CN116073381A - Automatic equipment point distribution decision method considering reliability of power distribution network - Google Patents

Abstract

This application relates to a decision-making method for automatic equipment layout considering the reliability of distribution network, including establishing a topology model for the connection relationship between internal components and nodes of distribution network; using block Gaussian elimination method to realize the connection relationship of distribution network nodes According to the judgment results of the connection relationship of distribution network nodes, the analysis of the consequences of faults on load points is realized; combined with the analytical solution method of distribution network reliability, the load reliability index and system reliability index of distribution network are solved; by combining The investment cost and benefit improvement of distribution network automation equipment are two parts, and the objective function of the distribution network automation equipment optimization distribution solution model is established; considering the physical constraints, reliability index constraints and topological relationship constraints of distribution automation equipment, the optimal layout is obtained. planning model. On the premise of satisfying the reliability of the distribution network, the application optimizes the distribution scheme of the automation equipment to reduce the construction cost of the automation equipment and the failure cost in the operation of the distribution network.

Description

A decision-making method for automation equipment placement considering distribution network reliability

Technical Field

The present application relates to the field of power distribution automation, and in particular to a method for making decisions on the placement of automation equipment taking into account the reliability of a power distribution network.

Background Art

The functions and technical contents of distribution automation have undergone revolutionary changes. Its function is to transform the distribution network to realize the "hand-in-hand" or ring network power supply mode. The feeder automation system can detect and locate the faults of the distribution lines, automatically isolate the faulty sections, and restore the power supply to the non-faulty sections. This reduces the scope of power outages, reduces the power outage time of user terminals, and greatly improves the reliability of power supply. By real-time monitoring of the operating status, load transfer and capacitor switching are carried out in a timely manner to ensure the quality of power supply. The distribution automation transformation project is an extremely difficult project with high cost and high construction complexity. Among them, the representative problem is how to reasonably arrange the terminal equipment of distribution automation. The reasonable arrangement of distribution automation terminal equipment mainly involves two aspects: one is the number of terminal equipment and the other is the configuration location of terminal equipment. Distribution automation terminal equipment is expensive, and the coverage of the entire area will greatly increase the cost, thereby reducing the return on investment.

Summary of the invention

The purpose of the embodiments of the present application is to provide a method for making decisions on the location of automated equipment taking into account the reliability of a distribution network. Based on the network topology theory of the distribution network, a topological analysis of a distribution network with any structure is performed, and the topological analysis is introduced into the reliability analysis and calculation of the distribution network. The analysis results are introduced into the process of optimizing the location of automated equipment. On the premise of meeting the reliability of the distribution network, the location plan of the automated equipment is optimized, and the construction cost of the automated equipment and the failure cost in the operation of the distribution network are reduced.

To achieve the above objectives, this application provides the following technical solutions:

The present application provides an automation equipment deployment decision method considering the reliability of a distribution network, including the following specific steps:

Step 1: Establish a topological model for the connection relationship between components and nodes within the distribution network;

Step 2: Use block Gaussian elimination method to determine the connectivity relationship of distribution network nodes;

Step 3: Analyze the consequences of the fault on the load point based on the judgment result of the connection relationship of the distribution network nodes;

Step 4: Combine the analytical solution method of distribution network reliability to solve the distribution network load reliability index and system reliability index;

Step 5: By combining the investment cost and benefit improvement of distribution network automation equipment, establish the objective function of the distribution network automation equipment optimization point solution model;

Step 6: Taking into account the physical constraints, reliability index constraints and topological relationship constraints of distribution automation equipment, a planning model for optimal layout is obtained.

In the step 1, the topological model for the connection relationship between the internal components and nodes of the distribution network is specifically established by using the component information matrix and the node information matrix as the storage method of the original data, and the relevant parameter data of the input topological model includes the following three categories:

1) Node data: node number, node active power, node capacity, load importance;

2) Component data: component number, first node number, last node number, component capacity, component type;

3) Component failure parameters: component failure rate, component repair time, second remote control equipment action time, third remote control equipment action time, manual equipment action time;

An undirected graph adjacency matrix is used to describe the connection relationship between the internal components of the power grid.

In step 2, the specific process of block Gaussian elimination method is as follows:

开展如下所示的分块处理，通过将邻接矩阵的各个分块进行计算；(1) Adjacency matrix

Carry out the block processing as shown below, by calculating each block of the adjacency matrix;

，

,

、

分别采用高斯消元法进行消去、前代、回代操作；(2) The main diagonal sub-blocks of the matrix after block processing

,

Gaussian elimination method is used to perform elimination, forward substitution and back substitution operations respectively;

、

反映子块

、

之间的联系，对其需要进行连接关系映射计算；(3) Two sub-blocks on the non-main diagonal line

,

Reflect sub-block

,

The connection between them needs to be mapped and calculated;

，

，

，

计算后，便获得新的邻接矩阵

，对矩阵

进行一次完整的高斯消元法计算后，便可以获得连通矩阵

；(4) Sub-block

,

,

,

After calculation, we get the new adjacency matrix

, for the matrix

After a complete Gaussian elimination calculation, the connectivity matrix can be obtained

;

进行行扫描或者列扫描，获取相同的元素对应的行数、列数，便可以获取不同节点之间的连通关系。(5) Connectivity matrix

By performing row scanning or column scanning and obtaining the number of rows and columns corresponding to the same elements, the connectivity relationship between different nodes can be obtained.

In step 3, by modifying the adjacency matrix parameters corresponding to the distribution network topology, the disconnection of various distribution automation equipment inside the distribution network is simulated to identify and locate the distribution automation devices in play. The specific process is as follows:

、各个集合内部所包含的节点

以及连通片边界开关设备集合

，(1) Manually disconnect the circuit breaker equipment inside the distribution network. Through the above-mentioned topological analysis method, the set of circuit breaker connection pieces can be obtained.

, the nodes contained in each collection

And the connection piece boundary switch device collection

,

、各个集合内部所包含的节点

以及连通片边界开关设备集合

；(2) Manually disconnect the manual switch device inside the distribution network. Through the above-mentioned topological analysis method, the set of manual switch connection pieces can be obtained.

, the nodes contained in each collection

And the connection piece boundary switch device collection

;

、各个集合内部所包含的节点

以及连通片边界开关设备集合

；(3) Artificially disconnect the two remote switch devices in the distribution network. Through the above-mentioned topological analysis method, the set of connected pieces of the two remote switches can be obtained.

, the nodes contained in each collection

And the connection piece boundary switch device collection

;

、各个集合内部所包含的节点

以及连通片边界开关设备集合

；(4) Artificially disconnect the three remote switch devices inside the distribution network. Through the above-mentioned topological analysis method, the set of connected pieces of the three remote switches can be obtained.

, the nodes contained in each collection

And the connection piece boundary switch device collection

;

(5) According to the node number of the faulty component, search for the boundary switch device corresponding to the fault in the above four different boundary switch device sets, and store the search results in the system.

、故障区域

、恢复区域

、转供区域

，故障查找时间模型如下：In step 4, the power outage duration of each load point is modeled according to the fault impact analysis results and divided into unaffected areas.

, Fault area

, restore area

, transfer area

, the fault finding time model is as follows:

，

,

为巡线排查故障准备工作的时间，

为馈线段

的长度，

为工作人员巡线排查故障的速度，

为排查故障的目标区域内包含的馈线段集合。in,

Time to prepare for line inspection and troubleshooting.

Feeder segment

Length,

The speed at which staff patrol the lines to troubleshoot faults,

It is the set of feeder segments included in the target area for troubleshooting.

In step 5, by combining the investment cost and benefit improvement of distribution network automation equipment, the objective function of the distribution network automation equipment optimization point solution model is established as follows:

1) Minimum equipment investment cost

，

,

为设备采购、改造、安装总成本；

为馈线集合

中位于馈线

上节点

的二遥开关指示变量，当

时，说明该位置为安装二遥设备，当

时，说明该位置安装二遥设备；

为馈线集合

中位于馈线

上节点

的三遥开关指示变量，其含义与二遥开关指示变量

一致；

、

分别为二遥设备、三遥设备综合成本价，In the above formula,

The total cost of equipment purchase, modification and installation;

Feeder Collection

Feeder

Previous Node

The second remote switch indicates the variable, when

When

When it is, it indicates that the second remote device is installed at this location;

Feeder Collection

Feeder

Previous Node

The meaning of the three remote switch indicator variables is the same as that of the two remote switch indicator variables.

Consistency;

,

They are the comprehensive cost prices of two-remote control equipment and three-remote control equipment respectively.

For loan purchases of equipment, the loan interest should also be considered, and the final cost is shown in the following formula:

，

,

为银行贷款年化利率，

为银行贷款年限，In the formula

is the annualized interest rate of bank loans,

is the bank loan term,

以及使用年限

进行折旧均摊，获得设备采购、改造、安装的年均成本，其计算式如下：The final cost is calculated based on the residual value of the equipment.

And the service life

Depreciation is amortized to obtain the average annual cost of equipment procurement, transformation, and installation. The calculation formula is as follows:

，

,

2) The distribution network benefits are greatly improved

量化模型如下所示：Annual power outage loss of load

The quantitative model is as follows:

，

,

为负荷点

的年平均负荷，

为负荷点

单位电量损失成本，in

Load point

The annual average load,

Load point

Unit electricity loss cost,

3) Overall objective function

如下：Therefore, the total objective function after considering the average annual cost of equipment procurement, transformation, installation, maintenance and annual load power outage loss is

as follows:

。

.

In step 6, the physical constraints, reliability index constraints and topological relationship constraints of the distribution automation equipment are comprehensively considered to obtain the optimal layout planning model, which is as follows:

1) Physical constraints of distribution automation equipment

上节点

处的自动化设备，最多仅能存在一种类型，通常不可同时安装二遥、三遥设备，因此有For feeder

Previous Node

There can be only one type of automation equipment at most. Usually, two-remote control and three-remote control equipment cannot be installed at the same time.

，

,

The specific nodes in the optimization model should be subject to mandatory constraints, and the following quantitative constraints should be imposed:

，

,

2) Distribution network reliability index constraints

The minimum path method is used for calculation, and the calculation process is equivalent to the following constraints:

，

,

There should be:

，

,

In the process of optimizing the layout, it is necessary not only to meet the reliability index of each important load, but also to meet the reliability index of the entire system. The average power supply index ASAI can be used as a reference. The calculation method is as follows:

，

,

为重要负荷年停电持续时间参考值；

为负荷点

处用户数量；

为系统平均供电可考虑指标参考值。In the above formula,

It is the reference value of annual power outage duration for important loads;

Load point

Number of users;

The index reference value can be considered for average power supply to the system.

Compared with the prior art, the beneficial effects of the present application are: through the distribution network topology theory, the network is modeled and analyzed, the impact of faults is analyzed, the reliability index is calculated, and it is applied to the optimization solution model, and the optimal solution for the layout scheme is obtained through iterative solution. In this case, the equipment can be reasonably located and arranged, which greatly improves the system efficiency, automatically locates the fault in a shorter time, realizes rapid power transfer, and ultimately improves the power supply reliability. This application can help power grid companies improve the management efficiency and power supply reliability of distribution networks, and has a driving effect on the development of power grid distribution automation and the construction of power grid intelligence.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

FIG1 is a flow chart of the method implemented in the present application.

Figure 2 is a schematic diagram of a simple distribution network structure.

Figure 3 is a schematic diagram of the regional division of a simple distribution network.

Figure 4 is a schematic diagram of the F4 feeder of the RBTS BUS6 system.

DETAILED DESCRIPTION

The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

The terms "comprises," "comprising," or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

The terms "first", "second", etc. are only used to distinguish one entity or operation from another entity or operation, and should not be understood as indicating or implying relative importance, nor should they be understood as requiring or implying any such actual relationship or order between these entities or operations.

1 , an embodiment of the present application provides an automation equipment deployment decision method considering the reliability of a distribution network, including the following specific steps:

Step 1: Establish a topological model for the connection relationship between components and nodes within the distribution network;

Step 2: Use block Gaussian elimination method to determine the connectivity relationship of distribution network nodes;

Step 3: Analyze the consequences of the fault on the load point based on the judgment result of the connection relationship of the distribution network nodes;

Step 4: Combine the analytical solution method of distribution network reliability to solve the distribution network load reliability index and system reliability index;

Step 5: By combining the investment cost and benefit improvement of distribution network automation equipment, establish the objective function of the distribution network automation equipment optimization point solution model;

Step 6: Taking into account the physical constraints, reliability index constraints and topological relationship constraints of distribution automation equipment, a planning model for optimal layout is obtained.

Distribution network topology model and analysis method

1.1 Topological structure description of distribution network

The structure of urban distribution networks is complex and varied, mainly including single-ring networks, double-ring networks, and inter-ring connections. Generally, a ring design and open-loop operation are adopted. When the distribution network loses one power supply, the power supply to the non-fault area can be restored by switching operations. In order to be able to universally describe the topological structure of the distribution network and effectively analyze its topological structure, this application uses the component information matrix and the node information matrix as the storage method of the original data. The relevant parameter data of the input system usually includes the following three categories:

1) Node data: node number, node active power, node capacity, load importance, etc.

2) Component data: component number, first node number, last node number, component capacity, component type (including switchgear classification), etc.

3) Component failure parameters: component failure rate, component repair time, second remote device action time, third remote device action time, manual device action time, etc.

Taking the simple distribution network structure shown in Figure 2 as an example, its connection matrix is an undirected graph model, so the undirected graph adjacency matrix is used to describe the connection relationship between the internal components of the power grid. The connection information of the simple distribution network in Figure 2 is extracted and converted into the following adjacency matrix:

，

,

1.2 Topological analysis method of distribution network

The adjacency matrix can accurately reflect the direct connection relationship between two arbitrary nodes of the topology, but does not take into account the role of the transfer characteristics in the connectivity relationship, that is, two nodes can also form an indirect connection relationship through other nodes. Therefore, it is not comprehensive to use the adjacency matrix to express the topological relationship. It is difficult to directly judge the connection relationship of all nodes by the value of the matrix elements, and it is not suitable for the processing process of the computer. After the topological analysis process, the adjacency matrix can be converted into the form of a connectivity matrix, thereby forming a matrix element connectivity sheet structure that is more suitable for computer scanning and recognition, which facilitates subsequent processing and calculation processes. The present application adopts the improved Gaussian elimination method as the basic method of topological analysis and solution, and its algorithm process is as follows:

开展如下列图示的分块处理，通过将邻接矩阵的各个分块进行计算，从而降低矩阵维度，达到降阶的效果，有效减少单次拓扑分析的计算量：(1) Adjacency matrix

Carry out block processing as shown in the following figure, and reduce the matrix dimension by calculating each block of the adjacency matrix, so as to achieve the effect of order reduction and effectively reduce the amount of calculation of a single topological analysis:

，

,

、

分别采用高斯消元法进行消去、前代、回代操作。邻接矩阵的消去过程是从拓扑中的第一个节点（

）开始，按照规定顺序逐次确定拓扑关系中各个节点经由中间节点

构成的间接连接关系(2) The main diagonal sub-blocks of the matrix after block processing

,

Gaussian elimination is used to perform elimination, previous generation, and back generation operations. The elimination process of the adjacency matrix is from the first node in the topology (

) starts, and determines the nodes in the topological relationship one by one through the intermediate nodes in the specified order.

Indirect connection relationship

，

,

，计算

的元素值，即节点

与节点

的直接连通关系与经由中间节点

构成的间接连通关系。中间层的循环用于更新节点

，计算

的元素值，即节点

与节点

的直接连通关系以及经由中间节点

构成的间接连通关系。最外层循环用于不断获取并更新中间节点

，以获取节点

与节点

通过不同中间节点

间接连接的连接关系。In the above process, the innermost loop is used to continuously obtain and update nodes.

,calculate

The element value of the node

With Node

The direct connection relationship and the intermediate node

The indirect connection relationship formed by the middle layer is used to update the node

,calculate

The element value of the node

With Node

Direct connectivity and connectivity through intermediate nodes

The outermost loop is used to continuously obtain and update the intermediate nodes.

, to get the node

With Node

Through different intermediate nodes

An indirect connection relationship.

作为记录矩阵，记录前代过程中的拓扑关系：After the matrix is eliminated, the matrix needs to be operated on in the previous generation, and the node information of the matrix is passed from front to back one by one, using the unit matrix

As a record matrix, it records the topological relationship in the previous generation process:

，

,

和邻接矩阵

，将同一连通片上的节点信息由后至前传递到所有节点：After the matrix previous generation operation is completed, further back generation operation is required, starting from the last node, according to the record matrix

and the adjacency matrix

, pass the node information on the same connected piece to all nodes from back to front:

，

,

之间共

个节点的所有连通关系由子块

表示，节点

至节点

之间共

个节点的所有连通关系由子块

表示。After completing all the above calculation processes, node 1 to node

Between

All connectivity relationships of nodes are represented by sub-blocks

Indicates that the node

To Node

Between

All connectivity relationships of nodes are represented by sub-blocks

express.

、

反映子块

、

之间的联系，对其需要进行如下（3.a）至（3.d）的连接关系映射计算。(3) Two sub-blocks on the non-main diagonal line

,

Reflect sub-block

,

The connection between them requires the following connection relationship mapping calculations (3.a) to (3.d).

、

结构如下(3.a) Sub-block after Gaussian elimination in step (2)

,

The structure is as follows

，

,

、

分别为子块

、

中连通片的个数，

、

分别为第

、第

个连通片中所包含的节点的个数。in

,

Sub-blocks

,

The number of connected pieces in

,

Respectively

、

The number of nodes contained in a connected patch.

、

中的各个连通片区对外等效为连通集合整体，表示为一个“1”，即如下所示：(3.b) Sub-blocks

,

Each connected area in is externally equivalent to the connected set as a whole, represented by a "1", as shown below:

，

,

、

中。According to the equivalent results, the connectivity relationship is mapped to the sub-blocks in the following two steps:

,

middle.

中的

个连通片，从第1个连通片开始，其内部包含节点

，在子块

中寻找节点

对应行，在子块

中寻找节点

对应列，分别按行、按列逐次进行逻辑或运算，将连通集合的连接关系多对一映射到非对角子块中，计算后的子块

、

分别为

、

矩阵。(3.c) The first step is for the sub-block

In

connected pieces, starting from the first connected piece, which contains nodes

, in the sub-block

Find nodes in

Corresponding row, in sub-block

Find nodes in

Corresponding columns, logical OR operations are performed row by row and column by column, and the connection relationship of the connected set is mapped many-to-one to the non-diagonal sub-blocks. The calculated sub-blocks

,

They are

,

matrix.

中的

个连通片，从第1个连通片开始，其内部包含节点

，在子块

中寻找节点

对应列，在子块

中寻找节点

对应行，分别按列、按行依次进行逻辑或运算，将连通集合的连接关系多对一映射到非对角子块中，计算后的子块

、

分别为

、

矩阵。(3.d) The second step is for the sub-blocks

In

connected pieces, starting from the first connected piece, which contains nodes

, in the sub-block

Find nodes in

Corresponding columns, in sub-blocks

Find nodes in

Corresponding rows, logical OR operations are performed in sequence by column and row, and the connection relationship of the connected set is mapped many-to-one to the non-diagonal sub-blocks. The calculated sub-blocks

,

They are

,

matrix.

，

，

，

计算后，便获得新的邻接矩阵

。对矩阵

进行一次完整的高斯消元法计算后，便可以获得连通矩阵

。(4) Sub-block

,

,

,

After calculation, we get the new adjacency matrix

. For the matrix

After a complete Gaussian elimination calculation, the connectivity matrix can be obtained

.

进行行扫描或者列扫描，获取相同的元素对应的行数、列数，便可以获取不同节点之间的连通关系。(5) Connectivity matrix

By performing row scanning or column scanning and obtaining the number of rows and columns corresponding to the same elements, the connectivity relationship between different nodes can be obtained.

进行了分块处理，能够有效的减少计算过程中矩阵的维度，在系统节点数量较大时，计算量大幅降低。The above process has an effect on the adjacency matrix

Block processing is performed, which can effectively reduce the dimension of the matrix during the calculation process. When the number of system nodes is large, the amount of calculation is greatly reduced.

Positioning identification and fault impact analysis of distribution automation equipment

2.1 Identification and positioning of distribution automation devices

There are a large number of distribution network automation equipment with telemetry, telesignaling and remote control functions inside the distribution network to realize the rapid identification, location and removal of distribution network faults, so as to maximize the normal and stable operation of the distribution network. The degree to which each load point inside the distribution network is affected by the fault is closely related to the type and distribution location of the internal automation equipment. Therefore, accurate and rapid identification and location of the automation equipment that plays a role is of great significance for fault impact analysis. The impact range and recovery range of the fault are both based on the distribution network automation equipment. That is, after the fault occurs, the automation device near the fault point will play a role, isolate the fault area, and restore the non-fault area.

There are many types of distribution network equipment, including manual switches and various types of switchgear with different degrees of automation. Different switchgear have different operating speeds. When a fault occurs, the switchgear with a high level of automation usually operates first, and the equipment with a lower level of automation operates later, continuously narrowing the scope of the fault area. This application takes manual switches and "two remote" and "three remote" switches as the main research objects. The following Figure 3 is used as an example to illustrate the effects of different switches, where S1 is a manual switch, S2 is a "two remote" switch, and S3 is a "three remote" switch.

When a fault occurs, the feeder's outlet circuit breaker B1 protection trips, and the "three-remote" switch S3 has the highest degree of automation, automatically isolating the fault area and realizing power transfer in some areas. Then the "two-remote" switch S2 indicates the fault range and notifies the relevant staff to operate, further reducing the scope of the power outage. Finally, the staff uses the manual switch to isolate the smallest fault area and restore all load nodes outside the fault area. In the above process, the entire feeder is divided into 5 areas, of which area 1 is the unaffected area, area 2 is the recovery area, area 3 is the fault area, and areas 4 and 5 are power transfer areas. The division of regions is closely related to the distribution location and type of distribution automation equipment. This application adopts the topological analysis method mentioned above. By modifying the adjacency matrix parameters corresponding to the distribution network topology, it simulates the disconnection of various distribution automation equipment inside the distribution network, and realizes the identification and positioning of the distribution automation devices that play a role. The specific process is as follows:

、各个集合内部所包含的节点

以及连通片边界开关设备集合

，(1) Manually disconnect the circuit breaker equipment inside the distribution network. Through the above-mentioned topological analysis method, the set of circuit breaker connection pieces can be obtained.

, the nodes contained in each collection

And the connection piece boundary switch device collection

,

、各个集合内部所包含的节点

以及连通片边界开关设备集合

；(2) Manually disconnect the manual switch device inside the distribution network. Through the above-mentioned topological analysis method, the set of manual switch connection pieces can be obtained.

, the nodes contained in each collection

And the connection piece boundary switch device collection

;

、各个集合内部所包含的节点

以及连通片边界开关设备集合

；(3) Artificially disconnect the two remote switch devices in the distribution network. Through the above-mentioned topological analysis method, the set of connected pieces of the two remote switches can be obtained.

, the nodes contained in each collection

And the connection piece boundary switch device collection

;

、各个集合内部所包含的节点

以及连通片边界开关设备集合

；(4) Artificially disconnect the three remote switch devices inside the distribution network. Through the above-mentioned topological analysis method, the set of connected pieces of the three remote switches can be obtained.

, the nodes contained in each collection

And the connection piece boundary switch device collection

;

(5) According to the node number of the faulty component, search for the boundary switch device corresponding to the fault in the above four different boundary switch device sets, and store the search results in the system.

2.2 Fault Impact Analysis

According to the analysis of the simple distribution network example in Figure 3 above, it can be seen that the existence of distribution automation equipment does not affect the annual load power outage number index. Its impact on the reliability of the distribution network is mainly reflected in the annual load power outage duration index, which specifically affects the fault detection process, fault isolation process and power supply restoration process time.

Optimal layout model for distribution automation equipment

3.1 Load point outage time model

As mentioned above, the power outage time of a load point depends on its own location and the distribution of terminals between the fault point and the load point. Therefore, the power outage duration of various load points can be modeled based on the results of the fault impact analysis. Classification is based on the above 8 division areas:

，(1) Unaffected areas

,

以及停电持续时间

如下：All loads within the unaffected area will not be affected by the fault, so the internal load point failure rate is

and duration of the power outage

as follows:

，

,

，(2) Fault area

,

与故障修复时间

构成。故障修复时间取决于故障程度，通常远大于自动化设备动作时间，因此可以忽略自动化设备动作时间。其内部负荷点故障率

以及停电持续时间

如下：The fault area, that is, the smallest fault area, is a place where all loads cannot be powered normally due to the fault and can only be powered normally after the fault repair work is completed. The duration of power outage at the load point within the area is determined by the fault finding time.

Fault repair time

The fault repair time depends on the fault severity and is usually much longer than the automation equipment action time, so the automation equipment action time can be ignored. The internal load point failure rate

and duration of the power outage

as follows:

，

,

，(3) Restoration area

,

以及开关作用时间

、

。开关作用时间由起到恢复作用的配电自动化设备种类与性能决定。其内部负荷点故障率

以及停电持续时间

如下：After a fault occurs, the loads in the recovery area are affected by the circuit breaker and lose power. However, with the help of various distribution automation equipment, power supply can be restored. The duration of the power outage includes the fault finding time.

And the switch action time

,

The switching time is determined by the type and performance of the distribution automation equipment that plays a role in recovery. The internal load point failure rate

and duration of the power outage

as follows:

，

,

与手动开关操作时间

均为0。若该区域为为二遥开关或者手动开关恢复区域，其故障查找时间

与手动开关操作时间

均不为0。If the area is a three-remote switch recovery area, the three-remote switch can play a role in rapid and automatic fault isolation, and its fault finding time

Manual switch operation time

If the area is a two-remote switch or manual switch recovery area, the fault finding time

Manual switch operation time

Both are not 0.

，(4) Transfer area

,

以及转供过程的开关作用时间

、

。其内部负荷点故障率

以及停电持续时间

如下：After a fault occurs, the loads in the transfer area can resume power supply under the action of distribution automation equipment and interconnection lines. The duration of the power outage includes the time for fault finding.

And the switching time of the transfer process

,

Its internal load point failure rate

and duration of the power outage

as follows:

，

,

与手动开关操作时间

均为0。若该区域为为二遥开关或者手动开关转供区域，其故障查找时间

与手动开关操作时间

均不为0。The switch action time is determined by the type and performance of the distribution automation equipment that plays a role in recovery. If the area is a three-remote switch transfer area, the three-remote switch can play a role in rapid and automatic fault isolation, and its fault finding time

Manual switch operation time

If the area is a two-remote switch or manual switch transfer area, the fault finding time is

Manual switch operation time

Both are not 0.

3.2 Fault finding time model

、

以及故障修复时间

通常可以认定为是定值，而故障查找时间

受地理、环境、交通、人员等各个因素影响，通常是变化的。当配电网中没有任何自动化设备时，检修人员需要对整条配电线路进行故障排查，故障查找时间

较长。当配电网内部装设有自动化设备后，二遥、三遥设备可以将部分故障电流信息传递给主站，便于检修人员对故障进行初步定位，缩小故障查找范围，有效减少故障查找过程的时间。根据这一关系可以得到故障查找时间模型如下：In the above model, the action time of various automation equipment

,

and troubleshooting time

It can usually be considered as a fixed value, and the fault finding time

Affected by various factors such as geography, environment, transportation, and personnel, it is usually variable. When there is no automation equipment in the distribution network, maintenance personnel need to troubleshoot the entire distribution line, and the fault finding time

Long. When the distribution network is equipped with automation equipment, the second and third remote control equipment can transmit part of the fault current information to the main station, which is convenient for maintenance personnel to initially locate the fault, narrow the scope of fault search, and effectively reduce the time of the fault search process. Based on this relationship, the fault search time model can be obtained as follows:

，

,

为巡线排查故障准备工作的时间，

为馈线段

的长度，

为工作人员巡线排查故障的速度，

为排查故障的目标区域内包含的馈线段集合，该区域为一个以二遥、三遥开关为边界的包含故障元件的最小区域，馈线段集合可以通过前述拓扑分析过程获得。in,

Time to prepare for line inspection and troubleshooting.

Feeder segment

Length,

The speed at which staff patrol the lines to troubleshoot faults,

The feeder segment set contained in the target area for troubleshooting is a minimum area containing faulty components with two-remote and three-remote switches as boundaries. The feeder segment set can be obtained through the above-mentioned topology analysis process.

3.3 Objective function and constraints of automation equipment optimization layout

(1) Optimizing the objective function of site placement decision

In order to facilitate the solution of the optimal distribution of distribution automation equipment, it is necessary to specify the objective function of the solution problem. This application believes that the ultimate goal of the optimization process is to ensure the improvement of the economic benefits brought by distribution automation equipment, which is reflected in the following two aspects:

1) Minimum equipment investment cost

The cost of distribution automation equipment, especially three-remote control equipment, is relatively high, so not all equipment can be modified or replaced with two-remote control or three-remote control equipment. Investment costs should be minimized while ensuring the effectiveness of the equipment.

，

,

为设备采购、改造、安装总成本；

为馈线集合

中位于馈线

上节点

的二遥开关指示变量，当

时，说明该位置为安装二遥设备，当

时，说明该位置安装二遥设备；

为馈线集合

中位于馈线

上节点

的三遥开关指示变量，其含义与二遥开关指示变量

一致；

、

分别为二遥设备、三遥设备综合成本价，In the above formula,

The total cost of equipment purchase, modification and installation;

Feeder Collection

Feeder

Previous Node

The second remote switch indicates the variable, when

When

When it is, it indicates that the second remote device is installed at this location;

Feeder Collection

Feeder

Previous Node

The meaning of the three remote switch indicator variables is the same as that of the two remote switch indicator variables.

Consistency;

,

They are the comprehensive cost prices of two-remote control equipment and three-remote control equipment respectively.

For loan purchases of equipment, the loan interest should also be considered, and the final cost is shown in the following formula:

，

,

为银行贷款年化利率，

为银行贷款年限，In the formula

is the annualized interest rate of bank loans,

is the bank loan term,

以及使用年限

进行折旧均摊，获得设备采购、改造、安装的年均成本，其计算式如下：The final cost is calculated based on the residual value of the equipment.

And the service life

Depreciation is amortized to obtain the average annual cost of equipment procurement, transformation, and installation. The calculation formula is as follows:

，

,

2) The distribution network benefits are greatly improved

量化模型如下所示：Annual power outage loss of load

The quantitative model is as follows:

，

,

为负荷点

的年平均负荷，

为负荷点

单位电量损失成本，in

Load point

The annual average load,

Load point

Unit electricity loss cost,

3) Overall objective function

如下：Therefore, the total objective function after considering the average annual cost of equipment procurement, transformation, installation, maintenance and annual load power outage loss is

as follows:

。（2）优化布点决策约束条件

（2）Optimizing the constraints of site placement decisions

1) Physical constraints on automation equipment installation

上节点

处的自动化设备，最多仅能存在一种类型，通常不可同时安装二遥、三遥设备，因此有For feeder

Previous Node

There can be only one type of automation equipment at most. Usually, two-remote control and three-remote control equipment cannot be installed at the same time.

，

,

According to the State Grid Corporation of China's corporate standard "Technical Guidelines for Distribution Automation Planning and Design" and China Southern Power Grid Co., Ltd.'s corporate standard "Guidelines for Distribution Automation Planning", distribution automation equipment needs to be installed at key nodes within the distribution network. Trunk line contact switches should be retrofitted with three remote controls, switch stations, ring network units and distribution rooms with more incoming and outgoing lines should be retrofitted with three remote controls, and key section switches at important users and more users should be retrofitted with two or three remote controls, and the number of key section switches for each line should not exceed three. According to the above technical guidelines, specific nodes within the optimization model should be subject to mandatory constraints, and the following quantity constraints should be imposed:

，

,

2) Distribution network reliability index constraints

The configuration of distribution automation equipment is to improve the reliability of the distribution network, so the system reliability index and load reliability index should be used as constraints for optimizing the layout. The duration of load power outages in the distribution network can be calculated by analytical methods. This application uses the minimum path method for calculation, and its calculation process can be equivalent to the following constraints:

，

,

There are a large number of important users in the distribution network. In the event of a fault, their electricity consumption should be guaranteed first. Here, the annual power outage duration indicator of users is taken as the research object. Its calculation has been introduced in the previous article. It should have:

，

,

In the process of optimizing the layout, it is necessary not only to meet the reliability index of each important load, but also to meet the reliability index of the system as a whole. There are many types of system reliability indexes. This application uses the average power supply index ASAI as a reference, and its calculation method is as follows:

，

,

为重要负荷年停电持续时间参考值；

为负荷点

处用户数量；

为系统平均供电可考虑指标参考值。In the above formula,

It is the reference value of annual power outage duration for important loads;

Load point

Number of users;

The index reference value can be considered for average power supply to the system.

3) Distribution network topology constraints

The satisfaction of the distribution network topology relationship constraints is guaranteed by the aforementioned topology analysis process.

After the above steps, the overall model is

，

,

This model is a mixed integer nonlinear programming model, which can be solved by GAMS solver or artificial intelligence algorithm to obtain the optimal layout decision results of automation equipment.

As shown in Figure 4, this application takes the F4 feeder of IEEE RBTS BUS6 as an example to illustrate the method proposed in this application. The parameters such as the line and user load of the adopted system are set with reference to the standard example of the IEEE RBTS BUS6 system. The equipment between nodes 2-3 is the outlet circuit breaker of the F4 feeder, which is considered to be 100% reliable in this application. The equipment between nodes 8-10, 15-18, 22-23, 24-26, and 44-45 is the section switch of the line, which is the alternative location for the distribution automation equipment.

The failure rate of power equipment in this feeder is shown in the following table:

Table 1 Power equipment fault parameters

The total cost of purchasing and installing the distribution automation equipment used in this application is RMB 10,000 per unit for a "two-remote control" device and RMB 50,000 per unit for a "three-remote control" device. The equipment has a service life of 10 years, and its depreciation rate is calculated as 20% in the first year, 15% in the second year, 10% in the third year, and 5% in the fourth year and thereafter. After ten years, the residual value of the equipment is RMB 2,000 per unit for a "two-remote control" device and RMB 10,000 per unit for a "three-remote control" device.

，馈线整体的可靠性指标ASAI要求为99.9%以上，人员巡线故障排查速度为5千米/小时，银行贷款利率为4.90%。Other parameters are set as follows: The unit power loss of the feeder

The overall reliability index ASAI of the feeder is required to be above 99.9%, the personnel patrol and troubleshooting speed is 5 km/h, and the bank loan interest rate is 4.90%.

By solving the optimization layout planning model of the RBTS BUS6 system, the optimal layout solution can be calculated to configure "two remote" devices at nodes 8-10 and 44-45, and "three remote" devices at nodes 22-23. At this time, the "two remote" devices and "three remote" devices in the F4 feeder divide the feeder appropriately, which can well realize the auxiliary fault location function, help line patrol personnel to quickly troubleshoot faults, and reduce the time required for line traversal and troubleshooting. Among them, the "three remote" devices can realize the rapid removal of faults and the rapid recovery of the remaining loads. Under the above results, the optimal value of the objective function is 17231.2 yuan, and the overall reliability index ASAI of the feeder is 99.9912%.

The above description is only an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of protection of the present application.

Claims (7)

1. A method for decision-making on the layout of automated equipment considering the reliability of a distribution network, characterized in that it comprises the following specific steps: Step 1: Establish a topological model for the connection relationship between components and nodes within the distribution network; Step 2: Use block Gaussian elimination method to determine the connectivity relationship of distribution network nodes; Step 3: Analyze the consequences of the fault on the load point based on the judgment result of the connection relationship of the distribution network nodes; Step 4: Combine the analytical solution method of distribution network reliability to solve the distribution network load reliability index and system reliability index; Step 5: By combining the investment cost and benefit improvement of distribution network automation equipment, establish the objective function of the distribution network automation equipment optimization point solution model; Step 6: Taking into account the physical constraints, reliability index constraints and topological relationship constraints of distribution automation equipment, a planning model for optimal layout is obtained. 2. According to the method for decision-making on the layout of automated equipment considering the reliability of a distribution network in claim 1, it is characterized in that in the step 1, the topological model for the connection relationship between the internal components and nodes of the distribution network is established by using a component information matrix and a node information matrix as a storage method for the original data, and the relevant parameter data of the input topological model include the following three categories: 1) Node data: node number, node active power, node capacity, load importance; 2) Component data: component number, first node number, last node number, component capacity, component type; 3) Component failure parameters: component failure rate, component repair time, second remote control equipment action time, third remote control equipment action time, manual equipment action time; An undirected graph adjacency matrix is used to describe the connection relationship between the internal components of the power grid. 3. According to the method for decision-making on the layout of automated equipment considering the reliability of distribution network in claim 1, it is characterized in that in the step 2, the specific process of the block Gaussian elimination method is as follows: (1) Adjacency matrix

Carry out the block processing as shown below, by calculating each block of the adjacency matrix;

, (2) The main diagonal sub-blocks of the matrix after block processing

,

Gaussian elimination method is used to perform elimination, forward substitution and back substitution operations respectively; (3) Two sub-blocks on the non-main diagonal line

,

Reflect sub-block

,

The connection between them needs to be mapped and calculated; (4) Sub-block

,

,

,

After calculation, we get the new adjacency matrix

, for the matrix

After a complete Gaussian elimination calculation, the connectivity matrix can be obtained

; (5) Connectivity matrix

By performing row scanning or column scanning and obtaining the number of rows and columns corresponding to the same elements, the connectivity relationship between different nodes can be obtained. 4. According to the method for decision-making on the layout of automation equipment considering the reliability of distribution network in claim 1, it is characterized in that in said step 3, by modifying the adjacency matrix parameters corresponding to the distribution network topology, the disconnection of various types of distribution automation equipment inside the distribution network is simulated to realize the identification and positioning of the distribution automation device in play, and the specific process is as follows: (1) Artificially disconnect the circuit breaker equipment inside the distribution network. Through the above-mentioned topological analysis method, the set of circuit breaker connection pieces can be obtained.

, the nodes contained in each collection

And the connection piece boundary switch device collection

, (2) Manually disconnect the manual switch device inside the distribution network. Through the above-mentioned topological analysis method, the set of manual switch connection pieces can be obtained.

, the nodes contained in each collection

And the connection piece boundary switch device collection

; (3) Artificially disconnect the two remote switch devices in the distribution network. Through the above-mentioned topological analysis method, the set of connected pieces of the two remote switches can be obtained.

, the nodes contained in each collection

And the connection piece boundary switch device collection

; (4) Artificially disconnect the three remote switch devices inside the distribution network. Through the above-mentioned topological analysis method, the set of connected pieces of the three remote switches can be obtained.

, the nodes contained in each collection

And the connection piece boundary switch device collection

; (5) According to the node number of the faulty component, search for the boundary switch device corresponding to the fault in the above four different boundary switch device sets, and store the search results in the system. 5. The method for decision-making on automatic equipment placement considering the reliability of distribution network according to claim 1 is characterized in that in said step 4, the duration of power outage of various load points is modeled according to the results of fault impact analysis and divided into unaffected areas.

, Fault area

, restore area

, transfer area

, the fault finding time model is as follows:

, in,

Time to prepare for line inspection and troubleshooting.

Feeder segment

Length,

The speed at which staff patrol the lines to troubleshoot faults,

It is the set of feeder segments included in the target area for troubleshooting. 6. According to the method for decision-making on the layout of automation equipment considering the reliability of distribution network in claim 1, it is characterized in that in said step 5, by combining the investment cost of distribution network automation equipment and the benefit improvement, the objective function of the distribution network automation equipment optimization layout solution model is established, 1) Minimum equipment investment cost

, In the above formula,

The total cost of equipment purchase, modification and installation;

Feeder Collection

Feeder

Previous Node

The second remote switch indicates the variable, when

When

When it is, it indicates that the second remote device is installed at this location;

Feeder Collection

Feeder

Previous Node

The meaning of the three remote switch indicator variables is the same as that of the two remote switch indicator variables.

Consistency;

,

They are the comprehensive cost prices of two-remote control equipment and three-remote control equipment respectively. For loan purchases of equipment, the loan interest should also be considered, and the final cost is shown in the following formula:

, In the formula

is the annualized interest rate of bank loans,

is the bank loan term, The final cost is calculated based on the residual value of the equipment.

And the service life

Depreciation is amortized to obtain the average annual cost of equipment procurement, transformation, and installation. The calculation formula is as follows:

, 2) The distribution network benefits are greatly improved Annual power outage loss of load

The quantitative model is as follows:

, in

Load point

The annual average load,

Load point

Unit electricity loss cost, 3) Overall objective function Therefore, the total objective function after considering the average annual cost of equipment procurement, transformation, installation, maintenance and annual load power outage loss is

as follows:

. 7. According to the method for decision-making on the layout of automation equipment considering the reliability of distribution network in claim 1, it is characterized in that in said step 6, the physical constraints, reliability index constraints and topological relationship constraints of the distribution automation equipment are comprehensively considered, and the planning model for optimizing the layout is obtained, specifically, 1) Physical constraints of distribution automation equipment For feeder

Previous Node

There can be only one type of automation equipment at most. Usually, two-remote control and three-remote control equipment cannot be installed at the same time.

, The specific nodes in the optimization model should be subject to mandatory constraints, and the following quantitative constraints should be imposed:

, 2) Distribution network reliability index constraints The minimum path method is used for calculation, and the calculation process is equivalent to the following constraints:

, There should be:

, In the process of optimizing the layout, it is necessary not only to meet the reliability index of each important load, but also to meet the reliability index of the entire system. The average power supply index ASAI can be used as a reference. The calculation method is as follows:

, In the above formula,

It is the reference value of annual power outage duration for important loads;

Load point

Number of users;

The index reference value can be considered for average power supply to the system.

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