CN110768256A - A method, device and system for identifying topology of station area based on voltage harmonic spectrum - Google Patents

Abstract

The invention discloses a method, device and system for identifying the topology of a station area based on a voltage harmonic spectrum, belonging to the field of low-voltage distribution automation systems. The method performs the topology identification of the platform area by comparing the voltage harmonic spectrum distance between the transformer in the station area and the household meter; the device is composed of a three-phase voltage acquisition module, a local communication module and a main processing module, and the three-phase voltage acquisition module is used for Collect the voltage on the low-voltage side of the transformer in the station area, and the local communication module is used to collect the voltage harmonic data of each household meter. The main processing module is used to calculate the voltage harmonic spectrum and compare the voltage harmonic spectrum distance between the station area and the household meter. Topology identification; the system consists of multiple identification devices and servers deployed in different station areas. The server is used to identify the zone and the category to which the abnormal user list belongs. The invention can effectively identify and verify the correctness of the topology structure data of the low-voltage distribution network, and improve the informationization and intelligence level of the management of the low-voltage distribution network.

Description

A method, device and system for identifying topology of station area based on voltage harmonic spectrum

technical field

The invention belongs to the field of low-voltage power distribution automation systems, and more particularly, relates to a method, device and system for identifying a topology of a station area based on a voltage harmonic spectrum.

Background technique

The platform area (or low-voltage platform area) refers to the power supply area on the low-voltage side of the 10kV/0.4kV distribution transformer. The topology of the station area refers to the relationship between the station area and the household meter (station area-household), and further, it is the affiliation of the household meter belonging to a certain phase of the three phases A, B, and C in the station area (station area-household). phase-household). In the construction of the information system of the distribution network, it is necessary to sort out the distribution relationship. On the basis of the graphical display of the power grid GIS platform, an accurate "station-line-transformation (station area)-household" relationship should be established to realize the distribution network. The informatization and intelligence of power grid power management will improve the service level of smart power consumption and the operational efficiency of production and marketing.

In the past, not enough attention was paid to the station area. There are mainly two wrong manifestations in the topology relationship of the station area, especially the household change relationship: (1) Some users have incomplete user file information due to historical reasons; (2) The topology of user file information records The relationship does not match the actual topological relationship. These errors will affect the normal development of services based on the distribution network topology. In order to check and correct these errors, the common practice of power grid companies is: when the actual topology of the distribution network changes, they need to manually record these changes and update the platform-related data, or specially organize human field inspections to correct these errors. These methods consume a lot of manpower, time, and accuracy.

Therefore, the correct identification and verification of the topology relationship of the low-voltage distribution network, especially the correct household-transformation relationship, is the basis and key to the refinement of the current distribution network management.

SUMMARY OF THE INVENTION

Aiming at the above defects or improvement needs of the prior art, the present invention proposes a method, device and system for identifying the topology of a station area based on a voltage harmonic spectrum, thereby solving the problem of existing problems when the actual topology structure of the distribution network changes. The technical problems of manual identification and verification of the topology relationship of low-voltage distribution network are time-consuming, labor-intensive and inaccurate.

In order to achieve the above object, according to one aspect of the present invention, a method for identifying the topology of a station area based on a voltage harmonic spectrum is provided, comprising:

Measure the voltage of each phase on the low-voltage side of the distribution transformer in the station area, and obtain the voltage harmonic spectrum of each phase of the distribution transformer in the station area through harmonic analysis;

Use the local metering network to obtain the voltage harmonic content rate of each household meter to form the voltage harmonic spectrum of each household meter;

Obtain the target distance between the voltage harmonic spectrum of each of the household meters and the voltage harmonic spectrum of each phase of the distribution transformer in the station area, and determine each household according to the relationship between the target distance and the preset distance threshold. Whether the table belongs to the said station area.

Preferably, the acquisition of the target distance between the voltage harmonic spectrum of each household meter and the voltage harmonic spectrum of each phase of the distribution transformer in the station area is based on the difference between the target distance and a preset distance threshold. relationship, to determine whether each household table belongs to the said station area, including:

For the voltage harmonic spectrum of any target household meter, obtain the minimum value of the distance between the voltage harmonic spectrum of the target household meter and the voltage harmonic spectrum of each phase of the distribution transformer in the station area;

If the minimum value of the distance is greater than the preset distance threshold, it is determined that the target household table does not belong to the station area;

If the minimum value of the distance is less than the preset distance threshold, it is determined that the target household table belongs to the station area, and the phase where the target household table is located is the phase corresponding to the minimum value of the distance.

According to another aspect of the present invention, there is provided a station topology identification device based on a voltage harmonic spectrum, comprising: a three-phase voltage acquisition module, a local communication module and a main processing module;

The three-phase voltage acquisition module is used to measure the voltage of each phase on the low-voltage side of the distribution transformer in the platform area;

The local communication module is used to communicate with each household meter in the local network to obtain the voltage harmonic content rate of each household meter;

The main processing module is used to obtain the voltage harmonic spectrum of each phase of the distribution transformer in the station area through harmonic analysis, and form the voltage harmonic spectrum of each household meter according to the voltage harmonic content rate of each household meter, and obtain the voltage harmonic spectrum of each household meter. The target distance between the voltage harmonic spectrum of each household meter and the voltage harmonic spectrum of each phase of the distribution transformer in the station area is determined according to the relationship between the target distance and the preset distance threshold. Whether it belongs to the said station area.

Preferably, the main processing module is specifically used to obtain the voltage harmonic spectrum of the target household meter and the voltage harmonic spectrum of each phase of the distribution transformer in the station area for the voltage harmonic spectrum of any target household meter The minimum value of the distance between them; if the minimum value of the distance is greater than the preset distance threshold, it is determined that the target household table does not belong to the station area; if the minimum value of the distance is less than the preset distance threshold , then it is determined that the target household table belongs to the station area, and the phase where the target household table is located is the phase corresponding to the minimum value of the distance.

Preferably, the device further comprises: a remote communication module;

The remote communication module is used to report the ID of the household meter that does not belong to the station area, its voltage harmonic spectrum, and the voltage harmonic spectrum of the station area.

Preferably, the device further comprises: a human-machine interface module, a power supply module and a storage module;

The man-machine interface module is used for on-site information viewing;

the power supply module, used to provide power for the device;

The storage module is used to store information such as configuration information and local voltage harmonic spectrum.

According to another aspect of the present invention, a system for identifying the topology of a station area based on a voltage harmonic spectrum is provided, comprising: a server and the station area based on the voltage harmonic spectrum according to any one of the above-mentioned voltage harmonic atlases deployed in a plurality of station areas topology identification device;

The server is configured to receive the three-phase voltage harmonic spectrum of each station area, the ID of the abnormal household meter and the voltage harmonic spectrum of each abnormal household meter reported by each of the devices, and for any target abnormal household meter, obtain the The distance between the voltage harmonic spectrum of the target abnormal household meter and the voltage harmonic spectrum of each phase of each station area, find the minimum distance, the station area corresponding to the minimum distance is the station area to which the target abnormal household meter belongs, and the The phase of the station area corresponding to the minimum distance is the phase of the station area to which the target abnormal household table belongs.

In general, compared with the prior art, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

(1) The station topology identification method provided by the present invention has higher accuracy and reliability. Using the voltage harmonic spectrum distance as the judgment basis, it reflects the load composition and operation characteristics of the corresponding station area that is different from other stations, which is the essential feature that distinguishes it from other stations, so it can ensure its accuracy. At the same time, the transformer in the station area has a natural isolation effect on the voltage harmonic spectrum, that is, when the harmonic crosstalk to other stations through the transformer, it will be distorted and superimposed with the harmonics of other stations to form a new harmonic spectrum. The harmonic spectrum of the original station area must be very different, avoiding the crosstalk problem of the traditional method and ensuring its reliability;

(2) The method for identifying the topology of the station area based on the voltage harmonic spectrum provided by the present invention has the advantages of less computation, quickness and simplicity.

(3) The device used in the present invention is deployed on the low-voltage side of the transformer in each station area, and the distance of the voltage harmonic spectrum is calculated in a distributed manner, avoiding the disadvantage of high concentration and large amount of calculation in the traditional method, and saving communication traffic and computing resources. .

Description of drawings

1 is a schematic flowchart of a method for identifying a topology of a station area based on a voltage harmonic spectrum provided by an embodiment of the present invention;

2 is a structural diagram of a device provided by an embodiment of the present invention;

FIG. 3 is a structural diagram of a station topology identification system based on a voltage harmonic spectrum provided by an embodiment of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

The invention provides a method, device and system for identifying the topology of a station area based on a voltage harmonic spectrum. Using the principle that the voltage harmonic spectrum of the transformer in the same station area is similar to that of the household meter, the identification and identification of the topology relationship between household transformers in a low-voltage distribution network are realized. The verification solves the problem of inconsistency or even omission between the topological relationship of the user file information record and the actual topological relationship, and provides a basis for improving the reliability of power supply, realizing the four-point management of line loss, and improving the level of customer service.

As shown in FIG. 1 is a schematic flowchart of a method for identifying the topology of a station area based on a voltage harmonic spectrum provided by an embodiment of the present invention. The method shown in FIG. 1 includes the following steps:

S1: Obtain the voltage harmonic spectrum of the station area;

In the embodiment of the present invention, the voltage harmonic map represents a set of multi-dimensional vectors composed of the content ratios of various harmonics of the voltage. The harmonics of the voltage can be obtained by performing a Fast Fourier Transform (FFT) on the sequence of voltage samples.

On the low-voltage side of the transformer in the station area, measure the voltage of each phase, and obtain the voltage harmonic spectrum of the three-phase transformer A, B, and C through harmonic analysis, which are UGA, UGB, and UGC, respectively.

S2: Obtain the voltage harmonic spectrum of the household meter;

Use the local metering network to obtain the harmonic content rate of each household meter voltage to form a voltage harmonic map UGM;

S3: Calculation and Recognition:

The distance between the household meter voltage harmonic spectrum and the transformer voltage harmonic spectrum is calculated by Euclidean Distance. Let the vector X={x _i |i=1,2,…N}, x _i represent the i-th element of the voltage harmonic vector X, and the vector Y={y _i |i=1,2,…N}, y _i represents the ith element of the voltage harmonic vector Y. The Euclidean distance between the two sets of harmonic vectors X and Y is defined as:

N represents the maximum voltage harmonic order. In the embodiment of the present invention, the maximum voltage harmonic order is generally 31.

Comparing the distances between the voltage harmonic spectrum UGM of each household meter and the three-phase voltage harmonic spectrum UGA, UGB and UGC of the station area are D(UGM,UGA), D(UGM,UGB) and D(UGM,UGC respectively );

The one with the smallest distance is:

D _min =MIN{D(UGM,UGA),D(UGM,UGB),D(UGM,UGC)};

Set an appropriate distance threshold thD to determine whether the user belongs to the station area:

When D _min is greater than the threshold thD, it is considered that the household table does not belong to the station area;

When D _min is less than the threshold thD, it is considered that the household table belongs to the station area, and the phase where the household table is located is the corresponding phase corresponding to D _min .

In order to further increase the accuracy of identification, according to the different penetration of different harmonics to the transformer, the weight coefficient matrix K={k _i |i=1,2,…N} can be set, where 0≤k _i ≤1 . At this time, the calculation formula of the distance between the voltage harmonic spectra is improved as:

x_i表示电压谐波向量X的第i个元素，y_i表示电压谐波向量Y的第i个元素。Among them, X and Y respectively represent the two sets of vectors corresponding to the voltage harmonic spectrum, N represents the maximum harmonic order; k _i represents the weight coefficient of the i-th harmonic in the voltage harmonic spectrum, which is used to enhance the high-order harmonics in the voltage spectrum. The effect in , the larger _i is, the larger the value ki is, and the uniqueness is not limited in this embodiment of the present invention. An optional value of k _i is a discrete sequence

_xi represents the ith element of the voltage harmonic vector X, and _yi represents the ith element of the voltage harmonic vector Y.

In this embodiment of the present invention, the distance threshold thD may be determined according to actual needs, which is not uniquely limited in this embodiment of the present invention.

In the embodiment of the present invention, the distance between the voltage harmonic spectrum of the household meter and the voltage harmonic spectrum of the low voltage side of the transformer reflects that the distance between the voltage harmonic spectrum of the household meter and the voltage harmonic spectrum of the low voltage side of the transformer in the same station area is smaller, There is a large distance between the voltage harmonic spectrum of the household meter and the voltage harmonic spectrum of the low-voltage side of the transformer that are not in the same station area.

In the embodiment of the present invention, considering the dynamic changes of voltage harmonics, when acquiring the voltage harmonic spectrum in step S1 and step S2, clock synchronization between the topology identification device and the user's electricity meter needs to be performed to obtain the same time period. Taiwan area voltage harmonics and user meter voltage harmonics.

Figure 2 is a structural diagram of a device provided by an embodiment of the present invention. The device shown in Figure 2 includes: a three-phase voltage acquisition module, a local communication module, a main processing module, and a remote communication module.

As an optional implementation manner, the device further includes: a human-machine interface module, a power supply module and a storage module to form a complete terminal device.

The functions of each module of the device are described in detail as follows:

①The three-phase voltage acquisition module is used to collect the low-voltage side voltage of the transformer in the station area, and the voltage sampling value is sent to the main processing module; ②The local communication module is used to communicate with each meter in the local network, and obtain the harmonic content rate of each order of the meter; ③The main processing module is used to send instructions to the acquisition module and the local communication module to obtain the voltage harmonic spectrum on the low-voltage side of the transformer and the voltage harmonic spectrum on the user side of the meter, and use the above-mentioned voltage harmonic spectrum-based topology identification method to identify those that do not belong to the The household meter in this station area; ④The remote communication interface is used to report the harmonic voltage and harmonic spectrum, the household meter ID and its voltage harmonic spectrum that do not belong to the station area; ⑤The man-machine interface module uses buttons and screens for on-site information View; ⑥ The power supply module provides the power supply of the entire device; ⑦ The storage module is used to store the configuration information and the local voltage harmonic map and other information.

As shown in FIG. 3 is a structural diagram of a station topology identification system based on a voltage harmonic spectrum provided by an embodiment of the present invention. The specific implementation process is as follows:

(a) Let the voltage harmonic spectrum of abnormal household meter x be UGM(x), and the voltage harmonic spectrum of station j be UGA(j), UGB(j), UGC(j);

(b) For station area j, calculate the Euclidean distance between UGM(x) and UGA(j), UGB(j), and UGC(j), and take the smallest Dmin(j);

(c) Repeat step (b) for all the stations in the target area to obtain the distance between all stations and the household meter x voltage harmonic spectrum, sort them, and take the station area and phase corresponding to the smallest Dmin, which is the meter to which the meter belongs. Taiwan area and its differences;

(d) Repeat steps (a) to (c) until all abnormal electricity meters are identified.

The following is an illustration as shown in Figure 3 as an example of implementation:

In the implementation example of the invention, the system consists of a server and a plurality of devices deployed on the low-voltage side of the distribution transformer in each station.

In this embodiment, each part is described as follows:

(1) each station area topology identification device recognizes that the household table that does not belong to the station area is abnormal household table x through the steps described in a kind of station area topology identification method based on voltage harmonic spectrum;

(2) The topology identification device of the station area reports the voltage harmonic spectrum UGA(j), UGB(j), UGC(j), the ID of the abnormal household meter x and its voltage harmonic spectrum UGM(x) to the server in the station area j ;

(3) The server uses the above steps (a) to (d) to calculate and identify the station area to which each abnormal household table belongs and the difference.

It should be pointed out that, according to the needs of implementation, the various steps/components described in this application may be split into more steps/components, or two or more steps/components or partial operations of steps/components may be combined into new steps/components to achieve the purpose of the present invention.

Those skilled in the art can easily understand that the above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, etc., All should be included within the protection scope of the present invention.

Claims (7)

1. a platform topology identification method based on voltage harmonic spectrum, is characterized in that, comprises: Measure the voltage of each phase on the low-voltage side of the distribution transformer in the station area, and obtain the voltage harmonic spectrum of each phase of the distribution transformer in the station area through harmonic analysis; Use the local metering network to obtain the voltage harmonic content rate of each household meter to form the voltage harmonic spectrum of each household meter; Obtain the target distance between the voltage harmonic spectrum of each of the household meters and the voltage harmonic spectrum of each phase of the distribution transformer in the station area, and determine each household according to the relationship between the target distance and the preset distance threshold. Whether the table belongs to the said station area. 2. The method according to claim 1, wherein the acquisition of the target distance between the voltage harmonic spectrum of each of the household meters and the voltage harmonic spectrum of each phase of the distribution transformer in the station area is based on The relationship between the target distance and the preset distance threshold, to determine whether each household table belongs to the station area, includes: For the voltage harmonic spectrum of any target household meter, obtain the minimum value of the distance between the voltage harmonic spectrum of the target household meter and the voltage harmonic spectrum of each phase of the distribution transformer in the station area; If the minimum value of the distance is greater than the preset distance threshold, it is determined that the target household table does not belong to the station area; If the minimum value of the distance is less than the preset distance threshold, it is determined that the target household table belongs to the station area, and the phase where the target household table is located is the phase corresponding to the minimum value of the distance. 3. A station topology identification device based on a voltage harmonic spectrum, characterized in that, comprising: a three-phase voltage acquisition module, a local communication module and a main processing module; The three-phase voltage acquisition module is used to measure the voltage of each phase on the low-voltage side of the distribution transformer in the platform area; The local communication module is used to communicate with each household meter in the local network to obtain the voltage harmonic content rate of each household meter; The main processing module is used to obtain the voltage harmonic spectrum of each phase of the distribution transformer in the station area through harmonic analysis, and form the voltage harmonic spectrum of each household meter according to the voltage harmonic content rate of each household meter, and obtain the voltage harmonic spectrum of each household meter. The target distance between the voltage harmonic spectrum of each household meter and the voltage harmonic spectrum of each phase of the distribution transformer in the station area is determined according to the relationship between the target distance and the preset distance threshold. Whether it belongs to the said station area. 4. The device according to claim 3, wherein the main processing module is specifically used to obtain the voltage harmonic spectrum of the target household meter and the voltage harmonic spectrum of the target household meter for any target household meter. The minimum value of the distance between the voltage harmonic spectra of each phase of the distribution transformer in the station area; if the minimum value of the distance is greater than the preset distance threshold, it is determined that the target household meter does not belong to the station area; If the minimum value of the distance is smaller than the preset distance threshold, it is determined that the target household table belongs to the station area, and the phase of the target household table is the phase corresponding to the minimum value of the distance. 5. The device according to claim 3 or 4, wherein the device further comprises: a remote communication module; The remote communication module is used to report the ID of the household meter that does not belong to the station area, its voltage harmonic spectrum, and the voltage harmonic spectrum of the station area. 6. The device according to claim 5, wherein the device further comprises: a human-machine interface module, a power supply module and a storage module; The man-machine interface module is used for on-site information viewing; the power supply module, used to provide power for the device; The storage module is used to store information such as configuration information and local voltage harmonic spectrum. 7. A station topology identification system based on a voltage harmonic atlas, characterized in that, comprising: a server and a station based on a voltage harmonic atlas according to any one of claims 3 to 6 deployed in a plurality of stations. District topology identification device; The server is configured to receive the three-phase voltage harmonic spectrum of each station area, the ID of the abnormal household meter, and the voltage harmonic spectrum of each abnormal household meter reported by each of the devices, and for any target abnormal household meter, obtain the The distance between the voltage harmonic spectrum of the target abnormal household meter and the voltage harmonic spectrum of each phase of each station area, find the minimum distance, and the station area corresponding to the minimum distance is the station area to which the target abnormal household meter belongs. The phase of the station area corresponding to the minimum distance is the phase of the station area to which the target abnormal household table belongs.

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