CN106093704A - A method and system for monitoring and locating power grid stealing users - Google Patents

Abstract

The invention discloses a method for monitoring and locating electricity stealing users in a power grid. By comparing the sum of the current values at all load nodes of the power grid feed-out line with the total current value flowing into the load side of the power grid, it is preliminarily judged whether there is an abnormal power consumption phenomenon , and then compare the current error ratio of each branch with the preset current error ratio threshold, and finally determine the location of the power-stealing user. A system based on the method is also disclosed at the same time. The present invention does not require a large amount of hardware and software input, and is convenient for computer realization.

Description

A method and system for monitoring and locating power grid stealing users

technical field

The invention relates to a method and system for monitoring and locating electricity stealing users in a power grid, belonging to the field of electric power consumption.

Background technique

How to effectively solve the problem of power theft in power grid power management has always been a difficult problem for power supply companies. Some units or individuals use unscrupulous methods to try to evade electric energy measurement and make illegal profits. This kind of electricity theft has seriously endangered the legitimate rights and interests of power supply companies, and at the same time disrupted the fair order of power supply and consumption. The stable operation of the industry has brought many security risks. Therefore, it is of great significance to study and discuss anti-stealing technology.

The common ways of stealing electricity mainly include undervoltage method, undercurrent method, phase shift method, differential expansion method and meterless method. At the same time, the corresponding technical measures to prevent electricity theft are proposed, mainly including the use of special metering boxes, the sealing of the conductors from the low-voltage outlet of the transformer to the metering device, the use of lead sealing technology, and the improvement of the external structure of the meter to prevent electricity theft. It has played a certain curb effect on preventing electricity theft, but these measures are less effective due to the lack of real-time monitoring. Moreover, in the traditional electricity stealing user monitoring and positioning technology, a large amount of hardware and software needs to be invested, which is not easy to realize by computer.

Contents of the invention

In order to solve the above-mentioned technical problems, the present invention provides a method and system for monitoring and locating power grid stealing users.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A method for monitoring and locating power grid stealing users, comprising the following steps,

Step 1, obtain the total voltage and current value flowing into the load side of the power grid, and obtain the voltage and current value at each load node of the power grid feeder line;

Step 2. By comparing the sum of the current values at all load nodes of the power grid feeder line with the total current value flowing into the load side of the power grid, it is preliminarily judged whether there is any abnormal power consumption phenomenon. If there is an abnormal power consumption phenomenon, go to step 3 , if there is no abnormal power consumption phenomenon, determine the power stealing user;

Step 3, obtain the topological structure information of the power grid, and construct the loop impedance matrix of the power grid topology;

Step 4, according to the loop impedance matrix of the grid topology and the voltage values of all load nodes, the current calculation value of each branch is obtained;

Step 5, making a difference between the current measurement value and the current calculation value of each branch in the grid topology, to obtain the current error of each branch in the grid topology;

The current measurement value is the current value at each load node of the grid feeder line;

Step 6: Calculate the ratio of the current error of each branch in the power grid topology to the current calculation value, and compare it with the preset current error ratio threshold, and finally determine the location of the power-stealing user.

If the ratio of the current error of the branch to the current calculation value is greater than the preset current error ratio threshold, it is determined that the branch is a faulty branch, and there is a power-stealing user on the branch.

If there is a common load node in the two faulty branches, the common load node is a power stealing user.

A system for monitoring and locating users of power grid stealing electricity, including a data server, a total electric energy metering device, and several load node electric energy metering devices; A load node electric energy metering device is installed at the place, and the total electric energy metering device and the load node electric energy metering device are all connected to the data server;

The total electric energy metering device is used to measure and send the total voltage and current value flowing into the load side of the grid;

The load node electric energy metering device is used to measure and send the voltage and current value at each load node of the power grid feeder line;

The data server includes a sequentially connected power information acquisition module, an abnormal power consumption preliminary judgment module, a grid topology information acquisition module, a branch current calculation module, a branch current error calculation module, and a power stealing user determination module;

The power information acquisition module is used to obtain the total voltage and current value flowing into the load side of the power grid, and obtain the voltage and current value at each load node of the power grid feeder line;

The abnormal power consumption preliminary judgment module is used to preliminarily judge whether there is an abnormal power consumption phenomenon by comparing the sum of the current values at all load nodes of the power grid feeder line with the total current value flowing into the load side of the power grid;

The power grid topology information acquisition module is used to obtain the power grid topology information and construct the loop impedance matrix of the power grid topology when abnormal power consumption occurs;

The branch current calculation module is used to obtain the current calculation value of each branch according to the loop impedance matrix of the grid topology and the voltage values of all load nodes;

The branch current error calculation module is used to make a difference between the current measurement value and the current calculation value of each branch in the grid topology to obtain the current error of each branch in the grid topology;

The power stealing user determination module is used to calculate the ratio of the current error of each branch in the power grid topology to the current calculation value, and compare it with the preset current error ratio threshold to finally determine the location of the power stealing user.

The electricity stealing user determination module includes,

The branch current error ratio calculation module is used to calculate the ratio of the current error of each branch in the grid topology to the current calculation value, and obtain the current error ratio of each branch;

The fault branch determination module is used to compare the current error ratio of each branch with the preset current error ratio threshold. If the latter is smaller than the former, it is judged that there is a power stealing user in the corresponding branch, and the corresponding branch is determined as a fault branch. road.

The power stealing user determination module further includes a power stealing user locating module, which is used to determine that the common load node is a power stealing user when there is a common load node in two faulty branches.

The beneficial effect achieved by the present invention: the present invention preliminarily judges whether there is any abnormal power consumption phenomenon by comparing the sum of the current values at all load nodes of the power grid feeder line with the total current value flowing into the load side of the power grid, and then according to each branch Compared with the preset current error ratio threshold, the location of the power-stealing user is finally determined, which does not require a lot of hardware and software investment, and is convenient for computer implementation.

Description of drawings

Fig. 1 is the flowchart of the method of the present invention.

Fig. 2 is a schematic diagram of a power network installed with a smart meter.

Fig. 3 is a block diagram of the data server in the present invention.

Figure 4 is a schematic diagram of the topology of the actual power grid.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings. The following examples are only used to illustrate the technical solution of the present invention more clearly, but not to limit the protection scope of the present invention.

As shown in Figure 1, a method for monitoring and locating power grid stealing users includes the following steps:

Step 1, obtain the total voltage and current value flowing into the load side of the power grid, and obtain the voltage and current value at each load node of the power grid feeder line.

Step 2. By comparing the sum of the current values at all load nodes of the power grid feeder line with the total current value flowing into the load side of the power grid, it is preliminarily judged whether there is any abnormal power consumption phenomenon. If there is an abnormal power consumption phenomenon, go to step 3 , if there is no abnormal power consumption phenomenon, determine the power stealing user.

Step 3, obtain the topological structure information of the power grid, and construct the loop impedance matrix of the power grid topology.

Step 4, according to the loop impedance matrix of the grid topology and the voltage values of all load nodes, the current calculation value of each branch is obtained.

Step 5, the current error of each branch in the grid topology is obtained by making a difference between the current measurement value and the current calculation value of each branch in the grid topology; the current measurement value is the current value at each load node of the grid feeder line c.

Step 6: Calculate the ratio of the current error of each branch in the power grid topology to the current calculation value, and compare it with the preset current error ratio threshold, and finally determine the location of the power-stealing user.

If the ratio of the current error of the branch to the current calculation value is greater than the preset current error ratio threshold, it is determined that the branch is a faulty branch, and there is a power-stealing user on the branch. If there is a common load node in the two faulty branches, the common load node is a power stealing user.

A system for monitoring and locating electricity stealing users in a grid includes a data server, an electric energy total metering device, and several load node electric energy metering devices. Both the total electric energy metering device and the load node electric energy metering device are connected to the data server.

As shown in Figure 2, a total electric energy metering device (here a total ammeter is used) is installed on the side of the grid feeder to measure and send the total voltage and current value flowing into the load side of the grid; each load node of the grid feeder is installed The load node electric energy metering device (a load meter is used here) is used to measure and send the voltage and current value at each load node of the grid feeder line.

As shown in Figure 3, the data server includes a power information acquisition module, an abnormal power consumption preliminary judgment module, a grid topology information acquisition module, a branch current calculation module, a branch current error calculation module, and a power stealing user determination module connected in sequence.

The power information acquisition module is used to obtain the total voltage and current value flowing into the load side of the power grid, and obtain the voltage and current value at each load node of the power grid feeder line.

The abnormal power consumption preliminary judgment module is used to preliminarily judge whether there is abnormal power consumption by comparing the sum of the current values at all load nodes of the power grid feeder line with the total current value flowing into the load side of the power grid.

The grid topology information acquisition module is used to acquire the grid topology information and construct the loop impedance matrix of the grid topology when abnormal power consumption occurs.

Due to the large number of power grids in the grid, in order to facilitate management and accurately locate power-stealing users, each user in the grid can be numbered. Since the correspondence between the correlation matrix and the grid user nodes is relatively simple, the correlation matrix is used to represent the power grid user.

The power grid topology corresponding to Figure 2 is shown in Figure 4. Since the load impedance is represented by a point in the figure, a loop is formed between all load impedances and power supply points, so the loop matrix can be used to Accurately describe the corresponding relationship between each load node and the circuit where it is located.

This loop matrix is a kind of topology matrix, which has a load-branch correlation matrix of m loads (ie, m loops) and e branches (ie, e edges). The corresponding branch impedance matrix can be consistent with the order of each branch impedance in the load branch correlation matrix according to the order of all the branch impedances. It can be seen from Fig. 4 that according to the establishment rules of the association matrix, the following association matrix A related to the grid topology is formed,

$\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; =</span>\left(\begin{array}{cccc}\mathrm{<span\; class="notranslate">\; 1</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 1</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right)$

The elements in the matrix are 1 or -1 when the corresponding vertex is associated with an edge, and 0 when not associated.

In order to make calculation and analysis more convenient, according to the linear correlation properties of the matrix, a simplified matrix can be obtained, that is, the corresponding circuit matrix is B _a ,

${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; =</span>\left(\begin{array}{cccc}\mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}\\ \mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}\\ \mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}\\ \mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right)$

The circuit matrix B _a has the following relationship with the incidence matrix A:

B _a ＝(A ^-1 ) ^T

Due to the large number of power users, in order to further simplify the calculation, the load branch correlation matrix is the circuit matrix formed by crossing out the rows of the circuits without load impedance.

In Fig. 4, sides e ₁ ~ e ₄ correspond to branches z ₁ ~ z ₄ respectively, so the following corresponding loop impedance matrix can be obtained: (indicated by Z here)

$\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; =</span>\left(\begin{array}{ccc}{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}& {\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}& {\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ {\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}& {\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}& {\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ {\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}& {\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}& {\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}\end{array}\right)$

According to the number of the load, the corresponding loop impedance matrix is obtained as follows:

$\mathrm{<span\; class="notranslate">\; Z</span>}{\stackrel{<span\; class="notranslate">\; \&CenterDot;</span>}{\mathrm{<span\; class="notranslate">\; I</span>}}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; =</span>{\stackrel{<span\; class="notranslate">\; \&Center\; Dot;</span>}{\mathrm{<span\; class="notranslate">\; u</span>}}}_{\mathrm{<span\; class="notranslate">\; m</span>}}$

In the formula, is the calculated value of the load point current, is the exact value of the voltage at the measuring point.

The branch current calculation module is used to obtain the current calculation value of each branch according to the loop impedance matrix of the grid topology and the voltage values of all load nodes.

The branch current error calculation module is used to make a difference between the current measurement value and the current calculation value of each branch in the grid topology to obtain the current error of each branch in the grid topology.

The power stealing user determination module is used to calculate the ratio of the current error of each branch in the power grid topology to the current calculation value, and compare it with the preset current error ratio threshold to finally determine the location of the power stealing user.

The power stealing user determination module includes,

The branch current error ratio calculation module is used to calculate the ratio of the current error of each branch in the grid topology to the current calculation value, and obtain the current error ratio of each branch;

The fault branch determination module is used to compare the current error ratio of each branch with the preset current error ratio threshold. If the latter is smaller than the former, it is judged that there is a power stealing user in the corresponding branch, and the corresponding branch is determined as a fault branch. road.

The power-stealing user locating module is used to determine that the common load node is a power-stealing user when there is a common load node in two faulty branches.

The present invention compares the sum of the current values at all load nodes of the power grid feeder line with the total current value flowing into the load side of the power grid to preliminarily judge whether there is an abnormal power consumption phenomenon, and then according to the current error ratio of each branch and the preset current Compared with the error ratio threshold, the location of the electricity stealing user is finally determined; at the same time, the present invention does not need to add special devices to the existing network, and only needs to install a power metering device to detect the total power information flowing into the load side of the power grid and each load node. The power information at the location is input into the data server, and the algorithm in the data server is simple and easy for computer implementation.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, some improvements and modifications can also be made. It should also be regarded as the protection scope of the present invention.

Claims (6)

1. A monitoring and location method for power grid stealing users, characterized in that: comprising the following steps, Step 1, obtain the total voltage and current value flowing into the load side of the power grid, and obtain the voltage and current value at each load node of the power grid feeder line; Step 2. By comparing the sum of the current values at all load nodes of the power grid feeder line with the total current value flowing into the load side of the power grid, it is preliminarily judged whether there is any abnormal power consumption phenomenon. If there is an abnormal power consumption phenomenon, go to step 3 , if there is no abnormal power consumption phenomenon, determine the power stealing user; Step 3, obtain the topological structure information of the power grid, and construct the loop impedance matrix of the power grid topology; Step 4, according to the loop impedance matrix of the grid topology and the voltage values of all load nodes, the current calculation value of each branch is obtained; Step 5, making a difference between the current measurement value and the current calculation value of each branch in the grid topology, to obtain the current error of each branch in the grid topology; The current measurement value is the current value at each load node of the grid feeder line; Step 6: Calculate the ratio of the current error of each branch in the power grid topology to the current calculation value, and compare it with the preset current error ratio threshold, and finally determine the location of the power-stealing user. 2. A method for monitoring and locating power grid stealing users according to claim 1, characterized in that: if the ratio of the current error of the branch to the current calculation value is greater than the preset current error ratio threshold, then it is determined that the branch is It is a faulty branch, and there are power-stealing users on this branch. 3. A method for monitoring and locating power grid stealing users according to claim 2, characterized in that: if there is a common load node in the two faulty branches, then the common load node is a power stealing user. 4. The system based on the monitoring and positioning method of a kind of power stealing user in the power grid according to claim 1 is characterized in that: it includes a data server, a total electric energy metering device and some load node electric energy metering devices; A total metering device, a load node electric energy metering device is installed at each load node of the grid feeder line, and the electric energy total metering device and the load node electric energy metering device are both connected to the data server; The total electric energy metering device is used to measure and send the total voltage and current value flowing into the load side of the grid; The load node electric energy metering device is used to measure and send the voltage and current value at each load node of the power grid feeder line; The data server includes a sequentially connected power information acquisition module, an abnormal power consumption preliminary judgment module, a grid topology information acquisition module, a branch current calculation module, a branch current error calculation module, and a power stealing user determination module; The power information acquisition module is used to obtain the total voltage and current value flowing into the load side of the power grid, and obtain the voltage and current value at each load node of the power grid feeder line; The abnormal power consumption preliminary judgment module is used to preliminarily judge whether there is an abnormal power consumption phenomenon by comparing the sum of the current values at all load nodes of the power grid feeder line with the total current value flowing into the load side of the power grid; The power grid topology information acquisition module is used to obtain the power grid topology information and construct the loop impedance matrix of the power grid topology when abnormal power consumption occurs; The branch current calculation module is used to obtain the current calculation value of each branch according to the loop impedance matrix of the grid topology and the voltage values of all load nodes; The branch current error calculation module is used to make a difference between the current measurement value and the current calculation value of each branch in the grid topology to obtain the current error of each branch in the grid topology; The power stealing user determination module is used to calculate the ratio of the current error of each branch in the power grid topology to the current calculation value, and compare it with the preset current error ratio threshold to finally determine the location of the power stealing user. 5. The system based on the monitoring and positioning method of a power grid stealing user according to claim 4, characterized in that: the power stealing user determination module includes, The branch current error ratio calculation module is used to calculate the ratio of the current error of each branch in the grid topology to the current calculation value, and obtain the current error ratio of each branch; The fault branch determination module is used to compare the current error ratio of each branch with the preset current error ratio threshold. If the latter is smaller than the former, it is judged that there is a power stealing user in the corresponding branch, and the corresponding branch is determined as a fault branch. road. 6. The system based on the monitoring and positioning method of a power grid stealing user according to claim 5, characterized in that: the stealing user determination module also includes a stealing user positioning module, which is used to act as two fault branches There is a common load node, and it is determined that the common load node is a power stealing user.