Main and distribution network power flow real-time analysis system based on electric power grid structure

Abstract

The invention discloses a main and distribution network power flow real-time analysis system based on an electric power grid structure, relates to the technical field of power distribution network power flow analysis, and solves the technical problem that a main and distribution network power flow calculation result is unreliable due to the fact that line topological graphs of a main and distribution network are directly eliminated and corrected based on a voltage consistency principle in the prior art. In the process of correcting the line topological graph of the main and distribution networks based on the voltage consistency principle, whether the check nodes which do not conform to the voltage consistency principle are influenced by the distributed power supply is further analyzed, and if the check nodes are influenced by the distributed power supply, the corresponding check nodes are reserved, so that the accuracy of the line topological graph is improved, and the accuracy of the line topological graph is improved. Finally, the calculation precision of the power flow values of the main and distribution networks is improved; moreover, since the distributed power supply can influence the measurement data of the check node, the analysis of the influence of the distributed power supply on the check node is helpful for updating and improving the measurement data precision of the check node, thereby improving the correction precision of the electrical parameters.

Description

Technical Field

[0001] The present application belongs to the field of power distribution network flow analysis, and specifically is a real-time analysis system for main distribution network flow based on power grid structure. Background Art

[0002] Distribution network power flow calculation is a basic electrical calculation for analyzing the stable operation of power systems. It is the basis for power system safety, economic analysis, and implementation of control and dispatch. Theoretical power flow calculation methods for distribution networks mainly include forward-backward substitution method, PQ decomposition method, Newton method, etc. The theoretical methods are relatively mature. Most of these power flow calculation methods rely on the topological model and electrical parameters of the distribution network. However, in actual applications, inaccurate topological models and missing electrical parameters of equipment affect the accuracy of power flow calculation results.

[0003] In order to improve the accuracy of the power flow calculation results of the distribution network, the existing scheme verifies the electrical data, simplifies the topological data diagram and the measurement data through the equipment ledger, topological data and measurement data of each line to improve the accuracy of various types of data in the distribution network. However, the existing scheme simplifies the topological data diagram based on the principle of voltage consistency, and removes the check nodes in the topological data diagram that have a low correlation with the voltage consistency of the reference node. Although the topological data diagram is simplified, the method of directly removing the check nodes through voltage consistency analysis ignores the factors that affect the voltage of the check nodes and the impact of this factor on the distribution network, resulting in inaccurate power flow calculation of the distribution network.

[0004] The present application provides a real-time analysis system for main distribution network flow based on the power grid structure to solve the above technical problems. Summary of the invention

[0005] The present application aims to solve at least one of the technical problems existing in the prior art; to this end, the present application proposes a real-time analysis system for the main distribution network flow based on the power grid structure, which is used to solve the technical problem that the prior art directly eliminates and corrects the line topology diagram of the main distribution network based on the voltage consistency principle, affecting the accuracy of the line topology diagram, thereby causing unreliable main distribution network flow calculation results.

[0006] To achieve the above-mentioned purpose, the first aspect of the present application provides a real-time analysis system of main distribution network flow based on power grid structure, comprising: a data processing module, and a data acquisition module connected thereto;

[0007] Data acquisition module: used to obtain the line information of the main distribution network and the basic data of each power grid line; the line information includes the line ID and rated voltage of the power grid line, and the basic data includes the subordinate equipment ledger, topology data and measurement data;

[0008] Data processing module: used to construct the line topology diagram of each main distribution network according to the topology data; detect the distributed power supply in the main distribution network through the measurement data, and correct and simplify the line topology diagram according to the measurement data and the detected distributed power supply; and,

[0009] It is used to calculate the electrical parameters of each power grid line according to the subordinate equipment ledger, and correct the electrical parameters through the measured data and the simplified line topology diagram; it is used to calculate the power flow value of each power grid line in the main distribution network based on the electrical parameters, line topology diagram and measured data.

[0010] Preferably, after obtaining the measurement data, the measurement data is preprocessed, including:

[0011] Extract measurement data; when missing values ​​are found in the measurement data, mark the time corresponding to the missing value as the target time;

[0012] The missing value of the target moment is supplemented by the measurement data collected before and after the target moment in the measurement data and the measurement data of the same target moment in the historical period.

[0013] Preferably, constructing a line topology diagram of each main distribution network according to the topology data includes:

[0014] Extracting topological data; wherein the topological data includes the device ID of the distribution network device, the node or branch to which it belongs, the head-end relationship node, the terminal relationship node and the device label, the device label includes the T node, the load node, the switch and the branch, and the switch includes the outgoing switch and the tie switch;

[0015] The outgoing line switch is taken as the starting node, and the load node or the connecting switch is taken as the ending node; based on the belonging nodes or branches, the head-end relationship nodes, and the terminal relationship nodes, a line topology diagram is traversed between the starting node and the ending node.

[0016] Preferably, detecting the distributed power source in the main distribution network through measurement data includes:

[0017] Obtaining voltage curves of each node in the line topology diagram according to the measured data of the power grid line;

[0018] The starting node is used as the reference node, and the nodes other than the starting node are used as the check nodes; the correlation coefficient between the reference node and each check node is calculated based on the voltage similarity principle;

[0019] When the correlation coefficient is greater than the coefficient threshold, it is determined that the verification node has passed the verification; otherwise, it is determined whether a distributed power source exists through the measurement data of the verification node; wherein the correlation coefficient includes the Pearson correlation coefficient.

[0020] Preferably, judging whether there is a distributed power source through the measurement data of the verification node includes:

[0021] Obtain a voltage curve of a distributed power source, marked as a reference curve; wherein the distributed power source includes a photovoltaic power generation system or a wind power generation system;

[0022] A voltage curve of the verification node is fitted according to the line topology diagram and the voltage curve of the reference node, and is marked as a reference curve;

[0023] Eliminate the reference curve from the voltage curve of the verification node to obtain the target curve; calculate the correlation coefficient between the target curve and the voltage curve of the reference node;

[0024] When the correlation coefficient is greater than the coefficient threshold, the verification node has a distributed power source corresponding to the target curve and no correction is required; otherwise, it is determined that the verification node does not have a distributed power source and the verification node is removed from the line topology diagram.

[0025] Preferably, simplifying the corrected line topology diagram includes:

[0026] Remove branches without load nodes in the line topology diagram, and remove switches, branches, and load nodes upstream of T nodes and switches;

[0027] Aggregate the branches between two adjacent nodes, and keep only one switch between the two adjacent nodes to simplify the line topology diagram.

[0028] Preferably, the electrical parameters of each power grid line are calculated based on the subordinate equipment ledger, including:

[0029] Matching the benchmark parameters of the corresponding electrical equipment according to the equipment ID of each power grid line in the subordinate equipment ledger; wherein the benchmark parameters are matched from a pre-built distribution network parameter library;

[0030] The electrical parameters of each electrical device are calculated according to the reference parameters, and the electrical parameters are associated with the device ID; wherein the electrical parameters include the equivalent resistance and equivalent reactance of the power grid device.

[0031] Preferably, the electrical parameters are corrected by measuring the data and correcting the simplified line topology diagram, including:

[0032] Obtain the flow value of each verification node in the simplified line topology diagram according to the measured data of the power grid line; calculate the theoretical parameters corresponding to each power grid equipment according to the flow value; wherein the theoretical parameters include resistance parameters and reactance parameters;

[0033] The theoretical parameters and the electrical parameters are compared. When the corresponding parameter deviation between the two is greater than the deviation threshold, the electrical parameters are corrected by the parameter value in the theoretical parameters; otherwise, no correction is performed.

[0034] Preferably, when the power flow value of each correction node in the simplified line topology diagram is obtained, the measurement data of the power grid line is updated, including:

[0035] The target curve is optimized based on the benchmark curve of the distributed power source to obtain the standard curve;

[0036] When calculating the power flow value of each correction node, the output data of the distributed power source at the corresponding time is determined from the standard curve, and the measurement data is updated according to the output data; wherein the output data includes active power, reactive power or power factor.

[0037] Preferably, the flow value of each power grid line in the main distribution network is calculated based on the electrical parameters, the line topology diagram and the measurement data, including:

[0038] Coupling correlation and differentiation estimation based on electrical parameters, line topology and measurement data;

[0039] Based on the differentiated state estimation results, the forward-backward substitution method is used to calculate the power flow value of each power grid line.

[0040] Compared with the prior art, the beneficial effects of this application are:

[0041] 1. After the present application constructs the line topology map of the main distribution network according to the topology data, in the process of correcting the line topology map of the main distribution network based on the voltage consistency principle, the verification nodes that do not comply with the voltage consistency principle are not directly eliminated, but further analyzed to see whether they are affected by the distributed power source. If they are affected by the distributed power source, the corresponding verification nodes are retained. This can improve the accuracy of the line topology map, thereby improving the calculation accuracy of the main distribution network flow value; moreover, since the distributed power source will affect the measurement data of the verification node, analyzing the impact of the distributed power source on the verification node is helpful to update and improve the measurement data accuracy of the verification node, thereby improving the correction accuracy of the electrical parameters, and ultimately improving the reliability of the main distribution network flow analysis results.

[0042] 2. This embodiment optimizes the target curve of the verification node according to the determined benchmark curve of the distributed power source to obtain the measurement data change trend of the verification node under the influence of the distributed power source; when the measurement data of each node is used subsequently, the measurement data of the node with distributed power source is updated according to the measurement data change trend, which improves the timeliness of the measurement data and avoids the impact of data delay on the accuracy of the main distribution network flow analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 This is a schematic diagram of the method flow of real-time analysis of main distribution network current in Example 1 of the present application;

[0045] Figure 2 This is a schematic diagram of the system principle for real-time analysis of main distribution network current in Example 1 of the present application;

[0046] Figure 3 Schematic diagram of the update process of the measurement data of the power grid line in the second embodiment of the present application. DETAILED DESCRIPTION

[0047] The technical solution of the present application will be described clearly and completely in conjunction with the embodiments below. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0048] When simplifying the topological data graph based on the principle of voltage consistency, the existing solution will delete the check node if the correlation between the check node and the starting node does not meet the requirements, which means that the check node will not be considered in the subsequent power flow calculation of the distribution network. However, when distributed energy, such as photovoltaic energy and wind power energy, is connected to the distribution network, the distributed power source will affect the voltage of the corresponding node, such as voltage increase or voltage fluctuation, which will affect the judgment result based on voltage consistency. Therefore, when a large number of distributed power sources are connected to the distribution network, the existing solution is difficult to accurately realize the power flow calculation of the distribution network.

[0049] Embodiment 1:

[0050] See also Figure 1-Figure 2 , the first aspect of the present application provides a real-time analysis system for main distribution network flow based on power grid structure, including: a data processing module, and a data acquisition module connected thereto;

[0051] Data acquisition module: used to obtain the line information of the main distribution network and the basic data of each power grid line;

[0052] Data processing module: used to construct the line topology diagram of each main distribution network according to the topology data; detect the distributed power supply in the main distribution network through the measurement data, and correct and simplify the line topology diagram according to the measurement data and the detected distributed power supply; and, used to calculate the electrical parameters of each power grid line according to the subordinate equipment ledger, and correct the electrical parameters through the measurement data and the corrected and simplified line topology diagram; calculate the power flow value of each power grid line in the main distribution network based on the electrical parameters, line topology diagram and measurement data.

[0053] In this embodiment, the data acquisition module is mainly used to acquire the data required for the main distribution network flow calculation, and the data processing module processes and calculates the acquired data according to a given method to complete the analysis and calculation of the main distribution network flow. The data acquisition module is connected to the sensors and storage devices related to the data to be collected; the data processing module is connected to the data acquisition module, and is also connected to the necessary display terminal to display the flow analysis process and analysis results. It should be noted that the above "connected" means that there is data interaction between the two, and there is no restriction on the specific connection method.

[0054] The line information acquired by the data acquisition module is mainly the line ID and rated voltage of the power grid line. The basic data mainly includes the subordinate equipment ledger, topological data and measurement data. The topological data includes the equipment ID, the node or branch line, the head-end relationship node, the terminal relationship node and the equipment label of the distribution network equipment. The equipment label includes T-node, load node, switch and branch line. The switch includes the outgoing switch and the connecting switch. The topological data can usually obtain the cim file content of the power grid line, parse the cim file and organize the topological connection structure. The measurement data mainly includes equipment ID, time, current, three-phase voltage, active power, reactive power, etc.

[0055] After obtaining the measurement data, the present embodiment needs to pre-process the measurement data to improve the reliability and accuracy of the measurement data. The specific processing process can refer to the following steps:

[0056] Extract measurement data; when missing values ​​are identified in the measurement data, mark the time corresponding to the missing value as the target time; supplement the missing value of the target time based on the measurement data collected before and after the target time in the measurement data and the measurement data of the same target time in the historical period.

[0057] Example 1: Mark the measurement data of the previous sampling time and the next sampling time of the target time as X respectively. s and X x ; Mark the measured mean value of the target time in the historical period as X lm , the measured mean value at each sampling time in the historical period is marked as X ls ; Through the formula X m =|X s -X x|+|X lm -X ls |Calculate the measurement data X at the target time m ; Measurement data X m As the measurement data at the target moment, to make up for the problem of missing values.

[0058] Example 2: Establish a data curve corresponding to the measured data at each sampling time in the historical period, and extract or predict the measured data at the target time from the data curve. If extracting, directly bring the target time into the function corresponding to the data curve to get the measured data at the target time; if predicting, use the artificial intelligence algorithm to learn the data curve and then predict the measured data at the target time.

[0059] In order to accurately analyze the power flow value of the main distribution network, it is necessary to establish the topological structure of the main distribution network, and use this topological structure as the basis for subsequent analysis and calculation. Therefore, it is necessary to construct the topological structure of the main distribution network based on the acquired topological data. For details, please refer to the following steps:

[0060] Extract topological data; take the outgoing line switch in the topological data as the starting node, and the load node or the connecting switch as the ending node; based on the belonging node or branch line, the head-end relationship node, and the terminal relationship node, traverse between the starting node and the ending node to generate a line topological diagram.

[0061] Since the line topology diagram is the basis for the subsequent analysis and calculation of the power flow value of the main distribution network, and the power grid lines in the main distribution network are relatively complex, it is necessary to determine whether there are abnormalities in each node in the line topology diagram. If there are abnormalities, they need to be eliminated to improve the accuracy of the power flow value analysis. The existing scheme is based on the principle of voltage consistency. When the correlation coefficient between a node and the starting node does not meet the requirements, the corresponding node is removed from the line topology diagram. However, as mentioned above, the access of distributed power sources will affect the power flow value of the corresponding access point, especially the voltage fluctuation. Moreover, both the wind power system and the photovoltaic system are restricted by the natural environment. When the wind power system or the photovoltaic system is not working, the impact on the access point is small and the voltage consistency requirements may be met. However, if the wind power system or the photovoltaic system is working, the impact on the access point is large. At this time, the access point is very likely to not meet the voltage consistency requirements. Therefore, it is necessary to consider the problem of distributed power access to the main distribution network.

[0062] This embodiment first detects the distributed power supply in the main distribution network based on the measured data, and the detection process is still based on the principle of measured data and voltage consistency. For details, please refer to the following steps:

[0063] The voltage curve of each node in the line topology diagram is obtained according to the measurement data of the power grid line; the starting node is used as the reference node, and the nodes other than the starting node are used as the verification nodes; the correlation coefficient between the reference node and each verification node is calculated based on the voltage similarity principle; when the correlation coefficient is greater than the coefficient threshold, it is determined that the verification node has passed the verification; otherwise, it is determined whether there is a distributed power supply through the measurement data of the verification node.

[0064] The correlation coefficient in this embodiment includes the Pearson correlation coefficient. In other embodiments, other correlation coefficients or even algorithms that meet the requirements may be selected.

[0065] Exemplarily, after obtaining the voltage curves of the reference node and each verification node according to the measurement data, the Pearson correlation coefficient between any verification node and the reference node is calculated; if the Pearson correlation coefficient is greater than 0.95, the verification of the verification node passes; otherwise, it is necessary to determine whether there is a distributed power supply at the verification node.

[0066] It should be noted that the verification of the verification node does not necessarily mean that there is no distributed power supply at the corresponding verification node, but that the output of the distributed power supply has little effect on the power flow value of the verification node. The influence of the distributed power supply is also considered when collecting the power flow value of the verification node, which does not affect the analysis accuracy of the subsequent main distribution network power flow value.

[0067] When the Pearson correlation coefficient is not greater than the set coefficient threshold, the corresponding check node is analyzed to see whether it is affected by the distributed power source. If it is not affected by the distributed power source, the check node is eliminated; if it is affected by the distributed power source, the distributed power source needs to be used as important data for the subsequent distribution calculation of the main distribution network flow value. It should be noted that when the Pearson correlation coefficient is very small, the influence of the distributed power source cannot be directly excluded.

[0068] The main idea is to determine whether there is a distributed power source based on the measurement data of the verification node. The voltage curve corresponding to the verification node is determined based on the voltage consistency principle and the voltage curve of the starting node, and the correlation between the voltage curve and the reference curve of each distributed power source is calculated. If the correlation coefficient is greater than the set coefficient threshold, it is determined that the verification node has a corresponding distributed power source. It should be noted that since there is a certain error in the voltage curve of the verification node calculated based on the voltage curve of the starting node, the coefficient threshold can be smaller than the correlation coefficient when determining whether there is a distributed power source during comparison. Of course, the same set threshold can also be used. The specific steps for determining the distributed power source can be referred to as follows:

[0069] The voltage curve of the distributed power source is obtained and marked as the reference curve; the voltage curve of the verification node is fitted according to the line topology diagram and the voltage curve of the reference node and marked as the reference curve; the reference curve is removed from the voltage curve of the verification node to obtain the target curve; the correlation coefficient between the target curve and the voltage curve of the reference node is calculated; when the correlation coefficient is greater than the coefficient threshold, the verification node has a distributed power source corresponding to the target curve and no correction is required; otherwise, it is determined that the verification node does not have a distributed power source and the verification node is removed from the line topology diagram.

[0070] Exemplarily, it is assumed that the structure of the line topology diagram is: starting node → intermediate node 1 → intermediate node 2 → verification node; the line parameters (resistance and reactance) between each node are extracted from the measurement data, and the voltage drop from the starting node to the verification node can be calculated based on the line parameters. According to the voltage consistency principle, the voltage curve of the verification node can be fitted according to the voltage curve of the starting node. This voltage curve is theoretically the most reasonable voltage curve corresponding to the verification node, so it is marked as a reference curve.

[0071] For the acquisition of the target curve, the voltage curve of the verification node obtained according to the measurement data can be directly subtracted from the reference curve. The remaining curve is the result of the external influence that does not conform to the voltage consistency principle. The remaining curve is used as the target curve and compared with the reference curve of each distributed power source. If the correlation coefficient is the largest and greater than the set coefficient threshold, it can be determined that the target curve is generated by the effect of the corresponding distributed power source on the verification node. In other preferred embodiments, the reference curve can be removed from the voltage curve by proportional subtraction, filtering methods, etc. to obtain the target curve. The working principles of each method are not repeated here.

[0072] After determining whether there is a distributed power source at the check node, the line distribution map can be corrected. If there is a distributed power source at the check node, the check node is retained in the line topology map and marked. If the check node does not comply with the voltage consistency principle and there is no distributed power source, the check node is removed from the line topology map to complete the simplification of the line topology map.

[0073] In order to reduce the amount of data processing in the main distribution network power flow calculation, it is also necessary to simplify the corrected line topology diagram. The simplification steps can be referred to as follows:

[0074] Remove branches without load nodes in the line topology diagram, and remove switches, branches, and load nodes upstream of the T node and switch; aggregate branches between two adjacent nodes, and only retain one switch between two adjacent nodes to complete the simplification of the line topology diagram.

[0075] Next, we need to calculate the power flow value of the main distribution network based on the simplified line topology diagram. First, we need to calculate the electrical parameters of each power grid line based on the subordinate equipment records, including:

[0076] The benchmark parameters of the corresponding electrical equipment are matched according to the equipment ID of each power grid line in the subordinate equipment ledger; the electrical parameters of each electrical equipment are calculated according to the benchmark parameters, and the electrical parameters are associated with the equipment ID.

[0077] The above-mentioned benchmark parameters are obtained from the pre-built distribution network parameter library, which is a library built according to international regulations to clarify the correspondence between equipment models and typical parameters. The equipment is designed for three types: distribution transformers, overhead lines, and cables. The above-mentioned electrical parameters mainly include the equivalent resistance and equivalent reactance of each device.

[0078] Exemplarily, the electrical parameters of the distribution transformer are calculated using the following formula:

[0079]

[0080]

[0081] Among them, R 1 and X 1 are the equivalent resistance and reactance of the distribution transformer, G and B are the conductance and susceptance to ground, respectively. N , S N , P k , U k %、P 0 ,I 0 % are the rated voltage, rated power, short-circuit loss, short-circuit voltage percentage, no-load power loss and no-load current percentage of the distribution transformer respectively.

[0082] Calculate the electrical parameters of overhead lines and cables using the following formula:

[0083]

[0084] Among them, R 2 , X 2 and C 2 are the equivalent resistance, equivalent reactance and capacitance to ground of the overhead line, L 2 , R 2k , X 2k 、c 2k are the length of the overhead line, the equivalent resistance per unit length, the equivalent reactance per unit length, and the capacitance to ground per unit length; R 3 , X 3 and C 3 are the equivalent resistance, equivalent reactance and capacitance to ground of the cable respectively, L 3 , R3k , X 3k , C 3k They are respectively the length of the cable, the equivalent resistance per unit length, the equivalent reactance per unit length and the capacitance to ground per unit length.

[0085] In order to ensure the reliability of the electrical parameters, the present embodiment calibrates the electrical parameters by measuring the data and calibrating the simplified line topology diagram. The calibration steps can be referred to as follows:

[0086] According to the measured data of the power grid line, the flow value of each verification node in the simplified line topology diagram is obtained; according to the flow value, the corresponding theoretical parameters of each power grid equipment are calculated; the theoretical parameters and electrical parameters are compared, and when the corresponding parameter deviation between the two is greater than the deviation threshold, the electrical parameters are corrected by the parameter value in the theoretical parameters; otherwise, no correction is made. The above theoretical parameters include resistance parameters and reactance parameters;

[0087] Exemplarily, the resistance parameters and reactance parameters corresponding to each device ID are calculated according to the flow value of each node; the resistance relative deviation is calculated according to the resistance parameters and equivalent resistance corresponding to the device ID. If the resistance relative deviation is greater than the preset resistance deviation threshold, the equivalent resistance is corrected to the resistance parameter, otherwise it is not corrected.

[0088] Similarly, the reactance relative deviation is calculated based on the reactance parameters corresponding to the device ID and the equivalent reactance. If the reactance relative deviation is greater than the preset reactance deviation threshold, the equivalent reactance is corrected to the reactance parameter, otherwise, no correction is made.

[0089] Finally, the flow values ​​of each power line in the main distribution network are calculated based on the corrected electrical parameters, the corrected simplified line topology diagram and reliable measurement data. Please refer to the following steps:

[0090] Coupling correlation and differentiated estimation are performed based on electrical parameters, line topology and measurement data. Based on the differentiated state estimation results, the forward-backward method is used to calculate the power flow value of each power grid line.

[0091] Exemplary: The weighted least squares method is used to calculate the differential state estimate minJ(x) of the measurement data, and the calculation formula is: Among them, X real is the measured data at the sampling time, x is the voltage amplitude phase angle, h(x) is the nonlinear measurement function, R m is the confidence level of the measurement data; and in, σ xm It is the mean and standard deviation of the measured data at each sampling time in the historical period.

[0092] Obtain the differentiated state estimate of the voltage and power at the end of the distribution line, and calculate the calculated amount of the voltage and power at the first section section by section; calculate the difference error between the calculated amount of the voltage at the first end and the differentiated state estimate. If the difference error is less than or equal to the preset error threshold, record the calculated amount of the voltage at the first end, and calculate the flow value of each node based on the calculated amount of the voltage at the first end. If it is greater than the preset error threshold, obtain the differentiated state estimate of the voltage at the first end of the distribution line, and calculate the calculated amount of the voltage and power at the terminal section by section in combination with the calculated amount of the power at the first end; use the calculated amount of the voltage and power at the terminal as the differentiated state estimate of the voltage and power at the terminal of the distribution line, and repeat the above steps to complete the calculation of the flow value of the main distribution network.

[0093] In the process of correcting the line topology of the main distribution network based on the voltage consistency principle, the present embodiment does not directly eliminate the verification nodes that do not comply with the voltage consistency principle, but further analyzes whether they are affected by the distributed power source. If they are affected by the distributed power source, the corresponding verification node is retained. This can improve the accuracy of the line topology, thereby improving the calculation accuracy of the main distribution network flow value. Moreover, since the distributed power source will affect the measurement data of the verification node, analyzing the distributed power source is helpful to improve the measurement data accuracy of the verification node and improve the reliability of subsequent electrical parameters and flow values.

[0094] Example 2: Based on Example 1, in order to improve the delay of measured data when processing large-scale data, this example updates the measured data of the verification node according to the output characteristics of the distributed power source, but does not update the measured data of the verification node without the distributed power source, which can improve the accuracy of electrical parameter correction and further improve the calculation accuracy of the main distribution network flow value. Figure 3 , please refer to the following steps for details:

[0095] When obtaining the power flow value of each correction node in the simplified line topology diagram, the measurement data of the power grid line is updated, including:

[0096] The target curve is optimized based on the benchmark curve of the distributed power source to obtain the standard curve; when calculating the power flow value of each correction node, the output data of the distributed power source at the corresponding time is determined from the standard curve, and the measurement data is updated according to the output data.

[0097] The above-mentioned output data includes active power, reactive power or power factor, which is mainly used to indicate the influence of distributed power sources on the verification node. According to Example 1, the target curve is actually stripped from the voltage curve of the verification node based on the principle of voltage consistency. In principle, it can represent the output characteristics of the distributed power source. However, in order to improve the reliability of the target curve, this embodiment optimizes the target curve by corresponding to the benchmark curve of the distributed power source, mainly optimizing the numerical range, curve trend, etc., to obtain a standard curve. The standard curve can be understood as the output of the distributed power source to the verification node at different times, which changes with time. It should be noted that the standard curve represents the output of the distributed power source, which affects the measured data of the verification node, so the standard data is actually consistent with the change trend of the measured data.

[0098] When using the measurement data in the future, the measurement data of the (verification) nodes with distributed power sources should be updated according to the time of use, rather than directly using the previously collected measurement data. This can ensure the timeliness of the measurement data to the greatest extent and avoid affecting the entire calculation result due to data delay problems when processing large-scale data.

[0099] The above embodiments are only used to illustrate the technical method of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the preferred embodiments, a person of ordinary skill in the art should understand that the technical method of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present application.

Claims

1. A real-time analysis system for main distribution network flow based on power grid structure, characterized in that: include: A data processing module, and a data acquisition module connected thereto; Data acquisition module: used to obtain the line information of the main distribution network and the basic data of each power grid line; the line information includes the line ID and rated voltage of the power grid line, and the basic data includes the subordinate equipment ledger, topology data and measurement data; Data processing module: used to construct a line topology diagram of each main distribution network according to the topology data; detect the distributed power source in the main distribution network through the measurement data, and correct and simplify the line topology diagram according to the measurement data and the detected distributed power source; and, Used to calculate the electrical parameters of each power grid line according to the subordinate equipment ledger, correct the electrical parameters through the measured data and the corrected and simplified line topology diagram; calculate the power flow value of each power grid line in the main distribution network based on the electrical parameters, the line topology diagram and the measured data.

2. According to the real-time analysis system of main distribution network flow based on power grid structure in claim 1, it is characterized in that: After acquiring the measurement data, preprocessing the measurement data includes: Extracting the measurement data; when identifying that there are missing values ​​in the measurement data, marking the time corresponding to the missing value as the target time; The missing value of the target moment is supplemented according to the measurement data collected at the time before and after the target moment in the measurement data and the measurement data of the same target moment in the historical period.

3. According to the real-time analysis system of main distribution network flow based on power grid structure in claim 1, it is characterized in that: Constructing a line topology diagram of each main distribution network according to the topology data, including: Extract the topological data; wherein the topological data includes the device ID of the distribution network device, the node or branch to which it belongs, the head-end relationship node, the terminal relationship node and the device label, the device label includes the T node, the load node, the switch and the branch, and the switch includes the outgoing switch and the tie switch; The outgoing line switch is taken as the starting node, and the load node or the connecting switch is taken as the ending node; based on the belonging nodes or branches, the head-end relationship nodes, and the terminal relationship nodes, a line topology diagram is traversed between the starting node and the ending node.

4. According to the real-time analysis system of main distribution network flow based on power grid structure of claim 1, it is characterized in that: Detecting the distributed power source in the main distribution network through the measurement data includes: Acquire the voltage curve of each node in the line topology diagram according to the measured data of the power grid line; Taking the starting node as the reference node and taking the other nodes except the starting node as the check nodes; calculating the correlation coefficient between the reference node and each of the check nodes based on the voltage similarity principle; When the correlation coefficient is greater than the coefficient threshold, it is determined that there is no distributed power supply at the verification node; otherwise, it is determined whether there is a distributed power supply through the measurement data of the verification node; wherein the correlation coefficient includes the Pearson correlation coefficient.

5. A real-time analysis system for main distribution network flow based on power grid structure according to claim 4, characterized in that: The measurement data of the verification node is used to determine whether a distributed power source exists, including: Obtain a voltage curve of a distributed power source, marked as a reference curve; wherein the distributed power source includes a photovoltaic power generation system or a wind power generation system; Fitting a voltage curve of a verification node according to the line topology diagram and the voltage curve of the reference node, and marking it as a reference curve; Eliminating the reference curve from the voltage curve of the verification node to obtain a target curve; calculating a correlation coefficient between the target curve and the voltage curve of the reference node; When the correlation coefficient is greater than the coefficient threshold, the check node has a distributed power source corresponding to the target curve and no correction is required; otherwise, it is determined that the check node does not have a distributed power source and the check node is removed from the line topology diagram.

6. A real-time analysis system for main distribution network flow based on power grid structure according to claim 5, characterized in that: Simplifying the corrected line topology diagram includes: Remove branches without load nodes in the line topology diagram, and remove switches, branches, and load nodes upstream of T nodes and switches; The branch lines between two adjacent nodes are aggregated, and only one switch is retained between the two adjacent nodes, thereby completing the simplification of the line topology diagram.

7. A real-time analysis system for main distribution network flow based on power grid structure according to claim 6, characterized in that: Calculate the electrical parameters of each power grid line based on the subordinate equipment records, including: Matching the benchmark parameters of the corresponding electrical equipment according to the equipment ID of each of the power grid lines in the subordinate equipment ledger; wherein the benchmark parameters are matched from a pre-built distribution network parameter library; The electrical parameters of each electrical device are calculated according to the reference parameters, and the electrical parameters are associated with the device ID; wherein the electrical parameters include equivalent resistance and equivalent reactance of the power grid device.

8. A real-time analysis system for main distribution network flow based on power grid structure according to claim 7, characterized in that: Correcting the electrical parameters by using the measured data and the simplified circuit topology diagram after correction, including: Obtaining the power flow value of each check node in the simplified line topology diagram according to the measured data of the power grid line; calculating the theoretical parameters corresponding to each power grid device according to the power flow value; wherein the theoretical parameters include resistance parameters and reactance parameters; The theoretical parameter and the electrical parameter are compared, and when the corresponding parameter deviation between the two is greater than the deviation threshold, the electrical parameter is corrected by the parameter value in the theoretical parameter; otherwise, no correction is performed.

9. A real-time analysis system for main distribution network flow based on power grid structure according to claim 8, characterized in that: When the power flow value of each correction node in the simplified line topology diagram is obtained, the measurement data of the power grid line is updated, including: Optimizing the target curve based on the reference curve of the distributed power source to obtain a standard curve; When calculating the power flow value of each correction node, the output data of the distributed power source at the corresponding time is determined from the standard curve, and the measurement data is updated according to the output data; wherein the output data includes active power, reactive power or power factor.

10. The real-time analysis system for main distribution network flow based on power grid structure according to claim 1 is characterized in that: Calculating the power flow value of each power grid line in the main distribution network based on the electrical parameters, the line topology diagram and the measurement data, including: performing coupling correlation and differentiation estimation based on the electrical parameters, the line topology diagram and the measurement data; Based on the differentiated state estimation results, the forward-backward substitution method is used to calculate the power flow value of each power grid line.

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