An improved calculation method for line loss and voltage loss in substations

Abstract

The present invention provides an improved calculation method for the voltage loss method of the substation line loss, including: obtaining the voltage curve data on the distribution transformer side of the distribution substation to be calculated, and checking the validity of the voltage data on the distribution transformer side; obtaining the voltage and current curve data on the user side, and checking the validity and completeness of the voltage and current data on the user side; and calculating the technical line loss of the distribution substation according to the improved calculation method of voltage loss. The feature of the present invention is that the weighted average method of user-side current is adopted to reduce the strict requirements of the voltage loss method on data completeness. In the improved method, the user-side data is synchronously increased and decreased in the numerator and denominator of the calculation formula. When the data of non-main users is missing, or the user data at a small number of time points is incomplete, the calculation result is not greatly affected, thereby effectively improving the applicability of the voltage loss method in engineering practice and providing strong support for the technical management of substation line loss.

Description

Technical Field

[0001] The present invention relates to the field of low-voltage distribution network operation management, and in particular to an improved calculation method for a transformer area line loss and voltage loss method. Background Art

[0002] Calculating technical line loss using the voltage loss method is an effective support method for line loss management in substations. When the distribution line is free of voltage anomalies, calculating line voltage loss based on the voltages at the transformer and user sides accurately reflects the technical line loss caused by power transmission within the distribution network, given the current grid structure and user load characteristics. Currently, common voltage loss calculation methods require high data completeness. However, due to the large number of users in a substation, automated meter reading systems often struggle to achieve 100% success and completeness in collecting voltage and current curve data from all users, limiting their practical application value. Summary of the Invention

[0003] The purpose of the present invention is to improve the deficiencies of existing calculation methods, provide an improved calculation method for the line loss voltage loss method in the substation area, reduce the requirements for the completeness of user-side data, and improve the applicability of the line loss calculation of the voltage loss method in engineering practice.

[0004] The present invention is achieved through the following technical solutions:

[0005] In a first aspect, an improved calculation method for the line loss and voltage loss method in a transformer area is provided, comprising:

[0006] Step S1: obtaining the distribution transformer side voltage curve of the distribution substation to be calculated on a certain day, combining and preprocessing the distribution transformer side voltage curve data, and determining whether the processed distribution transformer side voltage data meets the calculation conditions;

[0007] Step S2: In response to the processed distribution transformer side voltage data meeting the calculation conditions, the voltage and current curves of all users in the substation area on that day are obtained, the voltage and current curve data of the users are combined and pre-processed, and it is determined whether the processed user voltage and current data meet the data conditions of the voltage loss method;

[0008] Step S3: In response to the processed distribution transformer side voltage data and the user voltage and current data meeting the data conditions of the voltage loss method, the technical line loss of the distribution station area is calculated using the improved voltage loss calculation method based on the processed distribution transformer side voltage data and the processed user voltage and current data.

[0009] In some embodiments, in step S3, based on the processed distribution transformer side voltage data and the processed user voltage and current data, the improved voltage loss calculation method is used to calculate the technical line loss δ of the distribution station area. U ,include:

[0010]

[0011] Where U 0j is the mean three-phase voltage on the distribution transformer side at time j; U ij , I ij are the voltage and current of user i at time j, respectively. The three phases of a three-phase user are calculated independently. n is the number of equivalent users, and a three-phase user is regarded as three users. k is the number of available data groups.

[0012] In some embodiments, in step S1, combining and preprocessing the distribution transformer side voltage curve data includes:

[0013] The voltage curve data of the distribution transformer side is combined at each time point to obtain the three-phase voltage of the distribution transformer side at each time point;

[0014] For the three-phase voltage on the distribution transformer side at each moment, calculate the maximum three-phase voltage difference ΔU group by group 0j ;

[0015] Based on the three-phase voltage on the distribution transformer side and the preset rated value U E , the maximum difference of three-phase voltage ΔU 0j , the abnormal three-phase voltage data on the distribution transformer side is eliminated to obtain the processed distribution transformer side voltage data.

[0016] Furthermore, in some embodiments, the maximum three-phase voltage difference ΔU is calculated 0j ,include:

[0017] ΔU 0j =max{U Aj 、U Bj 、U Cj}-min{U Aj 、U Bj 、U Cj}

[0018] Where U Aj 、U Bj 、U Cj are the three-phase voltages on the transformer side at time j respectively.

[0019] Furthermore, in some embodiments, based on the three-phase voltage on the distribution transformer side, the preset rated value U E , the maximum difference of three-phase voltage ΔU 0j , remove abnormal three-phase voltage data on the distribution transformer side, including:

[0020] If the three-phase voltage on the distribution transformer side is null;

[0021] Or the three-phase voltage on the distribution transformer side is lower than 0.78U E or higher than 1.22U E ;

[0022] or ΔU 0j >2V; the three-phase voltage on the distribution transformer side at that moment is treated as abnormal data and the entire group is eliminated.

[0023] In some embodiments, in step S1, determining whether the processed distribution transformer side voltage data meets the calculation conditions includes:

[0024] Whether the processed distribution transformer side voltage data meets the calculation conditions of the valid data group m>24, the distribution transformer side voltage data meets the calculation conditions.

[0025] Furthermore, in some embodiments, in step S2, combining and preprocessing the user's voltage and current curve data includes:

[0026] The voltage and current curve data of the user are combined at each time point to obtain the voltage U of user i at each time point. ij and current I ij ;

[0027] Calculate the voltage drop ΔU on the user side based on the three-phase voltage on the distribution transformer side and the voltage of user i at the corresponding moment ij ;

[0028] According to the user's voltage, current and preset rated value U E , Rated value I E , user side voltage drop ΔU ij , the abnormal user voltage and current data are eliminated to obtain the processed user voltage and current data.

[0029] Furthermore, in some embodiments, the user side voltage drop ΔU is calculated based on the three-phase voltage on the distribution transformer side and the voltage of user i at the corresponding moment. ij ,include:

[0030] ΔU ij =U 0j -U ij

[0031] Where U 0j is the mean three-phase voltage on the distribution transformer side at time j; U ij is the voltage of user i at time j, and the three phases of the three-phase user are calculated independently.

[0032] Furthermore, in some embodiments, according to the user voltage, current and preset rated value U E , Rated value I E , user side voltage drop ΔU ij , remove abnormal user voltage and current data, including:

[0033] If the user voltage is null;

[0034] Or the user voltage is lower than 0.78U E or higher than 1.22U E ;

[0035] Or the user current is higher than 1.22I E ;

[0036] Or user side voltage drop ΔU ij >15V, the voltage and current data points of the user at the corresponding time are eliminated, and the data group with a user data completeness rate greater than 80% is recorded as the available data group.

[0037] In some embodiments, in step S2, determining whether the processed user voltage and current data meet the data conditions of the voltage loss method includes:

[0038] The data group k>24, in which the completeness rate of user voltage and current data on that day is greater than 80%, meets the data conditions of the voltage loss method.

[0039] In a second aspect, the present invention provides an improved calculation device for a transformer area line loss and voltage loss method, comprising a processor and a storage medium;

[0040] The storage medium is used to store instructions;

[0041] The processor is configured to operate according to the instructions to execute the steps of the method according to the first aspect.

[0042] In a third aspect, the present invention provides a storage medium having a computer program stored thereon, which implements the steps of the method described in the first aspect when executed by a processor.

[0043] Advantages and beneficial effects of the present invention: The present invention adopts the user-side current weighted average method, and the user-side data increases and decreases synchronously in the numerator and denominator of the calculated value. When the user data at a small number of time points is incomplete or the non-main user data is missing, the calculation results of the improved calculation method are not greatly affected, which effectively reduces the requirements for the completeness of the user-side data and has great practical engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a flow chart of a method according to an embodiment of the present invention.

[0045] Figure 2 This is the voltage curve on the distribution transformer side in the example.

[0046] Figure 3 This is the voltage curve of all users in the substation area in the example.

[0047] Figure 4 This is the current curve of all users in the substation area in the example. DETAILED DESCRIPTION

[0048] The present invention will be further described below with reference to the accompanying drawings, and the specific steps are as follows:

[0049] Example 1

[0050] An improved calculation method for line loss and voltage loss in a transformer area includes:

[0051] Step S1: obtaining the distribution transformer side voltage curve of the distribution substation to be calculated on a certain day, combining and preprocessing the distribution transformer side voltage curve data, and determining whether the processed distribution transformer side voltage data meets the calculation conditions;

[0052] Step S2: In response to the processed distribution transformer side voltage data meeting the calculation conditions, the voltage and current curves of all users in the substation area on that day are obtained, the voltage and current curve data of the users are combined and pre-processed, and it is determined whether the processed user voltage and current data meet the data conditions of the voltage loss method;

[0053] Step S3: In response to the processed distribution transformer side voltage data and the user voltage and current data meeting the data conditions of the voltage loss method, the technical line loss of the distribution station area is calculated using the improved voltage loss calculation method based on the processed distribution transformer side voltage data and the processed user voltage and current data.

[0054] In some specific embodiments, an improved calculation method for a transformer area line loss and voltage loss method includes:

[0055] 1. Obtain the distribution transformer side voltage curve of the distribution area on a certain day from the automatic meter reading system. It is usually a 96-point density curve. Combine the curves according to the corresponding time points to obtain 96 groups of data. Calculate the maximum difference ΔU of the three-phase voltage for each group. 0j , the calculation formula is shown in formula (1).

[0056] ΔU 0j =max{U Aj 、U Bj 、U Cj}-min{U Aj 、U Bj 、U Cj} (1)

[0057] Where U Aj 、U Bj 、U Cj is the three-phase voltage on the transformer side at time j.

[0058] If the voltage is empty or exceeds the rated value U E ±22%, or ΔU 0j >2V, the entire abnormal data group is discarded. If the valid data group m>24, the distribution transformer side voltage data is considered to meet the calculation conditions.

[0059] 2. Obtain the voltage and current curves of all users in the area on that day from the automated meter reading system. Usually, they are 96-point density curves. Combine the curves at corresponding time points to obtain 96 sets of data. Calculate the user-side voltage drop ΔU for each group and household. ij , the calculation formula is shown in formula (2).

[0060] ΔU ij =U 0j -U ij (2)

[0061] Where U 0j is the mean three-phase voltage on the distribution transformer side at time j; U ij is the voltage of user i at time j, and the three phases of the three-phase user are calculated independently.

[0062] If the user voltage is null, or the voltage exceeds the rated value U E ±22%, or the current exceeds the rated value I E +22%, or ΔU ij >15V, the user data point is eliminated, and the data set with a user data completeness rate greater than 80% is recorded as the usable data set. If the number of usable data sets k>24, it is considered that the data conditions of the voltage loss method are met.

[0063] 3. According to the improved calculation formula, that is, formula (2), calculate the technical line loss δ of the distribution station area U .

[0064]

[0065] Where, I ij is the current of user i at time j; n is the number of equivalent users, and a three-phase user is regarded as three users; k is the number of available data groups.

[0066] In order to illustrate the implementation of the present invention in more detail, actual data are used for illustration below.

[0067] There are 86 single-phase users and 8 three-phase users in a certain distribution substation. The data collection time for all users is 15 minutes.

[0068] (1) Obtain the voltage data of the distribution transformer side on March 19, 2022 from the automated meter reading system, such as Figure 2 As shown, after combining the curve data and checking the data validity, 96 valid data groups are obtained, that is, m>24, and the voltage data on the distribution transformer side meets the calculation conditions.

[0069] (2) The voltage and current curves of all users (94 households) in the substation area on March 19, 2022, are obtained from the automatic meter reading system. Figure 3 、 Figure 4As shown, after combining the curve data, checking the data validity and completeness, 95 groups of available data were obtained, that is, k>24, which meets the data conditions of the voltage loss method.

[0070] (3) According to the improved calculation formula, calculate the technical line loss δ of the distribution station area U It is 0.22%.

[0071] Example 2

[0072] In a second aspect, this embodiment provides an improved calculation device for a transformer area line loss and voltage loss method, including a processor and a storage medium;

[0073] The storage medium is used to store instructions;

[0074] The processor is configured to operate according to the instructions to execute the steps of the method according to embodiment 1.

[0075] Example 3

[0076] In a third aspect, this embodiment provides a storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described in Example 1 are implemented.

[0077] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0078] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0079] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0080] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0081] With respect to the above description of the disclosed embodiments, those skilled in the art should understand that the above description is only a specific implementation manner of the present invention and does not limit the scope of protection of the present invention. Any technical solution obtained by any equivalent replacement or equivalent transformation should be included in the scope of protection of the present invention.

Claims

1. An improved calculation method for line loss and voltage loss in a transformer area, characterized in that: The following steps are involved: Step S1: obtaining the distribution transformer side voltage curve of the distribution substation to be calculated on a certain day, combining and preprocessing the distribution transformer side voltage curve data, and determining whether the processed distribution transformer side voltage data meets the calculation conditions; Step S2: In response to the processed distribution transformer side voltage data meeting the calculation conditions, the voltage and current curves of all users in the substation area on that day are obtained, the voltage and current curve data of the users are combined and pre-processed, and it is determined whether the processed user voltage and current data meet the data conditions of the voltage loss method; Step S3: In response to the processed distribution transformer side voltage data, user voltage and current data meeting the data conditions of the voltage loss method, the improved voltage loss calculation method is used to calculate the technical line loss δ of the distribution station area based on the processed distribution transformer side voltage data and the processed user voltage and current data. U , include: Where U 0j is the mean three-phase voltage on the distribution transformer side at time j; U ij , I ij are the voltage and current of user i at time j, respectively. The three phases of a three-phase user are calculated independently. n is the number of equivalent users, and a three-phase user is regarded as three users. k is the number of available data groups.

2. The improved calculation method of the line loss and voltage loss method of the transformer area according to claim 1 is characterized in that: In step S2, determining whether the processed user voltage and current data meet the data conditions of the voltage loss method includes: The data group k>24, in which the completeness rate of user voltage and current data on that day is greater than 80%, meets the data conditions of the voltage loss method.

3. The improved calculation method of the line loss and voltage loss method of a transformer substation according to claim 1, characterized in that: In step S1, the distribution transformer side voltage curve data is combined and preprocessed, including: The voltage curve data of the distribution transformer side is combined at each time point to obtain the three-phase voltage of the distribution transformer side at each time point; For the three-phase voltage on the distribution transformer side at each moment, calculate the maximum three-phase voltage difference ΔU group by group 0j ; Based on the three-phase voltage on the distribution transformer side and the preset rated value U E , the maximum difference of three-phase voltage ΔU 0j , the abnormal three-phase voltage data on the distribution transformer side is eliminated to obtain the processed distribution transformer side voltage data.

4. The improved calculation method of the line loss and voltage loss method of the transformer substation according to claim 3 is characterized in that: Calculate the maximum three-phase voltage difference ΔU 0j ,include: ΔU 0j =max{U Aj 、U Bj 、U Cj }-min{U Aj 、U Bj 、U Cj } Where U Aj 、U Bj 、U Cj are the three-phase voltages on the transformer side at time j respectively.

5. The improved calculation method of the line loss and voltage loss method of the transformer area according to claim 3 is characterized in that: Based on the three-phase voltage on the distribution transformer side and the preset rated value U E , the maximum difference of three-phase voltage ΔU 0j , remove abnormal three-phase voltage data on the distribution transformer side, including: If the three-phase voltage on the distribution transformer side is null; Or the three-phase voltage on the distribution transformer side is lower than 0.78U E or higher than 1.22U E ; or ΔU 0j >2V; the three-phase voltage on the distribution transformer side at that moment is treated as abnormal data and the entire group is eliminated.

6. The improved calculation method of the line loss and voltage loss method of a transformer substation according to claim 1, characterized in that: In step S1, determining whether the processed distribution transformer side voltage data meets the calculation conditions includes: Whether the processed distribution transformer side voltage data meets the calculation conditions of the valid data group m>24, the distribution transformer side voltage data meets the calculation conditions.

7. The improved calculation method of the line loss and voltage loss method of a transformer substation according to claim 1, characterized in that: In step S2, the user's voltage and current curve data are combined and pre-processed. include: The voltage and current curve data of the user are combined at each time point to obtain the voltage U of user i at each time point. ij and current I ij ; Calculate the voltage drop ΔU on the user side based on the three-phase voltage on the distribution transformer side and the voltage of user i at the corresponding moment ij ; According to the user's voltage, current and preset rated value U E , Rated value I E , user side voltage drop ΔU ij , the abnormal user voltage and current data are eliminated to obtain the processed user voltage and current data.

8. The improved calculation method of the line loss and voltage loss method of the transformer area according to claim 7 is characterized in that: Calculate the voltage drop ΔU on the user side based on the three-phase voltage on the distribution transformer side and the voltage of user i at the corresponding moment ij ,include: ΔU ij =U 0j -U ij Where U 0j is the mean three-phase voltage on the distribution transformer side at time j; U ij is the voltage of user i at time j, and the three phases of the three-phase user are calculated independently.

9. The improved calculation method of the line loss and voltage loss method of the transformer substation according to claim 7, characterized in that: According to the user's voltage, current and preset rated value U E , Rated value I E , user side voltage drop ΔU ij , remove abnormal user voltage and current data, including: If the user voltage is null; Or the user voltage is lower than 0.78U E or higher than 1.22U E ; Or the user current is higher than 1.22I E ; Or user side voltage drop ΔU ij >15V, the voltage and current data points of the user at the corresponding time are eliminated, and the data group with a user data completeness rate greater than 80% is recorded as the available data group.

10. An improved calculation device for the line loss and voltage loss method of a transformer substation, characterized in that: including processor and storage medium; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to execute the steps of the method according to any one of claims 1 to 9.

11. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.

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