Voltage transformer calibration system and method

Abstract

The voltage transformer calibration system and method provided by the present invention relates to the technical field of power equipment detection, and includes: a mutual inductance diagnosis module, which is used to receive the transformer diagnosis signaling sent by the error processing module, and then respectively perform abnormal analysis on the winding, core and insulation resistance in the voltage transformer to be calibrated, obtain the corresponding analysis results and comprehensively obtain the mutual inductance evaluation value; mark the corresponding analysis results and the mutual inductance evaluation value as the transformer analysis results; a judgment module, which receives this result for comparison and analysis, sets an abnormal threshold, and generates a corresponding abnormal signaling if the result exceeds the threshold, and the calibration execution module executes the corresponding calibration process according to the abnormal signaling. The automated process from data acquisition, error analysis to fault diagnosis and processing is realized, which reduces the dependence on the cumbersome operation steps of professional and technical personnel, reduces the labor cost, and avoids the risk of affecting the calibration results due to human operation errors, and improves the stability and reliability of the calibration work.

Description

Technical Field

[0001] The present invention relates to the technical field of power equipment detection, and in particular to a voltage transformer calibration system and method. Background Art

[0002] In today's power system, voltage transformers, as key electrical equipment, undertake important tasks such as converting high voltage into low voltage for measurement, protection and control. With the rapid development of the power industry, the scale of power systems continues to expand, and the number of voltage transformers is also increasing. In the existing technology, the calibration of voltage transformers is generally carried out one by one, and this traditional method has many disadvantages.

[0003] On the one hand, the efficiency of one-by-one verification is extremely low. When faced with a large group of voltage transformers, the verification work takes too long, which seriously affects the maintenance and update progress of the power system. On the other hand, the commonly used verification methods such as the comparison method and the standard transformer method, although they can achieve the verification purpose to a certain extent, are faced with the problem of low verification accuracy. Due to insufficient accuracy, measurement errors may occur in the actual operation of the voltage transformer, which in turn affects the accuracy and reliability of the power system. At the same time, these methods are complicated to operate and require professional technicians to perform tedious operation steps, which not only increases labor costs, but also easily affects the verification results due to human operational errors. In addition, the low efficiency also makes it difficult for the verification work to meet the high requirements of the continuous development of the power system for the verification speed of voltage transformers.

[0004] Therefore, it is necessary to provide a voltage transformer calibration system and method to solve the above technical problems. Summary of the invention

[0005] The present invention provides a voltage transformer calibration system and method, which solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the present invention provides a voltage transformer calibration system and method, comprising:

[0007] The mutual inductance data acquisition module is used to collect the output voltage signal data of the voltage transformer being tested in real time;

[0008] The error processing module is used to perform error analysis on the output voltage signal data of the voltage transformer to be tested, and obtain the error value of the voltage transformer to be tested; set an error threshold, and if the error value of the voltage transformer to be tested is greater than or equal to the set error threshold, generate a transformer diagnosis signal;

[0009] The transformer connection module is used to disconnect the primary side of the standard voltage transformer and the voltage transformer to be tested from the high-voltage power supply and short-circuit the secondary side thereof after receiving the transformer diagnosis signal; connect the primary side of the standard voltage transformer and the voltage transformer to be tested to the high-voltage power supply respectively, and connect the secondary side to the high-precision digital voltmeter respectively;

[0010] The mutual inductance diagnosis module is used to perform abnormal analysis on the winding, core and insulation resistance of the voltage transformer to be tested after receiving the mutual inductance diagnosis signaling sent by the error processing module, and obtain the winding analysis results, the core analysis results and the insulation resistance analysis results; comprehensively process the winding analysis results, the core analysis results and the insulation resistance analysis results to obtain the mutual inductance evaluation value; mark the winding analysis results, the core analysis results, the insulation resistance analysis results and the mutual inductance evaluation value as the mutual inductance analysis results;

[0011] A determination module is used to receive the results of the transformer analysis for comparison and analysis, set an abnormal threshold of any result of the transformer analysis results, compare any result of the transformer analysis results with its corresponding abnormal threshold, and if the result is greater than its corresponding abnormal threshold, generate an abnormal signal corresponding to the result; wherein the abnormal signal corresponding to the result includes abnormal signal of winding, core, insulation resistance and voltage transformer being tested;

[0012] The verification execution module is used to receive the abnormal signaling corresponding to the result to execute the verification process corresponding to the voltage transformer being verified; the model, number, location, verification date and transformer analysis result of the voltage transformer being verified are marked as a verification report.

[0013] Preferably, the mutual inductance data acquisition module includes a multi-channel connection unit; the multi-channel connection unit is used to simultaneously connect a plurality of calibrated voltage transformers to achieve multi-channel data acquisition.

[0014] Preferably, error analysis processing is performed on the output voltage signal data of the voltage transformer to be tested, specifically:

[0015] Use a high-precision digital voltmeter to measure the secondary output voltage values ​​of the standard voltage transformer and the voltage transformer to be tested, respectively, and mark them as the standard voltage value and the voltage value to be tested, respectively; use the comparison method to calculate the errors of the standard voltage value and the voltage value to be tested to obtain the error value of the voltage transformer to be tested.

[0016] Preferably, an abnormality analysis is performed on the winding of the voltage transformer to be tested, specifically:

[0017] A rated temperature group is set, including a plurality of different rated temperatures; a reference DC resistance value of the winding at the rated temperature is set, and a difference is calculated between the DC resistance value of the winding at the rated temperature and its corresponding reference DC resistance value to obtain a reference resistance difference value corresponding to the rated temperature;

[0018] The base resistance difference of the winding at all rated temperatures is weighted to obtain the corresponding resistance-temperature influence value of the winding;

[0019] Setting a reference current value of the winding, performing a difference calculation between the current value of the winding and its corresponding reference current value, and obtaining a reference current difference;

[0020] Monitor the voltage value at both ends of the winding, calculate the difference and absolute value of the voltage values ​​at both ends of the winding to obtain the terminal voltage difference value; calculate the average of the voltage values ​​at both ends of the winding to obtain the average voltage value; set the reference voltage value of the winding, subtract the corresponding reference voltage value from the average voltage value of the winding to obtain the reference voltage difference value; perform weighted processing on the reference voltage difference value and the terminal voltage difference value to obtain the pressure shadow value;

[0021] The resistance-temperature influence value, the reference current difference value, and the pressure shadow value are weighted to obtain the winding state influence value;

[0022] Set the winding monitoring time zone, calculate the mean and standard deviation of the state influence value in the winding monitoring time zone to obtain the state mean value and state fluctuation value; calculate the difference between the maximum and minimum state influence values ​​in the winding monitoring time zone to obtain the state extreme value;

[0023] The state influence value, state average value, state fluctuation value and state extreme value are weighted to obtain the winding influence value;

[0024] The winding influence values ​​of all windings in the voltage transformer to be calibrated are weighted to obtain the comprehensive winding influence value; the winding reference resistance difference, resistance-temperature influence value, reference current difference, terminal voltage difference, voltage average, pressure shadow value, state influence value, state average shadow value, state fluctuation value, state extreme value, winding influence value and winding comprehensive influence value are marked as winding analysis results.

[0025] Preferably, an abnormality analysis is performed on the core of the voltage transformer to be tested, specifically:

[0026] Set the reference excitation current value of the iron core, monitor the excitation current of the iron core, and subtract the corresponding reference excitation current value from the excitation current value of the iron core to obtain the excitation current difference;

[0027] Set the reference magnetic flux density value of the iron core, monitor the magnetic flux density value of the iron core, and subtract the magnetic flux density value of the iron core from the corresponding reference magnetic flux density value to obtain the magnetic flux density difference value;

[0028] The reference power loss of the iron core is set, the power loss of the iron core is monitored, and the power loss difference is obtained by subtracting the reference power loss from the power loss of the iron core;

[0029] Set the reference temperature of the iron core, monitor the temperature of the iron core, and subtract the corresponding reference temperature from the temperature of the iron core to obtain the temperature difference of the iron core;

[0030] The core influence value is obtained by weighting the difference in excitation current, flux density, power loss and core temperature of the core;

[0031] Set the core monitoring time zone, calculate the mean and standard deviation of the core impact value in the core monitoring time zone to obtain the core mean shadow value and core shadow wave value;

[0032] The core influence value, core average shadow value, and core shadow wave value are weighted to obtain the core comprehensive influence value; the core excitation current difference, flux density difference, power loss difference, core temperature difference, core average shadow value, core shadow wave value, and core comprehensive influence value are marked as core analysis results.

[0033] Preferably, an abnormality analysis is performed on the insulation resistance of the voltage transformer to be tested, specifically:

[0034] Obtain the leakage current value of the insulation resistance in the voltage transformer to be tested, set the leakage current threshold, and subtract the leakage current threshold from the leakage current value to obtain the leakage current difference;

[0035] The insulation resistance threshold is set according to the insulation structure and material characteristics of the voltage transformer to be tested, and the insulation loss value is obtained by performing a difference calculation between the insulation resistance value and the resistance threshold;

[0036] The leakage current difference and the insulation loss value are weighted to obtain the insulation impact value;

[0037] Set the insulation monitoring time zone, calculate the mean and standard deviation of the insulation impact value in the insulation monitoring time zone to obtain the insulation mean value and insulation wave resistance value;

[0038] The insulation influence value, insulation mean value and insulation resistance wave value of the voltage transformer to be tested are weighted to obtain the insulation resistance comprehensive influence value; the insulation influence value, insulation mean value, insulation resistance wave value and insulation resistance comprehensive influence value are marked as insulation resistance analysis results.

[0039] Preferably, the abnormal signaling corresponding to the receiving result is used to execute the verification process corresponding to the voltage transformer being verified, specifically:

[0040] If an abnormal signal corresponding to the winding is received, a winding abnormality alarm is issued, and the verification report of the voltage transformer being verified, the model, number, and position of the winding are marked as winding abnormality information, and the winding abnormality information is sent to the intelligent terminal of the corresponding maintenance personnel;

[0041] If an abnormal signal corresponding to the iron core is received, an iron core abnormality alarm is issued, and the calibration report of the voltage transformer being calibrated, the model, number, and position of the iron core are marked as iron core abnormality information, and the iron core abnormality information is sent to the corresponding maintenance personnel's smart terminal;

[0042] If an abnormal signal corresponding to the insulation resistance is received, an insulation resistance abnormal alarm is issued, and the verification report of the voltage transformer being verified, the model, number, and position of the insulation resistance are marked as insulation resistance abnormal information, and the insulation resistance abnormal information is sent to the corresponding maintenance personnel's smart terminal;

[0043] If an abnormal signal of the voltage transformer being tested is received, a transformer abnormality alarm is issued, and a verification report of the voltage transformer being tested is sent to the intelligent terminal of the corresponding maintenance personnel.

[0044] Preferably, the verification execution module also includes an error adjustment unit, which is used to set an adjustable error threshold after receiving an abnormal signal from the voltage transformer being verified. If the error value of the voltage transformer being verified is less than the adjustable error threshold, the error of the voltage transformer being verified is adjusted according to a preset adjustment strategy, and the verification is performed again after the adjustment until the error value meets the set requirements or reaches the upper limit of the adjustment times; if the error value of the voltage transformer being verified is greater than or equal to the adjustable error threshold, a transformer abnormality alarm is generated, and the verification report of the voltage transformer being verified is sent to the intelligent terminal of the corresponding maintenance personnel.

[0045] A voltage transformer calibration method comprises the following steps:

[0046] S1: real-time acquisition of output voltage signal data of the voltage transformer to be tested;

[0047] S2: Perform error analysis on the output voltage signal data of the voltage transformer to be tested to obtain the error value of the voltage transformer to be tested; set an error threshold, and if the error value of the voltage transformer to be tested is greater than or equal to the set error threshold, generate a transformer diagnosis signaling;

[0048] S3: After receiving the transformer diagnosis signaling, disconnect the primary sides of the standard voltage transformer and the voltage transformer to be tested from the high-voltage power supply, and short-circuit their secondary sides; connect the primary sides of the standard voltage transformer and the voltage transformer to be tested to the high-voltage power supply, and connect the secondary sides to the high-precision digital voltmeter respectively;

[0049] S4: after receiving the transformer diagnosis signaling, abnormal analysis is performed on the winding, core and insulation resistance of the voltage transformer to be tested, and winding analysis results, core analysis results and insulation resistance analysis results are obtained;

[0050] S5: Comprehensively process the winding analysis results, the core analysis results, and the insulation resistance analysis results to obtain a mutual inductance evaluation value; mark the winding analysis results, the core analysis results, the insulation resistance analysis results, and the mutual inductance evaluation value as mutual inductor analysis results;

[0051] S6: receiving the mutual inductor analysis results for comparison and analysis, setting an abnormal threshold of any result of the mutual inductor analysis results, comparing any result of the mutual inductor analysis results with its corresponding abnormal threshold, and if the result is greater than its corresponding abnormal threshold, generating an abnormal signaling corresponding to the result;

[0052] S7: Receive an abnormal signal corresponding to the result to execute a verification process corresponding to the voltage transformer being verified.

[0053] Compared with the related art, the voltage transformer calibration system and method provided by the present invention have the following beneficial effects:

[0054] 1. The present invention can quickly and accurately calibrate the voltage transformer through automated data collection and error analysis processing, significantly improving the efficiency and accuracy of the calibration work and meeting the needs of large-scale calibration.

[0055] 2. The present invention automatically analyzes the various components of the voltage transformer being tested through an integrated mutual inductance diagnosis module, promptly detects anomalies and generates alarms, and promptly notifies maintenance personnel through intelligent terminals, thereby speeding up maintenance response and reducing potential downtime and maintenance costs.

[0056] 3. The present invention realizes an automated process from data collection, error analysis to fault diagnosis and processing, reduces the reliance on cumbersome operation steps of professional technicians, reduces labor costs, avoids the risk of affecting the verification results due to human operational errors, and improves the stability and reliability of the verification work. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 A principle block diagram of a voltage transformer calibration system provided by the present invention.

[0058] Figure 2 A flowchart of a voltage transformer calibration method provided by the present invention. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "class", "group" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0061] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0062] Please refer to Figure 1-2 A voltage transformer calibration system and method, comprising:

[0063] The mutual inductance data acquisition module is used to collect the output voltage signal data of the voltage transformer being tested in real time;

[0064] The error processing module is used to perform error analysis on the output voltage signal data of the voltage transformer being tested, specifically:

[0065] Use a high-precision digital voltmeter to measure the secondary output voltage values ​​of the standard voltage transformer and the voltage transformer to be tested, and mark them as standard voltage values ​​respectively. 、The voltage value to be checked ; Use the comparison method to calculate the error between the standard voltage value and the voltage value to be checked to obtain the error value of the voltage transformer to be checked , the formula is: ; Set an error threshold. If the error value of the voltage transformer being tested is greater than or equal to the set error threshold, a transformer diagnostic signal is generated;

[0066] The transformer connection module is used to disconnect the primary side of the standard voltage transformer and the voltage transformer to be tested from the high-voltage power supply and short-circuit the secondary side thereof after receiving the transformer diagnosis signal; connect the primary side of the standard voltage transformer and the voltage transformer to be tested to the high-voltage power supply respectively, and connect the secondary side to the high-precision digital voltmeter respectively;

[0067] The mutual inductance diagnosis module is used to perform abnormal analysis on the winding, core and insulation resistance of the voltage transformer to be tested after receiving the mutual inductance diagnosis signaling sent by the error processing module, and obtain the winding analysis results, the core analysis results and the insulation resistance analysis results; comprehensively process the winding analysis results, the core analysis results and the insulation resistance analysis results to obtain the mutual inductance evaluation value; mark the winding analysis results, the core analysis results, the insulation resistance analysis results and the mutual inductance evaluation value as the mutual inductance analysis results;

[0068] A determination module is used to receive the results of the transformer analysis for comparison and analysis, set an abnormal threshold value for any result of the transformer analysis results, and compare any result in the transformer analysis results with its corresponding abnormal threshold value, specifically: if the comprehensive influence value of the winding is greater than its corresponding abnormal threshold value, then an abnormal signal corresponding to the winding is generated; if the comprehensive influence value of the iron core is greater than its corresponding abnormal threshold value, then an abnormal signal corresponding to the iron core is generated; if the comprehensive influence value of the insulation resistance is greater than its corresponding abnormal threshold value, then an abnormal signal corresponding to the insulation resistance is generated; if the mutual inductance evaluation value is greater than its corresponding abnormal threshold value, then an abnormal signal corresponding to the voltage transformer being tested is generated;

[0069] The verification execution module is used to receive the abnormal signaling corresponding to the result to execute the verification process corresponding to the voltage transformer being verified; the model, number, location, verification date and transformer analysis result of the voltage transformer being verified are marked as a verification report.

[0070] It should be further explained that when the error value of any voltage transformer being checked is greater than or equal to the set error threshold, the error processing module will immediately generate a transformer diagnostic signaling corresponding to the voltage transformer being checked; under normal circumstances, if multiple voltage transformers being checked generate transformer diagnostic signaling at the same time, they will be sorted in the order of the error values ​​of the voltage transformers being checked that generate the transformer diagnostic signaling to generate a checked list; wherein, the priority of the transformer with a larger error value is higher, which can ensure that the transformer with a larger error can be checked and processed first, thereby improving the overall efficiency and reliability of the system;

[0071] During the calibration, the voltage transformer with the highest priority is calibrated. When the calibration process of the transformer is started, the transformer connection module automatically controls the primary side of the standard voltage transformer and the voltage transformer to be calibrated to be disconnected from the high-voltage power supply, and the secondary side is short-circuited; then, the primary side of the standard voltage transformer and the voltage transformer to be calibrated are respectively connected to the high-voltage power supply, and the secondary side is respectively connected to the high-precision digital voltmeter; then, the transformer connection module, the mutual inductance diagnosis module, the determination module and the calibration execution module are controlled to perform corresponding analysis and calibration processing on the voltage transformer to be calibrated in turn;

[0072] When the verification of a voltage transformer is completed, the next voltage transformer to be verified that generates a transformer diagnostic signal will be verified in the order of the verified list; the above verification process is repeated until all transformers that need to be verified have completed the verification; within the set time, the verified list will be routinely updated; after the above process, the demand for automated and large-scale verification of the voltage transformer to be verified is met. The automated process is a common and effective verification method. In the prior art, the automated process is an existing conventional process, so it is not explicitly proposed and is explained here.

[0073] In the present application, the mutual inductance data acquisition module includes a multi-channel connection unit; the multi-channel connection unit is used to simultaneously connect multiple voltage transformers to be calibrated to achieve multi-channel data acquisition.

[0074] In this application, the winding of the voltage transformer to be tested is analyzed for abnormalities, specifically:

[0075] A rated temperature group is set, including multiple different rated temperatures; a reference DC resistance value of the winding at the rated temperature is set, and a difference is calculated between the DC resistance value of the winding at the rated temperature and its corresponding reference DC resistance value to obtain a reference resistance difference EDt corresponding to the rated temperature, where t represents the number of the corresponding rated temperature in the rated temperature group;

[0076] The base resistance difference of the winding at all rated temperatures is weighted to obtain the corresponding resistance-temperature influence value ED of the winding, which is expressed by the formula: ; Wherein, T represents the total number of rated temperatures in the rated temperature group, and ta represents the weight corresponding to the reference resistance difference at the rated temperature t;

[0077] Set the reference current value of the winding, calculate the difference between the current value of the winding and its corresponding reference current value, and obtain the reference current difference DC1;

[0078] Monitor the voltage value at both ends of the winding, calculate the difference and absolute value of the voltage value at both ends of the winding to obtain the terminal voltage difference value; calculate the average of the voltage values ​​at both ends of the winding to obtain the average voltage value; set the reference voltage value of the winding, subtract the corresponding reference voltage value from the average voltage value of the winding to obtain the reference voltage difference value; perform weighted processing on the reference voltage difference value and the terminal voltage difference value to obtain the voltage shadow value DC2;

[0079] The resistance-temperature influence value, the reference current difference, and the pressure shadow value are weighted to obtain the winding state influence value DC, which is expressed by the formula: ; Wherein, d1, d2, and d3 represent the weights corresponding to the resistance-temperature influence value, the reference current difference, and the pressure shadow value of the winding respectively;

[0080] Set the winding monitoring time zone, calculate the mean and standard deviation of the state influence value in the winding monitoring time zone to obtain the state mean value DJ1 and the state fluctuation value DJ2; calculate the difference between the maximum and minimum state influence values ​​in the winding monitoring time zone to obtain the state extreme difference value DJ3;

[0081] The state influence value, state average value, state fluctuation value and state extreme value are weighted to obtain the winding influence value DJ, which is expressed by the formula: ; Among them, j1, j2, j3, and j4 represent the weights corresponding to the state influence value, state mean value, state fluctuation value, and state extreme value of the winding respectively;

[0082] The winding influence values ​​of all windings in the voltage transformer to be tested are weighted to obtain the winding comprehensive influence value D, which is expressed by the formula: ; Wherein, i represents the number of the winding in the voltage transformer being tested, N represents the total number of windings in the voltage transformer being tested, DJi and ib represent the winding influence value corresponding to the winding numbered i and its corresponding weight respectively;

[0083] The winding's benchmark resistance difference, resistance-temperature influence value, benchmark current difference, terminal voltage difference, voltage average, pressure shadow value, state influence value, state average shadow value, state fluctuation value, state extreme value, winding influence value and winding comprehensive influence value are marked as winding analysis results.

[0084] In this application, an abnormal analysis is performed on the core of the voltage transformer to be tested, specifically:

[0085] Set the reference excitation current value of the iron core, monitor the excitation current of the iron core, and subtract the corresponding reference excitation current value from the excitation current value of the iron core to obtain the excitation current difference LC1;

[0086] Set the reference magnetic flux density value of the iron core, monitor the magnetic flux density value of the iron core, and subtract the magnetic flux density value of the iron core from the corresponding reference magnetic flux density value to obtain the magnetic flux density difference value LC2;

[0087] The reference power loss of the core is set, the power loss of the core is monitored, and the power loss difference LC3 is obtained by subtracting the reference power loss from the power loss of the core;

[0088] Set the reference temperature of the iron core, monitor the temperature of the iron core, and subtract the corresponding reference temperature from the temperature of the iron core to obtain the iron core temperature difference LC4;

[0089] The core influence value LC is obtained by weighting the difference in excitation current, flux density, power loss, and core temperature of the core. The formula is: ; Among them, c1, c2, c3, c4 represent the weights corresponding to the difference in excitation current, flux density, power loss, and temperature of the core respectively;

[0090] Set the core monitoring time zone, calculate the mean and standard deviation of the core influence value in the core monitoring time zone to obtain the core mean shadow value JY1 and the core shadow wave value JY2;

[0091] The core influence value, core average shadow value, and core shadow wave value are weighted and the formula is expressed as: , and obtain the iron core comprehensive influence value JY; where y1, y2, and y3 represent the weights corresponding to the iron core influence value, the iron core average shadow value, and the iron core shadow wave value, respectively;

[0092] The core excitation current difference, flux density difference, power loss difference, core temperature difference, core average shadow value, core shadow wave value, and core comprehensive impact value are marked as core analysis results.

[0093] In this application, the insulation resistance of the voltage transformer to be tested is analyzed for abnormalities, specifically:

[0094] Obtain the leakage current value of the insulation resistance in the voltage transformer to be tested, set the leakage current threshold, and subtract the leakage current threshold from the leakage current value to obtain the leakage current difference;

[0095] The insulation resistance threshold is set according to the insulation structure and material characteristics of the voltage transformer to be tested, and the insulation loss value is obtained by performing a difference calculation between the insulation resistance value and the resistance threshold;

[0096] The leakage current difference and the insulation loss value are weighted to obtain the insulation impact value XL1;

[0097] Set the insulation monitoring time zone, calculate the mean and standard deviation of the insulation impact value in the insulation monitoring time zone to obtain the insulation mean impact value XL2 and the insulation wave resistance value XL3;

[0098] The insulation influence value, insulation average value and insulation wave resistance value of the voltage transformer to be tested are weighted to obtain the insulation comprehensive influence value XL, which is expressed by the formula: ; Among them, x1, x2, and x3 respectively represent the weights corresponding to the insulation influence value, insulation mean value, and insulation wave resistance value of the voltage transformer being tested.

[0099] It should be noted that the DC resistance value, current value and voltage value at both ends of the winding, the excitation current, power loss, magnetic flux density value and temperature of the core, and the leakage current value of the insulation resistance are all collected by special sensors or equipment. Specifically, the sensors or equipment are mainly used to collect parameters at the corresponding positions on the voltage transformer to be tested. Under normal circumstances, they are connected to the collection points through several connecting lines, and control switches are provided on these connecting lines. Under normal circumstances, the control switches will be in the closed state to avoid the sensors or equipment from continuously collecting data, reducing energy consumption and data interference; when the transformer diagnostic signaling corresponding to the voltage transformer to be tested is generated, the control switch on the connecting line corresponding to the voltage transformer to be tested is immediately controlled to open, so that the corresponding sensors or equipment can collect the DC resistance value, current value and voltage value at both ends of the winding, the excitation current, power loss, magnetic flux density value and temperature of the core, and the leakage current value of the insulation resistance on the voltage transformer to be tested.

[0100] In this application, the abnormal signaling corresponding to the receiving result is used to execute the verification process corresponding to the voltage transformer being verified, specifically:

[0101] If an abnormal signal corresponding to the winding is received, a winding abnormality alarm is issued, and the verification report of the voltage transformer being verified, the model, number, and position of the winding are marked as winding abnormality information, and the winding abnormality information is sent to the intelligent terminal of the corresponding maintenance personnel;

[0102] If an abnormal signal corresponding to the iron core is received, an iron core abnormality alarm is issued, and the calibration report of the voltage transformer being calibrated, the model, number, and position of the iron core are marked as iron core abnormality information, and the iron core abnormality information is sent to the corresponding maintenance personnel's smart terminal;

[0103] If an abnormal signal corresponding to the insulation resistance is received, an insulation resistance abnormal alarm is issued, and the verification report of the voltage transformer being verified, the model, number, and position of the insulation resistance are marked as insulation resistance abnormal information, and the insulation resistance abnormal information is sent to the corresponding maintenance personnel's smart terminal;

[0104] If an abnormal signal of the voltage transformer being tested is received, a transformer abnormality alarm is issued, and a verification report of the voltage transformer being tested is sent to the intelligent terminal of the corresponding maintenance personnel.

[0105] In the present application, the verification execution module also includes an error adjustment unit, which is used to set an adjustable error threshold after receiving an abnormal signal from the voltage transformer being verified. If the error value of the voltage transformer being verified is less than the adjustable error threshold, the error of the voltage transformer being verified is adjusted according to a preset adjustment strategy, and the verification is performed again after the adjustment until the error value meets the set requirements or reaches the upper limit of the adjustment times; if the error value of the voltage transformer being verified is greater than or equal to the adjustable error threshold, a transformer abnormality alarm is generated, and the verification report of the voltage transformer being verified is sent to the corresponding maintenance personnel's intelligent terminal.

[0106] Please refer to Figure 2 , a voltage transformer calibration method, comprising the following steps:

[0107] S1: real-time acquisition of output voltage signal data of the voltage transformer to be tested;

[0108] S2: Perform error analysis on the output voltage signal data of the voltage transformer to be tested to obtain the error value of the voltage transformer to be tested; set an error threshold, and if the error value of the voltage transformer to be tested is greater than or equal to the set error threshold, generate a transformer diagnosis signaling;

[0109] S3: After receiving the transformer diagnosis signaling, disconnect the primary sides of the standard voltage transformer and the voltage transformer to be tested from the high-voltage power supply, and short-circuit their secondary sides; connect the primary sides of the standard voltage transformer and the voltage transformer to be tested to the high-voltage power supply, and connect the secondary sides to the high-precision digital voltmeter respectively;

[0110] S4: after receiving the transformer diagnosis signaling, abnormal analysis is performed on the winding, core and insulation resistance of the voltage transformer to be tested, and winding analysis results, core analysis results and insulation resistance analysis results are obtained;

[0111] S5: Comprehensively process the winding analysis results, the core analysis results, and the insulation resistance analysis results to obtain a mutual inductance evaluation value; mark the winding analysis results, the core analysis results, the insulation resistance analysis results, and the mutual inductance evaluation value as mutual inductor analysis results;

[0112] S6: receiving the mutual inductor analysis results for comparison and analysis, setting an abnormal threshold of any result of the mutual inductor analysis results, comparing any result of the mutual inductor analysis results with its corresponding abnormal threshold, and if the result is greater than its corresponding abnormal threshold, generating an abnormal signaling corresponding to the result;

[0113] S7: Receive an abnormal signal corresponding to the result to execute a verification process corresponding to the voltage transformer being verified.

[0114] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed in this disclosure. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0115] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A voltage transformer calibration system, It is characterized in that include: The mutual inductance data acquisition module is used to collect the output voltage signal data of the voltage transformer being tested in real time; The error processing module is used to perform error analysis on the output voltage signal data of the voltage transformer to be tested, so as to obtain the error value of the voltage transformer to be tested; An error threshold is set, and if the error value of the voltage transformer being tested is greater than or equal to the set error threshold, a transformer diagnosis signal is generated; The transformer connection module is used to disconnect the primary side of the standard voltage transformer and the voltage transformer to be tested from the high-voltage power supply and short-circuit the secondary side thereof after receiving the transformer diagnosis signal; connect the primary side of the standard voltage transformer and the voltage transformer to be tested to the high-voltage power supply respectively, and connect the secondary side to the high-precision digital voltmeter respectively; The mutual inductance diagnosis module is used to perform abnormal analysis on the winding, core and insulation resistance of the voltage transformer to be tested after receiving the mutual inductance diagnosis signaling sent by the error processing module, and obtain the winding analysis result, the core analysis result and the insulation resistance analysis result; Among them, the specific process of performing abnormal analysis on the winding of the voltage transformer to be tested and obtaining the winding analysis result is as follows: A rated temperature group is set, including a plurality of different rated temperatures; a reference DC resistance value of the winding at the rated temperature is set, and a difference is calculated between the DC resistance value of the winding at the rated temperature and its corresponding reference DC resistance value to obtain a reference resistance difference value corresponding to the rated temperature; The base resistance difference of the winding at all rated temperatures is weighted to obtain the corresponding resistance-temperature influence value of the winding; Setting a reference current value of the winding, performing a difference calculation between the current value of the winding and its corresponding reference current value, and obtaining a reference current difference; Monitor the voltage value at both ends of the winding, calculate the difference and absolute value of the voltage values ​​at both ends of the winding to obtain the terminal voltage difference value; calculate the average of the voltage values ​​at both ends of the winding to obtain the average voltage value; set the reference voltage value of the winding, subtract the corresponding reference voltage value from the average voltage value of the winding to obtain the reference voltage difference value; perform weighted processing on the reference voltage difference value and the terminal voltage difference value to obtain the pressure shadow value; The resistance-temperature influence value, the reference current difference value, and the pressure shadow value are weighted to obtain the state influence value of the winding; Set the winding monitoring time zone, calculate the mean and standard deviation of the state influence value in the winding monitoring time zone to obtain the state mean value and state fluctuation value; calculate the difference between the maximum and minimum state influence values ​​in the winding monitoring time zone to obtain the state extreme value; The state influence value, state average value, state fluctuation value and state extreme value are weighted to obtain the winding influence value; The winding influence values ​​of all windings in the voltage transformer to be verified are weighted to obtain the winding comprehensive influence value; the winding reference resistance difference, resistance-temperature influence value, reference current difference, terminal voltage difference, voltage average, pressure shadow value, state influence value, state average shadow value, state fluctuation value, state extreme difference value, winding influence value and winding comprehensive influence value are marked as winding analysis results; The winding analysis results, the core analysis results and the insulation resistance analysis results are comprehensively processed to obtain a mutual inductance evaluation value; the winding analysis results, the core analysis results, the insulation resistance analysis results and the mutual inductance evaluation value are marked as mutual inductor analysis results; A determination module is used to receive the results of the transformer analysis for comparison and analysis, set an abnormal threshold of any result of the transformer analysis results, compare any result of the transformer analysis results with its corresponding abnormal threshold, and if the result is greater than its corresponding abnormal threshold, generate an abnormal signal corresponding to the result; wherein the abnormal signal corresponding to the result includes abnormal signal of winding, core, insulation resistance and voltage transformer being tested; The verification execution module is used to receive the abnormal signaling corresponding to the result to execute the verification process corresponding to the voltage transformer being verified; the model, number, location, verification date and transformer analysis result of the voltage transformer being verified are marked as a verification report.

2. A voltage transformer calibration system according to claim 1, It is characterized in that The mutual inductance data acquisition module includes a multi-channel connection unit; the multi-channel connection unit is used to simultaneously connect multiple voltage transformers to be verified to achieve multi-channel data acquisition.

3. A voltage transformer calibration system according to claim 1, It is characterized in that The error analysis and processing of the output voltage signal data of the voltage transformer to be tested is carried out as follows: Use a high-precision digital voltmeter to measure the secondary output voltage values ​​of the standard voltage transformer and the voltage transformer to be verified, and mark them as the standard voltage value and the voltage value to be verified respectively; The error value of the voltage transformer to be tested is obtained by performing error calculation on the standard voltage value and the voltage value to be tested using the comparison method.

4. A voltage transformer calibration system according to claim 1, It is characterized in that Perform abnormal analysis on the core of the voltage transformer being tested, specifically: Set the reference excitation current value of the iron core, monitor the excitation current of the iron core, and subtract the corresponding reference excitation current value from the excitation current value of the iron core to obtain the excitation current difference; Set the reference magnetic flux density value of the iron core, monitor the magnetic flux density value of the iron core, and subtract the magnetic flux density value of the iron core from the corresponding reference magnetic flux density value to obtain the magnetic flux density difference value; The reference power loss of the iron core is set, the power loss of the iron core is monitored, and the power loss difference is obtained by subtracting the reference power loss from the power loss of the iron core; Set the reference temperature of the iron core, monitor the temperature of the iron core, and subtract the corresponding reference temperature from the temperature of the iron core to obtain the temperature difference of the iron core; The core influence value is obtained by weighting the difference in excitation current, flux density, power loss and core temperature of the core; Set the core monitoring time zone, calculate the mean and standard deviation of the core impact value in the core monitoring time zone to obtain the core mean shadow value and core shadow wave value; The core influence value, core average shadow value, and core shadow wave value are weighted to obtain the core comprehensive influence value; the core excitation current difference, flux density difference, power loss difference, core temperature difference, core average shadow value, core shadow wave value, and core comprehensive influence value are marked as core analysis results.

5. A voltage transformer calibration system according to claim 1, It is characterized in that Perform abnormal analysis on the insulation resistance of the voltage transformer being tested, specifically: Obtain the leakage current value of the insulation resistance in the voltage transformer to be tested, set the leakage current threshold, and subtract the leakage current threshold from the leakage current value to obtain the leakage current difference; The insulation resistance threshold is set according to the insulation structure and material characteristics of the voltage transformer to be tested, and the insulation loss value is obtained by performing a difference calculation between the insulation resistance value and the resistance threshold; The leakage current difference and the insulation loss value are weighted to obtain the insulation impact value; Set the insulation monitoring time zone, calculate the mean and standard deviation of the insulation impact value in the insulation monitoring time zone to obtain the insulation mean value and insulation wave resistance value; The insulation influence value, insulation average value and insulation resistance wave value of the voltage transformer to be tested are weighted to obtain the insulation resistance comprehensive influence value; the insulation influence value, insulation average value, insulation resistance wave value and insulation resistance comprehensive influence value are marked as insulation resistance analysis results.

6. A voltage transformer calibration system according to claim 1, It is characterized in that The abnormal signaling corresponding to the receiving result is used to execute the verification process corresponding to the voltage transformer being verified, specifically: If an abnormal signal corresponding to the winding is received, a winding abnormality alarm is issued, and the verification report of the voltage transformer being verified, the model, number, and position of the winding are marked as winding abnormality information, and the winding abnormality information is sent to the intelligent terminal of the corresponding maintenance personnel; If an abnormal signal corresponding to the iron core is received, an iron core abnormality alarm is issued, and the calibration report of the voltage transformer being calibrated, the model, number, and position of the iron core are marked as iron core abnormality information, and the iron core abnormality information is sent to the corresponding maintenance personnel's smart terminal; If an abnormal signal corresponding to the insulation resistance is received, an insulation resistance abnormal alarm is issued, and the verification report of the voltage transformer being verified, the model, number, and position of the insulation resistance are marked as insulation resistance abnormal information, and the insulation resistance abnormal information is sent to the corresponding maintenance personnel's smart terminal; If an abnormal signal of the voltage transformer being tested is received, a transformer abnormality alarm is issued, and a verification report of the voltage transformer being tested is sent to the intelligent terminal of the corresponding maintenance personnel.

7. A voltage transformer calibration system according to claim 1, It is characterized in that The verification execution module also includes an error adjustment unit, which is used to set an adjustable error threshold after receiving an abnormal signal from the voltage transformer being verified. If the error value of the voltage transformer being verified is less than the adjustable error threshold, the error of the voltage transformer being verified is adjusted according to a preset adjustment strategy, and the verification is performed again after the adjustment until the error value meets the set requirements or reaches the upper limit of the adjustment times; if the error value of the voltage transformer being verified is greater than or equal to the adjustable error threshold, a transformer abnormality alarm is generated, and the verification report of the voltage transformer being verified is sent to the intelligent terminal of the corresponding maintenance personnel.

8. A voltage transformer calibration method, using a voltage transformer calibration system according to any one of claims 1 to 7, It is characterized in that The following steps are involved: S1: real-time acquisition of output voltage signal data of the voltage transformer to be tested; S2: Perform error analysis on the output voltage signal data of the voltage transformer to be tested, and obtain the error value of the voltage transformer to be tested; An error threshold is set, and if the error value of the voltage transformer being tested is greater than or equal to the set error threshold, a transformer diagnosis signal is generated; S3: After receiving the transformer diagnosis signaling, disconnect the primary sides of the standard voltage transformer and the voltage transformer to be tested from the high-voltage power supply, and short-circuit their secondary sides; connect the primary sides of the standard voltage transformer and the voltage transformer to be tested to the high-voltage power supply, and connect the secondary sides to the high-precision digital voltmeter respectively; S4: after receiving the transformer diagnosis signaling, abnormal analysis is performed on the winding, core and insulation resistance of the voltage transformer to be tested, and winding analysis results, core analysis results and insulation resistance analysis results are obtained; S5: Comprehensively process the winding analysis results, the core analysis results, and the insulation resistance analysis results to obtain a mutual inductance evaluation value; mark the winding analysis results, the core analysis results, the insulation resistance analysis results, and the mutual inductance evaluation value as mutual inductor analysis results; S6: receiving the mutual inductor analysis results for comparison and analysis, setting an abnormal threshold of any result of the mutual inductor analysis results, comparing any result of the mutual inductor analysis results with its corresponding abnormal threshold, and if the result is greater than its corresponding abnormal threshold, generating an abnormal signaling corresponding to the result; S7: Receive an abnormal signal corresponding to the result to execute a verification process corresponding to the voltage transformer being verified.

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