A probabilistic power flow calculation accuracy evaluation method for power grid

Abstract

The application discloses a kind of for power grid probabilistic power flow calculation accuracy evaluation method, belong to probabilistic power flow calculation accuracy evaluation technical field, including: identification probabilistic power flow calculation corresponding power grid area, in combination with probabilistic power flow calculation is segmented to power grid area, obtain several unit areas;According to unit area and power grid area generation area information chart;Real-time acquisition is based on probabilistic power flow calculation in power grid area analysis result data, according to analysis result data acquisition corresponding standard result data, according to standard result data calibration analysis result data, identify the abnormal position corresponding to the analysis result data that does not satisfy calibration standard;Abnormal position is marked in area information chart;Identify the unit area corresponding to abnormal position in area information chart, unit area is marked as traceability area;Determine the abnormal reason of probabilistic power flow calculation based on traceability area, optimize adjustment is carried out to probabilistic power flow calculation based on abnormal reason.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of probability power flow calculation accuracy evaluation, and specifically relates to a probability power flow calculation accuracy evaluation method for a power grid. BACKGROUND

[0002] In the actual operation of a power system, network topology structure, transformer ratio, node injection power and other factors are not fixed but have many uncertainties. These uncertain factors pose a potential threat to the safe and stable operation of the power system. With the continuous development of the power industry, large-scale access of new energy represented by solar energy and wind energy to the power grid has brought obvious intermittency and randomness to the power grid. The emergence of new concepts such as microgrids, distributed power sources and electric vehicles in distribution networks has greatly enhanced the interaction between power sources, loads and power grids, further exacerbating the uncertainty of the power system. Under this background, probability power flow calculation emerged as the times require. Probability power flow calculation combines probability theory and can fully consider various uncertain factors in the power system, thereby more comprehensively reflecting the system operation condition.

[0003] However, the current probability power flow calculation accuracy evaluation method for a power grid still has some deficiencies. The existing evaluation method may not be able to comprehensively and accurately measure the deviation between the probability power flow calculation result and the actual system operation condition, and it is difficult to effectively evaluate the processing capability of the algorithm for various uncertain factors and the coverage degree of the complex characteristics of the power grid. Based on this, in order to solve the problem of probability power flow calculation accuracy evaluation, the application provides a probability power flow calculation accuracy evaluation method for a power grid. SUMMARY

[0004] In order to solve the problems existing in the above scheme, the application provides a probability power flow calculation accuracy evaluation method for a power grid.

[0005] The object of the application can be achieved by the following technical scheme:

[0006] A probability power flow calculation accuracy evaluation method for a power grid comprises the following steps:

[0007] Step 1: identify the power grid area corresponding to the probability power flow calculation, segment the power grid area according to the probability power flow calculation, and obtain a plurality of unit areas; generate a region information map according to the unit areas and the power grid area.

[0008] Further, the method for segmenting the power grid area according to the probability power flow calculation comprises:

[0009] Set a unit area standard, and set a corresponding unit calibration item according to the unit area standard;

[0010] Collecting regional information of a power grid region, determining calibration priority of each unit calibration item, dividing the power grid region according to the calibration priority of the unit calibration item and the regional information, and obtaining corresponding unit regions.

[0011] Further, the method for determining the calibration priority of each unit calibration item comprises:

[0012] Pre-setting a power grid simulation region; identifying unit calibration items, arranging the unit calibration items according to different priority sequences, and obtaining several selected priority sequences;

[0013] Simulating and dividing the power grid simulation region according to the selected priority sequences, and obtaining the division efficiency corresponding to the selected priority sequences;

[0014] Selecting the selected priority sequence with the highest division efficiency as a target priority sequence, and determining the calibration priority of each unit calibration item according to the target priority sequence.

[0015] Further, the method for dividing the power grid region according to the calibration priority of the unit calibration item and the regional information comprises:

[0016] Identifying the calibration priority, marking the unit calibration item as i according to the calibration priority, i=1, 2, …, n, n is the number of the calibration priority;

[0017] Identifying the calibration item standard corresponding to the unit calibration item i=1 according to the unit region standard, calibrating the regional information according to the calibration item standard, and obtaining the selected region satisfying the calibration item standard in the current power grid region;

[0018] Identifying the calibration item standard corresponding to the unit calibration item i=2 according to the unit region standard, calibrating the selected region according to the calibration item standard and the regional information, and eliminating the selected region not satisfying the calibration item standard;

[0019] Identifying the calibration item standard corresponding to the unit calibration item i=3 according to the unit region standard, calibrating the selected region according to the calibration item standard and the regional information, and eliminating the selected region not satisfying the calibration item standard;

[0020] By analogy, until the calibration item standard corresponding to the unit calibration item i=n is identified according to the unit region standard, the selected region is calibrated according to the calibration item standard and the regional information, and the selected region satisfying the calibration item standard is marked as a unit region.

[0021] Further, the method for determining whether the corresponding selected region satisfies the calibration item standard comprises:

[0022] The region information is characterized extracted according to the unit calibration item, and the selected region information of the corresponding selected region is obtained.

[0023] The unit calibration model is established, the selected region information corresponding to the corresponding unit calibration item and the calibration item standard are analyzed through the unit calibration model, and the calibration judgment result of the corresponding selected region is obtained, and the calibration judgment result includes meeting the calibration item standard and not meeting the calibration item standard.

[0024] Further, the expression of the unit calibration model is:

[0025] ;

[0026] In the formula, (s j , BZ j ) is input data, s j represents the selected region information of the corresponding unit calibration item, j represents the corresponding unit calibration item, j=1, 2, …, m, and m is the number of calibration priority order; BZ j represents the calibration item standard of the corresponding unit calibration item; s j →BZ j represents that the corresponding selected region information meets the calibration item standard; the output data is a single calibration value DP(s j , BZ j ), and the unit calibration value is 1 or 0;

[0027] When the unit calibration value is 1, the corresponding selected region meets the calibration item standard;

[0028] When the unit calibration value is 0, the corresponding selected region does not meet the calibration item standard.

[0029] Step two: real-time acquisition of analysis result data based on probability power flow calculation in the power grid region, acquisition of corresponding standard result data according to the analysis result data, calibration of the analysis result data according to the standard result data, identification of the abnormal position corresponding to the analysis result data that does not meet the calibration standard; and marking of the abnormal position in the region information map.

[0030] Further, another method for determining the abnormal position includes:

[0031] The variable verification data includes input variable adjustment data and output result allowable range; the variable verification data is summarized to establish a verification library according to whether it can be applied to the verification of the corresponding unit region;

[0032] Real-time identification of analysis result data based on probability power flow calculation in the power grid region, classification of the analysis result data according to the unit region, formation of unit result data of the corresponding unit region; identification of unit input data of the corresponding unit region according to the unit result data;

[0033] According to the unit input data, corresponding variable verification data is matched from the verification library, input variable adjustment data and output result allowable range corresponding to the variable verification data are identified, simulation analysis is carried out according to the input variable adjustment data and the unit input data, and simulation analysis result data of the unit area is obtained;

[0034] According to the output result allowable range, the simulation analysis result data and the unit result data are calibrated, and whether the corresponding unit area is abnormal is judged;

[0035] When it is judged that the unit area is normal, no corresponding operation is performed;

[0036] When it is judged that the unit area is abnormal, the corresponding abnormal position is determined according to the simulation analysis result data and the unit result data.

[0037] Step three: identifying the unit area corresponding to the abnormal position in the area information map, marking the unit area as a trace area, determining the abnormal reason of the probability power flow calculation based on the trace area, and optimizing and adjusting the probability power flow calculation based on the abnormal reason.

[0038] A probability power flow calculation accuracy evaluation device for a power grid, comprising:

[0039] A memory for storing a computer program;

[0040] A processor for executing the computer program to realize the steps of the above-mentioned probability power flow calculation accuracy evaluation method for a power grid.

[0041] Compared with the prior art, the beneficial effects of the present application are:

[0042] By reasonably dividing the power grid area based on the probability power flow technology, the originally huge overall power grid calculation task is divided into multiple relatively independent sub-areas, which facilitates rapid determination of abnormal areas, also facilitates reduction of the influence of subsequent optimization adjustment, and helps users to determine the normality of other areas; by determining the calibration priority of each unit calibration item, the division efficiency of the power grid area is improved, analysis of areas that do not meet the requirements is avoided, and the analysis efficiency is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0044] Figure 1A flowchart of the method of the present application. DETAILED DESCRIPTION

[0045] The technical solutions of the present application will be described below in conjunction with embodiments, obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0046] As shown in Figure 1 A method for evaluating the accuracy of probabilistic power flow calculation of a power grid, comprising:

[0047] Step one: identify the power grid area corresponding to the probabilistic power flow calculation, segment the power grid area in combination with the probabilistic power flow calculation, obtain a plurality of unit areas; generate a region information map according to the unit area and the power grid area, that is, intuitively display the power grid area and each unit area through the information map.

[0048] Among them, the power grid area is segmented in combination with the probabilistic power flow calculation, and the core of the probabilistic power flow calculation is to analyze the influence of uncertainty (such as load fluctuation, new energy output) on the state of the power grid. If the input variables (such as load, distributed power) in a certain region are relatively independent, and the coupling with other regions is weak, then the probabilistic power flow calculation result of the region can be approximately independently verified, and then the region can be segmented into a unit area, which can be segmented based on the existing method according to this standard.

[0049] In one embodiment, the method for segmenting the power grid area in combination with the probabilistic power flow calculation comprises:

[0050] Set the unit area standard, such as input independence, topological decoupling, calculation target consistency, etc. For example, input independence: the correlation coefficient (such as Pearson correlation coefficient) between the uncertainty factors (such as load, wind power) in the region and other regions is less than 0.3; topological decoupling: the electrical connection between regions is weak, or the external influence can be ignored through equivalent method (such as Thevenin equivalent); calculation target consistency: the accuracy evaluation of the state variables (such as voltage, power) in the region does not depend on the external region.

[0051] According to the unit calibration item corresponding to the unit area standard, each unit calibration item is set for a specific unit area standard, such as the unit calibration item corresponding to the input independence;

[0052] Collect the region information of the power grid area, determine the calibration priority of each unit calibration item, and gradually determine the corresponding selected region of the power grid area according to the calibration priority of the unit calibration item and the region information, until the corresponding selected region meets the unit area standard. Mark the corresponding selected region as a unit area.

[0053] By determining the calibration priority of each unit calibration item, the partition efficiency of the power grid area is improved, and the analysis efficiency is reduced by avoiding analyzing the area that does not meet the requirements.

[0054] In one embodiment, the calibration priority of each unit calibration item is determined, which can be determined based on the existing mode, such as directly manually setting.

[0055] In one embodiment, the method for determining the calibration priority of the unit calibration item comprises:

[0056] According to the historical data, a power grid simulation area convenient for simulation analysis is preset, which is generally selected according to the existing power grid area, and preferably the power grid area applying the probability flow calculation.

[0057] The unit calibration items are identified, and the unit calibration items are arranged according to different priorities to obtain a plurality of possible priority sequences to be selected;

[0058] The power grid simulation area is simulated and divided according to the corresponding priority sequence to be selected, and the division efficiency corresponding to the corresponding priority sequence to be selected is obtained.

[0059] The priority sequence to be selected with the highest division efficiency is selected to determine the calibration priority of each unit calibration item.

[0060] In one embodiment, the corresponding candidate area of the power grid area is gradually determined according to the calibration priority of the unit calibration item and the area information, comprising:

[0061] The calibration priority is identified, and the unit calibration items are marked as i according to the calibration priority, i=1, 2, …, n, n is the number of calibration priorities, such as the calibration priority from 1 to 10, then n is 10;

[0062] According to the unit area standard, the calibration item standard corresponding to the unit calibration item i=1 is identified, the area information is calibrated according to the calibration item standard, and the candidate area that meets the calibration item standard is determined for the current power grid area;

[0063] According to the unit area standard, the calibration item standard corresponding to the unit calibration item i=2 is identified, and the calibration item standard and the area information are calibrated to the candidate area, and the candidate area that does not meet the calibration item standard is removed;

[0064] According to the unit area standard, the calibration item standard corresponding to the unit calibration item i=3 is identified, and the calibration item standard and the area information are calibrated to the candidate area, and the candidate area that does not meet the calibration item standard is removed;

[0065] By analogy, until the calibration item standard corresponding to the unit calibration item i=n is identified according to the unit area standard, the to-be-selected area is calibrated according to the calibration item standard and the area information, and the to-be-selected area meeting the calibration item standard is marked as a unit area.

[0066] In one embodiment, whether the corresponding to-be-selected area meets the calibration item standard and the calibration of the area information according to the calibration item standard can be realized by using the existing judgment and calibration methods, such as commonly used machine learning and deep learning algorithms to establish corresponding intelligent models for intelligent calibration.

[0067] In one embodiment, the method for judging whether the corresponding to-be-selected area meets the calibration item standard comprises:

[0068] According to the unit calibration item, the area information is feature extracted, and the area information of the to-be-selected area and the calibration item standard is extracted and marked as to-be-selected area information;

[0069] A unit calibration model is established, and the expression of the unit calibration model is:

[0070] ;

[0071] In the formula, (s j , BZ j ) is input data, s j represents the to-be-selected area information of the corresponding unit calibration item, j represents the corresponding unit calibration item, j=1, 2, …, m, and m is the number of calibration priorities; BZ j represents the calibration item standard of the corresponding unit calibration item; s j → BZ j represents that the corresponding to-be-selected area information meets the calibration item standard; the output data is a single calibration value DP (s j , BZ j ), and the unit calibration value is 1 or 0; the corresponding historical area information is used to set the corresponding training data for training.

[0072] The to-be-selected area information and the calibration item standard of the corresponding unit calibration item are analyzed by using the unit calibration model, and the unit calibration value of the corresponding to-be-selected area is obtained;

[0073] When the unit calibration value is 1, the corresponding to-be-selected area meets the calibration item standard.

[0074] When the unit calibration value is 0, the corresponding to-be-selected area does not meet the calibration item standard.

[0075] Step two: real-time acquisition of analysis result data based on probabilistic power flow calculation in the power grid area, acquisition of corresponding standard result data according to the analysis result data, the standard result data being deterministic power flow or high-precision measured data; calibration of the analysis result data according to the standard result data, identification of the area position corresponding to the analysis result data that does not meet the calibration standard, and marking as an abnormal position, if the specific position cannot be accurately determined, the approximate area can be marked, or even the corresponding unit area is marked as an abnormal position; if the 95% quantile of the probability distribution of the voltage of a node deviates from the measured value by more than 5%, the calibration standard does not meet the calibration standard, and the calibration standard is set according to the accuracy requirement of the probabilistic power flow calculation; the abnormal position is marked in the area information map.

[0076] In one embodiment, the determination of the abnormal position can also be performed in the following manner, comprising:

[0077] The preset variable verification data is set for the power grid and the probabilistic power flow calculation, including input variable adjustment data and output result allowable range, that is, the corresponding input data is adjusted, and the result should be within the output result allowable range, otherwise it is an abnormal situation; for example, the input data is wind power output fluctuation rate and load standard deviation, and the output data is voltage out-of-limit probability, the input variable adjustment data is formed by changing the input data, and the change of the output data is determined, and the output result allowable range is integrated within the expectation; for example, if the wind power output fluctuation rate increases by 10% and the voltage out-of-limit probability rises by more than the expected threshold, it is an abnormal situation.

[0078] The variable verification data is summarized and a verification library is established according to whether it can be applied to the verification of the corresponding unit area, that is, it is stored according to the corresponding unit area.

[0079] Real-time identification of analysis result data based on probabilistic power flow calculation in the power grid area, classification of the analysis result data according to the unit area, formation of unit result data of the corresponding unit area; identification of the corresponding input data according to the unit result data, and marking as unit input data; matching of the corresponding variable verification data from the verification library according to the unit input data, that is, matching combined with the input variable adjustment data, one is to directly match the unit input data, and the other is that the corresponding adjustment range is within the allowable range, the corresponding output result allowable range is updated according to the corresponding adjustment range, and it is ensured that the matched variable verification data is for the unit input data of the unit area;

[0080] Identification of the input variable adjustment data and the output result allowable range corresponding to the variable verification data, simulation analysis according to the input variable adjustment data and the unit input data, and acquisition of the simulation analysis result data of the unit area;

[0081] According to the output result allowed range, the simulation analysis result data and the unit result data are calibrated to determine whether the corresponding unit area is analyzed abnormally;

[0082] When the unit area is determined to be analyzed normally, no corresponding operation is performed;

[0083] When the unit area is determined to be analyzed abnormally, the corresponding abnormal position is determined according to the difference between the simulation analysis result data and the unit result data.

[0084] Step three: identifying the unit area corresponding to the abnormal position in the area information map, marking the unit area as a trace area; determining the abnormal reason of the probability power flow calculation based on the trace area, and optimizing and adjusting the probability power flow calculation based on the abnormal reason.

[0085] In one embodiment, the specific abnormal reason can be determined in combination with existing reason analysis techniques, such as matching the corresponding historical abnormal data; the abnormal reason can also be determined manually; when the abnormal reason is clear, the specific optimization and adjustment is to adjust the corresponding abnormal reason by manual or other existing methods.

[0086] In one embodiment, the present application provides a probability power flow calculation accuracy evaluation device for a power grid, comprising:

[0087] a memory for storing a computer program;

[0088] a processor for executing the computer program to realize the steps of the above-mentioned embodiment of the probability power flow calculation accuracy evaluation method for the power grid.

[0089] The evaluation device provided in the embodiment can include, but is not limited to, a smart phone, a tablet computer, a notebook computer or a desktop computer, etc.

[0090] The above formulas are all calculated by removing the dimension and taking the numerical value, the formula is obtained by collecting a large amount of data to simulate the closest real situation, and the preset parameters and the preset threshold in the formula are set by the person skilled in the art according to the actual situation or obtained by a large amount of data simulation.

[0091] The above embodiments are only used to illustrate the technical method of the present application and are not limited. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical method of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical method of the present application.

Claims

1. A probabilistic power flow calculation accuracy evaluation method for a power grid, characterized in that, The method comprises the following steps: Step 1: identifying the power grid area corresponding to the probabilistic power flow calculation, segmenting the power grid area according to the probabilistic power flow calculation, and obtaining a plurality of unit areas; generating an area information map according to the unit areas and the power grid area; Step 2: obtaining analysis result data based on the probabilistic power flow calculation in the power grid area, obtaining corresponding standard result data according to the analysis result data, calibrating the analysis result data according to the standard result data, identifying abnormal positions corresponding to the analysis result data that do not meet the calibration standard, and marking the abnormal positions in the area information map; Step 3: identifying the unit area corresponding to the abnormal position in the area information map, marking the unit area as a traceable area, determining the abnormal reason of the probabilistic power flow calculation based on the traceable area, and optimizing and adjusting the probabilistic power flow calculation based on the abnormal reason. The method for segmenting the power grid area according to the probabilistic power flow calculation comprises: Setting a unit area standard, and setting a corresponding unit calibration item according to the unit area standard; Collecting area information of the power grid area, determining a calibration priority order of each unit calibration item, and dividing the power grid area according to the calibration priority order of the unit calibration item and the area information to obtain a corresponding unit area; The method for determining the calibration priority order of each unit calibration item comprises: Pre-setting a power grid simulation area; identifying unit calibration items, arranging the unit calibration items according to different priority orders, and obtaining a plurality of candidate priority sequences; Simulating and dividing the power grid simulation area according to the candidate priority sequences to obtain a division efficiency corresponding to the candidate priority sequences; Selecting the candidate priority sequence with the highest division efficiency as a target priority sequence, and determining the calibration priority order of each unit calibration item according to the target priority sequence; The method for dividing the power grid area according to the calibration priority order of the unit calibration item and the area information comprises: Identifying the calibration priority order, marking the unit calibration item as i according to the calibration priority order, i=1, 2, …, n, n is the number of the calibration priority order; Identifying the calibration item standard corresponding to the unit calibration item i=1 according to the unit area standard, calibrating the area information according to the calibration item standard to obtain a candidate area of the current power grid area meeting the calibration item standard; Identifying the calibration item standard corresponding to the unit calibration item i=2 according to the unit area standard, calibrating the candidate area according to the calibration item standard and the area information, and eliminating the candidate area not meeting the calibration item standard; Identifying the calibration item standard corresponding to the unit calibration item i=3 according to the unit area standard, calibrating the candidate area according to the calibration item standard and the area information, and eliminating the candidate area not meeting the calibration item standard; By analogy, until the calibration item standard corresponding to the unit calibration item i=n is identified according to the unit area standard, the candidate area is calibrated according to the calibration item standard and the area information, and the candidate area meeting the calibration item standard is marked as a unit area.

2. The method for probabilistic power flow calculation accuracy assessment of power grid according to claim 1, characterized in that, The method for judging whether the corresponding candidate area meets the calibration item standard comprises: Extracting features of the area information according to the unit calibration item to obtain candidate area information of the corresponding candidate area; The unit calibration model is established, the unit calibration model is used for analyzing the selected region information corresponding to the corresponding unit calibration item and the calibration item standard, and a calibration judgment result of the corresponding selected region is obtained. The calibration judgment result includes meeting the calibration item standard and not meeting the calibration item standard.

3. The method for probabilistic power flow calculation accuracy assessment of power grid according to claim 2, characterized in that, The expression of the unit calibration model is: ; In the formula: (s j , BZ j ) is input data, s j represents the to-be-selected region information of the corresponding unit calibration item, j represents the corresponding unit calibration item, j=1, 2, …, m, and m is the number of calibration priorities; BZ j represents the calibration item standard of the corresponding unit calibration item; s j →BZ j represents that the corresponding to-be-selected region information meets the calibration item standard; and the output data is a single calibration value DP(s j , BZ j ), and the unit calibration value is 1 or 0. When the unit calibration value is 1, the corresponding selected region meets the calibration item standard. When the unit calibration value is 0, the corresponding selected region does not meet the calibration item standard.

4. The method for probabilistic power flow calculation accuracy assessment of power grid according to claim 1, characterized in that, Another method for determining the abnormal position includes: presetting variable verification data, the variable verification data including input variable adjustment data and output result allowable range; the variable verification data is summarized and a verification library is established according to whether the variable verification data can be applied to the verification of the corresponding unit region; real-time identification of analysis result data based on probability flow calculation for analysis of the power grid region, classification of the analysis result data according to the unit region, formation of unit result data of the corresponding unit region; identification of unit input data of the corresponding unit region according to the unit result data; matching the corresponding variable verification data from the verification library according to the unit input data, identifying the input variable adjustment data and the output result allowable range corresponding to the variable verification data, and performing simulation analysis according to the input variable adjustment data and the unit input data to obtain simulation analysis result data of the unit region; calibration of the simulation analysis result data and the unit result data according to the output result allowable range, and judgment of whether the corresponding unit region is abnormal; when it is judged that the unit region is normal, no corresponding operation is performed; when it is judged that the unit region is abnormal, the corresponding abnormal position is determined according to the simulation analysis result data and the unit result data.

5. A probabilistic power flow calculation accuracy evaluation device for a power grid, characterized by, including: a memory for storing a computer program; a processor for executing the computer program to realize the method for evaluating the accuracy of probability flow calculation of the power grid according to any one of claims 1 to 4.

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