CN112909942B - Active power distribution network fault recovery method and system based on hybrid solving strategy - Google Patents
Active power distribution network fault recovery method and system based on hybrid solving strategy Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/007—Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources
- H02J3/0073—Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources for providing alternative feeding paths between load and source when the main path fails, e.g. transformers, busbars
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/28—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for meshed systems
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/388—Islanding, i.e. disconnection of local power supply from the network
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
- H02J3/466—Scheduling the operation of the generators, e.g. connecting or disconnecting generators to meet a given demand
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
- H02J2203/20—Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
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Abstract
The invention relates to an active power distribution network fault recovery method and system based on a hybrid solving strategy, wherein the method comprises the following steps: step S1, constructing an active power distribution network island division and network reconstruction unified model containing distributed power sources and energy storage, wherein an objective function of the model considers equivalent power loss load, sectional switch operation and network loss cost; step S2, solving the unified model by adopting a mixed solution strategy based on the combination of breadth-first search, depth-first search and second order cone optimization to obtain a line maintenance scheme; and step S3, realizing the fault recovery of the active power distribution network based on the line maintenance scheme. Compared with the prior art, the method has the advantages of improving the fault recovery rate, being high in solving speed of the overhaul scheme and the like.
Description
Technical Field
The invention relates to an active power distribution network fault recovery technology, in particular to an active power distribution network fault recovery method and system based on a hybrid solving strategy.
Background
Distribution network faults directly affect social production and daily power supply of residents. In response to sudden natural disasters, compared with protecting a power distribution network, the power grid party starts to seek a method for quickly recovering the power distribution system by using a black-start distributed power supply after the disasters occur, so as to improve reliability. The active distribution network (active distributionnetwork, AND) is provided with a distributed power supply (distributed generation, DG) which can be used as a black start power supply as a backup, AND the characteristic of flexible AND changeable network topology also provides more optimization possibility for the fault recovery strategy of the active distribution network. Therefore, a fault recovery strategy aiming at topology transformation of the distribution network becomes one of research hotspots in the field of distribution networks.
After the failure of the active power distribution network occurs, the distributed power supply is reasonably and effectively divided to form island operation to restore power supply, or the residual power loss area is connected with the main network to restore power supply by a method of changing the network topology structure through network reconstruction. Compared with the traditional power distribution network, the active power distribution network fault recovery with DG has more factors to be considered, the intermittence and fluctuation of load and DG output can bring more influencing factors to the original fault recovery method, and the existing fault recovery method also has the problem of insufficient fault recovery rate.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide an active power distribution network fault recovery method and system based on a hybrid solving strategy, wherein the active power distribution network fault recovery method and system have the advantages of improving the fault recovery rate and realizing high solving speed of a maintenance scheme.
The aim of the invention can be achieved by the following technical scheme:
an active power distribution network fault recovery method based on a hybrid solution strategy comprises the following steps:
step S1, constructing an active power distribution network island division and network reconstruction unified model containing distributed power sources and energy storage, wherein an objective function of the model considers equivalent power loss load, sectional switch operation and network loss cost;
step S2, solving the unified model by adopting a mixed solution strategy based on the combination of breadth-first search, depth-first search and second order cone optimization to obtain a line maintenance scheme;
and step S3, realizing the fault recovery of the active power distribution network based on the line maintenance scheme.
Further, the objective function is expressed as:
wherein: g 1,t Network loss for system t period; g 2,t The operation times of the sectionalized switch are the time period t of the system; g 3,t The equivalent load recovery amount of the system in the period t is calculated; lambda (lambda) i Load weight for node i; p (P) i,t Active power in a load t period of the load node i;representing a set of load nodes; upsilon (v) 1 、υ 2 、υ 3 Respectively a network loss cost coefficient, a switch operation cost coefficient and an equivalent power loss load cost coefficient, N T For the number of time periods that the entire fault is recovered, Δt is the duration of a single time period.
Further, the network loss calculation method comprises the following steps:
wherein: i ij,t For the effective value of the current of the branch i-j of the system t period, R ij The resistance value of the branch i-j; omega is the set of all branches of the active power distribution network;
the calculating method of the operation times of the sectionalizing switch comprises the following steps:
wherein: decision variable alpha ij,t For the state of the line i-j switch in the t period, taking 0 to represent that the line i-j switch is opened, and taking 1 to represent that the line i-j switch is closed;
the calculation method of the equivalent load recovery amount comprises the following steps:
wherein: decision variable y i,t For the load recovery state of the node i in the t period, taking 1 to indicate that the load i is recovered in the t period, and taking 0 to indicate that the load i is not recovered in the t period.
Further, constraint conditions of the active power distribution network island division and network reconstruction unified model comprise node voltage and branch current constraint, node power balance constraint, DG power constraint, network structure constraint, energy storage charge and discharge state and power constraint, energy storage residual capacity constraint, capacitor switching constraint and fault maintenance strategy constraint.
Further, in step S2, the solving of the unified model is specifically:
step S201: reading a fault planning power failure time T, the output power of the DG in the period, a load prediction power and an energy storage charge state;
step S202: traversing each DG and energy storage access node as root nodes, and determining a power circle by adopting a breadth-first search algorithm to obtain island feasible solutions;
step S203: according to the island feasible solution, obtaining an initial island dividing range by adopting a depth-first search algorithm, and then correcting the initial island dividing range according to an island fusion strategy to obtain an island dividing result in the period;
step S204: based on the island division result of the period, the position of the operable tie switch and the network topology structure, an active power distribution network island division and network reconstruction unified model of the period is obtained;
step S205: constructing an intermediate variable, carrying out linearization treatment on the unified model, and converting the unified model into a standard mixed integer second order cone model;
step S206: solving the standard mixed integer second order cone model by adopting a commercial solver;
step S207: and judging whether the calculation of all the time periods is finished, if so, outputting a final line maintenance scheme, and if not, returning to the step S201 to calculate the next time period.
Further, the correcting the initial island division range according to the island fusion strategy specifically includes:
and judging whether each island has an intersection or not under the initial island dividing range, if so, fusing the islands with the intersections, recording equivalent DGs and equivalent nodes directly connected with the same, returning to the step S202, if not, fusing whether the adjacent islands meet the fusing constraint condition, if so, canceling the fusion, and executing the step S204.
Further, the business solver includes a yalminip toolbox.
In step S205, a second order cone relaxation technique is used to perform convex relaxation on the unified model, and the unified model is converted into the standard mixed integer second order cone model.
Further, the feasible region of the standard mixed integer second order cone model is relaxed to be the whole second order cone, and the search space is in the convex cone range.
The invention also provides an active power distribution network fault recovery system based on the hybrid solving strategy, which comprises the following steps:
one or more processors, memory, and one or more programs stored in the memory, the one or more programs including instructions for performing the active power distribution network fault recovery method based on the hybrid solution strategy as described above.
Compared with the prior art, the invention has the following beneficial effects:
1. according to the invention, an active power distribution network fault recovery unified model which is matched with island division and network reconstruction is constructed, a corresponding mixed solving strategy is provided, each influence factor can be comprehensively considered, fault recovery of a non-fault power failure area can be completed together, and the reliability of an overhaul scheme is improved.
2. The objective function of the invention considers the equivalent power loss load, the sectional switch operation and the network loss cost, and can comprehensively consider and integrate the power loss amount during the fault period, the economical efficiency corresponding to the sectional switch operation and the energy efficiency corresponding to the network loss.
3. According to the method, the mixed solution strategy based on the combination of breadth-first search, depth-first search and second order cone optimization is adopted for solving, so that the accurate and efficient solution of the active power distribution network fault planning model can be realized, and the model solving efficiency is improved.
4. The invention integrates the constraint condition of capacitor switching, so that the fault recovery model can give consideration to active power and reactive power, and the fault recovery rate is improved.
5. The invention integrates the constraint condition of the fault maintenance strategy, optimizes the fault repair sequence by adjusting the switch decision variable of the fault line, further determines the optimal fault maintenance sequence and improves the power supply recovery rate.
Drawings
FIG. 1 is a schematic diagram of the steps of the method for recovering faults in an active power distribution network according to the present invention;
FIG. 2 is a solution flow diagram of an islanding partition and network reconfiguration unified model;
FIG. 3 is an IEEE 33 node active distribution network with DGs and stored energy;
FIG. 4 is an island division and network reconfiguration failure recovery result (14:00-15:00);
FIG. 5 is an island division and network reconfiguration failure recovery result (15:00-16:00);
FIG. 6 is an islanding and network reconfiguration failure recovery result (16:00-17:00);
FIG. 7 is an island division and network reconfiguration failure recovery result (17:00-18:00);
FIG. 8 is a graph showing the stored energy ES1 output during a fault;
fig. 9 is a graph showing the stored energy ES2 output during a fault.
Detailed Description
The invention will now be described in detail with reference to the drawings and specific examples. The present embodiment is implemented on the premise of the technical scheme of the present invention, and a detailed implementation manner and a specific operation process are given, but the protection scope of the present invention is not limited to the following examples.
As shown in fig. 1, the invention provides an active power distribution network fault recovery method based on a hybrid solution strategy, which comprises the following steps:
step S1, constructing an active power distribution network island division and network reconstruction unified model containing distributed power sources and energy storage, wherein an objective function of the model considers equivalent power loss load, sectional switch operation and network loss cost;
step S2, solving the unified model by adopting a mixed solution strategy based on the combination of breadth-first search, depth-first search and second order cone optimization to obtain a line maintenance scheme;
and step S3, realizing the fault recovery of the active power distribution network based on the line maintenance scheme.
In the step S1, a fault recovery strategy of combining island division with network reconstruction is adopted, after the active power distribution network faults occur, the power supply requirement of a part of important loads is preferentially met through the island division on the basis of considering the importance degree of the loads, and meanwhile, a large number of unrecoverable nodes, namely nodes which cannot recover the power supply through the network reconstruction, are also avoided as much as possible after the island division; and then, based on the network topology structure after island division, carrying out power supply recovery on the residual load nodes by adopting network reconstruction, optimizing system power flow and network loss, and simultaneously reducing the operation times of the switch as much as possible. The established unified model objective function of island division and network reconstruction of the active power distribution network is the minimum comprehensive operation cost in the period of active power distribution network faults, wherein the equivalent power loss load, the sectional switch operation and the network loss cost are considered, and the objective function is specifically expressed as:
wherein: g 1,t Network loss for system t period; g 2,t The operation times of the sectionalized switch are the time period t of the system; g 3,t The equivalent load recovery amount of the system in the period t is calculated; lambda (lambda) i Load weight for node i; p (P) i,t Active power in a load t period of the load node i;representing a set of load nodes; upsilon (v) 1 、υ 2 、υ 3 Respectively a network loss cost coefficient, a switch operation cost coefficient and an equivalent power loss load cost coefficient, N T For the number of time periods that the entire fault is recovered, Δt is the duration of a single time period.
The network loss calculation method comprises the following steps:
wherein: i ij,t For the effective value of the current of the branch i-j of the system t period, R ij The resistance value of the branch i-j; omega is the set of all branches of the active distribution network.
The calculating method of the operation times of the sectionalizing switch comprises the following steps:
wherein: decision variable alpha ij,t For the state of the line i-j switch in the t period, taking 0 to represent that the line i-j switch is opened, and taking 1 to represent that the line i-j switch is closed;
the calculation method of the equivalent load recovery amount comprises the following steps:
wherein: decision variable y i,t For the load recovery state of the node i in the t period, taking 1 to indicate that the load i is recovered in the t period, and taking 0 to indicate that the load i is not recovered in the t period.
Constraint conditions of the unified model of island division and network reconstruction of the active power distribution network comprise node voltage and branch current constraint, node power balance constraint, DG power constraint, network structure constraint, energy storage charge and discharge state and power constraint, energy storage residual capacity constraint, capacitor switching constraint and fault maintenance strategy constraint.
(1) Node voltage and branch current constraints
After the load is restored to grid connection through island division or network reconstruction, the system can be ensured to normally and stably operate, and the node voltage and the branch current in the network need to meet certain constraint conditions, namely:
wherein: v (V) i max 、V i min Respectively representing the upper and lower limits of the voltage of the node i; i ij,t The current flowing through the branch i-j at the t period;the maximum value of the current allowed to flow for branch i-j.
(2) Node power balancing constraints
Meeting the requirement of power balance is the key of stable operation of the active power distribution network after island division or network reconstruction. As is known from kirchhoff's law, the sum of the powers flowing into a node must be equal to the sum of the powers flowing out of that node, so the power balance constraint of the node should be satisfied, namely:
wherein: v (V) i,t 、V j,t The voltage of nodes i and j in the t period; g ij 、B ij The conductance and susceptance of branch i-j, respectively; delta ij,t The phase angle difference of the voltage of the branch i-j at the t period; c (i) is a node set connected with the node i.
(3) DG power constraint
Since wind power (WT) and Photovoltaic (PV) output have strong intermittence and volatility, to enable the system to operate stably after island division and network reconfiguration, DG power constraints should be satisfied:
wherein: p (P) DG,i,t 、Q DG,i,t Active and reactive power output of DG at node i in t period;the upper limit of the active output and the reactive output of DG at the node i of the t period is set; />And the lower limits of the DG active output and the DG reactive output at the node i of the t period are set.
(4) Network structure constraints
In the fault recovery process, the active power distribution network needs to meet connectivity constraint and radial constraint in consideration of a fault recovery strategy of combining island division and network reconstruction, namely:
wherein: f (f) di For the virtual load of the node i, the virtual load is used for ensuring that all load nodes meet connectivity constraint in the fault recovery processBundles, if there is a load node that is orphaned, then the node virtual power balance constraint is not satisfied, i.eTherefore, if the node virtual power balance constraint needs to be met, all load nodes need to be kept connected, meanwhile, as the network line connection quantity of the power distribution network is equal to N-1, N is the quantity of the nodes, and the connectivity constraint is met, namely the radial constraint is met, the virtual load and the virtual traffic have the function of ensuring that the network connectivity constraint and the radial constraint are met. Generally, the units 1, f ij,t For the virtual flow flowing at the branch i-j of the period t, N b For the number of branches, N n N is the number of nodes s Is the number of power sources.
(5) Energy storage charge-discharge state and power constraint
The energy storage device can be used in island division and network reconstruction processes, but the charging and discharging power of the energy storage is not greater than the limit value, so that the energy storage charging and discharging state and power constraint need to be satisfied, namely:
wherein: the decision variables are respectively the energy storage charge and discharge states y e,i,t And the energy storage charge and discharge power P e,i,t 。y e,i,t A 0-1 variable representing the charge and discharge states of the energy stored at the node i in the period t is taken as 0 to represent charge and taken as 1 to represent discharge;respectively representing the maximum power of charge and discharge of energy storage at a node i; p (P) e,i,t Representing the power at node i at which the stored energy is charged or discharged during period t.
(6) Energy storage remaining capacity constraint
The energy storage has certain capacity limitation, can not be excessively charged and discharged, and the energy storage residual capacity constraint should be satisfied, namely:
wherein:the residual capacity of energy storage at the node i in the t period; />And->Maximum and minimum capacity limits of energy storage at node i; η (eta) ch 、η dis Respectively the charge and discharge efficiency of the energy storage.
(7) Capacitor switching constraints
In order to cope with reactive power requirements of loads during island operation of an active power distribution network and under-voltage problems caused by reactive power deficiency after network reconstruction, switching capacitor banks are required to perform reactive power compensation in island division and network reconstruction fault recovery processes, and capacitor switching constraint needs to be met, namely:
wherein:reactive compensation capacity of the capacitor at the node i of the t period; />Representing the reactive compensation capacity put into a single capacitor; decision variable->The number of capacitors put into the node i for the t period; />The total number of capacitors available for input at node i.
(8) Fault overhaul policy constraints
When a plurality of lines in an active power distribution network are in fault, the maintenance sequence of the faults of each line is required to be reasonably arranged in a planned power failure period, and the specific method is that partial constraint is applied to the switch state variables of each fault line in a unified model of network reconstruction and island division, namely: the total number of the closed switches in the line of the next period is more than the total number of the closed switches of the previous period, but the number of the lines which can be overhauled at most in each period cannot be exceeded, when island division and network reconstruction of each period are finished, the rest fault lines are repaired by optimizing decision variables of the switches of each fault line, the topological structure of the optimized network is indirectly adjusted, and finally the optimal fault overhauling strategy of the lines in the whole fault period is determined.
Wherein: decision variable beta ij,t Representing the state of each faulty line switch; omega shape E A set of all faulty lines; k is the number of lines that can be serviced at most in a single time period.
As shown in fig. 2, in step S2, the solving of the unified model is specifically:
step S201: reading a fault planning power failure time T, the output power of the DG in the period, a load prediction power and an energy storage charge state;
step S202: traversing each DG and energy storage access node as root nodes, and determining a power circle by adopting a breadth-first search algorithm to obtain island feasible solutions;
step S203: according to the island feasible solution, obtaining an initial island dividing range by adopting a depth-first search algorithm, and then correcting the initial island dividing range according to an island fusion strategy to obtain an island dividing result in the period;
the correcting of the initial island division range according to the island fusion strategy specifically comprises the following steps: judging whether each island has an intersection or not under the initial island dividing range, if so, fusing the islands with the intersections, recording equivalent DGs and equivalent nodes directly connected with the same, returning to the step S202, if not, fusing whether the adjacent islands meet the fusing constraint condition or not, if so, canceling the fusion, and executing the step S204;
step S204: based on the island division result of the period, the position of the operable tie switch and the network topology structure, an active power distribution network island division and network reconstruction unified model of the period is obtained;
step S205: constructing an intermediate variable, carrying out linearization treatment on the unified model, and converting the unified model into a standard mixed integer second order cone model;
step S206: solving the standard mixed integer second order cone model by adopting a commercial solver, wherein the commercial solver comprises a MOSEK algorithm package and the like in a YALMIP toolbox;
step S207: and judging whether the calculation of all the time periods is finished, if so, outputting a final line maintenance scheme, and if not, returning to the step S201 to calculate the next time period.
In step S205, a large number of quadratic terms and trigonometric function terms exist in the unified model of island division and network reconstruction, which is a MINLP problem, and a second order cone relaxation technique is adopted to perform convex relaxation on the model. The island division of the active power distribution network and the quadratic term and the trigonometric function term existing in the network reconstruction unified model are non-convex and difficult to directly solve in mathematics as shown in the formulas (4) and (6). According to the method, by introducing the intermediate variable, the island division and network reconstruction unified model is subjected to convex relaxation treatment by utilizing a second order cone relaxation technology, and further, a mature commercial solver can be adopted to rapidly obtain the global optimal solution. The intermediate variables introduced are shown in formulas (13) to (17).
C ij,t ＝V i,t V j,t cos(δ ij,t ) (15)
D ij,t ＝V i,t V j,t sin(δ ij,t ) (16)
Since the quadratic term is contained in the formula (17), the model still has non-convexity, and the model is further relaxed as shown in the formula (18).
The second order cone form of the modified material is shown as a formula (19) after the modified material is shown as a formula (18).
The network loss formula (4) containing square terms in the original model and the node power balance constraint formula (6) containing square terms and trigonometric function terms are respectively shown as formulas (20) to (22) after second order cone relaxation.
At this time, the feasible region is relaxed to be the whole second-order cone, the search space is limited in the convex cone range, the solution can be completed by adopting a commercial solver with the convex feasible region.
The above functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on this understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.
In another embodiment, an active power distribution network fault recovery system based on a hybrid solution strategy is provided, comprising: one or more processors, memory, and one or more programs stored in the memory, the one or more programs including instructions for performing the active power distribution network fault recovery method based on the hybrid solution strategy as described above.
Examples
The embodiment adopts an IEEE 33 node active power distribution network containing DG and Energy Storage (ES), the structure is shown in figure 3, and the node numbers are marked in the figure; the maximum load of the system is 3715kW+2300kvar. The load grade parameters are shown in table 1, and the specific access nodes and rated power of each DG and energy storage are shown in tables 2 and 3.
TABLE 1 node load rating parameter
Table 2 DG rated power and access point
Table 3 energy storage access points and parameters
In order to verify the effectiveness of the active power distribution network fault recovery method, under extreme weather conditions, when a major accident occurs in which a plurality of lines simultaneously fail in the power distribution network, the lines 6-7, 10-11, 15-16, 22-23 and 26-27 are set to permanently fail, and the period of failure and power failure is 14:00-18:00. In the embodiment, the number of the most overhauling lines in a single period is 1, and after the island division and network reconstruction in each period are finished, the fault repairing sequence is optimized by adjusting the switch decision variable of the fault line on the premise of meeting the constraint of the fault repairing strategy in the formula (12), so that the optimal fault repairing strategy is determined. The main objective of the fault recovery strategy of the island division and network reconstruction provided by the invention is to recover load power supply as much as possible, and the rest objective functions are used for assisting in optimizing the network running state.
The fault recovery strategy of the island division and network reconstruction is adopted, the constraint of the fault maintenance strategy is considered, before island division and network reconstruction operation is carried out in each period, the network topology structure is adjusted by optimizing and adjusting the switch decision variable of a fault line, the finally determined line maintenance strategy is 22-23, 10-11, 15-16 and 6-7 in sequence, and the fault recovery result of each period is shown in fig. 4-9 and table 4. It can be seen that the rated power of ES1 is larger, and the ES1 and the WT2 are mutually matched to participate in island division, but the rated capacity of ES2 is smaller, so that the ES2 can only play a role in network reconfiguration, and the method of the invention can realize that all load nodes 8, 9, 16, 24, 30 and 31 of class 1 recover power supply.
TABLE 4 failure recovery results for various periods
To verify the superiority of the fault recovery strategy provided by the invention, the operation results of the fault recovery strategy which is not matched with the island division and the network reconstruction but is considered, and the fault maintenance strategy which is matched with the island division and the network reconstruction but is not matched with the island division and the network reconstruction are respectively compared, and the results are shown in Table 5.
Table 5 fault recovery strategy comparison
It can be seen that, using policy 1, that is, the island division and the network reconfiguration are not mutually matched, although the load recovered by the island division reaches the maximum, as the island division and the network reconfiguration are respectively and independently performed, only the local optimal solution of the island division is obtained, so that part of nodes cannot recover power supply by the network reconfiguration, and the power supply recovery rate is only 87.15%. And the strategy 2, namely island division and network reconstruction are adopted to carry out power supply recovery, but no fault maintenance strategy is adopted, the order of repairing lines is random, and the power supply recovery rate is 92.43%. By comparing the strategy 2 with the strategy 1, the method considers the mode of matching the island division with the network reconstruction to jointly carry out fault recovery on the active power distribution network, and the island division and the network reconstruction are carried out simultaneously, namely, the load which cannot be recovered in the reconstruction process is considered, and the result shows that the power loss load electric quantity is reduced by 508.7 kW.h, so that the superiority of the unified model of the island division and the network reconstruction is proved. When the strategy 3 is adopted, namely island division and network reconstruction are matched for power restoration and a fault maintenance strategy is considered, the power restoration rate can reach 97.27%, and the power loss load electric quantity is respectively reduced by 974.4 kW.h and 465.7 kW.h compared with strategies 1 and 2, so that the fault maintenance strategy adopted by the invention can more reasonably arrange the fault restoration process, thereby further improving the power restoration rate.
The foregoing describes in detail preferred embodiments of the present invention. It should be understood that numerous modifications and variations can be made in accordance with the concepts of the invention by one of ordinary skill in the art without undue burden. Therefore, all technical solutions which can be obtained by logic analysis, reasoning or limited experiments based on the prior art by the person skilled in the art according to the inventive concept shall be within the scope of protection defined by the claims.
Claims (8)
1. The active power distribution network fault recovery method based on the hybrid solving strategy is characterized by comprising the following steps of:
step S1, constructing an active power distribution network island division and network reconstruction unified model containing distributed power sources and energy storage, wherein an objective function of the model considers equivalent power loss load, sectional switch operation and network loss cost;
step S2, solving the unified model by adopting a mixed solution strategy based on the combination of breadth-first search, depth-first search and second order cone optimization to obtain a line maintenance scheme;
step S3, realizing the fault recovery of the active power distribution network based on the line maintenance scheme;
the objective function is expressed as:
wherein: g 1,t Network loss for system t period; g 2,t The operation times of the sectionalized switch are the time period t of the system; g 3,t The equivalent load recovery amount of the system in the period t is calculated; lambda (lambda) i Load weight for node i; p (P) i,t Active power in a load t period of the load node i;representing a set of load nodes; upsilon (v) 1 、υ 2 、υ 3 Respectively a network loss cost coefficient, a switch operation cost coefficient and an equivalent power loss load cost coefficient, N T For the number of time periods that the entire fault is recovered, Δt is the duration of a single time period;
the network loss calculation method comprises the following steps:
wherein: i ij,t For the effective value of the current of the branch i-j of the system t period, R ij The resistance value of the branch i-j; omega is the set of all branches of the active power distribution network;
the calculating method of the operation times of the sectionalizing switch comprises the following steps:
wherein: decision variable alpha ij,t For the state of the line i-j switch in the t period, taking 0 to represent that the line i-j switch is opened, and taking 1 to represent that the line i-j switch is closed;
the calculation method of the equivalent load recovery amount comprises the following steps:
wherein: decision variable y i,t For the load recovery state of the node i in the t period, taking 1 to indicate that the load i is recovered in the t period, and taking 0 to indicate that the load i is not recovered in the t period.
2. The hybrid solution strategy-based active power distribution network fault recovery method according to claim 1, wherein the constraint conditions of the active power distribution network island division and network reconstruction unified model comprise node voltage and branch current constraint, node power balance constraint, DG power constraint, network structure constraint, energy storage charge and discharge state and power constraint, energy storage residual capacity constraint, capacitor switching constraint and fault maintenance strategy constraint.
3. The method for active power distribution network fault recovery based on the hybrid solution strategy according to claim 1, wherein in step S2, the solving of the unified model is specifically:
step S201: reading a fault planning power failure time T, the output power of the DG in the period, a load prediction power and an energy storage charge state;
step S202: traversing each DG and energy storage access node as root nodes, and determining a power circle by adopting a breadth-first search algorithm to obtain island feasible solutions;
step S203: according to the island feasible solution, obtaining an initial island dividing range by adopting a depth-first search algorithm, and then correcting the initial island dividing range according to an island fusion strategy to obtain an island dividing result in the period;
step S204: based on the island division result of the period, the position of the operable tie switch and the network topology structure, an active power distribution network island division and network reconstruction unified model of the period is obtained;
step S205: constructing an intermediate variable, carrying out linearization treatment on the unified model, and converting the unified model into a standard mixed integer second order cone model;
step S206: solving the standard mixed integer second order cone model by adopting a commercial solver;
step S207: and judging whether the calculation of all the time periods is finished, if so, outputting a final line maintenance scheme, and if not, returning to the step S201 to calculate the next time period.
4. The method for recovering an active power distribution network fault based on a hybrid solution strategy according to claim 3, wherein the correcting the initial island division range according to the island fusion strategy is specifically:
and judging whether each island has an intersection or not under the initial island dividing range, if so, fusing the islands with the intersections, recording equivalent DGs and equivalent nodes directly connected with the same, returning to the step S202, if not, fusing whether the adjacent islands meet the fusing constraint condition, if so, canceling the fusion, and executing the step S204.
5. The hybrid solution strategy based active power distribution network fault recovery method of claim 3 wherein the business solver comprises a yalminip toolbox.
6. The method for active power distribution network fault recovery based on hybrid solution strategy according to claim 3, wherein in step S205, a second order cone relaxation technique is adopted to perform convex relaxation on the unified model, and the unified model is converted into the standard mixed integer second order cone model.
7. The hybrid solution strategy-based active distribution network fault recovery method according to claim 3, wherein the feasible region of the standard hybrid integer second order cone model is relaxed to be a whole second order cone, and the search space is inside a convex cone range.
8. An active power distribution network fault recovery system based on a hybrid solution strategy, comprising:
one or more processors, memory, and one or more programs stored in the memory, the one or more programs comprising instructions for performing the hybrid solution strategy-based active power distribution network fault recovery method of any of claims 1-7.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109120009A (en) * | 2018-09-11 | 2019-01-01 | 国网天津市电力公司电力科学研究院 | The active distribution network fault recovery method that meter and distributed generation resource power output change at random |
| CN109586277A (en) * | 2018-11-01 | 2019-04-05 | 国网新疆电力有限公司检修公司 | Multi-agent system distributed and coordinated control system and its distribution network failure restoration methods |
| CN110350508A (en) * | 2019-05-16 | 2019-10-18 | 东南大学 | Method that is a kind of while considering the active distribution network fault recovery unified model that reconstruct is divided with isolated island |
| CN111313557A (en) * | 2020-03-25 | 2020-06-19 | 马瑞 | Intelligent self-healing switch cabinet based on 5G internet of things |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109120009A (en) * | 2018-09-11 | 2019-01-01 | 国网天津市电力公司电力科学研究院 | The active distribution network fault recovery method that meter and distributed generation resource power output change at random |
| CN109586277A (en) * | 2018-11-01 | 2019-04-05 | 国网新疆电力有限公司检修公司 | Multi-agent system distributed and coordinated control system and its distribution network failure restoration methods |
| CN110350508A (en) * | 2019-05-16 | 2019-10-18 | 东南大学 | Method that is a kind of while considering the active distribution network fault recovery unified model that reconstruct is divided with isolated island |
| CN111313557A (en) * | 2020-03-25 | 2020-06-19 | 马瑞 | Intelligent self-healing switch cabinet based on 5G internet of things |
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