] The minimum amount of power loss in the distribution network:

[0132]

[0133] In the formula, α k is the load weight coefficient. The load is divided into primary load, secondary load and tertiary load. The weight coefficient of the primary load is 2.0, the weight coefficient of the secondary load is 1.5, and the weight coefficient of the tertiary load is 1.0. P k is the loss of load of node k, and N is the total number of loss of load.

[0134] The line loss is minimum:

[0135]

[0136] In the formula, P x is the active power loss on line x, and L is the total number of lines.

[0137] The multi-objective function is converted into a single objective function to simplify the calculation process. More load restoration is taken as the main target, and the network loss is taken as the secondary target. After the two objective functions are weighted, the comprehensive objective function is:

[0138]

[0139] The optimization variable of the model is the on-off state of the branch of the distribution network, which is specifically represented as:

[0140] A={A1,A2,A3…A n}

[0141] In the formula, A is the branch on-off matrix, which represents the switch state of each branch of the entire distribution network. A n is the switch state of the branch numbered n, and A n = 0 indicates that it is disconnected, and A n = 1 indicates that it is turned on.

[0142] 2. The constraint conditions of the fault restoration model include: active power balance constraint at both ends of SOP, capacity constraint at both ends of SOP, SOP transfer capacity constraint, node voltage constraint, branch current constraint, distribution network power flow constraint, radial distribution network constraint, and power constraint in island.

[0143] Specifically, the active power balance constraint at both ends of SOP, the capacity constraint at both ends of SOP, the SOP transfer capacity constraint, the node voltage constraint, the branch current constraint, the distribution network power flow constraint and the preset SOP transfer capacity constraint condition are the same, in addition to the mathematical expression of the SOP transfer capacity constraint as follows:

[0144] P2≤P max

[0145] In the formula, P max is the SOP transfer capacity, and P2 is the active power output on the fault side of the SOP.

[0146] Radial distribution network constraint:

[0147] g∈G

[0148] Power constraint in island:

[0149]

[0150] where g is the reconstructed network topology, G is the set of radial network topology, P eq,T is the total output of the optical storage system in the island in period T, b is the node in the island, D is the set of nodes in the island, P b is the load size of each node in the island in period T.

[0151] Fourthly, considering the time-varying nature of distributed power and load, according to the fault occurrence time and duration of the distribution network, an island division scheme is proposed, based on the fault recovery model, a binary particle swarm optimization algorithm is used to optimize and solve the main network reconstruction scheme, and the fault recovery scheme corresponding to the specific fault occurrence time and recovery time is obtained by combining the island division scheme and the main network reconstruction scheme, the specific steps are as follows:

[0152] 1. Load prediction:

[0153] Considering the time-varying nature of the load, the load will show different load levels at different time periods of each day. Therefore, the load of each node of the day-ahead distribution network is predicted. Table 2 shows the daily load demand of different levels of nodes.

[0154] Table 2

[0155]

[0156] After the fault occurs, the fault occurrence period and the fault recovery time are determined, the output of the distributed power is predicted, and then the actual power supply of the optical storage system in the recovery time and the power supply demand of the load are determined, and the island is divided accordingly.

[0157] 2. Island division considering the output fluctuation of distributed power and the time-varying nature of load

[0158] Before island division, the fault occurrence period and the fault recovery time are determined, the output of the distributed power is predicted, and then the actual power supply of the optical storage system in the recovery time and the power supply demand of the load are determined.

[0159] Since the optical storage system capacity of node 26 and node 29 is small, it is not enough to be divided into an island with other nodes, so it is directly integrated into the main network operation, only the optical storage system at node 14 participates in island division, and the island division scheme under two fault durations is shown in Table 3.

[0160] Table 3

[0161]

[0162]

[0163] 3. Considering the time-varying of distributed power and load, according to the time and duration of power distribution network fault, the binary particle swarm optimization algorithm is used to optimize the solution of main network reconstruction scheme, including the following steps:

[0164] (1) Determine the fault occurrence time and recovery time (the fault occurs from 11:00 to 12:00, and the recovery time is divided into two kinds, 1h and 2h), and then determine the power supply of the light storage system in the main network and the power demand of the load;

[0165] (2) Set the SOP outlet voltage to 12.28kV, use the binary particle swarm optimization algorithm to solve the reconstruction network, set the particle number, iteration number and population dimension, initialize the particle velocity and particle initial velocity;

[0166] In the binary particle swarm optimization algorithm, the velocity vector iteration formula of the particle is the same as that of the particle swarm optimization algorithm, and the position vector is determined by the Sigmoid function and the piecewise comparison method.

[0167] Sigmoid function:

[0168]

[0169] Piecewise comparison:

[0170]

[0171] The velocity vector iteration process is still:

[0172]

[0173] wherein, is the position of the i-th particle at the t+1 generation, is the velocity of the i-th particle at the t+1 generation, rand is a random number with a value between 0 and 1, ω is the particle inertia coefficient, which is 0.6, c1 and c2 are particle learning coefficients, which are 2.0, are the individual optimal solution and the global optimal solution in the current iteration process, respectively.

[0174] (3) Take the open side of the distribution network as the optimization variable, search for the optimal topology structure of fault recovery, and solve the objective function value. Check if the node voltage is out of limit, if the node voltage is below the lower limit, continue to reduce the load of the main network; if the node voltage is above the upper limit, or does not meet the SOP operation constraint, discard the topology scheme under the current outlet voltage, and search again;

[0175] (4) iterates the particle swarm for multiple times, and outputs the optimal solution and the corresponding objective function value after the number of iterations.

[0176] (5) combining the island division scheme and the main network reconstruction scheme, a fault recovery scheme corresponding to a specific fault occurrence time and recovery time is formed.

[0177] The fault occurs at 11:00-12:00, and the results of each fault recovery strategy under two recovery times are shown in Table 4.

[0178] Table 4

[0179]

[0180] As can be seen from Table 4, replacing the traditional tie switch in the line with SOP can effectively improve the fault recovery capability of the distribution network. When the fault duration is prolonged, the main network cannot complete power supply for part of the secondary load with large power demand, and the output of the light storage system is not much different in the two time periods, and most of the power grid is secondary load, so the power restoration ratio is low when the fault lasts for 2h. If the same network reconstruction scheme is used in different time periods, it is not necessarily the optimal scheme for some operating states, and sometimes it is even an infeasible scheme that threatens the safe and stable operation of the system.

[0181] The application takes into account the time-varying nature of distributed power and load, and according to the fault occurrence time and duration of the distribution network, adopts a binary particle swarm optimization algorithm, combines SOP, and optimizes and solves the main network reconstruction scheme in a targeted manner. In combination with the foregoing steps, a fault recovery scheme corresponding to a specific fault occurrence time and recovery time is formed.

[0182] Example 2

[0183] In a second aspect, an active distribution network fault recovery device considering SOP is provided, as shown in Figure 3 The active distribution network fault recovery device considering SOP includes:

[0184] A determination module is configured to determine the SOP transfer capacity based on a predetermined SOP transfer capacity constraint condition.

[0185] A solution module is configured to substitute the SOP transfer capacity into a pre-constructed active distribution network fault recovery model, and solve the pre-constructed active distribution network fault recovery model to obtain a distribution network branch on-off adjustment vector for fault recovery.

[0186] The pre-constructed active distribution network fault recovery model includes a target function, model optimization variables and constraint conditions configured for the pre-constructed active distribution network fault recovery model.

[0187] determine the SOP transfer capacity based on a preset SOP transfer capacity constraint condition;

[0188] substitute the SOP transfer capacity into a pre-constructed active power distribution network fault recovery model, and solve the pre-constructed active power distribution network fault recovery model to obtain a distribution network branch on-off adjustment vector for fault recovery;

[0189] The pre-constructed active power distribution network fault recovery model comprises a target function, model optimization variables and constraint conditions configured for the pre-constructed active power distribution network fault recovery model.

[0190] Preferably, before the determination of the SOP transfer capacity based on the preset SOP transfer capacity constraint condition, the method comprises:

[0191] When both ends of the SOP are connected to the networking side subnetwork, the control mode of the normal side of the SOP is U dc Q control mode, and the control mode of the fault side is PQ control mode.

[0192] When one end of the SOP is connected to the networking side subnetwork and the other end is connected to the disconnection side subnetwork, the control mode of the normal side of the SOP is U dc Q control mode, and the control mode of the fault side is V f control mode.

[0193] Preferably, the determination of the SOP transfer capacity based on the preset SOP transfer capacity constraint condition comprises:

[0194] The maximum active power output by the SOP fault side when the power distribution network satisfies the preset SOP transfer capacity constraint condition is taken as the SOP transfer capacity.

[0195] The preset SOP transfer capacity constraint condition comprises at least one of the following: node voltage constraint, branch current constraint, power distribution network power flow constraint, SOP two-end active power balance constraint, and SOP two-end capacity constraint.

[0196] Further, the mathematical expression of the SOP two-end active power balance constraint is as follows:

[0197] P1+P2=0

[0198] The mathematical expression of the SOP two-end capacity constraint is as follows:

[0199]

[0200] In the above formulae, P1 and P2 are respectively the active power input by the normal side of the SOP and the active power output by the fault side of the SOP, Q1 and Q2 are respectively the reactive power at both ends of the SOP, and S1 and S2 are respectively the access capacity at both ends of the SOP.

[0201] Preferably, the calculation formula of the objective function is as follows:

[0202]

[0203] In the above formula, f is the target value of the objective function, a k is the weight coefficient of node k, P k is the loss load of node k, N is the total number of loss load nodes other than the island node, L is the total number of lines, P x is the active power loss on line x.

[0204] Further, when node k is a first-level load, a k = 2, when node k is a second-level load, a k = 1.5, when node k is a third-level load, a k = 1.

[0205] Further, the model optimization variable is a distribution network branch on-off adjustment vector for fault restoration, and the mathematical expression is as follows:

[0206] A = {A1, A2, A3…A n}

[0207] In the above formula, A is the distribution network branch on-off adjustment vector for fault restoration, A n is the switch state of branch n, A n = 0 indicates off, and A n = 1 indicates on.

[0208] Further, the constraint condition configured for the pre-constructed active distribution network fault restoration model includes at least one of the following: SOP active power balance constraint, SOP capacity constraint, SOP transfer capacity constraint, node voltage constraint, branch current constraint, distribution network power flow constraint, radial distribution network constraint, and island internal power constraint.

[0209] Further, the mathematical expression of the SOP transfer capacity constraint is as follows:

[0210] P2≤ P max

[0211] In the above formula, P max is the SOP transfer capacity, and P2 is the active power output on the fault side of the SOP.

[0212] Embodiment 3

[0213] Based on the same inventive concept, the present application further provides a computer device, which comprises a processor and a memory, the memory is used to store a computer program, the computer program comprises program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor can be a central processing unit (CPU), and can also be 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., which are the computing core and control core of the terminal, and are suitable for implementing one or more instructions, and are specifically suitable for loading and executing one or more instructions in the computer storage medium to implement a corresponding method flow or a corresponding function, so as to implement the steps of the active power distribution network fault recovery method considering the SOP in the above embodiment.

[0214] Embodiment 4

[0215] Based on the same inventive concept, the present application further provides a storage medium, specifically a computer readable storage medium (Memory), which is a memory device in the computer device, and is used to store programs and data. It can be understood that the computer readable storage medium here can include the built-in storage medium in the computer device, and of course can also include the expansion storage medium supported by the computer device. The computer readable storage medium provides a storage space, and the storage space stores the operating system of the terminal. Moreover, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and the instructions can be one or more computer programs (including program codes). It should be noted that the computer readable storage medium here can be a high-speed RAM memory, or a non-volatile memory such as at least one disk memory. One or more instructions stored in the computer readable storage medium can be loaded and executed by the processor to implement the steps of the active power distribution network fault recovery method considering the SOP in the above embodiment.

[0216] Those skilled in the art will appreciate that embodiments of the application can be devised for a method, a system, or a computer program product. Accordingly, the present application can be embodied in the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application can take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) embodying computer readable program code.

[0217] The present application is described in reference to the flowchart illustrations and / or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the 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, create means for implementing the functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0218] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0219] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0220] Finally, it should be noted that the above-mentioned embodiments are merely intended for describing and illustrating, not limiting the technical solutions of the present application. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, and any modifications or equivalent replacements without departing from the spirit and scope of the present application should be covered in the protection scope of the claims of the present application.

Claims

1. A method for active power distribution network restoration considering SOP, characterized in that, The method comprises: determining the SOP transfer capacity based on a preset SOP transfer capacity constraint condition; substituting the SOP transfer capacity into a pre-constructed active power distribution network fault recovery model, and solving the pre-constructed active power distribution network fault recovery model to obtain a power distribution network branch on-off adjustment vector for fault recovery; wherein the pre-constructed active power distribution network fault recovery model comprises a target function, a model optimization variable and a constraint condition configured for the pre-constructed active power distribution network fault recovery model; the determination of the SOP transfer capacity based on the preset SOP transfer capacity constraint condition comprises: taking the maximum active power output by the SOP fault side when the power distribution network meets the preset SOP transfer capacity constraint condition as the SOP transfer capacity; wherein the preset SOP transfer capacity constraint condition comprises at least one of the following: a node voltage constraint, a branch current constraint, a power distribution network power flow constraint, a SOP two-end active power balance constraint, and a SOP two-end capacity constraint; a mathematical expression of the SOP two-end active power balance constraint is as follows: P1+P2=0 a mathematical expression of the SOP two-end capacity constraint is as follows: in the above formula, P1 and P2 are respectively the active power input by the normal side and the active power output by the fault side of the SOP, Q1 and Q2 are respectively the reactive power on both sides of the SOP, and S1 and S2 are respectively the access capacity on both sides of the SOP; a calculation formula of the target function is as follows: In the above formula, f is the target value of the target function, α k is the weight coefficient of node k, P k is the loss load of node k, N is the total number of loss load nodes other than the island node, L is the total number of lines, P x is the active power loss on line x; the power distribution network power flow constraint: Node v is directly connected to the SOP fault side exit, where ψ v is the set of branch end nodes with node v as the head end, φ v is the set of branch head nodes with node v as the end; P jv , Q jv are the active and reactive power transmitted from node j to node v, P jk , Q jk are the active and reactive power transmitted from node k to node v, R jv , X jv are the resistance and reactance of branch jv, V v , V j are the voltages of nodes v and j; Z vj is the branch impedance, S vj is the branch v j head capacity, P v , Q v are the active and reactive power flowing into node v except for branch vj, which are as follows: In the formula, P v，SOP , Q v，SOP are the active power and the reactive power provided by the SOP to the node v, P v，DG , Q v，DG are the active power and the reactive power delivered by the optical storage system connected to the node v to the node v, P v，LOAD , Q v，LOAD are the active power and the reactive power consumed by the load on the node v.

2. The method of claim 1, wherein, before the determination of the SOP transfer capacity based on the preset SOP transfer capacity constraint condition, the method comprises: When both ends of the SOP are networking side subnets, the control mode of the normal side of the SOP is U dc Q control mode, and the control mode of the fault side is PQ control mode When the SOP is at one end of the networking side subnet and the other end of the disconnection side subnet, the control mode of the normal side of the SOP is U dc Q control mode, and the control mode of the fault side is V f Control mode.

3. The method of claim 1, wherein, When node k is a primary load, a k = 2, when node k is a secondary load, a k = 1.5, when node k is a tertiary load, a k = 1.

4. The method of claim 1, wherein, the model optimization variable is a power distribution network branch on-off adjustment vector for fault recovery, and a mathematical expression thereof is as follows: A = {A1, A2, A3... A n} In the above equation, A is a distribution network branch on-off regulation vector for fault recovery, A n is the switch state of branch n, A n = 0 indicates off, A n = 1 indicates on.

5. The method of claim 1, wherein, the constraint condition configured for the pre-constructed active power distribution network fault recovery model comprises at least one of the following: the SOP two-end active power balance constraint, the SOP two-end capacity constraint, the SOP transfer capacity constraint, the node voltage constraint, the branch current constraint, the power distribution network power flow constraint, the radial power distribution network constraint, and the islanded power constraint.

6. The method of claim 5, wherein, a mathematical expression of the SOP transfer capacity constraint is as follows: P2≤ P max In the above equation, P max is the SOP transfer capability, and P2is the active power of the SOP failure side output.

7. A device for active power distribution network restoration considering SOP, characterized in that, The device comprises: a determination module configured to determine the SOP transfer capacity based on a preset SOP transfer capacity constraint condition; a solving module configured to substitute the SOP transfer capacity into a pre-constructed active power distribution network fault recovery model, and solve the pre-constructed active power distribution network fault recovery model to obtain a power distribution network branch on-off adjustment vector for fault recovery; wherein the pre-constructed active power distribution network fault recovery model comprises a target function, a model optimization variable and a constraint condition configured for the pre-constructed active power distribution network fault recovery model; the determination module is specifically configured to: take the maximum active power output by the SOP fault side when the power distribution network meets the preset SOP transfer capacity constraint condition as the SOP transfer capacity; wherein the preset SOP transfer capacity constraint condition comprises at least one of the following: a node voltage constraint, a branch current constraint, a power distribution network power flow constraint, a SOP two-end active power balance constraint, and a SOP two-end capacity constraint; a calculation formula of the target function is as follows: In the above formula, f is the target value of the target function, α k is the weight coefficient of node k, P k is the loss load of node k, N is the total number of loss load nodes other than island nodes, L is the total number of lines, P x is the active power loss on line x; The mathematical expression of the active power balance constraint at both ends of the SOP is as follows: P1+P2=0 The mathematical expression of the capacity constraint at both ends of the SOP is as follows: In the above formula, P1 and P2 are the active power input on the normal side and the active power output on the fault side of the SOP respectively, Q1 and Q2 are the reactive power on both sides of the SOP respectively, and S1 and S2 are the access capacity on both sides of the SOP respectively; The power flow constraint of the power distribution network is as follows: Node v is directly connected to the SOP fault side exit, where ψ v is the set of branch end nodes with node v as the head end, φ v is the set of branch head end nodes with node v as the end; P jv , Q jv are the active and reactive power transmitted from node j to node v, P jk , Q jk are the active and reactive power transmitted from node k to node v, R jv , X jv are the resistance and reactance of branch jv, V v , V j are the voltages of nodes v and j; Z vj is the branch impedance, S vj is the branch v j head capacity, P v , Q v are the active and reactive power flowing into node v except for branch vj, which are as follows: where P v，SOP , Q v，SOP are the active and reactive power provided by the SOP to the node v, P v，DG , Q v，DG are the active and reactive power delivered by the optical storage system connected to the node v to the node v, and P v，LOAD , Q v，LOAD are the active and reactive power consumed by the load at the node v.

8. The apparatus of claim 7, wherein, The optimization variable of the model is a branch on-off adjustment vector for fault restoration, and the mathematical expression thereof is as follows: A = {A1, A2, A3... A n} In the above equation, A is a distribution network branch on-off adjustment vector for fault recovery, A n is the switch state of branch n, A n = 0 indicates off, A n = 1 indicates on.

9. The apparatus of claim 7, wherein, The constraint condition configured for the pre-constructed active power distribution network fault restoration model comprises at least one of the following: the active power balance constraint at both ends of the SOP, the capacity constraint at both ends of the SOP, the SOP transfer capacity constraint, the node voltage constraint, the branch current constraint, the power distribution network power flow constraint, the radial power distribution network constraint, and the power constraint within the island.

10. A computer device, comprising: Comprise: One or more processors; The processor is configured to store one or more programs; When the one or more programs are executed by the one or more processors, the active power distribution network fault restoration method considering the SOP is implemented.

11. A computer readable storage medium, characterized in that, The computer program is stored thereon, and when the computer program is executed, the active power distribution network fault restoration method considering the SOP is implemented.

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