CN109921420B - Elastic power distribution network restoring force improving method and device and terminal equipment - Google Patents
Elastic power distribution network restoring force improving method and device and terminal equipment Download PDFInfo
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Abstract
The invention belongs to the technical field of operation and control of power systems. The method and the device for improving the restoring force of the elastic power distribution network and the terminal equipment are provided, and the method for improving the restoring force of the elastic power distribution network comprises the following steps: establishing a line loss analysis model; establishing an elastic power distribution network restoring force evaluation model; and constructing a target function by restoring force and economic cost by adopting a restoring force improving method combining the capacities of the reinforced tower and the expanded battery exchange station, and obtaining an elastic power distribution network restoring force improving scheme according to the line loss analysis model and the elastic power distribution network restoring force evaluation model. The elastic distribution network restoring force improving method can effectively improve the restoring force of the elastic distribution network within a certain economic range.
Description
Technical Field
The invention belongs to the technical field of operation and control of electric power systems, and particularly relates to a method and a device for improving resilience of an elastic power distribution network and terminal equipment.
Background
In recent years, extreme natural disasters are increasingly frequent, the power supply of a power grid is seriously damaged, the national economy suffers great economic loss, and how to improve the elastic resilience of a power distribution network becomes one of the key contents of the current research. Resilience refers to the ability of the system to resist, adapt to and quickly recover from a disturbance event, and a grid with resilience is called a resilient grid. For the evaluation of the resilience of the elastic power distribution network, the existing research results are widely researched from the aspects of evaluation indexes and evaluation methods. However, in the existing achievement, when a restoring force improving measure is researched, the difference of the restoring force of the power grid under different investment costs is rarely considered, and economic factors influencing the restoring of the power grid are ignored.
Disclosure of Invention
In view of this, embodiments of the present invention provide a method and an apparatus for improving a restoring force of an elastic power distribution network, and a terminal device, so as to solve the problem in the prior art that the restoring force of a power grid is maximally enhanced by reasonably adopting a restoring force improving method within a certain economic range.
The first aspect of the embodiment of the invention provides a method for improving the restoring force of an elastic power distribution network, which comprises the following steps:
establishing a line loss analysis model;
establishing an elastic power distribution network restoring force evaluation model;
and constructing a target function by restoring force and economic cost by adopting a restoring force improving method combining the capacities of the reinforced tower and the expanded battery exchange station, and obtaining an elastic power distribution network restoring force improving scheme according to the line loss analysis model and the elastic power distribution network restoring force evaluation model.
A second aspect of the embodiments of the present invention provides an elastic distribution network restoring force improving apparatus, including:
the circuit loss analysis model establishing module is used for establishing a circuit loss analysis model;
the restoring force evaluation model establishing module is used for establishing an elastic power distribution network restoring force evaluation model;
and the analysis module is used for constructing a target function by adopting a restoring force improving method combining the capacities of the reinforced towers and the expanded battery exchange stations according to restoring force and economic cost, and obtaining an elastic power distribution network restoring force improving scheme according to the line loss analysis model and the elastic power distribution network restoring force evaluation model.
A third aspect of the embodiments of the present invention provides a terminal device, which includes a memory, a processor, and a computer program that is stored in the memory and is executable on the processor, and when the processor executes the computer program, the steps of the method for improving the restoring force of the elastic distribution network according to the first aspect are implemented.
A fourth aspect of the embodiments of the present invention provides a computer-readable storage medium, where a computer program is stored, and the computer program, when executed by a processor, implements the steps of the method for improving the restoring force of an elastic power distribution network according to the first aspect.
Compared with the prior art, the embodiment of the invention has the following beneficial effects: the embodiment of the invention fully considers economic factors, constructs a target function by using the restoring force and the economic cost, reasonably distributes the investment cost of two measures of reinforcing a tower and expanding the capacity of a battery exchange station according to the line loss analysis model and the elastic power distribution network restoring force evaluation model, and effectively improves the restoring force of the elastic power distribution network within a certain economic range. Meanwhile, the restoring force improving method combining the capacities of the reinforced pole tower and the expanded battery exchange station is adopted, so that the advantages of the capacities of the reinforced pole tower and the expanded battery exchange station are well exerted, the cost is saved, the resource waste is avoided, and the restoring force improving index is better than that of the restoring force improving method singly adopted.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.
Fig. 1 is a schematic flow chart illustrating an implementation process of a method for improving a restoring force of an elastic distribution network according to an embodiment of the present invention;
FIG. 2 is a flow chart of solving particle swarm optimization algorithm;
FIG. 3 is a power distribution network topology diagram;
FIG. 4 is a tower loss probability graph;
FIG. 5 is a diagram of the number of remaining battery packs in the battery exchange station;
FIG. 6 is a schematic view of a lifting device provided in accordance with an embodiment of the present invention;
fig. 7 is a schematic diagram of a terminal device according to an embodiment of the present invention.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.
The terms "comprises" and "comprising," as well as any other variations, in the description and claims of this invention and the drawings described above, are intended to mean "including but not limited to," and are intended to cover non-exclusive inclusions. For example, a process, method, or system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus. Furthermore, the terms "first," "second," and "third," etc. are used to distinguish between different objects and are not used to describe a particular order.
In order to explain the technical means of the present invention, the following description will be given by way of specific examples.
Example 1:
fig. 1 is a schematic flow chart of an implementation process of a method for improving a restoring force of an elastic distribution network, where referring to fig. 1, the method for improving the restoring force of the elastic distribution network may include:
step S101, a line loss analysis model is established.
The line loss analysis model is used for analyzing the damage condition of the power grid line under natural disasters such as earthquakes, and the damage condition of the line is determined by calculating the damage probability of the pole tower.
Optionally, the process of establishing the line loss analysis model in step S101 is as follows:
the damage of the power grid under the earthquake disaster comprises the inclination and the collapse of a tower, the disconnection of an overhead line and the like. The seismic motion at different positions is related to the position of a seismic source and the seismic level, and the seismic motion acceleration is attenuated continuously along with the increase of the distance. Considering various factors influencing seismic dynamic acceleration, the relationship between the factors and the acceleration is as follows:
lg(αPGA)＝a+bM-clg[R+d exp[eM]]+
wherein alpha isPGAThe earthquake dynamic acceleration is the earthquake magnitude, M is the earthquake magnitude, R is the distance, the random quantity with variance sigma is obtained, and a, b, c, d and e are all preset constants.
The earthquake damage levels respectively corresponding to the influences of normal use, component yielding, structure yielding and structure collapse of each tower of the elastic power distribution network in the earthquake are used as limit states, and the quantitative indexes are L1、L2、L3And L4And the conditional probability that each tower achieves damage at each level under different earthquake levels meets the following requirements:
P(Si|αPGA)＝P(Lmax>Li|αPGA)
wherein S isiIn a seismic damage level, LmaxSeismic acceleration alpha for each towerPGAMaximum horizontal displacement of the apex of time, LiAnd (i is 1,2,3 and 4) is a horizontal displacement limit value of each tower top in different extreme states under each earthquake damage level.
Calculating the cumulative probability that each tower structure exceeds the limit state and reaches each earthquake damage level:
ln(Lmax)＝k ln(αPGA)+g
wherein k and g are preset coefficients, and sigma is LmaxThe log condition standard deviation of (a), μ is the poisson coefficient.
And S102, establishing an elastic power distribution network resilience evaluation model.
When an extreme earthquake disaster occurs, the power distribution network is damaged in different degrees due to the collapse of the tower, so that the phenomenon of load loss in a certain range is easily caused, and how to recover more power loss loads and maintain the sustainable operation of recovering the loads becomes an important link for researching the recovery force. In order to fully research the restoration level of the power grid under the earthquake disaster, an elastic power distribution network restoration force evaluation model is established.
Optionally, the process of establishing the elastic power distribution network resilience evaluation model in step S102 is as follows:
construction of load recovery index frecAnd a recovery continuation index fsus。
The load recovery index is used to measure the recovery rate of the load in the loss region, wherein the key load plays a crucial role in the recovery rate. Load recovery index frecAnd (4) calculating the recovery conditions of different key loads by considering the important degree of the load recovery after the disaster, and measuring the recovery force of the power distribution network after the disaster.
Load recovery index frecComprises the following steps:
wherein N isrecTo restore the number of load nodes, NlossThe total number of load nodes is lost for the disaster. Omegarec,iAnd ωloss,jAs node load weight, Prec,iRepresenting the active power of the recovery node i, Ploss,jThe active power of the load node j is lost.
Because the power grid needs a certain time for repairing, it is necessary to maintain the continuous operation of the power grid, and the recovery continuity represents the condition of recovering and maintaining the operation according to the load of the loss area divided by the island after a disaster. Index f of recovery persistencesusWhen the power supply resources are provided for the damaged area, whether the power supply time of the damaged area can be maintained as much as possible is shown, when the power supply time is longer than the shortest time for the load to be restored through tower repair, the restoration continuity is good, and otherwise, the continuity needs to be further improved.
Index f of recovery persistencesusComprises the following steps:
wherein B is the total set of lost areas,
the runtime after recovery for the region b,
and restoring normal operation for the area b through line repair.
Thus obtaining the elastic power distribution network restoring force index fsumComprises the following steps:
fsum＝k1frec+k2fsus
wherein k is1For constructing a load recovery index frecWeight coefficient with respect to restoring force, k2To construct a recovery persistence index fsusA weight coefficient with respect to the restoring force. f. ofsumThe method is used for measuring the overall restoring force level of the elastic power distribution network.
And S103, constructing a target function by restoring force and economic cost by adopting a restoring force improving method combining the capacities of the reinforced tower and the expanded battery exchange station, and obtaining an elastic power distribution network restoring force improving scheme according to the line loss analysis model and the elastic power distribution network restoring force evaluation model.
Within certain economic limits, measures to increase resilience may include tower reinforcement and battery exchange station battery capacity expansion. The tower on the line is reinforced, so that the earthquake resistance of the tower can be effectively improved, and the line loss caused by the collapse of the tower under earthquake disasters is reduced. However, in order to maintain the effective operation of the load in the loss area after the earthquake, the emergency resources need to be increased to ensure the sustainable operation of the load. At the moment, the residual batteries of the electric automobile exchange station participate in power grid recovery, and the batteries among different power exchange stations can be flexibly scheduled, so that the coordination effect among resources is realized.
On the one hand, the tower reinforcement can effectively improve the earthquake resistance of the tower, but the cost is high, a large amount of manpower and material resources are needed, and the lifting effect is restrained to a certain extent. On the other hand, the expansion of the battery capacity of the battery exchange station can provide a large amount of flexible resources, but due to the randomness of the damage of a power grid in earthquake disasters, the surplus battery of the battery exchange station is easily caused to be too much, and meanwhile, the maintenance cost is increased sharply due to the overlarge capacity of the battery exchange station, so that the serious waste of the resources is caused. In the embodiment, the restoring force improving method combining the capacities of the reinforced tower and the expanded battery exchange station is adopted, so that the advantages of two improving measures can be fully exerted, and meanwhile, the defects in the load restoring process are avoided.
Optionally, in step S103, a target function is constructed with restoring force and economic cost, and a restoring force improvement scheme of the elastic distribution network is obtained according to the line loss analysis model and the elastic distribution network restoring force evaluation model, which may include:
and solving the multi-target problem by taking the maximum restoring force in a preset investment sum range as an objective function, taking node voltage constraint, node power balance, line tide, restored load constraint and battery discharge as constraint conditions according to the line loss analysis model and the elastic power distribution network restoring force evaluation model and combining the objective function and the constraint conditions to obtain the elastic power distribution network restoring force improvement scheme.
In order to fully analyze the restoring force level of the elastic power distribution network, the maximum value of the restoring force of the elastic power distribution network in a certain economic range is researched, and the total investment C is presetsumAnd the maximum restoring force is the objective function within the range of the preset total investment, so that the objective function is obtained:
wherein, C1Cost incurred for reinforcing the tower, C2Cost of expanding battery exchange station capacity, CsumTo preset the total investment, k1For constructing a load recovery index frecWeight coefficient with respect to restoring force, k2To construct a recovery persistence index fsusWeight coefficient with respect to restoring force, fsumThe index is the resilience index of the elastic power distribution network.
The restoring force improving scheme is set to be n groups reinforced by the tower, and the capacity of the battery exchange station is expanded by m groups, so that the cost C generated by reinforcing the tower is obtained1Can be as follows:
C1＝n(cφ1Vφ1+cφ2Lφ2)
wherein n is the number of the reinforced towers, cφ1Cost factor for consolidating the foundation, cφ2Cost factor V for tower material reinforcementφ1For consolidating the volume of the foundation, Lφ2The length of the tower column base is increased.
Cost C of expanding battery exchange station capacity2Can be as follows:
C2＝mC0
wherein m is the number of capacity expansion sets of the battery exchange station, C0For the cost of a single battery pack.
The actual investment sum for reinforcing the tower and expanding the capacity of the battery exchange station is C1+C2。
In the process of solving the elastic power distribution network restoring force improvement scheme, the target of the elastic power distribution network restoring force improvement scheme is considered, and the constraint conditions of the elastic power distribution network restoring force improvement scheme are considered, wherein the constraint conditions are node voltage constraint, node power balance, line load flow, restoring load constraint and battery discharge:
wherein, Ui,minRepresenting the minimum value, U, of the i-node voltagei,maxRepresenting the maximum value of the i-node voltage, Pinp,iInputting active power, Q, to the nodeinp,iFor input of reactive power, P, to the nodeload,iAnd Qload,iFor node load consumption, Pline,jFor line active power, Qline,jFor line reactive power, Pline,i,maxFor maximum power allowed by the line, Qline,i,maxMinimum power allowed for the line; λ is 0 or 1, and λ is equal to 0 when the line is open; omega is the number of lines connected to node i, Prec,iTo restore node active power, Ploss,jFor active power of the power-loss node, NlossFor the load set in the entire loss region, NrecFor restoring a load set, SOC, throughout a loss regioniDischarge capacity of the ith cell at time T, TBatIs the discharge time of the battery, omegaBatFor the number of remaining schedulable batteries, M is the total number of exchange batteries, CsumIs a preset total investment.
In some embodiments, a particle swarm optimization algorithm can be adopted, the multi-objective problem is solved according to the line loss analysis model and the elastic distribution network restoring force evaluation model and by combining an objective function and constraint conditions, and an elastic distribution network restoring force improvement scheme is obtained.
The Particle Swarm Optimization (PSO) algorithm is a global random search algorithm based on Swarm intelligence, which is inspired by artificial life research results and proposed by simulating migration and clustering behaviors in a bird Swarm foraging process, wherein various organisms in nature have certain Swarm behaviors, and one of main research fields of artificial life is to explore the Swarm behaviors of natural organisms so as to construct a Swarm model of the artificial life on a computer. PSO was inspired from this model and used to solve optimization problems. In PSO, the potential solution to each optimization problem is a bird in the search space, called a particle. PSO is initialized to a population of random particles (random solution), and then the optimal solution is found by iteration
As shown in fig. 2, solving by using a particle swarm optimization algorithm, according to the line loss analysis model and the elastic distribution network resilience evaluation model, and combining an objective function and a constraint condition to solve a multi-objective problem, may include:
step S201, inputting the iteration times, the number of groups which can be called by the exchange station battery, the total investment, the particle position and the particle speed into a particle swarm optimization algorithm model, and setting parameters.
Step S202, initializing an original population, and determining a restoring force index of the current maximum restoring force improvement scheme.
Initializing the original population is initializing a population of random particles. And meanwhile, initializing the restoring force index of the maximum restoring force lifting scheme, and allocating an initial value to the restoring force index of the maximum restoring force lifting scheme.
Step S203, according to constraint condition C in the objective function1+C2≤CsumAnd determining the reinforcement number n of a group of towers and the capacity expansion group number m of the battery exchange station.
Constraint C in satisfying the objective function1+C2≤CsumAnd then, a plurality of groups of m and n are combined, and m and n meeting constraint conditions can be obtained through calculation according to the reinforcing cost of a single tower and the cost of a single battery.
Step S204, determining a loss line set and a loss area set according to the currently determined tower reinforcement number n and the battery exchange station capacity expansion number m through a line loss analysis model, repairing the power grid according to a loss line repairing principle and an exchange station battery scheduling principle, and obtaining a current elastic power distribution network restoring force index fsum。
And determining the reinforcement number n of a group of towers and the capacity expansion number m of the battery exchange station, and reinforcing the towers and expanding the capacity of the battery exchange station according to the restoring force improving scheme.
Optionally, the step S204 of determining the lost line set and the lost area set through the line loss analysis model may include:
determining the loss probability of each tower of each line of the elastic power distribution network according to the line loss analysis model;
adopting a roulette algorithm to determine whether the line corresponding to each tower is damaged or not according to the loss probability of each tower;
and determining a lost line set and a lost area set according to whether the line is damaged.
After an extreme earthquake disaster, in order to determine the loss condition of a specific line in the power distribution network after the restoring force promotion scheme is implemented, the loss probability of each tower of each line is determined according to a line loss analysis model, the line loss is random due to towers with different loss probabilities, and the damage of any tower in a certain line can cause the damage of the line, a random selection algorithm wheel roulette algorithm is adopted to determine whether the line is damaged, and the higher the loss probability of the tower is, the higher the possibility of the line loss is. And then, according to the line loss situation, determining a loss line set and a loss area set after the disaster occurs.
Repairing the lost line according to the line weight according to the lost line set and the lost area set to obtain the repairing time of the whole lost area, and finally scheduling the remaining batteries of the exchange station to supply power according to the area importance degree, thereby calculating and obtaining the current elastic power distribution network restoring force index f under the restoring force improving schemesum。
Optionally, the principle of repairing the lost line may be: and repairing the tower according to the weight of the lost line. In this embodiment, the lost line weight is:
therein, ζyTo lose weight of line y, ByThe set of areas affected by the loss line y, and B is the entire loss area. The larger the loss line weight is, the wider the influence range is, and the earlier the power grid loss is repaired, so that the damaged power grid is repaired according to the loss line weight.
Optionally, the exchange station battery scheduling principle may be: and scheduling the battery according to the region importance degree. In this embodiment, the area importance degree is:
wherein, ω isiTo the extent of importance of region i, NiIs the number of loads in region i, wi,jIs the weight, P, of the load j in the region ii,jIs the active power of load j in zone i.
And after the earthquake disaster, dividing a loss area according to the island, and if the battery exchange station is in the area range, preferentially supplying the residual battery of the battery exchange station to the loss area. If the loss area is not in the loss area, the battery is dispatched to the battery exchange stations of other loss areas, the area with high importance degree is preferentially supplied for ensuring important load recovery, and the battery is dispatched according to the importance degree of the area and the influence of the repair sequence on the line repair time.
Step S205, the current elastic power distribution network restoring force index fsumComparing with the restoring force index of the current maximum restoring force promotion scheme, if the current elastic power distribution network restoring force index fsumGreater than the restoring force index of the current maximum restoring force promotion scheme, then the restoring force index f of the current elastic power distribution networksumUpdating the restoring force index of the current maximum restoring force promotion scheme and the restoring force index f of the current elastic power distribution networksumThe corresponding scheme is a maximum restoring force boosting scheme.
Step S206, determining whether the preset iteration count is satisfied, if not, repeating step S203 to step S206, and if so, turning to step S207.
And step S207, outputting the maximum restoring force improving scheme and the corresponding maximum restoring force of the power grid.
Therefore, the maximum restoring force improvement scheme within the range of the total investment is obtained.
Optionally, in order to ensure that the loss rate of the important load is the lowest, the tower on the line is reinforced according to the importance degree of the power grid line, namely the line weight, so that the power supply of the trunk road is preferentially recovered. The weight of each line in the elastic power distribution network is as follows:
wherein, wiIs the load level weight of the ith node, LiIs the load capacity of the ith node; n is a radical ofxiSet of loads influenced by the xi line, wjIs the load level weight of the jth node. L isjIs the load of the jth node, NtotalIs the load aggregate of the whole line.
The following examples of the present invention are verified by practical examples.
And selecting an actual power distribution network with 45 nodes in a certain area of Hubei province for verification, wherein a topological graph is shown in figure 3. The line lengths of the grid are shown in table 1 and the load importance levels are shown in table 2. The grid is provided with battery exchange stations at nodes 4, 15 and 28, respectively, and diesel-electric sets 1 and 2 act on nodes 17 and 28, respectively. The seismic source is selected to be located 25km in the north direction of the node 7, and the seismic level is 6.5. The total preset investment is 30 ten thousand yuan, and the power of the diesel generating sets 1 and 2 is 500 kW. The battery exchange stations 1,2 and 3 have an initial capacity of 100 batteries, one for each 2 batteries, a capacity of 30kW h each, a discharge power of 6kW, a discharge efficiency of 1 and a cost of 1200 yuan each.
TABLE 1 feeder segment Length
| Line | Length/km | Line | Length/km | Line | Length/km |
| 1 | 1.60 | 16 | 0.50 | 31 | 0.25 |
| 2 | 0.50 | 17 | 0.70 | 32 | 0.30 |
| 3 | 0.50 | 18 | 0.50 | 33 | 1.00 |
| 4 | 2.50 | 19 | 0.30 | 34 | 0.40 |
| 5 | 1.20 | 20 | 1.45 | 35 | 0.20 |
| 6 | 2.00 | 21 | 0.40 | 36 | 0.25 |
| 7 | 2.50 | 22 | 0.20 | 37 | 1.50 |
| 8 | 1.50 | 23 | 1.60 | 38 | 1.00 |
| 9 | 0.80 | 24 | 1.30 | 39 | 1.50 |
| 10 | 0.50 | 25 | 0.45 | 40 | 0.50 |
| 11 | 0.50 | 26 | 0.50 | 41 | 1.50 |
| 12 | 0.80 | 27 | 0.80 | 42 | 0.60 |
| 13 | 0.80 | 28 | 0.55 | 43 | 1.20 |
| 14 | 1.50 | 29 | 0.50 | 44 | 0.50 |
| 15 | 1.50 | 30 | 0.80 |
TABLE 2 load rating
| Load rating | Weight of | Node point |
| First stage | 0.6 | 2,4,5,8,9,12,13,17,20,21,27,28,31,32,34,35 |
| Second stage | 0.3 | 3,6,7,11,14,15,16,18,24,25,30,37,39,40,42,44,45 |
| Three-stage | 0.1 | 10,15,19,22,23,26,29,33,36,38,41,43 |
According to the line loss analysis model, loss probability curves of towers at different distances can be obtained through analysis, as shown in fig. 4. By analyzing the attenuation characteristics of the earthquake peak acceleration, the damage of the earthquake peak acceleration to the power grid is related to the distance from the earthquake source, the probability of damage to the tower closest to the earthquake source is the largest, and the loss of the tower can cause the faults such as line breakage and the like of the corresponding line. For the convenience of research, the influence of earthquake on the power grid is divided into 5 intervals according to the actual length and the geographic position of the power grid, and the lines and the loss probability contained in different intervals are shown in table 3. The tower selection refers to a 35kV power distribution network design guide, and according to geographical characteristics of a selected region, the tower at the position is selected from an angle steel tower and a steel pipe pole.
TABLE 3 line loss probability
| Region(s) | Line | Probability of loss |
| 1 | 6,7,8,26,38,39 | 0.65 |
| 2 | 4,5,9,10,27,28,29,30,40 | 0.52 |
| 3 | 11,12,13,25,31,32,33,34,41,42,44 | 0.40 |
| 4 | 2,3,14,18,19,20,21,22,23,24,35,36,37,43 | 0.30 |
| 5 | 1,15,16,17 | 0.20 |
When a restoring force improving measure is not taken, according to the loss probability of lines in different areas, obtaining the line lost due to tower collapse in the power grid by using a roulette algorithm as follows: 6. 7, 9, 20, 25, 26, 28, 37 and 44. Maintenance personnel can preferentially maintain the towers on the important lines according to the line weight, and the power supply of the area with the large affected range can be recovered as soon as possible. According to a specified repair strategy, comparing the influences of different maintenance orders on the restoring force of the power grid to obtain the optimal repair orders of the two teams, namely 6 → 7 → 9 → 44 → 20 → 25; 6 → 7 → 26 → 28 → 37.
The change curve of the number of the remaining battery packs and the change rule of the energy storage of the remaining batteries of a certain typical battery exchange station are shown in fig. 5. As can be seen from fig. 5, the number of remaining battery packs in the battery exchange station shows different trends in the condition that the daily driving demand of the user is satisfied. After 22:00, as the number of battery charging sets becomes more and more, the number of remaining sets starts to steadily increase; at 07:00, the number of the remaining battery groups is sharply reduced due to the occurrence of early peak; at 15:00, the number of battery replacement charging sets is increased slightly, and the available usage amount is increased. And (3) combining the change of the battery energy storage in the graph, dividing the change of the number of the residual battery packs in one day of the exchange station into three typical scenes for analysis, wherein the typical scenes are a sufficient period, a floating period and a valley period in sequence, and the number of the corresponding battery groups which can be called is 40, 20 and 5.
According to the restoring force evaluation model, in combination with the objective function and the constraint condition, the restoring force index of the power grid when no lifting measure is taken is calculated by utilizing the particle swarm algorithm, and is shown in table 4.
TABLE 4 resilience index
| No measures taken | Recovery of persistence | Rate of load recovery | Restoring force |
| Sufficient period | 0.715 | 0.648 | 0.682 |
| Floating period | 0.645 | 0.626 | 0.636 |
| Low ebb period | 0.573 | 0.584 | 0.578 |
According to the table, in the three typical scenes, when the number of the remaining battery packs is sufficient, the restoring force of the power grid is maximum.
According to the embodiment, the restoring force levels of the power grid under three typical schemes are respectively discussed aiming at the power grid restoring force improving method and combining the economy of the power grid.
First, strengthen shaft tower
The total investment being wholly used for line strengthening, i.e. C1≤Csum，C 20. The total length of the system is about 40km, 44 lines are totally arranged, the step foundation is generally poured in a layered mode, no gap is reserved between an upper layer and a lower layer, and the thickness of each layer of concrete is 200: 300mm, the cost per square is 100 yuan, the price of the angle steel is 3630 yuan/ton, and the total cost for reinforcing each tower is not more than 2000 yuan.
The reinforced line loss probability is calculated according to the line loss analysis model, as shown in table 5.
TABLE 5 line loss probability
| Region(s) | Line | Probability of loss |
| 1 | 6,7,8,26,38,39 | 0.50 |
| 2 | 4,5,9,10,27,28,29,30,40 | 0.38 |
| 3 | 11,12,13,25,31,32,33,34,41,42,44 | 0.27 |
| 4 | 2,3,14,18,19,20,21,22,23,24,35,36,37,43 | 0.17 |
| 5 | 1,15,16,17 | 0.10 |
Obtaining the line lost due to tower collapse in the power grid by using a roulette algorithm according to the loss probability of the line, wherein the line lost due to tower collapse is as follows: 6, 7, 20, 26, 28 and 37. According to a specified repair strategy, the repair sequence of the two teams is as follows: 6 → 7 → 26 → 20; 6 → 7 → 26 → 28 → 37.
And calculating the resilience index of the power grid by using a particle swarm algorithm according to the resilience evaluation model and in combination with the objective function and the constraint condition, as shown in table 6.
TABLE 6 scheme 1 resilience index
| Scheme one | Recovery of persistence | Rate of load recovery | Restoring force |
| Sufficient period | 0.748 | 0.716 | 0.732 |
| Floating period | 0.714 | 0.659 | 0.687 |
| Low ebb period | 0.695 | 0.603 | 0.649 |
As can be seen from the table 5, in the first scheme, the loss probability of the line is reduced on the original basis by reinforcing the tower, the loss line is calculated by using a roulette algorithm, the loss line is reduced, the loss range is reduced, the repair is quicker, and the load needs to be maintained for corresponding reduction of the operation time. As can be seen from Table 6, the load recovery rate index and the recovery continuation index are both effectively improved. At the moment, the total investment cost of the power grid is 27.9 ten thousand yuan.
Expanding battery exchange station capacity
The total investment is fully used for expansionExchange capacity, i.e. C2≤Csum、C 10. After the capacity of the exchange station is expanded, 40 groups of batteries are added to each exchange station. At the moment, each exchange station has sufficient period, floating period and valley period, the number of the corresponding batteries can be adjusted to 80, 60 and 45. Because the pole tower is not reinforced, so the circuit loss probability is consistent with when not taking the lifting measure, and the loss circuit still is: 6, 7, 9, 20, 25, 26, 28, 37 and 44. The optimal repair sequence of the two teams is as follows: 6 → 7 → 9 → 44 → 20 → 25; 6 → 7 → 26 → 28 → 37.
And calculating the resilience index of the power grid by using a particle swarm algorithm according to the resilience evaluation model and in combination with the objective function and the constraint condition, as shown in table 7.
TABLE 7 recipe two resilience index
| Scheme two | Recovery of persistence | Rate of load recovery | Restoring force |
| Sufficient period | 0.729 | 0.765 | 0.747 |
| Floating period | 0.714 | 0.710 | 0.712 |
| Low ebb period | 0.677 | 0.683 | 0.680 |
And in the second scheme, the battery capacity of the exchange station is expanded, and the battery exchange station can provide more schedulable resources for the power grid after the extreme disaster occurs. As can be seen from table 7, both the load recovery rate index and the recovery persistence index are effectively improved, wherein the load recovery rate index is obviously improved. At the moment, the total investment cost of the power grid is 28.8 ten thousand yuan.
Third, the capacity of the reinforced pole tower and the expanded battery exchange station are combined
The total investment is divided into two parts, one part is used for reinforcing the tower, and the other part is used for expanding the capacity of the battery exchange station, namely C1+C2≤CsumAnd C1≠0、C2Not equal to 0. The method comprises the steps of continuously generating an investment scheme combining two measures through a particle swarm algorithm, calculating the number of reinforced pole towers and the number of battery exchange station capacity expansion sets under different investment schemes under the condition of meeting constraint conditions, determining the number of loss lines and loss areas of a reinforced power grid through a line loss analysis model and a roulette algorithm, repairing the loss lines according to a loss line repairing principle to obtain repairing time of the whole loss area, finally scheduling batteries according to the area importance degree to supply power to obtain the restoring force of the power grid under the investment scheme, and finally comparing the restoring force under various schemes to obtain a maximum restoring force improving scheme within a certain economic range and output the maximum restoring force corresponding to the power grid. In the calculation example, the optimal scheme is to reinforce the lines 1,2,3,4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 26, 27, 29, 30, 31 and 33, each substation is expanded by 18 groups of batteries, so that the number of the adjustable batteries in the sufficient period, the floating period and the valley period of each substation is respectively as follows: group 58, group 38 and group 23. The lost line is determined by the roulette algorithm to be: 6. 7, 20, 25, 26, 28, 37 and 44, the repair order of the two teams is: 6 → 7 → 26 → 44 → 20 → 25; 6 → 7 → 26 → 28 →37。
TABLE 8 recipe three resilience index
| Scheme three | Recovery of persistence | Rate of load recovery | Restoring force |
| Sufficient period | 0.734 | 0.765 | 0.750 |
| Floating period | 0.759 | 0.676 | 0.718 |
| Low ebb period | 0.750 | 0.626 | 0.688 |
In the third scheme, the practical application of the tower reinforcement and the battery exchange station expansion are comprehensively considered, and a lifting scheme combining two measures is adopted in a certain economic range, so that the maximum restoring force is favorably realized. Make the loss line reduce through consolidating the shaft tower, the loss area reduces, and then makes the repair time reduce, is favorable to improving the ability that the electric wire netting dealt with extreme natural disasters. And the capacity of the battery exchange station is expanded, so that more loads can be ensured to stably operate. As can be seen from table 8, both the load recovery rate index and the recovery continuation index are effectively improved. At the moment, the investment amounts of the capacities of the reinforced tower and the expanded battery exchange station are respectively 16.8 ten thousand yuan and 12.96 ten thousand yuan, and the total investment cost of the power grid is 29.76 ten thousand yuan.
According to the scheme I and the scheme II, the load recovery rate and the recovery continuity index can be effectively improved no matter the tower is reinforced or the capacity of the battery exchange station is expanded. The tower is reinforced, the loss probability of the tower is mainly influenced, the line loss is effectively reduced, the repairing time is shortened, and the influence on the recovery continuity index is large. The capacity of the battery exchange station is expanded mainly to rapidly provide standby resources for a power grid, and the residual battery pack and the diesel engine set of the battery exchange station maintain effective operation of load recovery together, so that the load recovery rate index is greatly influenced. And the third scheme combines the capacities of the reinforced tower and the expanded battery exchange station, so that the advantages of two lifting measures are fully exerted, the restoring force index is greatly improved compared with the first scheme and the second scheme, and the problems of excessive resources and excessive maintenance cost caused by the fact that the cost of the reinforced tower is too high alone and the capacity of the expanded battery exchange station is too high alone are solved.
Therefore, within a certain economic range, the restoring force of the power grid can be effectively improved by reasonably distributing the investment cost of two measures of reinforcing the tower and expanding the capacity of the battery exchange station, and the stable operation of restoring the load is realized while more loads are restored as far as possible after the disaster occurs in the power grid.
Example 2:
fig. 6 is a schematic diagram of a lifting device according to an embodiment of the present invention, for performing the method steps in the embodiment corresponding to fig. 1. As shown in fig. 6, in the present embodiment, the lifting device 6 includes:
a line loss analysis model establishing module 61, configured to establish a line loss analysis model;
a resilience evaluation model building module 62, configured to build a resilience evaluation model of the elastic power distribution network;
and the analysis module 63 is configured to construct a target function by using a restoring force improving method combining the capacities of the reinforced towers and the expanded battery exchange stations, and obtain an elastic power distribution network restoring force improving scheme according to the line loss analysis model and the elastic power distribution network restoring force evaluation model.
It will be clear to those skilled in the art that, for convenience and simplicity of description, the foregoing division of the functional units and modules is merely used as an example, and in practical applications, the above function distribution may be performed by different functional units and modules as needed, that is, the internal structure of the lifting device is divided into different functional units or modules to perform all or part of the above described functions. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the above-mentioned apparatus may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
Example 3:
fig. 7 is a schematic diagram of a terminal device according to an embodiment of the present invention. As shown in fig. 7, in the present embodiment, the terminal device 7 includes: a processor 70, a memory 71 and a computer program 72 stored in said memory 71 and executable on said processor 70. The processor 70, when executing the computer program 72, implements the steps in the embodiments as described in embodiment 1, such as steps S101 to S103 shown in fig. 1. Alternatively, the processor 70, when executing the computer program 72, implements the functionality of the modules/units in the lifting device embodiments described above, such as the functionality of the modules 61 to 63 shown in fig. 6.
Illustratively, the computer program 72 may be partitioned into one or more modules/units that are stored in the memory 71 and executed by the processor 70 to accomplish the present application. The one or more modules/units may be a series of computer program instruction segments capable of performing specific functions, which are used to describe the execution process of the computer program 72 in the terminal device 7. For example, the computer program 72 may be divided into a line loss analysis model building module, a resilience evaluation model building module, and an analysis module, and the specific functions of each module are as follows:
the circuit loss analysis model establishing module is used for establishing a circuit loss analysis model;
the restoring force evaluation model establishing module is used for establishing an elastic power distribution network restoring force evaluation model;
and the analysis module is used for constructing a target function by adopting a restoring force improving method combining the capacities of the reinforced towers and the expanded battery exchange stations according to restoring force and economic cost, and obtaining an elastic power distribution network restoring force improving scheme according to the line loss analysis model and the elastic power distribution network restoring force evaluation model.
The terminal device can be a mobile phone, a tablet computer and other computing devices. The terminal device may include, but is not limited to, a processor 70, a memory 71. It will be understood by those skilled in the art that fig. 7 is only an example of the terminal device 7, and does not constitute a limitation to the terminal device 7, and may include more or less components than those shown, or combine some components, or different components, for example, the terminal device 7 may further include an input-output device, a network access device, a bus, etc.
The Processor 70 may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The memory 71 may be an internal storage unit of the terminal device 7, such as a hard disk or a memory of the terminal device 7. The memory 71 may also be an external storage device of the terminal device 7, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), and the like, which are provided on the terminal device 7. Further, the memory 71 may also include both an internal storage unit and an external storage device of the terminal device 7. The memory 71 is used for storing the computer program 72 and other programs and data required by the terminal device 7. The memory 71 may also be used to temporarily store data that has been output or is to be output.
Example 4:
an embodiment of the present invention further provides a computer-readable storage medium, in which a computer program is stored, and the computer program, when executed by a processor, implements the steps in the embodiments described in embodiment 1, for example, step S101 to step S103 shown in fig. 1.
In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.
In the embodiments provided in the present application, it should be understood that the disclosed method, apparatus and terminal device for enhancing the resilience of an elastic distribution network may be implemented in other manners. For example, the above-described embodiments of the lifting device are merely illustrative, and for example, the division of the modules or units is only one logical division, and in actual implementation, there may be another division, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The integrated modules/units, if implemented in the form of software functional units and sold or used as separate products, may be stored in a computer readable storage medium. Based on such understanding, all or part of the flow in the method of the embodiments described above can be realized by a computer program, which can be stored in a computer-readable storage medium and can realize the steps of the embodiments of the methods described above when the computer program is executed by a processor. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, usb disk, removable hard disk, magnetic disk, optical disk, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), electrical carrier wave signals, telecommunications signals, software distribution medium, and the like. It should be noted that the computer readable medium may contain other components which may be suitably increased or decreased as required by legislation and patent practice in jurisdictions, for example, in some jurisdictions, computer readable media which may not include electrical carrier signals and telecommunications signals in accordance with legislation and patent practice.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.
Claims (9)
1. A method for improving restoring force of an elastic power distribution network is characterized by comprising the following steps:
establishing a line loss analysis model;
establishing an elastic power distribution network restoring force evaluation model;
a restoring force improving method combining the capacities of a reinforced tower and an expanded battery exchange station is adopted, a target function is constructed according to the restoring force and the economic cost, and an elastic power distribution network restoring force improving scheme is obtained according to the line loss analysis model and the elastic power distribution network restoring force evaluation model;
the establishing of the line loss analysis model comprises the following steps:
under the earthquake disaster, the earthquake dynamic acceleration is as follows:
lg(αPGA)＝a+bM-clg[R+dexp[eM]]+
wherein alpha isPGAThe seismic acceleration is seismic oscillation acceleration, M is seismic magnitude, R is distance, random quantity with variance sigma is obtained, and a, b, c, d and e are all preset constants;
each pole tower of each line of the elastic power distribution network is normally used in earthquakeThe earthquake damage levels respectively corresponding to the affected part, the component yield, the structure yield and the structure collapse are used as limit states, and the quantitative index is L1、L2、L3And L4And the conditional probability that each tower achieves damage at each level under different earthquake levels meets the following requirements:
P(Si|αPGA)＝P(Lmax>Li|αPGA)
wherein S isiIn a seismic damage level, LMAXSeismic acceleration alpha for each towerPGAMaximum horizontal displacement of the apex of time, Li(i is 1,2,3 and 4) is the tower top horizontal displacement limit value of each tower in different extreme states under each earthquake damage grade;
calculating the cumulative probability that each tower structure exceeds the limit state and reaches each earthquake damage level
ln(Lmax)＝kln(αPGA)+g
Wherein k and g are preset coefficients, and sigma is LmaxThe logarithmic condition standard deviation of (1), mu is the poisson coefficient; phi (-) is a standard normal distribution function;
the establishment of the elastic power distribution network resilience evaluation model comprises the following steps:
construction of load recovery index f for evaluating resilience of elastic power distribution networkrecAnd a recovery sustainability comprehensive index fsus；
The constructed load recovery index frecComprises the following steps:
wherein N isrecTo restore the number of load nodes, NlossThe total number of load nodes lost for the disaster; omegarec,iAnd ωloss,jAs node load weight, Prec,iIndicating the existence of a recovery node iWork power, Ploss,jLoss of active power at load node j;
the construction recovery persistence index fsusComprises the following steps:
wherein B is the total set of lost areas,
the runtime after recovery for the region b,
restoring normal operation time for the area b after line repair;
the method includes the steps of constructing a target function by using restoring force and economic cost, and obtaining an elastic power distribution network restoring force promotion scheme according to the line loss analysis model and the elastic power distribution network restoring force assessment model, and includes the following steps:
the maximum restoring force in a preset investment total range is an objective function, node voltage constraint, node power balance, line tide, restoring load constraint and battery discharge are used as constraint conditions, a multi-objective problem is solved according to the line loss analysis model and the elastic power distribution network restoring force evaluation model and by combining the objective function and the constraint conditions, and an elastic power distribution network restoring force improvement scheme is obtained;
the objective function is:
wherein, C1Cost incurred for reinforcing the tower, C2Cost of expanding battery exchange station capacity, CsumTo preset the total investment, k1For constructing a load recovery index frecWeight coefficient with respect to restoring force, k2To construct a recovery persistence index fsusWeight coefficient with respect to restoring force, fsumThe index is the resilience index of the elastic power distribution network;
the constraint conditions are as follows:
wherein, Ui,minIs the minimum value of the i-node voltage, Ui,maxIs the maximum value of the i-node voltage, Pinp,iInputting active power, Q, to the nodeinp,iFor input of reactive power, P, to the nodeload,iAnd Qload,iFor node load consumption, Pline,jFor line active power, Qline,jFor line reactive power, Pline,i,maxFor maximum power allowed by the line, Qline,i,maxMinimum power allowed for the line; λ is 0 or 1, and λ is equal to 0 when the line is open; omega is the number of lines connected to node i, Prec,iTo restore node active power, Ploss,jFor active power of the power-loss node, NlossFor the load set in the entire loss region, NrecFor restoring a load set, SOC, throughout a loss regioniDischarge capacity of the ith cell at time T, TBatIs the discharge time of the battery, omegaBatFor the number of remaining schedulable batteries, M is the total number of exchange batteries, CsumIs a preset total investment.
2. The method for improving restoring force of an elastic power distribution network according to claim 1, wherein the cost C generated by the reinforcing tower is1Comprises the following steps:
C1＝n(cφ1Vφ1+cφ2Lφ2)
wherein n is the number of the reinforced towers, cφ1Cost factor for consolidating the foundation, cφ2Cost factor V for tower material reinforcementφ1For consolidating the volume of the foundation, Lφ2The length of the tower column base is increased;
cost C generated by expanding capacity of battery exchange station2Comprises the following steps:
C2＝mC0
wherein m is the capacity expansion amount of the battery exchange station, C0For the cost of a single battery pack.
3. The method for improving restoring force of an elastic power distribution network according to claim 1, wherein the objective function and the constraint condition are combined to solve a multi-objective problem, specifically:
1) inputting the iteration times, the number of groups which can be called by a battery of the exchange station, the total investment, the particle position and the particle speed into a particle swarm optimization algorithm model;
2) initializing an original population, and determining a restoring force index of a current maximum restoring force improvement scheme;
3) according to constraints C in the objective function1+C2≤CsumDetermining a group of tower reinforcement number n and a battery exchange station capacity expansion number m;
4) determining a loss line set and a loss area set according to the currently determined tower reinforcement number n and the battery exchange station capacity expansion number m through a line loss analysis model, repairing the power grid according to a loss line repairing principle and an exchange station battery scheduling principle, and obtaining a current elastic power distribution network restoring force index fsum；
5) The current elastic power distribution network restoring force index fsumComparing with the restoring force index of the current maximum restoring force promotion scheme, if the current elastic power distribution network restoring force index fsumGreater than the restoring force index of the current maximum restoring force promotion scheme, then the restoring force index f of the current elastic power distribution networksumUpdating the restoring force index of the current maximum restoring force promotion scheme and the restoring force index f of the current elastic power distribution networksumThe corresponding scheme is a maximum restoring force improving scheme;
6) judging whether the preset iteration times are met, if not, repeating the steps 3) to 6), and if so, turning to the step 7);
7) and outputting the maximum restoring force promoting scheme and the corresponding maximum restoring force of the power grid.
4. The method for improving restoring force of an elastic power distribution network according to claim 3, wherein the determining a set of loss lines and a set of loss regions through a line loss analysis model comprises:
determining the loss probability of each tower of each line of the elastic power distribution network according to the line loss analysis model;
adopting a roulette algorithm to determine whether the line corresponding to each tower is damaged or not according to the loss probability of each tower;
and determining a lost line set and a lost area set according to whether the line is damaged.
5. The method for improving resilience of an elastic power distribution network according to claim 3, wherein the exchange station battery scheduling principle is as follows: scheduling the battery according to the region importance degree;
the region importance degree is as follows:
wherein, ω isiTo the extent of importance of region i, NiIs the number of loads in region i, wi,jIs the weight, P, of the load j in the region ii,jIs the active power of load j in zone i;
the principle of repairing the lost line is as follows: repairing the tower according to the weight of the lost line;
the lost line weight is:
therein, ζyTo lose weight of line y, ByThe set of areas affected by the loss line y, and B is the entire loss area.
6. The method for improving the restoring force of the elastic power distribution network according to any one of claims 1 to 5, wherein the method for reinforcing the tower is to reinforce the tower according to the importance degree of the line, namely the weight of the line;
the weight of each line in the elastic power distribution network is as follows:
wherein, wiIs the load level weight of the ith node, LiIs the load capacity of the ith node; n is a radical ofxiSet of loads influenced by the xi line, wjIs the load level weight of the jth node; l isjIs the load of the jth node, NtotalIs the load aggregate of the whole line.
7. An elastic distribution network restoring force enhancing device, comprising:
the circuit loss analysis model establishing module is used for establishing a circuit loss analysis model;
the restoring force evaluation model establishing module is used for establishing an elastic power distribution network restoring force evaluation model;
the analysis module is used for constructing a target function by restoring force and economic cost by adopting a restoring force improving method combining the capacities of the reinforced towers and the expanded battery exchange stations, and obtaining an elastic power distribution network restoring force improving scheme according to the line loss analysis model and the elastic power distribution network restoring force evaluation model;
the line loss analysis model building module is specifically configured to:
under the earthquake disaster, the earthquake dynamic acceleration is as follows:
lg(αPGA)＝a+bM-clg[R+dexp[eM]]+
wherein alpha isPGAThe seismic acceleration is seismic oscillation acceleration, M is seismic magnitude, R is distance, random quantity with variance sigma is obtained, and a, b, c, d and e are all preset constants;
the normal use of each tower of each line of the elastic power distribution network is influenced in earthquake, and the members are bentThe earthquake damage levels respectively corresponding to the yield of the clothes, the structure and the collapse of the structure are taken as limit states, and the quantitative indexes are L1、L2、L3And L4And the conditional probability that each tower achieves damage at each level under different earthquake levels meets the following requirements:
P(Si|αPGA)＝P(Lmax>Li|αPGA)
wherein S isiIn a seismic damage level, LMAXSeismic acceleration alpha for each towerPGAMaximum horizontal displacement of the apex of time, Li(i is 1,2,3 and 4) is the tower top horizontal displacement limit value of each tower in different extreme states under each earthquake damage grade;
calculating the cumulative probability that each tower structure exceeds the limit state and reaches each earthquake damage level
ln(Lmax)＝kln(αPGA)+g
Wherein k and g are preset coefficients, and sigma is LmaxThe logarithmic condition standard deviation of (1), mu is the poisson coefficient; phi (-) is a standard normal distribution function;
the restoring force evaluation model establishing module is specifically configured to:
construction of load recovery index f for evaluating resilience of elastic power distribution networkrecAnd a recovery sustainability comprehensive index fsus；
The constructed load recovery index frecComprises the following steps:
wherein N isrecTo restore the number of load nodes, NlossThe total number of load nodes lost for the disaster; omegarec,iAnd ωloss,jAs node load weight, Prec,iRepresenting the active power of the recovery node i, Ploss,jLoss of active power at load node j;
the construction recovery persistence index fsusComprises the following steps:
wherein B is the total set of lost areas,
the runtime after recovery for the region b,
restoring normal operation time for the area b after line repair;
the analysis module is specifically configured to:
the maximum restoring force in a preset investment total range is an objective function, node voltage constraint, node power balance, line tide, restoring load constraint and battery discharge are used as constraint conditions, a multi-objective problem is solved according to the line loss analysis model and the elastic power distribution network restoring force evaluation model and by combining the objective function and the constraint conditions, and an elastic power distribution network restoring force improvement scheme is obtained;
the objective function is:
wherein, C1Cost incurred for reinforcing the tower, C2Cost of expanding battery exchange station capacity, CsumTo preset the total investment, k1For constructing a load recovery index frecWeight coefficient with respect to restoring force, k2To construct a recovery persistence index fsusWeight coefficient with respect to restoring force, fsumThe index is the resilience index of the elastic power distribution network;
the constraint conditions are as follows:
wherein, Ui,minIs the minimum value of the i-node voltage, Ui,maxIs the maximum value of the i-node voltage, Pinp,iInputting active power, Q, to the nodeinp,iFor input of reactive power, P, to the nodeload,iAnd Qload,iFor node load consumption, Pline,jFor line active power, Qline,jFor line reactive power, Pline,i,maxFor maximum power allowed by the line, Qline,i,maxMinimum power allowed for the line; λ is 0 or 1, and λ is equal to 0 when the line is open; omega is the number of lines connected to node i, Prec,iTo restore node active power, Ploss,jFor active power of the power-loss node, NlossFor the load set in the entire loss region, NrecFor restoring a load set, SOC, throughout a loss regioniDischarge capacity of the ith cell at time T, TBatIs the discharge time of the battery, omegaBatFor the number of remaining schedulable batteries, M is the total number of exchange batteries, CsumIs a preset total investment.
8. A terminal device, comprising a memory, a processor and a computer program stored in the memory and operable on the processor, wherein the processor executes the computer program to implement the steps of the method for improving the resilience of an elastic power distribution network according to any one of claims 1 to 6.
9. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, which when executed by a processor implements the steps of the method for improving the restoring force of an elastic distribution network according to any one of claims 1 to 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910300366.3A CN109921420B (en) | 2019-04-15 | 2019-04-15 | Elastic power distribution network restoring force improving method and device and terminal equipment |
Applications Claiming Priority (1)
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