CN104881708A - Method for reconstructing power distribution network based on topology correction - Google Patents
Method for reconstructing power distribution network based on topology correction Download PDFInfo
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Abstract
The invention discloses a method for reconstructing a power distribution network based on topology correction, and belongs to the field of power system automation. The method is characterized by comprising the following steps: introducing basic parameters of the power distribution network to form a network topological structure chart; performing ringing based on a current correct network state by adopting a network ringing method; performing real-number encoding of ringing; editing real-number encoding of all ring segments into a chromosome in sequence; correcting the unqualified chromosome; and obtaining an optimum scheme and outputting parameters, such as transmission loss and on-off frequency of the network. The method has advantages that information, such as a power distribution network framework and a power load is subjected to comprehensive analysis; network optimization is realized; network loss is reduced; power supply capacity is improved; and dynamic control of the power distribution network is achieved.
Description
Technical field
Technical field of the present invention is distribution system automation field, be specially the reconstruction method of power distribution network based on topology correction, particularly a kind ofly can realize the network optimization, comprehensive analyze the information such as Distribution Network Frame structure and power load and according to the result of network reconfiguration on-line analysis, adopt the mode of automatic or manual intervention to realize closed-loop control, realize the reconstruction method of power distribution network of the functions such as the dynamic regulation of power distribution network.
Background technology
The research of power distribution network reconfiguration is risen in the eighties of last century later stage eighties, because it to receive the concern of many scholars reducing network loss and the vital role improved in security of system etc.Early stage For Distribution Networks Reconfiguration mainly studies the reconstruction of distribution planning stage.Power distribution network when normal operation radially, because reticulate texture determines that tree structure is not unique, make power distribution network determine that the tree-shaped method of operation is not unique by reticulate texture, switch folding condition can form multiple combination, and any combination all forms a kind of method of operation.Although interconnection switch disconnects when normal operation, with the tree-shaped running status of the Radiation maintaining system, its existence makes the webbed structure of system.The essence of power distribution network reconfiguration is exactly meeting under certain constraint condition, by changing network breaker in middle state, optimize the network structure of power distribution network, thus improve the trend distribution of distribution system, ideally reach optimal load flow distribution, make distribution system loss minimization or other indexs optimum.
Network Reconfiguration Algorithm is an optimized algorithm in essence, is the planning problem of a discrete variable.Wherein, eliminate branch road overload and voltage out-of-limit, balanced feeder line load, is constraint condition, and makes loss minimization be objective function.In this algorithm, by genetic algorithm, realize automatic optimal.Our company, in genetic algorithm, had realized the polyalgorithm such as power distribution network Optimal reactive power, power distribution network Optimizing Reconstruction, and this respect accumulation is many.Genetic algorithm can find an optimization solution in engineering, and comparatively speaking, computing velocity is not very fast.On the path selecting reconstruct, need, to each supply path, to carry out the check of switch rupturing capacity, by calculation of short-circuit current, carry out detailed calculating and check, the correctness in the path after guaranteeing to reconstruct, after can not there is reconstruct, cause the unsafe situation of system.
Existing algorithm is objective function mainly with loss minimization greatly, and meeting under various service condition, is that the power distribution network reconfiguration of objective function is still a non-linear hybrid optimization problem with loss minimization.Due to the nonlinear characteristic of power distribution network reconfiguration, the iteration be optimized each time all needs to carry out primary distribution Load flow calculation, and continuous print distribution power system load flow calculation needs a large amount of computing times.In order to improve computing velocity, ensure the Distributing network structure drawing global optimum or suboptimum, restructing algorithm main at present has as follows: branch exchange method (Branch Exchange Method, BEM), optimal flow pattern (Optimal Flow Pattern, OFP), expert system approach (Expert System, ES), artificial neural network method (Artificial Neural Networks, ANN), simulated annealing (Simulated Annealing, SA), genetic algorithm (Genetic Algorithm, GA), tabu search algorithm (Tabu Search, TS) etc.Application number is that 201210150190.9 invention disclosed names are called " the random neighborhood searching algorithm of power distribution network reconfiguration ", provides a kind of excellent counting yield can stablize the reconstruction method of power distribution network based on branch exchange obtaining optimum solution of having; Application number is that 201410395124.4 invention disclosed names are called " a kind of heuristic reconstruction method of power distribution network based on minimum spanning tree ", provides a kind of minimal spanning tree algorithm and heuritic approach being combined and solves the method for For Distribution Networks Reconfiguration problem; But due to the switch combination enormous amount as optimized variable, exhaustive search will face " shot array " problem.And solution space is too huge, makes the calculated amount when direct Mathematical very large, when thus will take a large amount of machines, and the reliability of convergence cannot be ensured.
Summary of the invention
The supply path caused on reconstruction for prior art is inaccurate, assess the cost the problem such as larger, the present invention proposes a kind of meet the prerequisite of security constraint under, the method of operation of distribution line is changed by methods such as switching manipulations, eliminate branch road overload and voltage out-of-limit, balanced feeder line load, makes the network reconstruction method of loss minimization.
The technical scheme realizing above-mentioned purpose is:
A kind of reconstruction method of power distribution network, comprises the following steps:
Step S1, imports power distribution network basic parameter, forms network topology structure figure;
Step S2, extracts the information about node in network topology structure;
Whether whether step S3, be active network according to network, be whether the network topology structure that Radial network judges to be formed in S1 is correct, if incorrect, return step S1, regenerate new network topology structure figure; If correct, enter step S4;
Step S4, adopts network to divide and around-Francely carries out a point ring based on current network state, obtain network topology and divide ring;
Described network divides around-France step as follows:
A) node, membership information is read;
B) respectively from power supply point and frontier node, the branch road not participating in coding is got rid of;
C) remove after some do not participate in the branch road of coding, according to Fig. 2, carry out a point ring operation;
D) according to current operating conditions, topological diagram is divided into some " ring " road.Ensure that each loop has and only has a switch to open, so both ensure that the radial pattern of network, in turn ensure that loads all in network can not power-off.
Step S5, carries out real coding to point ring in S4, ensures that each loop only has a switch to be in open mode, so each real number only correspond to the state that a particular switch is opened;
The step of described real coding is as follows:
A) the switch number had according to loop carries out real coding.As a loop has N number of switch, then can with 0-(N-1) represent first to N number of switch be disconnect, rest switch is closed;
B) call genetic algorithm, intersect between ring with ring, generate a new generation, the coding that often generation one is new once calculates, and according to fitness function, obtains the chromosome that fitness is high.Circulation like this, until meet objective function or arrive the evolutionary generation set;
C) scheme obtained is best network reconfiguration scheme.
Step S6, for step S5, compiles a chromosome by the real coding of all ring sections according to sequencing;
Step S7, calls genetic algorithm program, intersects to the chromosome in population, makes a variation, and revise there will be some underproof chromosomes in genetic algorithmic procedures, concrete steps are as follows:
A) the power S of the required band of all power supplys is judged
sourcewhether can meet the desired power S of load
load, and certain nargin will be retained.Get 0.9S
source>=S
load.S in this algorithm
sourceand S
loadaccording to electric current S
loadmode to provide.Its conversion formula is:
In formula: U is voltage, and perunit value computing is taken as 1;
S
loadfor applied power, S
load=P
load+ jQ
load;
B) when the conditions are satisfied, flow process shown in Fig. 3 is adopted to carry out chromosomal correction.
Step S8, draws preferred plan, and the parameter such as network loss size, on-off times in output network, reconstruct terminates.
The beneficial effect of patent of the present invention is:
1, there is the function being reconstructed power distribution network network in conjunction with distribution power system load flow calculation analysis result, realizing the network optimization, improve power supply capacity;
2, there is comprehensive information such as analysis Distribution Network Frame structure and power load etc., and by changing the related measures such as the distribution method of operation, reach the function of the object reducing network loss;
3, there is the result according to network reconfiguration on-line analysis, adopt the mode of automatic or manual intervention to realize closed-loop control, realize the function of the dynamic regulation of power distribution network.
Accompanying drawing illustrates:
Fig. 1: the main flow figure of reconstruction method of power distribution network of the present invention
Fig. 2: network divides the main flow figure of ring algorithm
Fig. 3: the main flow figure of Real Coding Genetic Algorithm
Fig. 4: the main flow figure of chromosome correction algorithm
Embodiment
Below in conjunction with drawings and Examples, the present invention will be further described
Consult Fig. 1, the method for this power distribution network reconfiguration comprises:
Step S1, import power distribution network basic parameter and (comprise each node in power distribution network, branch road, switch and power information), form network topology structure figure, that is: each element in power distribution network and circuit are numbered, generate database, two tables are comprised in database, be respectively NODE (node) and BRANCH (branch road), the parameter that wherein table NODE comprises has: the numbering of each node, title, type, voltage modulus value, voltage phase angle, maximum current limit value, load active power and load reactive power, the content that table BRANCH comprises is depending on provided branch road form, if the branch road form provided is the form that impedance adds switch, the parameter comprised in table BRANCH has: initial branch road, stop branch road, branch number, branch road title, resistance value, reactance value, electric conductivity value, susceptance value, maximum current-carrying value and folding condition, if the branch road provided is impedance branch separate with switching branches the form given, in table BRANCH except comprising above-mentioned parameter, also need to increase another parameter: branch road property value,
The initial value of described folding condition is 0 or 1, and 0 represents disconnection, and 1 represents closed; The initial value of described branch road attribute is 1 or 2, and 1 represents switching branches, and 2 represent impedance branch;
Step S2, extracts the parameter information about node in network topology structure, all parameters namely comprised in described table NODE: node serial number, title, type, voltage modulus value, voltage phase angle, maximum current limit value, load active power and load reactive power;
Step S3, whether judge whether network is correct network, and network basis for estimation is: whether be active network, be Radial network;
Step S4, adopts network to divide and around-Francely carries out a point ring based on current network state, obtain network topology and divide ring; Described network divides around-France concrete steps to can refer to Fig. 2:
The first step, reads the parameter information about node in network topology data;
Second step, according to node property by node-classification, is mainly divided into: power supply point, ordinary node, T node and frontier node;
3rd step, searches for the father node of this node from frontier node along branch road;
4th step, judges whether the father node in the 3rd step is T node, if not, then return previous step; If so, the 5th step is then carried out;
5th step, deletes all branch roads of frontier node to this T node;
6th step, judges whether contain frontier node in deleted branch road, if having, then returns the 3rd step; If no, then carry out the 7th step;
7th step, judges whether network is single supply network, if so, then carries out the 8th step; If not, then from power supply point, along circuit search next node, directly enter the tenth step;
8th step, from power supply point, along circuit search next node;
9th step, judges whether described next node is T node, if not, then continue the next node of this node of search; If so, the tenth step is then carried out;
Tenth step, deletes all branch roads of power supply point to this node, using this node as new power supply point;
11 step, travels through from power supply point;
12 step, judges whether the branch switch be connected with power supply point is off, and if so, then enters next step after this power supply point of first search; If not, then directly enter next step;
13 step, along branch road search next node;
14 step, judges whether the node in previous step is T node, if so, then carries out next step; If not, then return execution previous step;
15 step, using the node in previous step as new power supply point;
16 step, searches the power supply point except the power supply point just formed,
17 step, if the path distance that two Node Switch states are out is 10000, two Node Switch states be closed path distance is 1;
18 step, judges that the distance of institute's pathway is whether between 10001 to 19999, if not, then change loop undesirable, return execution the 11 step; If so, then next step is carried out;
19 step, gets the loop that distance is the shortest, records and preserve this loop, and being deleted from network topology by this loop;
20 step, judges whether contain branch road in the network of previous step, if having, then returns execution the 11 step, if do not have, then divide loops bundle.
Step S5, carries out real coding to point ring in step S4, ensures that each loop only has a switch to be in open mode, so each real number only correspond to the state that a particular switch is opened;
The concrete steps of described real coding can refer to Fig. 3:
The first step, the loop dividing ring link to obtain on network in step S4 is a unit with each loop, arranges sequentially, and arrangement cannot be changed after determining;
Second step, sorts each switching branches in order, and sequence cannot be changed after determining;
3rd step, calculates the number of switches N of each unit, represents K switch opens with K (K is between 1 ~ N), and all the other (N-1) individual switches close;
4th step, carries out real coding by each unit according to the order sequenced, and obtains shape as K1, K2, K3 ... the coding of Kn;
5th step, forms a population (concrete number definable) by being randomly formed some not identical real codings;
6th step, calls genetic algorithm program, intersects, makes a variation, revises, obtain new population to the dyeing topic in population;
7th step, decodes to the every item chromosome in the new chromosome complex obtained;
8th step, after having decoded, adds that the power supply that network divides loop order section to remove and tip branch road obtain a network operation state topology figure;
9th step, judges whether the network that previous step is formed is single supply network, if not, then search for from power supply point, a point island is carried out to network, more respectively Load flow calculation is carried out to each island; If so, directly next step is performed;
Tenth step, carries out Load flow calculation to this network topology;
11 step, obtains the data such as each branch current, node voltage, network impairment;
12 step, judges that whether each branch current in network, voltage is qualified, if defective, revises the electric current in network, voltage, until qualified, then perform next step; If qualified, directly carry out next step;
13 step, obtains the network structure of a loss minimization;
14 step, judges whether the network structure of previous step reaches evolution function, if not, then returns execution the 6th step; If so, then heredity terminates, and obtains preferred plan.
Step S6, for step S5, compiles a chromosome by the real coding of all ring sections according to sequencing;
Step S7, calls genetic algorithm program, intersects to the chromosome in population, makes a variation, and revise there will be some underproof chromosomes in genetic algorithmic procedures, concrete operations are:
A) the power S of the required band of all power supplys is judged
sourcewhether can meet the desired power S of load
load, and certain nargin will be retained.Get 0.9S
source>=S
load.S in this algorithm
sourceand S
loadaccording to electric current S
loadmode to provide.Its conversion formula is:
In formula: U is voltage, and perunit value computing is taken as 1;
S
loadfor applied power, S
load=P
load+ jQ
load;
B) when the conditions are satisfied, chromosomal correction is carried out.
The step of described chromosome correction can specifically with reference to Fig. 4:
The first step, extracts child chromosome;
Second step, judges that whether chromosome is qualified, if qualified, then does not need to revise; If defective, then perform next step;
3rd step, extracts underproof chromosomal all loops;
4th step, extracts the numerical value of initial switch state;
5th step, adjusts to from the Arbitrary Digit within original state 2 by the switch value of the chromosomal loop of required correction;
6th step, correction completes.
Step S8, draws preferred plan, and the parameter such as network loss size, on-off times in output network, reconstruct terminates.
Claims (8)
1. based on the reconstruction method of power distribution network of topology correction, it is characterized in that, comprise the steps:
The first step, imports power distribution network basic parameter, forms network topology structure figure;
Second step, extracts the information about node in network topology structure;
3rd step, judges that whether the network topology structure formed is correct;
4th step, adopts network to divide and around-Francely carries out a point ring based on current network state, obtain network topology and divide ring;
5th step, carries out real coding to a point ring for previous step;
6th step, compiles a chromosome by the real coding of all ring sections according to sequencing;
7th step, calls genetic algorithm program, is just carrying out there will be some underproof chromosomes in genetic algorithmic procedures;
8th step, draws preferred plan, the parameter such as network loss size, on-off times in output network.
2., as claimed in claim 1 based on the reconstruction method of power distribution network of topology correction, described power distribution network basic parameter comprises: each node, branch road, switch and power information in power distribution network.
3. as claimed in claim 1 based on the reconstruction method of power distribution network of topology correction, described formation network topology structure figure, that is: be numbered each element in power distribution network and circuit, generates database.
4. as claimed in claim 3 based on the reconstruction method of power distribution network of topology correction, described database comprises two tables, is respectively: table NODE (node) and table RANCH (branch road).
5., as claimed in claim 1 based on the reconstruction method of power distribution network of topology correction, whether the described network topology structure judging to be formed is correct, and whether whether basis for estimation is: be active network, be Radial network.
6., as claimed in claim 1 based on the reconstruction method of power distribution network of topology correction, described network divides and is around-Francely specifically refined as following sub-step:
(1) node, membership information is read;
(2) respectively from power supply point and frontier node, the branch road not participating in coding is got rid of;
(3) remove after some do not participate in the branch road of coding, according to Fig. 2, carry out a point ring operation;
(4) according to current operating conditions, topological diagram is divided into some " ring " road.
7., as claimed in claim 1 based on the reconstruction method of power distribution network of topology correction, described 5th step is refined as following sub-step:
(1) the switch number composition graphs 3 had according to loop carries out real coding;
(2) genetic algorithm is called, intersect between ring with ring, generate a new generation, the coding that often generation one is new once calculates, draft a fitness function, according to fitness function, obtain the chromosome that fitness is high, circulation like this, until meet objective function or arrive the evolutionary generation set.
8., as claimed in claim 1 based on the reconstruction method of power distribution network of topology correction, describedly carry out correction be refined as following sub-step to there will be some underproof chromosomes in genetic algorithmic procedures:
(1) the power S of the required band of all power supplys is judged
sourcewhether can meet the desired power S of load
load, and certain nargin will be retained.Get 0.9S
source>=S
load, S in this algorithm
sourceand S
loadaccording to electric current S
loadmode to provide.Its conversion formula is:
In formula: U is voltage, and perunit value computing is taken as 1;
S
loadfor applied power, S
load=P
load+ jQ
load;
(2) flow process shown in Fig. 4 when the conditions are satisfied, is adopted to carry out chromosomal correction.
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| CN106684875A (en) * | 2016-12-13 | 2017-05-17 | 国网北京市电力公司 | Network group, method for dividing distribution network areas, distribution network and analysis method thereof |
| CN109409583A (en) * | 2018-10-08 | 2019-03-01 | 吉林大学 | Low voltage power distribution network decreasing loss reconstructing method |
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| CN111083577A (en) * | 2019-10-18 | 2020-04-28 | 国网浙江省电力有限公司嘉兴供电公司 | Power communication topological structure optimization method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105553084A (en) * | 2016-03-04 | 2016-05-04 | 云南电网有限责任公司电力科学研究院 | Implementation method for automatic switching device of emergency power supply |
| CN105553084B (en) * | 2016-03-04 | 2019-03-29 | 云南电网有限责任公司电力科学研究院 | A kind of implementation method of automatic switching device of standby power supply |
| CN106684875A (en) * | 2016-12-13 | 2017-05-17 | 国网北京市电力公司 | Network group, method for dividing distribution network areas, distribution network and analysis method thereof |
| CN106684875B (en) * | 2016-12-13 | 2019-06-07 | 国网北京市电力公司 | Group of networks, method, power distribution network and its analysis method for dividing distribution web area |
| CN109409583A (en) * | 2018-10-08 | 2019-03-01 | 吉林大学 | Low voltage power distribution network decreasing loss reconstructing method |
| CN110348048A (en) * | 2019-05-31 | 2019-10-18 | 国网河南省电力公司郑州供电公司 | Based on the power distribution network optimal reconfiguration method for considering tropical island effect load prediction |
| CN110348048B (en) * | 2019-05-31 | 2022-09-30 | 国网河南省电力公司郑州供电公司 | Power distribution network optimization reconstruction method based on consideration of heat island effect load prediction |
| CN111083577A (en) * | 2019-10-18 | 2020-04-28 | 国网浙江省电力有限公司嘉兴供电公司 | Power communication topological structure optimization method |
| CN111179401A (en) * | 2019-12-31 | 2020-05-19 | 北京真景科技有限公司 | Topological grouping method based on 3D curved surface data |
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Application publication date: 20150902 |