Method and system for studying and judging low-voltage problem of transformer area

Abstract

The invention relates to the technical field of power system operation and maintenance, and discloses a method and system for studying and judging the low-voltage problem of a transformer area, and the method comprises the steps: constructing a power feature data set of each low-voltage user in a target transformer area; performing rule deduction on each electric power characteristic data group to obtain an initial low voltage cause research and judgment result of the target transformer area; based on the daily voltage change trend of each low-voltage user, constructing a low-voltage user visual image set of the target transformer area; performing time sequence analysis on the low-voltage user visual image set to obtain an auxiliary low-voltage cause research and judgment result of the target transformer area; and verifying the initial low-voltage cause research and judgment result based on the auxiliary low-voltage cause research and judgment result to obtain a target low-voltage cause research and judgment result of the target transformer area. According to the method, algorithm study and judgment and visual graph auxiliary study and judgment are combined, misjudgment possibly caused by a single analysis method is effectively reduced, and the reliability of low-voltage cause diagnosis is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power system operation and maintenance, and in particular to a method and system for analyzing and judging low voltage problems in a transformer substation. Background Art

[0002] In recent years, voltage quality issues have received increasing attention, and the management of low voltage problems has become a key task in power operation and maintenance.

[0003] Currently, low voltage issues at the substation level are easily identified through analysis of factors such as power transfer, terminal failure, and three-phase imbalance. However, for low voltage at the user end, online diagnosis is difficult due to unclear key factors and a lack of effective, transparent diagnostic methods. Existing methods for identifying low voltage issues at the substation level suffer from numerous shortcomings: First, a lack of ledger information prevents the determination of user phases, necessitating manual on-site investigations, which is time-consuming and labor-intensive. Second, they rely on multiple systems, including distribution, marketing, equipment, and metering. However, a single marketing and distribution map only displays the most recent low-voltage alarm substation information, failing to fully display non-standard low-voltage users and historical voltage distribution. Third, the low-voltage distribution map at the equipment center requires manual household-by-household querying, and the automated metering system complicates location analysis due to inconsistent user names and numbers. Fourth, none of the systems offer a visual display of low-voltage users. These issues inefficiently analyze the causes of low voltage at the substation level, severely hindering improvements in power quality and the optimization of operations and maintenance management.

[0004] Therefore, it is urgent to propose an innovative method for analyzing low voltage problems in substations to overcome the shortcomings of existing methods. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method and system for analyzing and judging low voltage problems in a transformer substation.

[0006] In a first aspect, an embodiment of the present invention provides a method for analyzing and determining a low voltage problem in a transformer area, comprising: Constructing a power characteristic data set for each low-voltage user in the target area, wherein the power characteristic data set includes user voltage, user access phase, user power supply radius, and user power consumption; Perform rule deduction on each of the power characteristic data groups to obtain an initial low voltage cause analysis result for the target substation; construct a low voltage user visualization atlas for the target substation based on the daily voltage change trend of each low voltage user, wherein the low voltage user visualization atlas includes low voltage user visualization maps at several time nodes within a day; Perform a time series analysis on the low-voltage user visualization atlas to obtain the auxiliary low-voltage cause analysis result of the target substation; verify the initial low-voltage cause analysis result based on the auxiliary low-voltage cause analysis result to obtain the target low-voltage cause analysis result of the target substation.

[0007] Preferably, the step of constructing a power characteristic data set for each low-voltage user in the target area includes: Based on the power business support system, the user voltage, power supply radius and power consumption of each low-voltage user in the target area are obtained; Performing phase discrimination on each of the low-voltage users based on least squares regression analysis to determine a user access phase corresponding to the low-voltage user; An electric power feature data set of each low-voltage user is constructed based on the user voltage, the user power supply radius, the user power consumption and the user access phase.

[0008] Preferably, performing phase discrimination on each of the low-voltage users based on least squares regression analysis to determine the user access phase corresponding to the low-voltage user includes: Performing a least squares regression analysis on the user voltage of each low-voltage user and the trunk current of the target substation to obtain a household-phase correlation coefficient corresponding to the low-voltage user; The user access phase corresponding to the low-voltage user is determined based on the household phase correlation coefficient of each low-voltage user.

[0009] Preferably, the rule deduction is performed on each of the power characteristic data groups to obtain the initial low voltage cause determination result of the target substation, including: Performing a threshold judgment on the user voltage of each power feature data group to obtain a classification result of each low-voltage user, wherein the classification result includes undervoltage users and normal users; The classification results of each low-voltage user are subjected to rule deduction to obtain the initial low-voltage cause analysis result of the target substation.

[0010] Preferably, the rule deduction of the classification result of each low-voltage user to obtain the initial low-voltage cause analysis result of the target substation includes: Deducing the classification result of each of the low-voltage users based on a first conditional judgment rule, obtaining a first initial low-voltage cause analysis result of the target substation, wherein the first conditional judgment rule includes that the proportion of undervoltage users in all low-voltage users exceeds a first threshold, the proportion of users in the same phase among the undervoltage users exceeds a second threshold, and the difference between the current of the phase and the currents of the remaining two phases is greater than a third threshold; Based on the second condition judgment rule, the classification result of each low-voltage user is deduced to obtain the second initial low-voltage cause analysis result of the target substation, wherein the second condition judgment rule includes that the proportion of undervoltage users in all low-voltage users exceeds the first threshold, the proportion of users of the same phase among undervoltage users exceeds the second threshold, the difference between the current of the phase and the current of the other two phases is not greater than the third threshold, the difference in user power supply radius between undervoltage users and normal users is not greater than the fourth threshold, and the difference in user power consumption between undervoltage users and normal users is less than the fifth threshold.

[0011] Preferably, the step of performing rule deduction on the classification result of each low-voltage user to obtain an initial low-voltage cause determination result of the target substation further includes: Deducing the classification result of each of the low-voltage users based on a third conditional judgment rule to obtain a third initial low-voltage cause analysis result of the target substation, wherein the third conditional judgment rule includes that the proportion of undervoltage users in all low-voltage users exceeds a first threshold, and the difference in user power supply radius between undervoltage users and normal users is greater than a fourth threshold; The classification result of each of the low-voltage users is deduced based on the fourth condition judgment rule to obtain a fourth initial low-voltage cause analysis result of the target substation, wherein the fourth condition judgment rule includes that the proportion of undervoltage users in all low-voltage users exceeds a first threshold, the proportion of users in the same phase among the undervoltage users exceeds a second threshold, and there is a user with a power consumption greater than a sixth threshold among the normal users in the same phase; The classification result of each low-voltage user is deduced based on the fifth conditional judgment rule to obtain the fifth initial low-voltage cause analysis result of the target substation, wherein the fifth conditional judgment rule includes that the number of undervoltage users is less than the seventh threshold.

[0012] Preferably, the performing of time series analysis on the low-voltage user visualization atlas to obtain auxiliary low-voltage cause analysis results of the target substation includes: Based on the first auxiliary condition judgment rule, the low-voltage user visualization diagram at each time node in a day is analyzed to obtain the first auxiliary low-voltage cause analysis result of the target substation, wherein the first auxiliary condition judgment rule includes that the user access phase of each undervoltage user is distributed in the same phase within a day, the difference between the current of the user access phase and the current of the other two phases is greater than the eighth threshold, the number of undervoltage users peaks during the daily load peak period, the user voltage of the undervoltage user reaches a valley value during the daily load peak period, and the user voltage difference between the undervoltage user at the edge node and the adjacent normal user in the low-voltage user visualization diagram does not exceed the ninth threshold; Based on the second auxiliary condition judgment rule, the low-voltage user visualization diagram at each time node in a day is analyzed to obtain the second auxiliary low-voltage cause analysis result of the target substation, wherein the second auxiliary condition judgment rule includes that each undervoltage user is spatially clustered within a day, the user access phase of each undervoltage user is distributed in the same phase within a day, the difference between the current of the user access phase and the current of the other two phases is not greater than the eighth threshold, and the user voltage difference between the undervoltage user at the edge node and the adjacent normal user in the low-voltage user visualization diagram exceeds the ninth threshold.

[0013] Preferably, the performing of time series analysis on the low-voltage user visualization atlas to obtain auxiliary low-voltage cause analysis results for the target substation further includes: Based on the third auxiliary condition judgment rule, the low-voltage user visualization diagram at each time node in a day is analyzed to obtain the third auxiliary low-voltage cause analysis result of the target substation, wherein the third auxiliary condition judgment rule includes that each undervoltage user is stably distributed at the terminal position within a day, the user access phase of each undervoltage user is distributed in an out-of-phase manner within a day, the difference between the currents of any two phases is not greater than the eighth threshold, the number of undervoltage users reaches a peak during the daily load peak period, the user voltage of the undervoltage user reaches a valley during the daily load peak period, and the user voltage difference between the undervoltage user at the edge node and the adjacent normal user in the low-voltage user visualization diagram does not exceed the ninth threshold; The low-voltage user visualization diagram at each time point in a day is analyzed based on the fourth auxiliary condition judgment rule to obtain the fourth auxiliary low-voltage cause analysis result of the target substation, wherein the fourth auxiliary condition judgment rule includes that each undervoltage user is spatially clustered within a day, and there are front-end users in the area where the undervoltage users are located whose user power consumption is greater than the tenth threshold; Based on the fifth auxiliary condition judgment rule, the low-voltage user visualization diagram at each time node in a day is analyzed to obtain the fifth auxiliary low-voltage cause analysis result of the target substation, wherein the fifth auxiliary condition judgment rule includes that the number of undervoltage users at each time node in a day is less than the eleventh threshold, and the user voltage difference between the undervoltage users at the edge nodes and the adjacent normal users in the low-voltage user visualization diagram exceeds the ninth threshold.

[0014] Preferably, the verifying the initial low voltage cause determination result based on the auxiliary low voltage cause determination result to obtain the target low voltage cause determination result of the target substation includes: If the auxiliary low voltage cause determination result is consistent with the initial low voltage cause determination result, the initial low voltage cause determination result is determined as the target low voltage cause determination result of the target substation; If the auxiliary low voltage cause determination result is inconsistent with the initial low voltage cause determination result, the initial low voltage cause determination result is corrected to obtain the target low voltage cause determination result of the target substation.

[0015] In a second aspect, an embodiment of the present invention provides a system for analyzing and determining low voltage problems in a transformer area, comprising: A data construction module is used to construct a power characteristic data set for each low-voltage user in the target area, wherein the power characteristic data set includes user voltage, user access phase, user power supply radius and user power consumption; A rule deduction module, configured to perform rule deduction on each of the power characteristic data groups to obtain an initial low voltage cause analysis result for the target substation; An atlas construction module is used to construct a low-voltage user visualization atlas of the target substation based on the daily voltage variation trend of each low-voltage user, wherein the low-voltage user visualization atlas includes low-voltage user visualization diagrams at several time nodes within a day; a time series analysis module is used to perform time series analysis on the low-voltage user visualization atlas to obtain auxiliary low-voltage cause analysis results for the target substation; The result determination module is used to verify the initial low voltage cause determination result based on the auxiliary low voltage cause determination result to obtain the target low voltage cause determination result of the target substation.

[0016] Compared with the existing technology, the method and system for analyzing low voltage problems in substations in the embodiment of the present invention have the following beneficial effects: by constructing a power characteristic data group and performing rule deduction, the potential causes of low voltage problems can be preliminarily identified, providing a basic direction for subsequent analysis; the low-voltage user visualization atlas generated based on the daily voltage change trend intuitively displays the voltage distribution at different time nodes in a day, and the time series analysis of the visualization atlas can assist in analyzing the potential causes of low voltage problems; the initial analysis results are verified by the auxiliary analysis results, which effectively reduces the misjudgment that may be caused by a single analysis method and improves the reliability of the diagnosis of the cause of low voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of a method for analyzing and determining low voltage problems in a transformer area according to an embodiment of the present invention; Figure 2 This is a structural diagram of a system for analyzing and judging low voltage problems in a transformer area according to an embodiment of the present invention; Reference numerals: 1. Data construction module; 2. Rule deduction module; 3. Atlas construction module; 4. Time series analysis module; 5. Result determination module. DETAILED DESCRIPTION

[0018] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0019] In the description of the present invention, it should be understood that the terms "first" and "second" etc. are used in the present invention to distinguish different objects rather than to describe a specific order.

[0020] In describing the present invention, it should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0021] like Figure 1 As shown, an embodiment of the present invention provides a method for analyzing and judging low voltage problems in a transformer area, including the steps of: S1. Construct a power characteristic data set for each low-voltage user in the target area; Specifically, the power characteristic data set includes user voltage, user access phase, user power supply radius and user power consumption. It can be understood that the user power supply radius is the distance between the user and the target substation head end.

[0022] Furthermore, step S1 includes: 1) Based on the power business support system, the user voltage, power supply radius and power consumption of each low-voltage user in the target area are obtained; Analyzing low-voltage issues in a substation relies on the power business support system, which includes multiple systems, including the power distribution system, marketing system, and GIS (Geographic Information System). The power business support system can obtain the user voltage, power supply radius, and power consumption of each low-voltage user within the target substation. Specifically, the power distribution system can obtain user voltage, the GIS system can obtain user power supply radius, and the marketing system can obtain user power consumption.

[0023] 2) Based on least squares regression analysis, the phase of each low-voltage user is identified to determine the user access phase corresponding to the low-voltage user; Due to the lack of records, the specific phases of low-voltage users are unclear. This leads to a lack of effective guidance when analyzing which phase low-voltage users are in. Operations and maintenance personnel have to conduct on-site door-to-door inspections, which is time-consuming and labor-intensive. Therefore, the present invention uses least squares regression analysis to visualize the household-phase relationships of low-voltage users.

[0024] Specifically, step 2) includes: i) Performing least squares regression analysis on the user voltage of each low-voltage user and the trunk current of the target substation to obtain the household-phase correlation coefficient of the corresponding low-voltage user; For a low-voltage user C, the following formula is used to express its user voltage: U C =U0-I 干 ·R 干 -I 支 ·R 支 Among them, U C Indicates the user voltage, U0 indicates the voltage at the head end of the target area, I 干 Indicates the mains current of the target area, R 干 Indicates the trunk resistance of the target area, I 支 Indicates the branch line current where the low-voltage user is located, R 支 Indicates the resistance of the branch line where the low-voltage user is located.

[0025] In low-voltage distribution networks, the impact of inductance and distributed capacitance on voltage is ignored, and it is assumed that the current distribution of each branch is only related to the resistance distribution in the low-voltage distribution network. Therefore, it can be considered that: I 支 =k·I 干 (k<1) U C =U0-I 干 ·R 干 -k·I 干 ·R 支 =U0-(R 干 +k·R 支 )·I 干 Here, k represents the proportional coefficient between the branch line current and the main line current. For a given low-voltage user, the proportional coefficient k is fixed. Therefore, it can be roughly assumed that the voltage fluctuation at the user end is absolutely negatively correlated with the current fluctuation at the head end of the target substation.

[0026] ii) determining the user access phase corresponding to each low-voltage user based on the household phase correlation coefficient of each low-voltage user.

[0027] Since the three-phase loads in the target substation are different, the voltage fluctuations of the three phases ABC are inconsistent. Therefore, for low-voltage users with direct voltage collection and transmission, the phase to which the low-voltage user belongs can be calculated by comparing the phase correlation coefficient of the household.

[0028] Specifically, for a low-voltage user C, by comparing the user voltage U C and the A phase current I on the main line A干 , Phase B current on the main line I B干, the C phase current on the main line I C干 The phase with the strongest negative correlation is the phase to which the low-voltage user is connected. For example, if the correlation coefficients between a low-voltage user and phase currents A, B, and C are -1, -0.5, and -0.2, respectively, then the user is inferred to be connected to phase A.

[0029] 3) Construct a power characteristic data set for each low-voltage user based on user voltage, user power supply radius, user power consumption and user access phase.

[0030] It can be understood that the power characteristic data group is a four-data group including user voltage, user power supply radius, user power consumption and user access phase.

[0031] S2. Rule deduction is performed on each power characteristic data set to obtain the initial low voltage cause analysis result of the target substation. Specifically, step S2 includes: 1) Perform threshold judgment on the user voltage of each power characteristic data group to obtain the classification result of each low-voltage user; Specifically, the classification results include undervoltage users and normal users. The threshold value set in this embodiment is 198V, that is, if the user voltage is less than 198V, the corresponding low-voltage user is defined as an undervoltage user, otherwise it is defined as a normal user.

[0032] 2) Conduct rule deduction on the classification results of each low-voltage user to obtain the initial low-voltage cause analysis results of the target substation.

[0033] Specifically, step 2) includes: 21) Deducing the classification results of each low-voltage user based on the first condition judgment rule to obtain a first initial low-voltage cause analysis result for the target substation; The first conditional judgment rule includes that the proportion of undervoltage users in all low-voltage users exceeds the first threshold, the proportion of users in the same phase among undervoltage users exceeds the second threshold, and the difference between the current of the phase and the current of the other two phases is greater than the third threshold. In other words, the first conditional judgment rule includes: low / (P low +P normal )>K1%,P low Among them, K2% and above are in the same phase, and the current of this phase is significantly greater than the current of the other two phases. low Indicates the number of undervoltage users, P normal represents the number of normal users, K1% represents the first threshold, and K2% represents the second threshold, which is a value greater than 90.

[0034] When the deduction result satisfies the first condition judgment rule, the first initial low voltage cause analysis result of the target substation is judged to be "phase aggregation".

[0035] 22) Deducing the classification results of each low-voltage user based on the second condition judgment rule to obtain a second initial low-voltage cause analysis result of the target substation; The second conditional judgment rule includes that the proportion of undervoltage users in all low-voltage users exceeds the first threshold, the proportion of users in the same phase among undervoltage users exceeds the second threshold, the difference between the current of the phase and the current of the other two phases is not greater than the third threshold, the difference in user power supply radius between undervoltage users and normal users is not greater than the fourth threshold, and the difference in user power consumption between undervoltage users and normal users is less than the fifth threshold. In other words, the second conditional judgment rule includes: R low / (P low +P normal )>K1%,P low More than K2% of the phase is the same phase, and the current of this phase is not significantly greater than the other two phase currents, P low (d) Not significantly greater than P normal (d), P low (q) and P normal (q) There is no significant difference. low (d) represents the power supply radius of the undervoltage user, P normal (d) represents the power supply radius of normal users, P low (q) represents the power consumption of undervoltage users, P normal (q) represents the user electricity consumption of normal users.

[0036] When the deduction result meets the second condition judgment rule, the second initial low voltage cause judgment result of the target substation is judged to be "line ear oxidation".

[0037] Furthermore, step 2) further includes: 23) Deducing the classification results of each low-voltage user based on the third condition judgment rule to obtain the third initial low-voltage cause analysis result of the target substation; The third condition judgment rule includes that the proportion of undervoltage users in all low-voltage users exceeds the first threshold, and the difference in user power supply radius between undervoltage users and normal users is greater than the fourth threshold. In other words, the third condition judgment rule includes: low / (P low +P normal )>K1%,P low (d) Significantly greater than P normal (d).

[0038] When the deduction result meets the third condition judgment rule, the third initial low voltage cause analysis result of the target substation is judged to be "the power supply radius is too long".

[0039] 24) Deducing the classification results of each low-voltage user based on the fourth condition judgment rule to obtain a fourth initial low-voltage cause analysis result of the target substation; The fourth condition judgment rule includes that the proportion of undervoltage users in all low-voltage users exceeds the first threshold, the proportion of users in the same phase among undervoltage users exceeds the second threshold, and there are users in the same phase with normal users whose power consumption exceeds the sixth threshold. In other words, the fourth condition judgment rule includes: low / (P low +P normal )>K1%,P low K2% or more of the same phase, in the same phase P normal There is P normal (q) Significantly older users.

[0040] When the deduction result meets the fourth condition judgment rule, the fourth initial low voltage cause judgment result of the target substation is judged to be "high power consumption by front-end users".

[0041] 25) Based on the fifth conditional judgment rule, the classification results of each low-voltage user are deduced to obtain the fifth initial low-voltage cause analysis result of the target substation.

[0042] The fifth conditional judgment rule includes that the number of undervoltage users is less than the seventh threshold. The seventh threshold set in this embodiment is 5. That is, the fifth conditional judgment rule includes: low is an integer from 1 to 5.

[0043] When the deduction result meets the fifth condition judgment rule, the fifth initial low voltage cause judgment result of the target substation is judged to be "single user meter front line fault".

[0044] S3. Build a visualization atlas of low-voltage users in the target area based on the daily voltage variation trend of each low-voltage user; After the initial low voltage cause analysis result is output in step S2, it is still necessary to introduce a low voltage user visualization diagram to assist in determining the cause of the low voltage.

[0045] Specifically, a time variable, T, is introduced to describe the daily evolution of user-side voltage, i.e., the daily voltage trend for low-voltage users. A set of n time nodes is formed, T = {t1, t2, t3, t4...tn}, where T includes important time nodes such as the morning peak, midday peak, and evening peak.

[0046] Furthermore, a visualization graph of low-voltage users is drawn at each time node in T, and a low-voltage user visualization graph set P = {P1, P2, P3...Pn} is constructed in ascending order of time nodes. In other words, the low-voltage user visualization graph set includes low-voltage user visualization graphs at several time nodes within a day.

[0047] The low-voltage user visualization diagram in this embodiment has the following characteristics: 1) The colors of the user icon "yellow", "green" and "red" respectively represent the "yellow", "green" and "red" phases connected by the user; 2) Undervoltage users are indicated by a "triangle" icon, and normal users are indicated by a "circle" icon; 3) The size of the icon indicates the amount of electricity used by the user. The larger the icon, the more electricity the user uses, and the smaller the icon, the less electricity the user uses. 4) The voltage value of the user is displayed in digital form above the user icon; 5) The upper left corner of the figure shows the three-phase voltage and three-phase current values ​​at the head end of the target substation.

[0048] S4. Performing a time series analysis on the low-voltage user visualization atlas to obtain the auxiliary low-voltage cause analysis results of the target substation. Specifically, step S4 includes: 1) Based on the first auxiliary condition judgment rule, analyze the low-voltage user visualization diagram at each time node in a day to obtain the first auxiliary low-voltage cause judgment result of the target substation; The first auxiliary condition judgment rule includes: the user access phase of each undervoltage user is distributed in the same phase within a day; the difference between the current of the user access phase and the current of the other two phases is greater than the eighth threshold; the number of undervoltage users reaches a peak during the daily load peak period; the user voltage of the undervoltage user reaches a valley during the daily load peak period; and the user voltage difference between the undervoltage user at the edge node and the adjacent normal user in the low-voltage user visualization diagram does not exceed the ninth threshold. In other words, the first auxiliary condition judgment rule includes: as time goes from t1 to tn, the undervoltage users from P1 to Pn are always in a certain phase, and the current of this phase is significantly greater than the current of the other two phases; the number of undervoltage users reaches a peak at the morning peak, noon peak, and evening peak time nodes of the day; the user voltage of the undervoltage user reaches a valley at the morning peak, noon peak, and evening peak time nodes of the day; and in the low-voltage area, there is no sudden drop between the user voltage of the undervoltage user at the edge node and the user voltage of the adjacent normal user.

[0049] When the timing analysis result satisfies the first auxiliary condition judgment rule, the first auxiliary low voltage cause judgment result of the target substation is judged to be "phase aggregation".

[0050] 2) Based on the second auxiliary condition judgment rule, the low-voltage user visualization diagram at each time node in a day is analyzed to obtain the second auxiliary low-voltage cause judgment result of the target substation; The second auxiliary condition judgment rule includes the following: each undervoltage user is spatially clustered within a day; the user access phase of each undervoltage user is distributed in the same phase within a day; the difference between the current of the user access phase and the current of the other two phases is no greater than the eighth threshold; and the user voltage difference between the edge node undervoltage user and the adjacent normal user in the low-voltage user visualization diagram exceeds the ninth threshold. In other words, the second auxiliary condition judgment rule includes: as time goes from t1 to tn, the undervoltage users from P1 to Pn are always in a certain area, not limited to the end of the power supply path; the undervoltage users have the same phase, but the current of this phase is not significantly greater than the current of the other two phases; in the low-voltage area, there is a sudden drop between the user voltage of the edge node undervoltage user and the user voltage of the adjacent normal user.

[0051] When the timing analysis result meets the second auxiliary condition judgment rule, the second auxiliary low voltage cause judgment result of the target area is judged to be "line ear oxidation".

[0052] Furthermore, step S4 further includes: 3) Based on the third auxiliary condition judgment rule, analyze the low-voltage user visualization map at each time node within a day to obtain the third auxiliary low voltage cause judgment result of the target substation; The third auxiliary condition judgment rule includes: each undervoltage user is stably distributed at the end position within a day; the user access phase of each undervoltage user is distributed out of phase within a day; the difference between the currents of any two phases is no greater than the eighth threshold; the number of undervoltage users reaches a peak during the daily load peak period; the user voltage of the undervoltage user reaches a valley during the daily load peak period; and the user voltage difference between the undervoltage user at the edge node and the adjacent normal user in the low-voltage user visualization diagram does not exceed the ninth threshold. In other words, the third auxiliary condition judgment rule includes: as time goes from t1 to tn, the undervoltage users from P1 to Pn are always located at the end of the power supply path; various phases exist in the undervoltage users; the current of any phase is not significantly different from the current of the other two phases; the number of undervoltage users reaches a peak during the morning peak, midday peak, and evening peak time points of the day; the user voltage of the undervoltage user reaches a valley during the morning peak, midday peak, and evening peak time points of the day; and in the low-voltage area, there is no sudden drop between the user voltage of the undervoltage user at the edge node and the user voltage of the adjacent normal user.

[0053] When the timing analysis results meet the third auxiliary condition judgment rule, the third auxiliary low voltage cause judgment result of the target substation is judged to be "the power supply radius is too long".

[0054] 4) Analyze the low-voltage user visualization diagram at each time point in a day based on the fourth auxiliary condition judgment rule to obtain the fourth auxiliary low-voltage cause analysis result of the target substation; The fourth auxiliary condition judgment rule includes the following: each undervoltage user is spatially clustered throughout the day, and the area in which the undervoltage user is located contains a front-end user with electricity consumption exceeding the tenth threshold. In other words, the fourth auxiliary condition judgment rule includes the following: from time t1 to tn, the undervoltage users from P1 to Pn are always located in a certain area, and there is a single-phase or three-phase user with significantly higher electricity consumption in the front end of this area. Specifically, when the power consumption of the front-end user increases, low voltage occurs; when the power consumption of the front-end user returns to normal, the low voltage phenomenon disappears.

[0055] When the timing analysis result meets the fourth auxiliary condition judgment rule, the fourth auxiliary low voltage cause judgment result of the target substation is judged to be "high power consumption by front-end users".

[0056] 5) Based on the fifth auxiliary condition judgment rule, the low-voltage user visualization diagram at each time node in a day is analyzed to obtain the fifth auxiliary low-voltage cause analysis result of the target substation.

[0057] The fifth auxiliary condition judgment rule includes the following: the number of undervoltage users at each time point in a day is less than the eleventh threshold, and the user voltage difference between undervoltage users at edge nodes and adjacent normal users in the low-voltage user visualization diagram exceeds the ninth threshold. In other words, the fifth auxiliary condition judgment rule includes the following: as time passes from t1 to tn, there are only a few undervoltage users from P1 to Pn, and in the low-voltage area, there is a sudden drop between the user voltage of undervoltage users at edge nodes and the user voltage of adjacent normal users.

[0058] When the timing analysis results meet the fifth auxiliary condition judgment rule, the fifth auxiliary low voltage cause judgment result of the target substation is judged to be "single user meter front line fault".

[0059] S5. Verify the initial low voltage cause analysis result based on the auxiliary low voltage cause analysis result to obtain the target low voltage cause analysis result of the target substation.

[0060] Specifically, step S5 includes: 1) If the auxiliary low voltage cause determination result is consistent with the initial low voltage cause determination result, the initial low voltage cause determination result is determined as the target low voltage cause determination result for the target substation; Through consistency judgment, if the results are consistent, the reliability of the initial low voltage cause analysis results is further enhanced.

[0061] 2) If the auxiliary low voltage cause determination result is inconsistent with the initial low voltage cause determination result, the initial low voltage cause determination result is corrected to obtain the target low voltage cause determination result of the target substation.

[0062] Through consistency judgment, if the results are inconsistent, it means that the initial low voltage cause analysis results may be misjudged. The initial low voltage cause analysis results need to be corrected and the rules need to be re-deduced to obtain highly reliable target low voltage cause analysis results.

[0063] An embodiment of the present invention provides a method for analyzing low voltage problems in a substation. By constructing a power feature data set and performing rule deduction, the method can preliminarily identify the potential causes of low voltage problems, providing a basic direction for subsequent analysis. A low-voltage user visualization atlas generated based on daily voltage change trends intuitively displays the voltage distribution at different time nodes within a day, and a time series analysis is performed on the visualization atlas, which can assist in analyzing the potential causes of low voltage problems. The initial analysis results are verified through the auxiliary analysis results, effectively reducing the misjudgment that may be caused by a single analysis method, and improving the reliability of the diagnosis of the cause of low voltage.

[0064] Based on the above-mentioned method for analyzing low voltage problems in the substation area, Figure 2 As shown, an embodiment of the present invention provides a system for analyzing and judging low voltage problems in a transformer area, comprising: Data construction module 1 is used to construct a power characteristic data set for each low-voltage user in the target area. The power characteristic data set includes user voltage, user access phase, user power supply radius and user power consumption; Rule deduction module 2 is used to perform rule deduction on each power characteristic data set to obtain the initial low voltage cause analysis result of the target substation; Atlas construction module 3, used to construct a low-voltage user visualization atlas of the target substation based on the daily voltage change trend of each low-voltage user, wherein the low-voltage user visualization atlas includes low-voltage user visualization maps at several time nodes within a day; The timing analysis module 4 is used to perform timing analysis on the low-voltage user visualization atlas to obtain the auxiliary low-voltage cause analysis results of the target substation; The result determination module 5 is used to verify the initial low voltage cause determination result based on the auxiliary low voltage cause determination result, and obtain the target low voltage cause determination result of the target substation.

[0065] It should be noted that each module in the above-mentioned system for analyzing and judging low-voltage problems in substations can be fully or partially implemented through software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules. For the specific definition of a system for analyzing and judging low-voltage problems in substations, please refer to the definition of a method for analyzing and judging low-voltage problems in substations above. The two have the same functions and effects and will not be repeated here.

[0066] In summary, the embodiment of the present invention provides a method and system for analyzing low voltage problems in substations. By constructing a power feature data set and performing rule deduction, the system can preliminarily identify the potential causes of low voltage problems, providing a basic direction for subsequent analysis. A low-voltage user visualization atlas generated based on daily voltage change trends intuitively displays the voltage distribution at different time nodes in a day, and performs time series analysis on the visualization atlas, which can assist in analyzing the potential causes of low voltage problems. The initial analysis results are verified through auxiliary analysis results, which effectively reduces the misjudgment that may be caused by a single analysis method and improves the reliability of low voltage cause diagnosis.

[0067] Each embodiment in this specification is described in a progressive manner, and the same or similar parts of each embodiment can be directly referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. It should be noted that the various technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A method for analyzing and judging low voltage problems in a transformer area, characterized in that: include: Constructing a power characteristic data set for each low-voltage user in the target area, wherein the power characteristic data set includes user voltage, user access phase, user power supply radius, and user power consumption; Performing rule deduction on each of the power characteristic data groups to obtain an initial low voltage cause analysis result of the target substation; Constructing a low-voltage user visualization atlas of the target substation based on the daily voltage variation trend of each low-voltage user, wherein the low-voltage user visualization atlas includes low-voltage user visualization graphs at several time nodes within a day; Perform a time series analysis on the low-voltage user visualization atlas to obtain the auxiliary low-voltage cause analysis result of the target substation; verify the initial low-voltage cause analysis result based on the auxiliary low-voltage cause analysis result to obtain the target low-voltage cause analysis result of the target substation.

2. The method for analyzing and judging low voltage problems in a transformer area according to claim 1, characterized in that: The step of constructing a power characteristic data set for each low-voltage user in the target area includes: Based on the power business support system, the user voltage, power supply radius and power consumption of each low-voltage user in the target area are obtained; Performing phase discrimination on each of the low-voltage users based on least squares regression analysis to determine a user access phase corresponding to the low-voltage user; An electric power feature data set of each low-voltage user is constructed based on the user voltage, the user power supply radius, the user power consumption and the user access phase.

3. The method for analyzing and judging low voltage problems in a transformer area according to claim 2, characterized in that: The performing phase discrimination on each low-voltage user based on least squares regression analysis to determine the user access phase corresponding to the low-voltage user includes: Performing a least squares regression analysis on the user voltage of each low-voltage user and the trunk current of the target substation to obtain a household-phase correlation coefficient corresponding to the low-voltage user; The user access phase corresponding to the low-voltage user is determined based on the household phase correlation coefficient of each low-voltage user.

4. The method for analyzing and judging low voltage problems in a transformer area according to claim 1, characterized in that: The rule deduction is performed on each of the power characteristic data groups to obtain the initial low voltage cause analysis result of the target substation, including: Performing a threshold judgment on the user voltage of each power feature data group to obtain a classification result of each low-voltage user, wherein the classification result includes undervoltage users and normal users; The classification results of each low-voltage user are subjected to rule deduction to obtain the initial low-voltage cause analysis result of the target substation.

5. The method for analyzing and judging low voltage problems in a transformer area according to claim 4, characterized in that: The performing rule deduction on the classification result of each of the low-voltage users to obtain the initial low-voltage cause analysis result of the target substation includes: deducing the classification result of each of the low-voltage users based on a first conditional judgment rule to obtain a first initial low-voltage cause analysis result of the target substation, wherein the first conditional judgment rule includes that the proportion of undervoltage users in all low-voltage users exceeds a first threshold, the proportion of users of the same phase among the undervoltage users exceeds a second threshold, and the difference between the current of the phase and the currents of the remaining two phases is greater than a third threshold; Based on the second condition judgment rule, the classification result of each low-voltage user is deduced to obtain the second initial low-voltage cause analysis result of the target substation, wherein the second condition judgment rule includes that the proportion of undervoltage users in all low-voltage users exceeds the first threshold, the proportion of users of the same phase among undervoltage users exceeds the second threshold, the difference between the current of the phase and the current of the other two phases is not greater than the third threshold, the difference in user power supply radius between undervoltage users and normal users is not greater than the fourth threshold, and the difference in user power consumption between undervoltage users and normal users is less than the fifth threshold.

6. The method for analyzing and judging low voltage problems in a transformer area according to claim 5, characterized in that: The performing rule deduction on the classification result of each of the low-voltage users to obtain the initial low-voltage cause analysis result of the target substation further includes: deducing the classification result of each of the low-voltage users based on a third conditional judgment rule to obtain a third initial low-voltage cause analysis result of the target substation, wherein the third conditional judgment rule includes that the proportion of undervoltage users in all low-voltage users exceeds a first threshold, and the difference in user power supply radius between undervoltage users and normal users is greater than a fourth threshold; The classification result of each of the low-voltage users is deduced based on the fourth condition judgment rule to obtain a fourth initial low-voltage cause analysis result of the target substation, wherein the fourth condition judgment rule includes that the proportion of undervoltage users in all low-voltage users exceeds a first threshold, the proportion of users in the same phase among the undervoltage users exceeds a second threshold, and there is a user with a power consumption greater than a sixth threshold among the normal users in the same phase; The classification result of each low-voltage user is deduced based on the fifth conditional judgment rule to obtain the fifth initial low-voltage cause analysis result of the target substation, wherein the fifth conditional judgment rule includes that the number of undervoltage users is less than the seventh threshold.

7. The method for analyzing and judging low voltage problems in a transformer area according to claim 4, characterized in that: The time series analysis of the low-voltage user visualization atlas is performed to obtain the auxiliary low-voltage cause analysis result of the target substation, including: Based on the first auxiliary condition judgment rule, the low-voltage user visualization diagram at each time node in a day is analyzed to obtain the first auxiliary low-voltage cause analysis result of the target substation, wherein the first auxiliary condition judgment rule includes that the user access phase of each undervoltage user is distributed in the same phase within a day, the difference between the current of the user access phase and the current of the other two phases is greater than the eighth threshold, the number of undervoltage users peaks during the daily load peak period, the user voltage of the undervoltage user reaches a valley value during the daily load peak period, and the user voltage difference between the undervoltage user at the edge node and the adjacent normal user in the low-voltage user visualization diagram does not exceed the ninth threshold; Based on the second auxiliary condition judgment rule, the low-voltage user visualization diagram at each time node in a day is analyzed to obtain the second auxiliary low-voltage cause analysis result of the target substation, wherein the second auxiliary condition judgment rule includes that each undervoltage user is spatially clustered within a day, the user access phase of each undervoltage user is distributed in the same phase within a day, the difference between the current of the user access phase and the current of the other two phases is not greater than the eighth threshold, and the user voltage difference between the undervoltage user at the edge node and the adjacent normal user in the low-voltage user visualization diagram exceeds the ninth threshold.

8. The method for analyzing and judging low voltage problems in a transformer area according to claim 7, characterized in that: The performing of time series analysis on the low-voltage user visualization atlas to obtain the auxiliary low-voltage cause analysis result of the target substation also includes: Based on the third auxiliary condition judgment rule, the low-voltage user visualization diagram at each time node in a day is analyzed to obtain the third auxiliary low-voltage cause analysis result of the target substation, wherein the third auxiliary condition judgment rule includes that each undervoltage user is stably distributed at the terminal position within a day, the user access phase of each undervoltage user is distributed in an out-of-phase manner within a day, the difference between the currents of any two phases is not greater than the eighth threshold, the number of undervoltage users reaches a peak during the daily load peak period, the user voltage of the undervoltage user reaches a valley during the daily load peak period, and the user voltage difference between the undervoltage user at the edge node and the adjacent normal user in the low-voltage user visualization diagram does not exceed the ninth threshold; The low-voltage user visualization diagram at each time point in a day is analyzed based on the fourth auxiliary condition judgment rule to obtain the fourth auxiliary low-voltage cause analysis result of the target substation, wherein the fourth auxiliary condition judgment rule includes that each undervoltage user is spatially clustered within a day, and there are front-end users in the area where the undervoltage users are located whose user power consumption is greater than the tenth threshold; Based on the fifth auxiliary condition judgment rule, the low-voltage user visualization diagram at each time node in a day is analyzed to obtain the fifth auxiliary low-voltage cause analysis result of the target substation, wherein the fifth auxiliary condition judgment rule includes that the number of undervoltage users at each time node in a day is less than the eleventh threshold, and the user voltage difference between the undervoltage users at the edge nodes and the adjacent normal users in the low-voltage user visualization diagram exceeds the ninth threshold.

9. The method for analyzing and judging low voltage problems in a transformer area according to claim 1, characterized in that: The verifying the initial low voltage cause determination result based on the auxiliary low voltage cause determination result to obtain the target low voltage cause determination result of the target substation includes: If the auxiliary low voltage cause determination result is consistent with the initial low voltage cause determination result, the initial low voltage cause determination result is determined as the target low voltage cause determination result of the target substation; If the auxiliary low voltage cause determination result is inconsistent with the initial low voltage cause determination result, the initial low voltage cause determination result is corrected to obtain the target low voltage cause determination result of the target substation.

10. A system for analyzing and judging low voltage problems in a transformer area, characterized in that: include: A data construction module is used to construct a power characteristic data set for each low-voltage user in the target area, wherein the power characteristic data set includes user voltage, user access phase, user power supply radius and user power consumption; A rule deduction module, configured to perform rule deduction on each of the power characteristic data sets to obtain an initial low voltage cause analysis result for the target substation; An atlas construction module is used to construct a low-voltage user visualization atlas of the target substation based on the daily voltage change trend of each low-voltage user, wherein the low-voltage user visualization atlas includes low-voltage user visualization diagrams at several time nodes within a day; a time series analysis module is used to perform time series analysis on the low-voltage user visualization atlas to obtain auxiliary low-voltage cause analysis results for the target substation; The result determination module is used to verify the initial low voltage cause determination result based on the auxiliary low voltage cause determination result to obtain the target low voltage cause determination result of the target substation.

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