CN117808362A - Cluster characteristic evaluation index system construction method considering source load characteristics - Google Patents

Cluster characteristic evaluation index system construction method considering source load characteristics Download PDF

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CN117808362A
CN117808362A CN202311855066.4A CN202311855066A CN117808362A CN 117808362 A CN117808362 A CN 117808362A CN 202311855066 A CN202311855066 A CN 202311855066A CN 117808362 A CN117808362 A CN 117808362A
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balance area
load
index
power
balance
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马原
马鑫晟
徐广达
刘佳林
陈璨
易姝娴
胡长斌
罗珊娜
朴政国
王泽众
龙飞
宗瑾
张鹏
贾奇
董勃绪
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State Grid Corp of China SGCC
North China University of Technology
State Grid Jibei Electric Power Co Ltd
Electric Power Research Institute of State Grid Jibei Electric Power Co Ltd
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State Grid Corp of China SGCC
North China University of Technology
State Grid Jibei Electric Power Co Ltd
Electric Power Research Institute of State Grid Jibei Electric Power Co Ltd
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Abstract

The invention provides a cluster characteristic evaluation index system construction method considering source load characteristics, and relates to the technical field of power distribution networks. The construction method of the evaluation index system comprises the following steps: step 1, modeling flexible energy acceptance assessment indexes of a balance area of a power distribution network; step 2, modeling a load capacity evaluation index of a balance area of the power distribution network; step 3, modeling a cluster characteristic evaluation index of a balance area of the power distribution network; step 4, modeling operation indexes of a power grid in a balance area of the power distribution network; step 5, modeling reliability and safety indexes of a balance area of the power distribution network; step 6, modeling power grid efficiency and benefit indexes of a power distribution network balance area; and 7, designing a power distribution network balance area index weight calculation method. The invention can accurately analyze and evaluate the cluster characteristics of flexible energy and load of a certain area, provides powerful data support for regional cluster division, lays a cushion for new energy consumption and coordination scheduling of new energy in a balance area of the power distribution network, and greatly improves the control flexibility in the balance area.

Description

Cluster characteristic evaluation index system construction method considering source load characteristics
Technical Field
The invention relates to the technical field of power distribution networks, in particular to a cluster characteristic evaluation index system construction method considering source-load characteristics.
Background
With the proposal of the dual-carbon target, the distributed energy source is rapidly developed, and the high-proportion source-load adjustable resource is connected to the power distribution network, so that the flexibility of the power distribution network and the utilization rate of the distributed resource are both improved, and meanwhile, the electricity cost is also reduced. The access of more and more flexible source load resources is a development assistance for building a modern intelligent power distribution network. The development of the distributed clean energy further promotes the construction and development of a new energy consumption system, and the intelligent regulation and control operation of the power distribution network is an important foundation for the construction of an intelligent power grid in the future. Under the background of modern high-quality intelligent power distribution network construction, a power distribution network taking the characteristics of source load into consideration is converted into an active power distribution network balance area from a passive unidirectional step-by-step power distribution network, so that the power distribution network balance area can complete efficient coordinated utilization of comprehensive energy, and becomes a resource allocation optimization platform. And various flexible resources are aggregated in the balance area, so that the regional collaborative operation is realized, and the consumption experience of a user and the safety performance of power supply are ensured.
The flexible resources are largely connected into the power distribution network to affect the structure, operation control and economic dispatching of the whole power system to different degrees, the coordination control of the balance area of the power distribution network taking the source load into consideration comprises three aspects of power supply, power grid and load, the design range is wide, the correlation is poor, the index in the comprehensive evaluation index system aiming at the traditional power grid is relatively single, and the method is not suitable for evaluating the balance area of the power distribution network taking the source load into consideration. Therefore, the research of the cluster characteristic evaluation index system of the balance area of the power distribution network taking the source load characteristics into consideration is a solid foundation for the construction of the smart power grid, and has important theoretical significance and engineering value for the construction of the balance area of the power distribution network. The establishment of the distribution network balance area cluster characteristic evaluation index system is based on the related construction and regulation system of the distribution network balance area, and the distribution network balance area cluster index system is established in combination with the planning, actual operation and scheduling of the distribution network balance area clusters, so that the problems of the distribution network balance area in operation are found out from the aspects of distributed energy acceptance capacity, load capacity, power grid operation state, safety economy and the like, and good operation management decision and planning of the distribution network are supported. The common methods for evaluating the power distribution network include a hierarchical analysis method, an entropy weight method, a gray correlation analysis method, a TOPSIS evaluation method and the like.
The conventional power distribution network evaluation index system mainly aims at the problems that the traditional power distribution network cannot accurately evaluate and control the situation of accessing flexible resources such as multi-source load and the like, and the power distribution network is affected by instability and load uncertainty of a distributed power supply due to a large amount of access of the flexible resources, so that the power distribution network has poor operation control capability, low safety and reliability, low efficiency and benefit of coordinated scheduling and the like. And most students consider and analyze limiting factors affecting the distributed power consumption capacity of the power distribution network from the whole power distribution network system and are in a passive power distribution network state. There are few studies of evaluation index systems from the viewpoint of active distribution network balance area cluster characteristics. Therefore, the cluster characteristics of the balance area of the power distribution network are required to be considered, the balance capacity of the balance area of the power distribution network is mined, and an active power distribution network balance area cluster characteristic evaluation index system considering the source load characteristics is established.
Disclosure of Invention
Aiming at the defects of the prior art, the invention considers the influence factors and mechanism analysis of the instability of the distributed photovoltaic output and the uncertainty of the load on the cluster characteristics of the balance area of the power distribution network from the perspective of the cluster of the balance area of the power distribution network, excavates the characteristic index representing the balance capacity of the balance area, establishes an evaluation index system of the cluster characteristics of the balance area of the power distribution network, and improves the sensing and scheduling capacity of the balance area of the power distribution network.
According to analysis of the distribution network balance area cluster characteristic evaluation index system, a process for establishing the distribution network balance area cluster characteristic evaluation index system can be specifically summarized, firstly, an evaluation range of a distribution network balance area is determined, influence factors and mechanism analysis of uncertainty of distributed photovoltaic output and load on the distribution network balance area are considered, characteristic indexes for representing balance capacity of the balance area are mined, and secondly, index content of the cluster characteristic evaluation index system is determined, wherein indexes of the distribution network balance area mainly comprise: distributed energy acceptance, load capacity, cluster characteristics, grid operating status, reliability and safety, and grid efficiency and benefit. Further, comprehensively considering the safety reliability, economy and coordination of power grid construction, combining a clustering analysis idea, establishing a comprehensive evaluation index system from four dimensions of safety reliability, efficiency and benefit, equipment level and operation control of a power distribution network balance area, finally, formulating corresponding scoring standards according to the difference of indexes by actual characteristics of the indexes, obtaining a comprehensive scoring function of each index by utilizing a data fitting tool, and solving the comprehensive weight of the indexes by combining a analytic hierarchy process, an inverse entropy weight process and an improved gray correlation method, thereby establishing the cluster characteristic evaluation index system of the power distribution network balance area.
In order to achieve the above purpose, the invention provides a cluster characteristic evaluation index system construction method considering source load characteristics; the method comprises the following steps:
step 1: modeling a flexible energy acceptance assessment index of a balance area of the power distribution network;
s101, flexible energy permeability of a balance area;
the index describes the proportion of flexible resources accessed in the balance area to the load in the balance area, and the flexible energy permeability of the balance area is as follows:
wherein: n is the number of flexible energy sources accessed in the balance area; d (D) i The installed capacity of the flexible energy source i; m is the load number; p (P) j Power for load j;
s102, the flexible energy generating capacity of the balance area is occupied;
the index describes the proportion of the generated energy of the flexible energy source in the balance area in the load electric quantity of the balance area within a certain time; the balance area flexible energy generating capacity is as follows:
wherein: t is time; d (D) i (t) is the power of the flexible energy source at the time t; p (P) j (t) is the power of the balance area load j at the moment t;
s103, flexible energy utilization rate of a balance area;
the index reflects the overall consumption condition of flexible energy sources in the balance area; the balance area flexible energy utilization rate is as follows:
wherein: p (P) ri (t) the available power generation power of the flexible energy source i in the balance area at the moment t;
Step 2: modeling a load capacity evaluation index of a balance area of the power distribution network;
s201, load prediction accuracy index;
the accuracy of load prediction in the balance area plays an important role in the output of flexible resources and the uncertainty of the load, can be used for grasping the real state in the balance area, is used for improving the perception of the real state in the balance area, and plays an important role in the resource allocation and coordination control decision of the balance area; the load prediction accuracy formula is:
wherein: p (P) 1 fc (i) A load prediction value indicating an i-th point; p (P) 1 (i) Then the actual value of the i-th point load is represented; p (P) 1 avg Then the average load value is indicated;
s202, load absorption rate indexes of a balance area;
the absorption rate index in the balance area represents the absorption ratio of flexible resources during the operation of the balance area of the power distribution network, and a specific formula can be expressed as follows:
wherein: p (P) res Representing the actual output of the flexible resource,representing the maximum output allowed by flexible resources in the real environment in the balance area;
step 3: modeling a cluster characteristic evaluation index of a balance area of the power distribution network;
s301, an intra-cluster association index ECI;
the intra-cluster association index represents the association degree among the nodes in the cluster, and the formula is as follows:
wherein: i is the node number, M is the total node number, M i Representing the cluster in which the node is located, e ij Representing the electrical distance between node i and node j,representing the sum of the electrical distances between node i and each node in the cluster, e total,i Representing the sum of the electrical distances of the nodes and all the nodes;
s302, an inter-cluster association index BCCI;
the inter-cluster association index represents the association degree between the node and the external cluster, and the formula is as follows:
wherein:representing the sum of the electrical distances between the node i and the nodes outside the cluster;
s303, cluster scale index CCI;
the cluster scale index represents the deviation degree between the number of nodes in a cluster and the expected value, and is used for checking the uniformity of the number of nodes among different clusters, and the formula is as follows:
s * ＝n/p * (10)
σ＝wIn(n) (11)
wherein: n represents the number of subgroups into which the cluster is divided, s p Representing the number of nodes in the p-th subgroup, s * Representing the number of nodes in the desired subgroup, when s p →s * When CCI approaches 1, representing more uniform cluster partitioning, and when s p At n, CCI approaches 0; w in the formula (11) is a penalty factor, wherein the larger w is, the higher tolerance to deviation is, and w is 0.2;
s304, an intra-cluster connectivity index CC;
the intra-cluster connectivity index CC represents the electrical connection relationship between the nodes in the cluster; the index CC is a binary variable, if the node inside the cluster is not directly electrically connected to all other nodes in the cluster, cc=0, otherwise cc=1; the index is used for ensuring that no isolated nodes exist inside the cluster;
Step 4: modeling power grid operation indexes in a balance area of the power distribution network;
s401 balance area transformer capacity-load ratio A 41 ；
Transformer capacity-load ratio index A 41 Representing all changes in the equilibrium zoneThe ratio of the sum of the capacities of the transformers to the peak value of the power load, the calculation of the capacity-to-load ratio requires voltage class division, and the capacity-to-load ratio reflects the safe operation margin of the transformer equipment and is used for providing important data support for load increase in a balance area or load transfer during faults:
s402 balance zone transformer efficiency A 42 ；
Transformer efficiency index A 42 The effective utilization rate of the transformer is shown, and the specific formula is as follows:
s403 balance area line load rate A 43 ；
Line load factor index A 43 Representing the average load rate of the lines in the balance area, and representing the utilization degree and the abundance of the lines in the balance area; the specific formula is as follows:
s404 Balanced region Peak Gu Chalv A 44 ；
Peak-valley difference index A of balance area 44 The specific calculation formula is as follows, wherein the specific calculation formula is as the ratio of the maximum difference value of the daily load of the power grid in the balance area to the daily maximum load of the power grid:
s405 Balanced region maximum load duration ratio A 45 ；
Balance zone maximum load duration ratio A 45 Expressed as the ratio of the equilibrium zone maximum load duration to the total recorded time during the recorded time; the finger is provided with The maximum load in the standard is 95% of the actual maximum load of the power grid in the balance area, and the actual condition of the index can be obtained through analysis of the obtained load continuous curve, wherein the specific calculation formula is as follows:
s406 balance area three-phase voltage unbalance degree A 46 ；
Balance area three-phase voltage unbalance index A 46 The method is expressed as a phenomenon that the actual value of the three-phase voltage deviates from the rated value in amplitude and phase difference, and is used for reflecting the degree of unbalance of the three-phase voltage, and a specific formula is expressed as follows:
wherein: u (U) 2 The negative sequence component square root value expressed as three-phase voltage; u (U) 1 The positive sequence component square average root value expressed as three-phase voltage;
s407 balance area supply voltage qualification rate A 47 ；
Balance area supply voltage qualification rate index A 47 The power supply voltage quality of the balancing area is expressed as the quality of the power supply voltage of the balancing area, and is used for reflecting the efficiency and the safety of the power load of the balancing area, and is a key index for the safe and stable operation of a system of the balancing area, and a specific calculation formula is as follows:
balance area supply voltage qualification rate A 47 ＝[0.5A+0.5(B+C+D)/3]×100％ (18)
Wherein: a represents the measured voltage at a 110kV line monitoring point; b represents the measured voltage at a 35kV line monitoring point; c represents the measured voltage at the monitoring point of the 10kV line; d represents the measured voltage at the 380/220v line monitoring point;
S408 load node i of balance area is insufficient in power to expected value A 48 ；
Balance area load node i power shortage expected value A 48 Expressed as the load studied over the recorded time periodThe electric power of the node i is insufficient to be an expected value or a rated value, and a specific calculation formula is as follows:
wherein F is EDNsi (x k ) Active power reduced for load node i at kth sampling of the balance area;
step 5: modeling the reliability and safety indexes of a balance area of the power distribution network;
s501, self-healing rate of power supply in a balance area;
the power supply self-healing rate of the balance area consists of two parts, namely a power supply fault self-healing rate and an average fault self-healing frequency of a user, and is used for reflecting the self-healing capacity of generating faults of the balance area so as to reduce the occurrence of the fault outage phenomenon; the intensity of the self-healing capacity reflects the reliability degree of power supply of the balance area;
1) Power failure self-healing rate:
wherein: the number of subscribers affected by each fault refers to the number of subscribers connected with each faulty line; the number of the self-healing users of each fault is the difference between the number of the users connected with each fault line and the actual power failure number of the users;
2) Average number of times of self-healing of faults for users:
s502, self-healing speed of a balance area;
the self-healing speed index of the balance area is used for quantitatively evaluating the self-healing capacity of the balance area of the power distribution network and reflecting short-time power failure or electricity failure of a circuit within 3 minutes of the balance area of the power distribution network The self-recovery capability of the line when the pressure suddenly drops; defining the self-healing recovery speed of the balance zone as the fault section positioning time T 1 Time T for isolation from fault and recovery from non-fault section 2 And (2) sum:
balance zone self-healing speed = T 1 +T 2 (23)
S503, the continuous voltage break frequency of the balance area;
the continuous voltage interruption frequency index of the balance area is used for reflecting the situation that the voltage in the balance area is interrupted for more than 3 minutes and the power is cut off for a long time in an hour unit:
s504, balancing the flexible equipment availability coefficient in the area;
the coefficient index of the flexible equipment in the balance area is used for reflecting the utilization degree of equipment in the areas such as a switch, a compensator, a filter, an electric energy quality controller and the like in the balance area, and a specific calculation formula is as follows:
s505, balancing area voltage qualification rate;
the voltage qualification rate of the balance area is used for an important judgment basis of the power supply quality when the balance area supplies power to a user, and the balance area can be divided into four types of A, B, C and D according to the voltage level; the voltage qualification rate of the high-voltage distribution network in the balance area is A and B; the voltage qualification rate of the medium-low voltage distribution network is C, D; the specific calculation formula of the voltage qualification rate in the balance area is as follows:
wherein: v (V) A Represents class A voltage qualification rate, V B ，V C ，V D Respectively representing the voltage qualification rate of A, B, C and D types;
Step 6: modeling power grid efficiency and benefit indexes in a power distribution network balance area;
s601, line average load rate;
the average load rate index of the line is expressed as the ratio of the sum of the maximum load rates of all lines in the balance area at the maximum load moment to the number of the bus lines in the balance area, and is used for reflecting the utilization efficiency of the lines in the balance area, and a specific calculation formula is as follows:
s602 primary average load factor;
the main average load rate index is expressed as the ratio of the total of the maximum load rates of all main transformers at the maximum load moment to the total capacity of the transformer substation, and is used for reflecting the capacity utilization rate and future development margin of the transformer substation main transformer in the balance area, and the specific calculation formula is as follows:
s603, integrating the line loss rate;
the comprehensive line loss rate index is the ratio of the difference between the power transmission end and the power receiving end in the balance area to the total power transmitted at the time, is used for reflecting the rationality of planning and operation control of the balance area, is an important economic and technical index of the balance area, and has the specific calculation formula as follows:
s604, increasing the power grid investment and the power supply load;
the unit power grid investment supply increasing load index is expressed as the ratio of the difference of the highest power consumption load of the current year and the highest power consumption load of the last year of the balance area, and is used for reflecting the amount of load which is increased by investment in a certain statistical time of the power grid;
S605, increasing sales power by unit power grid investment;
the unit power grid investment sales-increasing power index is expressed as the ratio of the difference value of the power sales of the balance area in the current year and the power sales of the balance area in the last year to the investment of the balance area in the last year, and is used for reflecting the economic benefit of the power grid investment of the balance area, and the specific calculation formula is as follows:
s606, unit electric network asset electricity selling income;
the electricity selling income index balance area of the unit power grid asset is used for reflecting the income benefit condition in the balance area, and the specific calculation formula is as follows:
step 7: designing a power distribution network balance area index weight calculation method;
s701, a subjective weight calculation method;
the subjective weight calculation method adopts a network analysis method (ANP) calculation; assuming that the network analysis method has n elements, which are C respectively 1 ,C 2 ,…C a Wherein the weight vectorThen +.>C 1 … C i-1 C i+1 … C n The normalized feature vector is specifically:
wherein y is ji Represents C j (j. Noteq.i) pair C i Can be further calculated by a Delphi expert survey method from the formula (34) to finally obtain a direct influence matrix W d The specific calculation formula is as follows:
and subjective weight omega s,i The specific calculation formula of (2) is as follows:
if omega s,i There is no unique limit value and the re-calculation of the weight vector W needs to be returned i ；
S702, calculating an objective weight;
the objective weight calculation method adopts an inverse entropy weight method for calculation; assuming that m evaluation targets and n evaluation indexes are provided, the index values are: x is x ij (i=1, 2, …, k; j=1, 2, …, m) the evaluation matrix is: x= (X ij ) n×m ，x ij The weight of each evaluation index can be scored by a plurality of experts to obtain;
the inverse entropy calculation formula of each evaluation index is as follows:
in the method, in the process of the invention,
objective weight omega o,i The calculation formula is as follows:
s703, synthesizing an optimal weighting method of subjective and objective weights;
important coefficient alpha of subjective weight i And an importance coefficient beta of objective weight i The calculation formulas of (a) are respectively as follows:
weight omega of optimal weighting method integrating subjective weight and objective weight i The specific calculation formula of (2) is as follows:
the invention provides a cluster characteristic evaluation index system construction method considering source load characteristics. The beneficial effects are as follows:
1. the invention builds the power distribution network balance area cluster characteristic evaluation index system taking the source load characteristics into consideration, and well lays down the flexible source load planning arrangement in the subsequent balance area through analyzing the area cluster bearing capacity. The reliability, the safety and the adaptability of the balance area of the power distribution network are further improved, and scientific and specific data support is provided for planning construction, regulation and control operation of the balance area of the power distribution network.
2. According to the invention, by establishing the cluster characteristic evaluation index system of the balance area of the power distribution network, the cluster characteristics of flexible energy and load of a certain area can be accurately analyzed and evaluated, and powerful data support is provided for further determining the boundary and scale of regional cluster division. The cluster characteristic evaluation index system of the power distribution network balance area takes the characteristics of the source load into consideration, lays a cushion for the coordination and the scheduling of new energy consumption and new energy in the power distribution network balance area, and greatly improves the control flexibility in the balance area.
Drawings
FIG. 1 is a schematic diagram of an evaluation index architecture according to the present invention;
FIG. 2 is a graph showing the annual load persistence curve in the equilibrium zone of step S405 of the present invention;
FIG. 3 is a schematic diagram illustrating a fault recovery process of step S502 of the present invention;
FIG. 4 is a schematic diagram of different access capacity power supply capability of the distribution network balancing area bearing capability analysis of the present invention;
FIG. 5 is a schematic diagram of power supply capacity at different access locations for carrying capacity analysis in a balancing area of a power distribution network according to the present invention;
FIG. 6 is a schematic diagram of voltage deviations of different access capacities of a distribution network balancing area for carrying capacity analysis according to the present invention;
FIG. 7 is a schematic diagram of voltage deviations at different access locations for carrying capacity analysis in a balancing area of a power distribution network according to the present invention;
FIG. 8 is a graph illustrating the capacity ratio loss of different distributed power sources for carrying capacity analysis in a balancing area of a power distribution network according to the present invention;
FIG. 9 is a schematic diagram of network loss at different access locations for carrying capacity analysis in a balancing area of a power distribution network according to the present invention;
FIG. 10 is a schematic diagram of a cluster-based power distribution network control architecture for power distribution network balancing area flexibility analysis in accordance with the present invention;
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1:
as shown in fig. 1, because the distribution points of the multiple flexible resources are wide, the coverage scale is large, the objects needing to be scheduled in a coordinated way are greatly increased, and the single passive power distribution network evaluation index system cannot meet the evaluation requirement. The large amount of source charges are connected into the power distribution network, so that the related information required to be collected by a source charge system is increased, the data required to be processed by a regulation and control system is increased, and the existing dispatching mechanism cannot finish high-precision and high-efficiency fine regulation and control management. At present, most of power distribution network evaluation index systems are considered from a passive power distribution network, the established evaluation index systems mainly relate to the aspects of planning, operation and maintenance, management and the like, the influence on the power distribution network caused by source load is not high, and no complete index system for evaluating the cluster characteristics of the balance area of the active power distribution network exists. The power distribution network balance area adopts an active control technology, the problem of uncertainty of energy sources such as source load and the like is solved, various resources in the power distribution network balance area are comprehensively scheduled, grid connection is orderly carried out, and finally, the rapid scheduling and efficient energy consumption of the energy sources are realized. The aim of researching and establishing an evaluation index system of the cluster characteristics of the balance area of the power distribution network is to excavate the adjustment capability of controllable source load flexible resources of the balance area of the power distribution network for quantifying the balance capability characteristic index of the balance area of the power distribution network, and provide reliable data analysis support for the allocation of the internal resources of the balance area of the power distribution network and the scheduling and the digestion of the resources. The power distribution network balance area cluster characteristic evaluation index system mainly comprises 6 aspects of flexible energy admittance capacity indexes, controllable load capacity indexes, cluster characteristic indexes, power grid operation indexes, reliability and safety indexes, power grid efficiency and benefit indexes. In the invention, from the perspective of the distribution network balance area cluster, the influence factors and mechanism analysis of the instability of the distributed photovoltaic output and the uncertainty of the load on the distribution network balance area cluster characteristics are considered, the characteristic index representing the balance capacity of the balance area is mined, an evaluation index system of the distribution network balance area cluster characteristics is established, and the sensing and scheduling capacity of the distribution network balance area is improved.
Example 2:
as shown in fig. 1-3, an embodiment of the present invention provides a method for constructing a cluster feature evaluation index system in consideration of source-load characteristics, where the construction method is as follows:
step 1: the power distribution network balance area flexible energy acceptance assessment index;
s101 balance zone flexible energy permeability. The index describes the proportion of flexible resources accessed in the balance area to the load in the balance area. The balance area flexible energy permeability is as follows:
wherein: n is the number of flexible energy sources accessed in the balance area; d (D) i The installed capacity of the flexible energy source i; m is the load number; p (P) j Is the power of load j.
S102, the balance area flexible energy generating capacity duty ratio. The index describes the proportion of the generated energy of the flexible energy source in the balance area in a certain time to the load electric quantity of the balance area. The balance area flexible energy generating capacity is as follows:
wherein: t is time; d (D) i (t) is the power of the flexible energy source at the time t; p (P) j And (t) is the power of the balance area load j at the moment t.
S103, balancing area flexible energy utilization rate. The index reflects the overall consumption of flexible energy in the balance area. The balance area flexible energy utilization rate is as follows:
wherein: p (P) ri And (t) is the available generated power of the balance area flexible energy source i at the moment t.
Step 2: load capacity evaluation indexes of a balance area of the power distribution network;
the load in the balancing area of the distribution network plays a critical role in the regulation in the entire balancing area. And provides a guarantee for the digestion capacity in the balance area.
S201, load prediction accuracy index:
wherein: p (P) 1 fc (i) Representing the i-th pointLoad prediction values of (2); p (P) 1 (i) Then the actual value of the i-th point load is represented; p (P) 1 avg Then the average load value is indicated;
the accuracy of the load prediction in the balance area plays an important role in the output of flexible resources and the uncertainty of the load, is beneficial to better grasping the real state in the balance area, improves the perception of the real state in the balance area, and plays an important role in the resource allocation and coordination control decision of the balance area.
S202, load absorption rate indexes of a balance area;
the absorption rate index in the balance area represents the absorption ratio of flexible resources during the operation of the balance area of the power distribution network, and can be specifically expressed as follows:
wherein: p (P) res Representing the actual output of the flexible resource,representing the maximum output allowed by flexible resources in the real environment in the balance area;
the load absorption rate of the balance area mainly reflects the utilization rate of flexible energy sources, and the compatibility of the balance area of the power distribution network is more objectively displayed. And when the load absorption rate index of the balance area is 100%, the balance area of the power distribution network is indicated to realize 100% flexible resource absorption.
Step 3: the cluster characteristic evaluation index of the balance area of the power distribution network;
the cluster characteristic indexes of the power distribution network balance area can better provide favorable data support for the next cluster division, and mainly comprise an intra-cluster association index, an inter-cluster association index, a cluster scale index and an intra-cluster connectivity index.
S301 intra-cluster association index (Electrical Cohesiveness Index, ECI)
The intra-cluster association index indicates the degree of association between nodes within the cluster. The formula is as follows:
/>
where i is the node number, M is the total node number, M i Representing the cluster in which the node is located, e ij Representing the electrical distance between node i and node j,representing the sum of the electrical distances of node i from each node in the cluster, etotal,i representing the sum of the electrical distances of the node from all nodes. If the cluster division is reasonable, the electrical distance between the nodes in the cluster should be smaller, i.e. the ECI value of the index is larger.
S302 inter-Cluster relevance index (Between-Cluster Connectedness Index, BCCI)
The inter-cluster association index indicates the degree of association between the node and the external cluster. The formula is as follows:
wherein,representing the sum of the electrical distances of node i from nodes outside the cluster. If the cluster division is reasonable, the electrical distance between the node and the external cluster should be large, i.e. the value of the index BCCI is large.
S303 Cluster Scale index (Cluster CountIndex, CCI)
The cluster scale index, which is an index used to verify the uniformity of the number of nodes among different clusters, represents the degree of deviation between the number of nodes within a cluster and the expectations. The formula is as follows:
s * ＝n/p * (10)
σ＝wIn(n) (11)
n represents the number of subgroups into which the cluster is divided, s p Representing the number of nodes in the p-th subgroup, s * Representing the number of nodes in the desired subgroup, when s p →s * When CCI approaches 1, representing more uniform cluster partitioning, and when s p At n, CCI approaches 0. W in formula (11) is a penalty factor, and the larger w is, the higher tolerance to deviation is indicated, and w=0.2 is taken here.
S304 internal connectivity index of the cluster (Cluster Connectedness, CC)
The intra-cluster connectivity indicator represents the electrical connection relationship between nodes within the cluster. The index CC is a binary variable, if the node inside the cluster is not directly electrically connected to all other nodes in the cluster, cc=0, otherwise cc=1. The index is to ensure that there are no isolated nodes inside the cluster.
Step 4: the power grid operation index of the balance area of the power distribution network;
the operation characteristic index of the balance area of the power distribution network is closely related to loss in the operation process of the power grid, and the established operation characteristic index of the power grid of the balance area of the power distribution network mainly comprises the capacity-load ratio of a transformer of the balance area, the efficiency of the transformer of the balance area, the line load rate of the balance area, the peak-valley difference rate balance area of the balance area, the maximum load duration duty ratio of the balance area, the three-phase voltage unbalance of the power grid of the balance area, the supply voltage qualification rate of the balance area, the load increase adaptation period, the expected power shortage value of load nodes i of the balance area and the like.
S401 balance area transformer capacity-load ratio A 41
The capacity-to-load ratio index of the transformer represents the ratio of the sum of the capacities of all transformers in the balance area to the peak value of the power load, the calculation of the capacity-to-load ratio needs to divide voltage grades, the capacity-to-load ratio index is closely related to the power supply safety of the balance area, and meanwhile reflects the safe operation margin of transformer equipment, so that better data support is provided for the increase of the load in the balance area or the transfer of the load during faults to a certain extent.
S402 balance zone transformer efficiency A 42
The transformer efficiency index represents the effective utilization rate of the transformer, and the specific formula is as follows:
s403 balance area line load rate A 43
The line load rate index represents the average load rate of the lines in the balance area, and mainly represents the utilization degree and the adequacy of the lines in the balance area. The specific formula is as follows:
generally, a certain safety margin is reserved for each device for the safe operation of the power system, but the existence of the safety margin can reduce the coordination efficiency of the system, and as a large number of flexible energy devices are connected into the balance area, the peak Gu Chazhi of the balance area can be reduced, the operation efficiency of the system in the balance area can be improved, and the operation loss of the system in the balance area can be reduced. In addition, a strategy of time-sharing electricity price and real-time electricity price is implemented in the balance area, so that a user is guided to use electricity in a time-sharing manner, and the peak load value of the balance area is reduced. Here represented by two indicators, the equilibrium zone peak Gu Chalv and the equilibrium zone maximum load duration.
S404 Balanced region Peak Gu Chalv A 44
The balance area peak Gu Chalv is expressed as the ratio of the maximum difference in grid daily load to the grid daily maximum load within the balance area. The specific calculation formula is as follows:
s405 Balanced region maximum load duration ratio A 45
The equilibrium zone maximum load duration is expressed as the ratio of the equilibrium zone maximum load duration to the total recorded time during the recorded time. Wherein the maximum load in the index takes a value of 95% of the actual maximum load of the power grid in the balance area. In addition, the actual condition of the index can be obtained through analysis of the obtained load continuous curve. As shown in fig. 2.
S406 balance area three-phase voltage unbalance degree A 46
The three-phase voltage unbalance index of the balance area is expressed as the phenomenon that the actual value of the three-phase voltage deviates from the rated value in amplitude and phase difference, and mainly reflects the intensity of the unbalance phenomenon of the three-phase voltage. The specific formula is expressed as:
in U 2 The negative sequence component square root value expressed as three-phase voltage; u (U) 1 Expressed as positive sequence component root mean square of three-phase voltage.
S407 balance area supply voltage qualification rate A 47
The qualification rate of the power supply voltage of the balance area is expressed as the quality of the power supply voltage of the balance area, reflects the efficiency and safety of the power load of the balance area, and is a key index for safe and stable operation of a system of the balance area. The specific calculation formula of the voltage qualification rate in the balance area is as follows:
Balance area supply voltage qualification rate A 47 ＝[0.5A+0.5(B+C+D)/3]×100％ (18)
Wherein: a represents the measured voltage at a 110kV line monitoring point; b represents the measured voltage at a 35kV line monitoring point; c represents the measured voltage at the monitoring point of the 10kV line; d represents the measured voltage at the 380/220v line monitoring point.
S408 load node i of balance area is insufficient in power to expected value A 48
The balance zone load node i under-power expected value is expressed as the under-power expected value or rating of the load node i under study over the recorded time period. The specific calculation formula is as follows:
wherein F is EDNsi (x k ) Active power is reduced for load node i at the kth sample of the balancing area.
Step 5: power distribution network balance area reliability and safety index
The construction of the balance area of the power distribution network needs to fully consider the power supply reliability and the power quality problem in the balance area. The power supply reliability index of the balance area mainly comprises: the four aspects of the self-healing rate of the power supply of the balance area, the self-healing speed of the balance area, the continuous voltage interruption frequency of the balance area and the availability coefficient of flexible equipment of the balance area reflect the reliability degree of continuous power utilization of a user under the condition of safe power supply of the balance area. The safety index of the balance area is mainly voltage qualification rate, the electric energy quality is mainly reflected by the voltage condition,
The balance area reliability index includes:
s501, self-healing rate of power supply in a balance area;
the power supply self-healing rate of the balance area consists of two parts, namely the power supply fault self-healing rate and the average fault self-healing times of a user, and reflects the self-healing capacity of the balance area for generating faults so as to reduce the occurrence of the fault outage phenomenon. The intensity of the self-healing capacity reflects the reliability degree of power supply of the balance area.
a. Self-healing rate of power supply failure
The number of subscribers affected by each fault refers to the number of subscribers connected to each faulty line; the number of users self-healing each time of failure is the difference between the number of users connected with each time of failure line and the actual number of users with power failure.
b. Average fault self-healing times of users
S502, self-healing speed of a balance area;
the self-healing capacity of the balance area of the power distribution network is quantitatively evaluated by the balance area self-healing speed index, and the self-healing capacity of the power distribution network is mainly reflected when the power of the line is cut off in a short time or the voltage suddenly drops within 3 minutes in the balance area of the power distribution network. The fault recovery process is shown in FIG. 3, and is performed by fault location T 1 And fault isolation and non-fault section recovery time T 2 After that, the load self-healing operation of the non-fault section is completed, and all recoverable loads are completely recovered, so that the balance zone self-healing recovery speed is defined as the fault section positioning time T 1 Time T for isolation from fault and recovery from non-fault section 2 And (3) summing. The high speed of the desired line requires an increase in equipment in the balancing area, and therefore, a proper self-healing speed needs to be selected according to the actual equipment in the balancing area and the user load situation.
Balance zone self-healing speed = T 1 +T 2 (23)
S503, the continuous voltage break frequency of the balance area;
the index of the continuous voltage interruption frequency of the balance area is used for reflecting the situation that the voltage in the balance area is interrupted for more than 3 minutes and the power is cut off for a long time in the unit of hours.
S504, balancing the flexible equipment availability coefficient in the area;
the utilization coefficient index of the flexible equipment in the balance area mainly reflects the utilization degree of equipment in the balance area, such as a switch, a compensator, a filter, an electric energy quality controller and the like. The specific calculation formula is as follows:
the safety index includes:
s505, balancing area voltage qualification rate;
the voltage qualification rate index of the balance area represents an important judgment basis of the power supply quality when the balance area supplies power to a user, and the balance area can be divided into four types of A, B, C and D according to the voltage level. The voltage qualification rate of the high-voltage distribution network in the balance area is A and B; and the voltage qualification rate of the medium-low voltage distribution network is C, D. The specific calculation formula of the voltage qualification rate in the balance area is as follows:
Wherein: v (V) A Represents class A voltage qualification rate, V B ，V C ，V D And respectively representing the voltage qualification rate of A, B, C and D types.
Step 6: power grid efficiency and benefit index of power distribution network balance area
On the premise of keeping the safe and reliable balance area of the power distribution network, the efficient coordination application of resources in the area is realized, the utilization efficiency of the resources in the balance area is required to be improved, and the maximum benefit is realized. The power grid utilization efficiency of the balance area is mainly reflected by the load rate of power grid equipment and mainly comprises the following steps: line average load rate, main average load rate and comprehensive line loss rate. The utilization efficiency of the power grid equipment in the balance area can be improved, the reasonable planning and distribution of resources in the balance area can be improved, the utilization rate of the assets in the area can be further improved, and the economical efficiency can be improved. The balance area power grid development benefit measures the economic potential of sustainable development of the balance area, and the benefit of power grid development in the balance area is beneficial to scale expansion and investment in the area to provide favorable data support, so that the balance area power grid development benefit has a certain practical significance. The development efficiency of the power grid in the balance area mainly comprises three aspects of unit power grid investment and increased supply load, unit power grid investment and increased sales power quantity and unit power grid asset electricity sales income. The specific definition and calculation formula of the index are as follows:
The power grid utilization efficiency index of the balance area comprises the following steps:
s601, line average load rate;
the average load rate index of the line is expressed as the ratio of the sum of the maximum load rates of all lines in the balance area at the maximum load moment to the number of the bus lines in the balance area, and reflects the utilization efficiency of the lines in the balance area, and a specific calculation formula is as follows:
s602 primary average load factor;
the main average load rate index is expressed as the ratio of the total of the maximum load rates of all main transformers at the maximum load moment to the total capacity of the transformer substation, and reflects the capacity utilization rate and future development margin of the transformer substation main transformer in the balance area. The specific calculation formula is as follows:
s603, integrating the line loss rate;
the comprehensive line loss rate index is the ratio of the difference between the power transmission end and the power receiving end in the balance area to the total power transmitted at the time, reflects the rationality of planning and operation control of the balance area, and is an important economic and technical index of the balance area. The specific calculation formula is as follows:
the balance area power grid development benefit index comprises:
s604, increasing the power grid investment and the power supply load;
the unit power grid investment and supply increasing load index is expressed as the ratio of the difference of the highest power consumption load of the current year and the highest power consumption load of the last year of the balance area and the power grid investment of the last year, and reflects the amount of load which is increased by investment in a certain statistical time of the power grid.
S605, increasing sales power by unit power grid investment;
the unit power grid investment sales-increasing power quantity index is expressed as the ratio of the difference value of the power sales quantity of the balance area in the current year and the power sales quantity of the balance area in the last year to the investment of the balance area in the last year, and reflects the economic benefit of the power grid investment of the balance area. The specific calculation formula is as follows:
s606, unit electric network asset electricity selling income;
the electricity selling income index of the unit power grid assets balances the percentage of all electricity selling income in the district and the fixed assets of the power grid in the balancing district, and reflects the income benefit condition in the balancing district. The specific calculation formula is as follows:
step 7: the index weight calculation method of the balance area of the power distribution network;
and evaluating an index system aiming at the cluster characteristics of the balance area of the power distribution network, wherein each index weight calculation adopts an optimal weighting method integrating subjective weights and objective weights.
S701, a subjective weight calculation method;
the subjective weight calculation method adopts network Analysis (ANP) calculation. That is, the network analysis method is assumed to have n elements, namely C 1 ,C 2 ,…C a Wherein the weight vectorThen +.>C 1 … C i-1 C i+1 … C n The normalized feature vector is specifically: />
Wherein y is ji Represents C j (j. Noteq.i) pair C i Can be further calculated by a Delphi expert survey method from the formula (34) to finally obtain a direct influence matrix W d . The specific calculation formula is as follows:
and subjective weight omega s,i The specific calculation formula of (2) is as follows:
if omega s,i There is no unique limit value and the re-calculation of the weight vector W needs to be returned i 。
S702, calculating an objective weight;
the objective weight calculation method adopts an inverse entropy weight method for calculation. That is, assuming that there are m evaluation targets and n evaluation indexes, the index value is: x is x ij (i=1, 2, …, k; j=1, 2, …, m) the evaluation matrix is: x= (X ij ) n×m ，x ij The multiple expert can weight each evaluation indexScoring is performed again to obtain the score.
The inverse entropy calculation formula of each evaluation index is as follows:
in the method, in the process of the invention,
objective weight omega o,i The calculation formula is as follows:
s703, synthesizing an optimal weighting method of subjective and objective weights;
important coefficient alpha of subjective weight i And an importance coefficient beta of objective weight i The calculation formulas of (a) are respectively as follows:
weight omega of optimal weighting method integrating subjective weight and objective weight i The specific calculation formula of (2) is as follows:
example 3: the technical scheme of the invention has the beneficial effects of analysis:
and (one) analyzing the bearing capacity of a balance area of the power distribution network:
the analysis of the bearing capacity of the balance area of the power distribution network needs to determine the mode and the capacity of the flexible resource access balance area, and the analysis of the bearing capacity of the balance area needs to just balance the load of the balance area before the accessed flexible energy is accessed with the input capacity of the upper balance area.
(1) Analysis of influence on power supply capacity
The power supply capacity is affected by the access position and the access capacity of the flexible energy, and fig. 4 and fig. 5 are respectively a power supply capacity line graph when the flexible energy with different capacities is accessed and a power supply capacity line graph when the flexible resource with different positions is accessed.
(2) Analysis of the impact on the quality of electrical energy
The voltage deviation is affected by the flexible energy access location and the access capacity, and when the access capacity and the access location change, the voltage deviation also changes. Fig. 6 and 7 are voltage deviation curves at the time of flexible energy access of different capacities and at the time of flexible energy access of different positions, respectively.
(3) Impact analysis on network loss
The network loss of the balance area of the power distribution network can be influenced by the flexible energy access position and the access capacity proportion, and when the access capacity and the access position change, the network loss of the balance area also changes. Fig. 8 and 9 are respectively a line graph of the balance area when flexible energy of different capacities is accessed and a line graph of the balance area when flexible energy of different positions is accessed.
The distribution network balance area cluster characteristic evaluation index system considering the source load characteristics lays a cushion for the planning and arrangement of flexible source loads in the subsequent balance areas through the analysis of the area cluster bearing capacity. The reliability, the safety and the adaptability of the balance area of the power distribution network are further improved, and scientific and specific data support is provided for planning construction, regulation and control operation of the balance area of the power distribution network.
And (II) analyzing the flexibility of a balance area of the power distribution network:
as shown in FIG. 10, by establishing a cluster characteristic evaluation index system of a balance area of the power distribution network, the cluster characteristics of flexible energy and load of a certain area can be accurately analyzed and evaluated, and powerful data support is provided for further determining the boundary and scale of regional cluster division. The cluster characteristic evaluation index system of the power distribution network balance area takes the characteristics of the source load into consideration, lays a cushion for the coordination and the scheduling of new energy consumption and new energy in the power distribution network balance area, and greatly improves the control flexibility in the balance area.
Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (1)

1. The cluster characteristic evaluation index system construction method taking the source load characteristics into consideration is characterized by comprising the following steps of:
step 1: modeling a flexible energy acceptance assessment index of a balance area of the power distribution network;
s101, flexible energy permeability of a balance area;
The index describes the proportion of flexible resources accessed in the balance area to the load in the balance area, and the flexible energy permeability of the balance area is as follows:
wherein: n is the number of flexible energy sources accessed in the balance area; d (D) i The installed capacity of the flexible energy source i; m is the load number; p (P) j Power for load j;
s102, the flexible energy generating capacity of the balance area is occupied;
the index describes the proportion of the generated energy of the flexible energy source in the balance area in the load electric quantity of the balance area within a certain time; the balance area flexible energy generating capacity is as follows:
wherein: t is time; d (D) i (t) is the power of the flexible energy source at the time t; p (P) j (t) is the power of the balance area load j at the moment t;
s103, flexible energy utilization rate of a balance area;
the index reflects the overall consumption condition of flexible energy sources in the balance area; the balance area flexible energy utilization rate is as follows:
wherein: p (P) ri (t) the available power generation power of the flexible energy source i in the balance area at the moment t;
step 2: modeling a load capacity evaluation index of a balance area of the power distribution network;
s201, load prediction accuracy index;
the accuracy of load prediction in the balance area plays an important role in the output of flexible resources and the uncertainty of the load, can be used for grasping the real state in the balance area, is used for improving the perception of the real state in the balance area, and plays an important role in the resource allocation and coordination control decision of the balance area; the load prediction accuracy formula is:
Wherein: p (P) 1 fc (i) A load prediction value indicating an i-th point; p (P) 1 (i) Then the actual value of the i-th point load is represented; p (P) 1 avg Then the average load value is indicated;
s202, load absorption rate indexes of a balance area;
the absorption rate index in the balance area represents the absorption ratio of flexible resources during the operation of the balance area of the power distribution network, and a specific formula can be expressed as follows:
wherein: p (P) res Representing the actual output of the flexible resource,representing the maximum output allowed by flexible resources in the real environment in the balance area;
step 3: modeling a cluster characteristic evaluation index of a balance area of the power distribution network;
s301, an intra-cluster association index ECI;
the intra-cluster association index represents the association degree among the nodes in the cluster, and the formula is as follows:
wherein: i is the node number, M is the total node number, M i Representing the cluster in which the node is located, e ij Representing the electrical distance between node i and node j,representing the sum of the electrical distances between node i and each node in the cluster, e total,i Representing the sum of the electrical distances of the nodes and all the nodes;
s302, an inter-cluster association index BCCI;
the inter-cluster association index represents the association degree between the node and the external cluster, and the formula is as follows:
wherein:representing the sum of the electrical distances between the node i and the nodes outside the cluster;
S303, cluster scale index CCI;
the cluster scale index represents the deviation degree between the number of nodes in a cluster and the expected value, and is used for checking the uniformity of the number of nodes among different clusters, and the formula is as follows:
s * ＝n/p * (10)
σ＝wIn(n) (11)
wherein: n represents the number of subgroups into which the cluster is divided, s p Representing the number of nodes in the p-th subgroup, s * Representing the number of nodes in the desired subgroup, when s p →s * When CCI approaches 1, representing more uniform cluster partitioning, and when s p At n, CCI approaches 0; w in the formula (11) is a penalty factor, wherein the larger w is, the higher tolerance to deviation is, and w is 0.2;
s304, an intra-cluster connectivity index CC;
the intra-cluster connectivity index CC represents the electrical connection relationship between the nodes in the cluster; the index CC is a binary variable, if the node inside the cluster is not directly electrically connected to all other nodes in the cluster, cc=0, otherwise cc=1; the index is used for ensuring that no isolated nodes exist inside the cluster;
step 4: modeling power grid operation indexes in a balance area of the power distribution network;
s401 balance area transformer capacity-load ratio A 41 ；
Transformer capacity-load ratio index A 41 The ratio of the sum of the capacities of all transformers in the balance area to the peak value of the power consumption load is represented, the calculation of the capacity-to-load ratio needs voltage class division, and the capacity-to-load ratio reflects the safe operation margin of the transformer equipment and is used for providing important data support for the increase of the load in the balance area or the transfer of the load in the fault state:
S402 balance zone transformer efficiency A 42 ；
Transformer efficiency index A 42 The effective utilization rate of the transformer is shown, and the specific formula is as follows:
s403 balance area line load rate A 43 ；
Line load factor index A 43 Representing the average load rate of the lines in the balance area, and representing the utilization degree and the abundance of the lines in the balance area; the specific formula is as follows:
s404 Balanced region Peak Gu Chalv A 44 ；
Peak-valley difference index A of balance area 44 The specific calculation formula is as follows, wherein the specific calculation formula is as the ratio of the maximum difference value of the daily load of the power grid in the balance area to the daily maximum load of the power grid:
s405 Balanced region maximum load duration ratio A 45 ；
Balance zone maximum load duration ratio A 45 Expressed as the ratio of the equilibrium zone maximum load duration to the total recorded time during the recorded time; the maximum load in the index takes 95% of the actual maximum load of the power grid in the balance area, and the actual condition of the index can be obtained through analysis of the obtained load continuous curve, wherein the specific calculation formula is as follows:
s406 balance area three-phase voltage unbalance degree A 46 ；
Balance area three-phase voltage unbalance index A 46 The method is expressed as a phenomenon that the actual value of the three-phase voltage deviates from the rated value in amplitude and phase difference, and is used for reflecting the degree of unbalance of the three-phase voltage, and a specific formula is expressed as follows:
Wherein: u (U) 2 The negative sequence component square root value expressed as three-phase voltage; u (U) 1 The positive sequence component square average root value expressed as three-phase voltage;
s407 balance area supply voltage qualification rate A 47 ；
Balance area supply voltage qualification rate index A 47 The power supply voltage quality of the balancing area is expressed as the quality of the power supply voltage of the balancing area, and is used for reflecting the efficiency and the safety of the power load of the balancing area, and is a key index for the safe and stable operation of a system of the balancing area, and a specific calculation formula is as follows:
balance area supply voltage qualification rate A 47 ＝[0.5A+0.5(B+C+D)/3]×100％ (18)
Wherein: a represents the measured voltage at a 110kV line monitoring point; b represents the measured voltage at a 35kV line monitoring point; c represents the measured voltage at the monitoring point of the 10kV line; d represents the measured voltage at the 380/220v line monitoring point;
s408 load node i of balance area is insufficient in power to expected value A 48 ；
Balance area load node i power shortage expected value A 48 The specific calculation formula is shown as the expected value or rated value of the electric power deficiency of the load node i researched in the recorded time period:
wherein F is EDNsi (x k ) Active power reduced for load node i at kth sampling of the balance area;
step 5: modeling the reliability and safety indexes of a balance area of the power distribution network;
s501, self-healing rate of power supply in a balance area;
the power supply self-healing rate of the balance area consists of two parts, namely a power supply fault self-healing rate and an average fault self-healing frequency of a user, and is used for reflecting the self-healing capacity of generating faults of the balance area so as to reduce the occurrence of the fault outage phenomenon; the intensity of the self-healing capacity reflects the reliability degree of power supply of the balance area;
1) Power failure self-healing rate:
wherein: the number of subscribers affected by each fault refers to the number of subscribers connected with each faulty line; the number of the self-healing users of each fault is the difference between the number of the users connected with each fault line and the actual power failure number of the users;
2) Average number of times of self-healing of faults for users:
s502, self-healing speed of a balance area;
the self-healing speed index of the balance area is used for quantitatively evaluating the self-healing capacity of the balance area of the power distribution network and reflecting the self-healing capacity of the circuit when the circuit is in short-time power failure or voltage dip within 3 minutes in the balance area of the power distribution network; defining the self-healing recovery speed of the balance zone as the fault section positioning time T 1 Time T for isolation from fault and recovery from non-fault section 2 And (2) sum:
balance zone self-healing speed = T 1 +T 2 (23) S503, the continuous voltage break frequency of the balance area;
the continuous voltage interruption frequency index of the balance area is used for reflecting the situation that the voltage in the balance area is interrupted for more than 3 minutes and the power is cut off for a long time in an hour unit:
s504, balancing the flexible equipment availability coefficient in the area;
the coefficient index of the flexible equipment in the balance area is used for reflecting the utilization degree of equipment in the areas such as a switch, a compensator, a filter, an electric energy quality controller and the like in the balance area, and a specific calculation formula is as follows:
S505, balancing area voltage qualification rate;
the voltage qualification rate of the balance area is used for an important judgment basis of the power supply quality when the balance area supplies power to a user, and the balance area can be divided into four types of A, B, C and D according to the voltage level; the voltage qualification rate of the high-voltage distribution network in the balance area is A and B; the voltage qualification rate of the medium-low voltage distribution network is C, D; the specific calculation formula of the voltage qualification rate in the balance area is as follows:
wherein: v (V) A Represents class A voltage qualification rate, V B ，V C ，V D Respectively representing the voltage qualification rate of A, B, C and D types;
step 6: modeling power grid efficiency and benefit indexes in a power distribution network balance area;
s601, line average load rate;
the average load rate index of the line is expressed as the ratio of the sum of the maximum load rates of all lines in the balance area at the maximum load moment to the number of the bus lines in the balance area, and is used for reflecting the utilization efficiency of the lines in the balance area, and a specific calculation formula is as follows:
s602 primary average load factor;
the main average load rate index is expressed as the ratio of the total of the maximum load rates of all main transformers at the maximum load moment to the total capacity of the transformer substation, and is used for reflecting the capacity utilization rate and future development margin of the transformer substation main transformer in the balance area, and the specific calculation formula is as follows:
S603, integrating the line loss rate;
the comprehensive line loss rate index is the ratio of the difference between the power transmission end and the power receiving end in the balance area to the total power transmitted at the time, is used for reflecting the rationality of planning and operation control of the balance area, is an important economic and technical index of the balance area, and has the specific calculation formula as follows:
s604, increasing the power grid investment and the power supply load;
the unit power grid investment supply increasing load index is expressed as the ratio of the difference of the highest power consumption load of the current year and the highest power consumption load of the last year of the balance area, and is used for reflecting the amount of load which is increased by investment in a certain statistical time of the power grid;
s605, increasing sales power by unit power grid investment;
the unit power grid investment sales-increasing power index is expressed as the ratio of the difference value of the power sales of the balance area in the current year and the power sales of the balance area in the last year to the investment of the balance area in the last year, and is used for reflecting the economic benefit of the power grid investment of the balance area, and the specific calculation formula is as follows:
s606, unit electric network asset electricity selling income;
the electricity selling income index balance area of the unit power grid asset is used for reflecting the income benefit condition in the balance area, and the specific calculation formula is as follows:
step 7: designing a power distribution network balance area index weight calculation method;
S701, a subjective weight calculation method;
the subjective weight calculation method adopts a network analysis method (ANP) calculation; assuming that the network analysis method has n elements, which are C respectively 1 ,C 2 ,…C a Wherein the weight vectorThen +.>C 1 … C i-1 C i+1 … C n The normalized feature vector is specifically:
wherein y is ji Represents C j (j. Noteq.i) pair C i Is influenced by the publicEquation (34) can be further calculated by using a Delphi expert survey method to finally obtain a direct influence matrix W d The specific calculation formula is as follows:
and subjective weight omega s,i The specific calculation formula of (2) is as follows:
if omega s,i There is no unique limit value and the re-calculation of the weight vector W needs to be returned i ；
S702, calculating an objective weight;
the objective weight calculation method adopts an inverse entropy weight method for calculation; assuming that m evaluation targets and n evaluation indexes are provided, the index values are: x is x ij (i=1, 2, …, k; j=1, 2, …, m) the evaluation matrix is: x= (X ij ) n×m ，x ij The weight of each evaluation index can be scored by a plurality of experts to obtain;
the inverse entropy calculation formula of each evaluation index is as follows:
in the method, in the process of the invention,
objective weight omega o,i The calculation formula is as follows:
s703, synthesizing an optimal weighting method of subjective and objective weights;
important coefficient alpha of subjective weight i And an importance coefficient beta of objective weight i The calculation formulas of (a) are respectively as follows:
Weight omega of optimal weighting method integrating subjective weight and objective weight i The specific calculation formula of (2) is as follows:
CN202311855066.4A 2023-12-29 2023-12-29 Cluster characteristic evaluation index system construction method considering source load characteristics Pending CN117808362A (en)

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