A method for predicting the synchronous line loss rate of a distribution substation based on equivalent resistance.

Abstract

This invention provides a method for predicting the synchronous line loss rate of a distribution transformer substation based on equivalent resistance, belonging to the field of line loss management technology. The method includes: acquiring the three-phase current and zero-sequence current curves of the distribution transformer substation to be predicted over a historical period, and calculating the load waveform characteristic coefficient; acquiring the daily power supply and daily synchronous line loss rate of the substation during this period, solving the synchronous line loss rate model of the distribution transformer substation based on equivalent resistance, and obtaining substation characteristic parameters such as equivalent resistance, foundation loss, and metering comprehensive deviation; and predicting the synchronous line loss rate of the substation under different power supply volumes. This invention proposes the concept of equivalent resistance, breaking through the usual theoretical calculation methods. It eliminates the need for parameters that are difficult to obtain accurately, such as the low-voltage line network structure, conductor type, and wire diameter, thus enabling the prediction of the synchronous line loss rate of the substation. It has practical engineering application value, can guide relevant personnel to formulate assessment indicators that conform to actual conditions, and provides effective support for the timely detection and management of substations with abnormal line losses.

Description

Technical Field

[0001] This invention relates to the field of line loss management technology, and in particular to a method for predicting the synchronous line loss rate of a distribution substation based on equivalent resistance. Background Technology

[0002] Synchronous line loss in distribution transformer substations is a comprehensive technical and economic indicator reflecting the production technology and management level of power supply enterprises. Distribution transformer substations have complex lines with numerous nodes, branches, and components, and the influencing factors on synchronous line loss are complex and diverse, posing a significant challenge to refined line loss management. Therefore, accurately predicting the synchronous line loss rate of distribution transformer substations, helping relevant personnel to formulate realistic performance indicators, and fully realizing the value of electrical energy has become a pressing practical problem that needs to be analyzed and solved. Summary of the Invention

[0003] Based on this, the present invention proposes a method for predicting the synchronous line loss rate of a distribution transformer area based on equivalent resistance, so as to realize the prediction of the synchronous line loss rate under different power supply volumes in the transformer area.

[0004] This invention is achieved through the following technical solution:

[0005] Firstly, a method for predicting the synchronous line loss rate of a distribution substation based on equivalent resistance is provided, including:

[0006] Step S1: Obtain the three-phase current and zero-sequence current curve data of the distribution transformer in the distribution area to be predicted over a historical period of time. Combine and preprocess the three-phase current and zero-sequence current curve data of the distribution transformer to obtain the preprocessed three-phase current and zero-sequence current curve data of the distribution transformer. Calculate the load waveform characteristic coefficient using the preprocessed three-phase current and zero-sequence current curve data of the distribution transformer.

[0007] Step S2: Obtain the power supply and synchronous line loss rate data of the corresponding distribution substation for each cycle during this period, combine and preprocess the power supply and synchronous line loss rate data to obtain the preprocessed power supply and synchronous line loss rate data.

[0008] Step S3: Based on the preprocessed power supply and line loss rate data of the transformer area and the corresponding load waveform characteristic coefficients, construct the overdetermined equation, and solve it to obtain the equivalent resistance, base loss and metering comprehensive deviation of the line loss rate prediction model of the equivalent resistance method.

[0009] Step S4: Based on the power supply of the transformer area and the corresponding load waveform characteristic coefficient, use the equivalent resistance method line loss rate prediction model to calculate the predicted value of the synchronous line loss rate of the transformer area corresponding to different power supply quantities.

[0010] In some embodiments, a period of time consists of n0 line loss calculation cycles T, and the power supply of the distribution area, the synchronous line loss rate, and the three-phase current and zero-sequence current curves on the distribution transformer side all correspond to the data values ​​within cycle T.

[0011] Furthermore, if it is a daily loss rate, then T = 24h.

[0012] In some embodiments, step S1 involves combining and preprocessing the power supply data of the transformer substation and the concurrent line loss rate data, including:

[0013] Combine the three-phase current and zero-sequence current curves of the distribution transformer side within cycle T according to time points;

[0014] If at any given time, any one of the three-phase currents or zero-sequence current on the transformer side exceeds the rated value of 1.22I... E If the value is empty, all three-phase current and zero-sequence current data at that time point are discarded to obtain the distribution transformer three-phase current and zero-sequence current curve data at m valid time points.

[0015] In some embodiments, the method for calculating the load waveform characteristic coefficient t includes:

[0016]

[0017] In the formula, E k For the power supply of the transformer substation during period T; Ia j Ib j Ic j In j These represent the three-phase current and zero-sequence current of the transformer at time j within cycle T, respectively; m is the number of valid time points of the current curve within cycle T in the preprocessed three-phase current and zero-sequence current curve data of the transformer.

[0018] In some embodiments, step S2 involves combining and preprocessing the power supply data of the transformer substation and the concurrent line loss rate data, including:

[0019] Combine the power supply of the transformer area and the line loss rate during the same period according to the cycle;

[0020] If the power supply of the transformer area is not greater than 0 or greater than the rated value P E *T, P E The rated capacity of the distribution transformer is T, and the calculation period is T.

[0021] Alternatively, the line loss rate during the same period is less than -1% or greater than 100%.

[0022] If any of the above conditions occur, the entire set of power supply and synchronous line loss rate data for the transformer area will be removed, resulting in n sets of preprocessed valid power supply and synchronous line loss rate data for the transformer area.

[0023] In some embodiments, in step S3, the equivalent resistance method line loss rate prediction model includes three unknown parameters: T0, R0, and ε. Where T0 is the base loss of the transformer substation during period T, R0 is the equivalent resistance of the low-voltage line in the transformer substation, representing the equivalent impedance of the energy consumed in the low-voltage line during the transmission of power supply current from the distribution transformer to the user load, and ε is the overall metering deviation. The methods for solving T0, R0, and ε include:

[0024] The pre-processed power supply of the transformer substation over a period of time is {E} k1 E k2 ..., E kn The line loss rate during the same period is {δ1, δ2, ..., δ}. n}, the corresponding load waveform characteristic coefficients {t1, t2, ..., t n}, construct the overdetermined equation A*X=Y, and the solution to the unknown parameter X is:

[0025] X = [A T *A] -1 *A T *Y

[0026]

[0027] In some embodiments, step S4 includes:

[0028] Based on power supply E k The load waveform characteristic coefficient t is calculated from the current curve within the time period, and t is then compared with the power supply E. k Substituting into the equivalent resistance method line loss rate prediction model, the predicted value δ of the synchronous line loss rate of the transformer area corresponding to different power supply quantities is calculated:

[0029]

[0030] In a second aspect, the present invention provides a device for predicting the synchronous line loss rate of a distribution station area based on equivalent resistance, including a processor and a storage medium;

[0031] The storage medium is used to store instructions;

[0032] The processor is configured to operate according to the instructions to perform the steps of the method according to the first aspect.

[0033] Thirdly, the present invention provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in the first aspect.

[0034] This method is based on historical operating data of the transformer substation to solve for characteristic parameters such as equivalent resistance and base loss. When there are no abnormalities in the historical line loss status of the transformer substation, the parameter solution results can reflect the true characteristics of the transformer substation, and the prediction results are reliable.

[0035] Advantages and beneficial effects of the present invention: The present invention proposes the concept of equivalent resistance, which breaks through the usual theoretical calculation method. It can predict the synchronous line loss rate of transformer areas without the need for parameters that are difficult to obtain, such as the low-voltage line network structure, conductor type, and wire diameter. It has practical engineering application value, can guide relevant personnel to formulate assessment indicators that conform to the actual situation, and provide effective support for timely detection and management of transformer areas with abnormal line loss. Attached Figure Description

[0036] Figure 1 This is a flowchart of a method according to an embodiment of the present invention.

[0037] Figure 2 These are the voltage curves on the transformer side and the user side in the example.

[0038] Figure 3 This is the current curve on the user side in the example. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings. The specific steps are as follows:

[0040] Example 1

[0041] A method for predicting the synchronous line loss rate of a distribution substation based on equivalent resistance, comprising:

[0042] Step S1: Obtain the three-phase current and zero-sequence current curve data of the distribution transformer in the distribution area to be predicted over a historical period of time, combine and preprocess the three-phase current and zero-sequence current curve data of the distribution transformer, and use the preprocessed three-phase current and zero-sequence current curve data of the distribution transformer to calculate the load waveform characteristic coefficient.

[0043] Step S2: Obtain the power supply and synchronous line loss rate data of the corresponding distribution substation for each cycle during this period, combine and preprocess the power supply and synchronous line loss rate data to obtain the preprocessed power supply and synchronous line loss rate data.

[0044] Step S3: Based on the preprocessed power supply and line loss rate data of the transformer area and the corresponding load waveform characteristic coefficients, construct the overdetermined equation, and solve it to obtain the equivalent resistance, base loss and metering comprehensive deviation of the line loss rate prediction model of the equivalent resistance method.

[0045] Step S4: Based on the power supply of the transformer area and the corresponding load waveform characteristic coefficient, use the equivalent resistance method line loss rate prediction model to calculate the predicted value of the synchronous line loss rate of the transformer area corresponding to different power supply quantities.

[0046] In some embodiments, a method for predicting the synchronous line loss rate of a distribution substation based on equivalent resistance includes:

[0047] 1. Obtain the three-phase current and zero-sequence current curves of the distribution transformer side within n0 line loss calculation cycles T from the automated meter reading system. Check the current curves cycle by cycle and calculate the load waveform characteristic coefficient. Combine the three-phase current and zero-sequence current curve data of the distribution transformer according to time points. If the current exceeds the rated value I... E +22% or null value, all three-phase and zero-sequence currents at that time point are removed, and the load waveform characteristic coefficient is calculated using the effective time point data. The calculation formula is shown in Equation (1).

[0048]

[0049] In the formula, E k For the power supply of the transformer substation during period T; Ia j Ib j Ic j In j These are the three-phase current and zero-sequence current on the transformer side at time j within period T, respectively; m is the number of effective time points of the current curve within period T.

[0050] 2. Obtain the power supply and synchronous line loss rate of the distribution area within n0 line loss calculation cycles T from the automated meter reading system. If it is a daily line loss rate, then T = 24h. Combine the power supply and synchronous line loss rate of the distribution area according to the cycle. When E k If the data is not greater than 0 or satisfies equation (2), and the line loss rate is less than -1% or greater than 100%, then the entire data set will be removed to obtain n sets of valid data.

[0051] E k >P E *T (2)

[0052] In the formula, P E This refers to the rated capacity of the distribution transformer.

[0053] 3. Let the power supply of the transformer substation over a certain period of time be denoted as {E}. k1 E k2 ..., E kn The line loss rate during the same period is {δ1, δ2, ..., δ}. n}, the corresponding load waveform characteristic coefficients {t1, t2, ..., t n}, construct the overdetermined equation A*X=Y, and solve for the equivalent resistance R0, the basic loss T0, and the comprehensive measurement deviation ε. The solution method is shown in equation (3).

[0054] X = [A T *A] -1 *AT *Y (3)

[0055] Specifically,

[0056] 4. Based on the power supply E k The current curve within the time period is used to calculate t, and t is then compared with the power supply E. k Substituting into the calculation model, the prediction of the line loss rate during the same period can be realized. The prediction model is shown in Equation (4).

[0057]

[0058] To illustrate the implementation of this invention in more detail, actual data will be used for explanation below.

[0059] The transformer substation has a capacity of 200kVA. The daily power supply, daily synchronous line loss rate, three-phase current on the transformer side, and zero-sequence current curves for this substation from January 1, 2022 to June 30, 2022 were obtained from the automated meter reading system. Specific data are as follows: Figure 2 As shown. After combining and preprocessing the curve data, there are 181 effective data groups. The load waveform characteristic coefficients are calculated for each group, and the overdetermined equation is solved. The equivalent resistance R0 = 0.0337Ω, T0 = 5.54kWh, and ε = 0.03% are obtained. The prediction model of the reasonable value of the synchronous line loss rate of the transformer area is shown in Equation (5).

[0060]

[0061] Example 2

[0062] Secondly, this embodiment provides a device for predicting the synchronous line loss rate of a distribution station area based on equivalent resistance, including a processor and a storage medium;

[0063] The storage medium is used to store instructions;

[0064] The processor is configured to operate according to the instructions to perform the steps of the method according to Embodiment 1.

[0065] Example 3

[0066] Thirdly, this embodiment provides a storage medium on which a computer program is stored, which, when executed by a processor, implements the steps of the method described in Embodiment 1.

[0067] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0068] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0069] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0070] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0071] Those skilled in the art should understand from the above description of the disclosed embodiments that the above description is only a specific implementation of the present invention and does not limit the scope of protection of the present invention. Any technical solution obtained by means of equivalent substitution or equivalent transformation should be included within the scope of protection of the present invention.

Claims

1. A method for predicting the synchronous line loss rate of a distribution substation based on equivalent resistance, characterized in that, Includes the following steps: Step S1: Obtain the three-phase current and zero-sequence current curve data of the distribution transformer in the area to be predicted over a historical period. Combine and preprocess the three-phase current and zero-sequence current curve data, and calculate the load waveform characteristic coefficient using the preprocessed three-phase current and zero-sequence current curve data. ,include: ； In the formula, This refers to the power supply volume of the distribution area during period T. , , , These are the three-phase current and zero-sequence current of the transformer at time j within period T, respectively; m is the number of valid time points of the current curve within period T in the preprocessed three-phase current and zero-sequence current curve data of the transformer. Step S2: Obtain the power supply and synchronous line loss rate data of the corresponding distribution substation for each cycle during this period, combine and preprocess the power supply and synchronous line loss rate data to obtain the preprocessed power supply and synchronous line loss rate data. Step S3: Based on the preprocessed power supply and line loss rate data of the transformer substation and the corresponding load waveform characteristic coefficients, construct overdetermined equations, and solve for the equivalent resistance, base loss, and comprehensive metering deviation of the line loss rate prediction model using the equivalent resistance method, including: The equivalent resistance method line loss rate prediction model includes , , Three unknown parameters, let's call them ,in For the base loss of the transformer area during period T, The equivalent resistance of the low-voltage lines in the distribution area represents the equivalent impedance of electrical energy loss generated in the low-voltage lines during the transmission of power supply current from the distribution transformer to the user load. For measurement overall deviation, , , The solution methods include: The pre-processed power supply of the transformer substation over a period of time is The line loss rate during the same period was The corresponding load waveform characteristic coefficient Constructing overdetermined equations The solution for the unknown parameter X is: ； ， ； Step S4: Based on the power supply volume of the transformer area and the corresponding load waveform characteristic coefficients, use the equivalent resistance method line loss rate prediction model to calculate the predicted line loss rate of the transformer area for different power supply volumes, including: According to power supply The load waveform characteristic coefficient is calculated from the current curve within the time period. ,Will and power supply Substituting into the equivalent resistance method line loss rate prediction model, the predicted values ​​of the synchronous line loss rate of the transformer area corresponding to different power supply quantities are calculated. : .

2. The method for predicting the synchronous line loss rate of a distribution substation based on equivalent resistance according to claim 1, characterized in that, A period of time consists of n0 line loss calculation cycles T, and the power supply of the distribution area, the synchronous line loss rate, and the three-phase current and zero-sequence current curves on the distribution transformer side all correspond to the data values ​​within cycle T.

3. The method for predicting the synchronous line loss rate of a distribution substation based on equivalent resistance according to claim 2, characterized in that, If it is a daily loss rate, then T=24h.

4. The method for predicting the synchronous line loss rate of a distribution substation based on equivalent resistance according to claim 1, characterized in that, In step S1, the power supply data of the transformer area and the synchronous line loss rate data are combined and preprocessed, including: Combine the three-phase current and zero-sequence current curves of the distribution transformer side within cycle T according to time points; If at any given time, any one of the three-phase currents or zero-sequence current on the distribution transformer side exceeds the rated value of 1.22... If the value is empty, all three-phase current and zero-sequence current data at that time point are discarded to obtain the distribution transformer three-phase current and zero-sequence current curve data at m valid time points.

5. The method for predicting the synchronous line loss rate of a distribution substation based on equivalent resistance according to claim 1, characterized in that, In step S2, the power supply and concurrent line loss rate data of the transformer substation are combined and preprocessed, including: Combine the power supply of the transformer area and the line loss rate during the same period according to the cycle; If the power supply of the transformer area is not greater than 0 or greater than the rated value , The rated capacity of the distribution transformer is T, and the calculation period is T. Alternatively, the line loss rate during the same period is less than -1% or greater than 100%. If any of the above conditions occur, the entire set of power supply and synchronous line loss rate data for the transformer area will be removed, resulting in n sets of preprocessed valid power supply and synchronous line loss rate data for the transformer area.

6. A device for predicting the synchronous line loss rate of a distribution substation based on equivalent resistance, characterized in that, Including processor and storage media; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to perform the steps of the method according to any one of claims 1 to 5.

7. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 5.

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