A method, system, device and medium for checking abnormality of current transformer

Abstract

The present invention discloses a method, system, device and medium for abnormal calibration of a current transformer. In response to a current transformer calibration request, basic data and measurement data of a transformer to be measured are collected. According to the basic data and the measurement data, calibration data corresponding to the current transformer calibration request is determined, the relative error rate of the measurement data is calculated, and whether there is an abnormality in the wiring of the current transformer is judged according to the relative error rate and the type of the current transformer. At the same time, the position of the wiring abnormality of the current transformer can be determined according to the measurement data, which improves the accuracy of judging the wiring abnormality of the current transformer, thereby improving the reliability of the operation of the relay protection in the power system.

Description

Technical Field

[0001] The abnormal calibration of the current transformer of the present invention relates to the technical field, and in particular to a method, system, device and medium for abnormal calibration of a current transformer. Background Art

[0002] A transformer is an extremely important electrical device in the power system. Whether it operates safely directly affects whether the power system can work continuously and stably. The correctness of the wiring of the conventional transformer differential protection circuit directly affects the normal operation of the power supply system. Making an analysis of the correctness of the differential protection circuit wiring in a timely manner is an essential and important link in the construction and maintenance of substations.

[0003] Therefore, in the existing technology, mainly by short-circuiting the low-voltage side of the transformer, then applying the commercial power of 380V to the high or medium-voltage side, and then using a phase meter to measure the magnitude and phase of the current in each secondary winding of the current transformer, and then manually drawing a hexagon diagram to determine the correctness of the wiring of the secondary circuit of the current transformer.

[0004] However, in the above existing technology, calculations are carried out manually, the hexagon diagram is drawn by hand, and then the result of the analysis of the wiring of the secondary circuit of the current transformer is obtained according to the calculation result. The entire analysis process has a large amount of calculation, and it is necessary for the staff to make a judgment based on experience, which has the disadvantage of large errors, resulting in low reliability of the operation of the power system relay protection. Summary of the Invention

[0005] The present invention provides a method, system, device and medium for abnormal calibration of a current transformer, which solves the disadvantages of the existing technology that rely too much on the personal experience and subjective judgment of the staff when judging the correctness of the wiring of the secondary circuit of the current transformer, resulting in large errors and low reliability of the operation of the power system relay protection.

[0006] A method and system for abnormal calibration of a current transformer provided by the present invention relate to a transformer to be tested, and the transformer to be tested is connected with a current transformer; the method includes:

[0007] Responding to a current transformer calibration request, collecting basic data and measurement data of the transformer to be tested;

[0008] Determining calibration data corresponding to the current transformer calibration request according to the basic data and the measurement data;

[0009] Calculating the relative error rate of the measurement data;

[0010] Judging whether there is an abnormality in the wiring of the current transformer according to the relative error rate and the type of the current transformer;

[0011] If it is determined that the wiring of the current transformer is abnormal, determine the abnormal wiring position of the current transformer based on the measurement data.

[0012] Optionally, the step of responding to the current transformer calibration request and collecting the basic data and measurement data of the transformer under test includes:

[0013] Respond to the current transformer calibration request, connect the output end of the preset transformer short-circuit test device to the high-voltage side of the transformer under test, and connect the input end of the transformer short-circuit test device to the mains three-phase socket to form and conduct a transformer short-circuit test loop;

[0014] Obtain the measurement data of the transformer under test through the transformer test device; the measurement data includes the primary current on the high-voltage side, the secondary current on the high-voltage side, the differential current sampling value of the differential protection device, the three-phase phases on the high-voltage side, and the three-phase phases on the low-voltage side;

[0015] Obtain the basic data of the transformer under test; the basic data includes the rated capacity of the transformer, the rated voltage on the high-voltage side, the short-circuit impedance, the transformation ratio of the current transformer on the high-voltage side, and the phase voltage between phases on the high-voltage side of the transformer.

[0016] Optionally, the calibration data includes the theoretical value of the primary current on the high-voltage side and the theoretical value of the secondary current on the high-voltage side; the step of determining the calibration data corresponding to the current transformer calibration request according to the basic data and the measurement data includes:

[0017] Substitute the basic data and the measurement data into the calculation formula of the primary current on the high-voltage side to calculate the theoretical value of the primary current on the high-voltage side;

[0018] The calculation formula of the primary current on the high-voltage side is specifically:

[0019]

[0020] Wherein, X T is the transformer impedance, U is the phase voltage between phases on the high-voltage side of the transformer, U d % is the short-circuit impedance, S e is the rated capacity of the transformer, U he is the rated voltage on the high-voltage side, I h1 is the theoretical value of the primary current on the high-voltage side;

[0021] Calculate the ratio of the theoretical value of the primary current on the high-voltage side to the transformation ratio of the current transformer on the high-voltage side to obtain the theoretical value of the secondary current on the high-voltage side.

[0022] Optionally, the step of calculating the relative error rate of the measurement data includes:

[0023] Calculate the first difference between the three-phase phases on the high-voltage side and the theoretical values of the three-phase phases on the high-voltage side, and determine the ratio of the first difference to the theoretical values of the three-phase phases on the high-voltage side as the first relative error rate;

[0024] Calculate the second difference between the three-phase phases on the low-voltage side and the theoretical values of the three-phase phases on the low-voltage side, and determine the ratio of the second difference to the theoretical values of the three-phase phases on the low-voltage side as the second relative error rate;

[0025] Calculate the third difference between the secondary current on the high-voltage side and the theoretical value of the secondary current on the high-voltage side, and determine the ratio of the third difference to the theoretical value of the secondary current on the high-voltage side as the third relative error rate.

[0026] Optionally, when the current transformer is a differential winding current transformer, the step of judging whether there is an abnormality in the wiring of the current transformer according to the relative error rate and the type of the current transformer includes:

[0027] Compare whether the differential current sampling value is less than or equal to a preset differential current threshold;

[0028] If not, it is determined that the wiring of the current transformer is abnormal;

[0029] If so, judge whether the first relative error rate is equal to a preset phase difference threshold;

[0030] If the first relative error rate is equal to the phase difference threshold, it is determined that the wiring of the current transformer is normal;

[0031] If the first relative error rate is not equal to the phase difference threshold, it is determined that the wiring of the current transformer is abnormal.

[0032] Optionally, when the current transformer is other current transformers, the step of judging whether there is an abnormality in the wiring of the current transformer according to the relative error rate and the type of the current transformer includes:

[0033] Judge whether the current transformer is a low-voltage side current transformer;

[0034] If the current transformer is the low-voltage side current transformer, judge whether the second relative error rate is equal to a preset phase difference threshold;

[0035] If the second relative error rate is equal to the phase difference threshold, it is determined that the wiring of the current transformer is normal;

[0036] If the second relative error rate is not equal to the phase difference threshold, it is determined that the wiring of the current transformer is abnormal;

[0037] If the current transformer is not the low-voltage side current transformer, determine whether the first relative error rate is equal to the phase difference threshold;

[0038] If the first relative error rate is equal to the phase difference threshold, determine that the wiring of the current transformer is normal;

[0039] If the first relative error rate is not equal to the phase difference threshold, determine that the wiring of the current transformer is abnormal.

[0040] Optionally, it further includes:

[0041] Determine whether the third relative error rate is greater than a preset high-voltage current threshold;

[0042] If so, determine that the current transformer has a fault;

[0043] If not, determine that the current transformer is normal.

[0044] An abnormal calibration system for a current transformer provided in the second aspect of the present invention relates to a transformer under test, and the transformer under test includes a current transformer; the system includes:

[0045] The data acquisition module is used to receive a current transformer calibration request and acquire the basic data and measurement data of the transformer under test;

[0046] The acquisition module is used to determine the calibration data corresponding to the current transformer calibration request according to the basic data and the measurement data;

[0047] The automatic calculation module is used to calculate the relative error rate of the measurement data;

[0048] The judgment module is used to judge whether there is an abnormality in the wiring of the current transformer according to the relative error rate and the type of the current transformer;

[0049] The analysis module is used to, if it is determined that the wiring of the current transformer is abnormal, determine the abnormal wiring position of the current transformer based on the measurement data.

[0050] An electronic device provided in the third aspect of the present invention includes a memory and a processor. When the computer program stored in the memory is executed by the processor, the processor executes the steps of an abnormal calibration method for a current transformer as described in any one of the above.

[0051] A computer-readable storage medium provided in the fourth aspect of the present invention stores a computer program, and when the computer program is executed, it implements an abnormal calibration method for a current transformer as described in any one of the above.

[0052] As can be seen from the above technical solutions, the present invention has the following advantages:

[0053] When the present invention responds to a current transformer calibration request, it collects the basic data and measurement data of the transformer to be tested, determines the calibration data corresponding to the current transformer calibration request according to the basic data and measurement data, calculates the relative error rate of the measurement data, and judges whether there is an abnormality in the wiring of the current transformer according to the relative error rate. If it is determined that there is an abnormality in the wiring of the current transformer, the abnormal wiring position of the current transformer is determined based on the measurement data, thereby solving the technical problem that when judging the abnormality of the current transformer wiring, manual calculation and manual drawing of the hexagon diagram are used, resulting in a large error, and the reliability of the operation of the relay protection of the power system is low. The present invention collects the basic data and measurement data of the transformer connected to the current transformer to be tested, calculates the relative error rate of the measurement data, judges whether the current transformer is abnormal according to the relative error rate, and at the same time can determine the abnormal wiring position of the current transformer based on the abnormal measurement data, effectively improving the accuracy of judging whether the wiring of the current transformer is abnormal, thereby improving the reliability of the operation of the relay protection of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0055] Figure 1 It is a flowchart of the steps of a method for calibrating current transformer abnormalities provided in Embodiment 1 of the present invention;

[0056] Figure 2 It is a flowchart of the steps of a method for calibrating current transformer abnormalities provided in Embodiment 2 of the present invention;

[0057] Figure 3 It is a structural block diagram of a system for calibrating current transformer abnormalities provided in Embodiment 3 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0058] The embodiments of the present invention provide a method, system, device and medium for calibrating current transformer abnormalities, which are used to solve the technical problem that in the prior art, when judging the correctness of the wiring of the secondary circuit of the current transformer, excessive reliance on the personal experience and subjective judgment of the staff results in a large error, leading to a low reliability of the operation of the relay protection of the power system.

[0059] In order to make the object, features, and advantages of the present invention more obvious and understandable, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present invention.

[0060] Please refer to Figure 1 , Figure 1 which is a flowchart of the steps of an abnormal calibration method for a current transformer provided in Embodiment 1 of the present invention.

[0061] An abnormal calibration method for a current transformer provided by the present invention includes:

[0062] Step 101: Respond to the current transformer calibration request, and collect the basic data and measurement data of the transformer under test.

[0063] The current transformer calibration request refers to a request sent by the staff after the installation of the current transformer to verify the correctness of the wiring of the current transformer to judge whether the current transformer is abnormally wired. For example, judging whether the current transformer is abnormal and the location of the current transformer abnormality.

[0064] The basic data refers to the parameters of the transformer under test connected to the current transformer calibration under the rated state. For example, the rated capacity of the transformer, the rated voltage of the high-voltage side, the short-circuit impedance, the transformation ratio of the current transformer on the high-voltage side, and the phase voltage between phases on the high-voltage side of the transformer.

[0065] The measurement data refers to the parameters obtained by measurement of the transformer under test connected to the current transformer calibration during the current transformer calibration. For example, the primary current on the high-voltage side of the transformer, the secondary current on the high-voltage side of the transformer, the differential current sampling value of the differential protection device, the three-phase phase on the high-voltage side, and the three-phase phase on the low-voltage side.

[0066] In this embodiment, when receiving the current transformer calibration request sent by the fault personnel, read the request, obtain the location of the current transformer, use the transformer connected to the current transformer as the transformer under test, and obtain the basic data and measurement data of the transformer under test.

[0067] Step 102: Determine the calibration data corresponding to the current transformer calibration request according to the basic data and measurement data.

[0068] The calibration data refers to the parameters involved when the current transformer converts a large current on one side into a low-voltage current on the secondary side according to the electromagnetic induction principle during normal operation, and is used to judge whether the current transformer fails. It includes, but is not limited to, the theoretical value of the primary current on the high-voltage side and the theoretical value of the secondary current on the high-voltage side.

[0069] In an embodiment of the present application, after obtaining the basic data and measurement data of the transformer to be tested, according to the current transformer calibration request, the data required for calculation are determined as the theoretical value of the primary current on the high-voltage side and the theoretical value of the secondary current on the high-voltage side. The basic data and measurement data involved in calculating the primary current on the high-voltage side and the secondary current on the high-voltage side are extracted, the theoretical value of the primary current on the high-voltage side and the theoretical value of the secondary current on the high-voltage side are calculated, and the calculated theoretical value of the primary current on the high-voltage side and the theoretical value of the secondary current on the high-voltage side are determined as calibration data.

[0070] It should be noted that in the current transformer calibration request, the data content required for current transformer calibration includes basic data, measurement data, and calibration data.

[0071] Step 103: Calculate the relative error rate of the measurement data;

[0072] The relative error rate refers to the error between the measurement data and the theoretical value. It can accurately represent the actual size of the deviation of the measurement value from the theoretical value and is the basis for judging whether the current transformer is abnormal.

[0073] The measurement data refers to the data obtained by measurement when the current transformer calibration is connected to the transformer to be tested during actual operation. For example, the three-phase phase on the high-voltage side, the three-phase phase on the low-voltage side, and the secondary current on the high-voltage side.

[0074] The theoretical value refers to the basic parameters of the transformer to be tested when the current transformer calibration is connected under the rated condition or the calibration data obtained by secondary calculation through the basic data and measurement data. For example, the theoretical value of the three-phase phase on the high-voltage side, the theoretical value of the three-phase phase on the low-voltage side, and the theoretical value of the secondary current on the high-voltage side.

[0075] In an embodiment of the present application, the measurement data and the theoretical value are obtained. By calculating the difference between the measurement data and the theoretical value, and then calculating the ratio of the difference to the theoretical value, the relative error rate of the measurement data is calculated.

[0076] Step 104: Judge whether there is an abnormality in the wiring of the current transformer according to the relative error rate and the type of the current transformer;

[0077] In this embodiment, since there are various types of current transformers, after obtaining the relative error rate, it is also necessary to judge the type of the current transformer. After determining the type of the current transformer, according to the relative error rate of the current transformer wiring category and combining the relative error rate when the current transformer is working normally, judge whether there is an abnormality in the wiring of the current transformer.

[0078] Among them, the relative error rate corresponds to the current transformer wiring category. For example, the first relative error rate corresponding to whether the current transformer points to the main transformer, and the second relative error rate corresponding to whether the current transformer points to the bus.

[0079] It should be noted that there are various types of current transformers, such as differential winding current transformers, other current transformers, and low-voltage side current transformers.

[0080] Step 105: If it is determined that the wiring of the current transformer is abnormal, determine the abnormal wiring position of the current transformer based on the measurement data.

[0081] In the embodiment of the present application, after it is determined that the wiring of the current transformer is abnormal, the relative error rate or differential current sampling value corresponding to the abnormal wiring of the current transformer can be obtained. According to the relative error rate calculation formula or the differential current sampling value, the measurement data of the abnormal wiring of the current transformer can be obtained. Different measurement data correspond to current transformers at different wiring positions, and the wiring position of the corresponding current transformer can be matched according to the abnormal measurement data. For example, the measurement data corresponding to the main transformer current transformer is the three-phase phase of the high-voltage side, the measurement data corresponding to the busbar current transformer is the three-phase phase of the low-voltage side, and the measurement data corresponding to the current transformer at the differential winding is the differential current sampling value.

[0082] It should be noted that the abnormality of the three-phase phase data of the high-voltage side indicates that a certain phase of the current transformer pointing to the main transformer is connected to the three phases of the low-voltage side or a certain phase of the current transformer pointing to the main transformer is connected to other phases of the high-voltage side, resulting in an imbalance in the three-phase phase of the high-voltage side. Therefore, the abnormal position can be determined as the current transformer pointing to the main transformer based on the abnormality of the three-phase phase data of the high-voltage side. The abnormality of the three-phase phase data of the low-voltage side indicates that a certain phase of the current transformer pointing to the busbar is connected to the three phases of the high-voltage side or a certain phase of the current transformer pointing to the busbar is connected to other phases of the low-voltage side, resulting in an imbalance in the three-phase phase of the low-voltage side. Therefore, the abnormal position can be determined as the current transformer pointing to the busbar based on the abnormality of the three-phase phase data of the low-voltage side. The differential current sampling value data is directly read from the current transformer at the differential winding, indicating that a certain part of the current transformer is connected to other positions, resulting in a large difference between the primary current and the secondary current. Therefore, the abnormal position can be determined as the current transformer at the differential winding based on the abnormality of the differential current sampling value.

[0083] In an embodiment of the present invention, when a current transformer calibration request sent by a faulty person is received, the request is read, the position of the current transformer is obtained, the transformer connected to the current transformer is used as the transformer to be tested, and the basic data and measurement data of the transformer to be tested are obtained. According to the current transformer calibration request, the data required for calculation are determined to be the primary current theoretical value on the high voltage side and the secondary current theoretical value on the high voltage side. By obtaining the basic data and measurement data, the primary current theoretical value on the high voltage side and the secondary current theoretical value on the high voltage side are calculated, and the calculated primary current theoretical value on the high voltage side and the secondary current theoretical value on the high voltage side are determined as calibration data. By calculating the difference between the measurement data and the theoretical value, and then calculating the ratio of the difference to the theoretical value, the relative error rate of the measurement data is calculated. The type of the current transformer is judged. After the type of the current transformer is determined, the relative error rate corresponding to the wiring category of the current transformer is obtained. Combining the relative error rate when the current transformer is working normally, it is judged whether the wiring of the current transformer is abnormal. After it is determined that the wiring of the current transformer is abnormal, the measurement data of the abnormal wiring of the current transformer can be obtained. Different measurement data correspond to current transformers at different wiring positions, and the wiring position of the corresponding current transformer can be matched according to the abnormal measurement data. The whole process can accurately verify the wiring of the current transformer without manual drawing of the hexagon diagram by the staff, improving the correctness of the current transformer wiring, and thus improving the reliability of the operation of the power system relay protection.

[0084] Please refer to Figure 2 , Figure 2 which is a step flowchart of a method for calibrating abnormal current transformers provided in the second embodiment of the present invention.

[0085] Step 201: Respond to the current transformer calibration request and collect the basic data and measurement data of the transformer to be tested;

[0086] Further, step 201 may include the following sub-steps:

[0087] Respond to the current transformer calibration request, connect the output end of the preset transformer short-circuit test device to the high voltage side of the transformer to be tested, and connect the input end of the transformer short-circuit test device to the three-phase mains socket to form a transformer short-circuit test loop and conduct it;

[0088] Obtain the measurement data of the transformer to be tested through the transformer test device; the measurement data includes the primary current on the high voltage side, the secondary current on the high voltage side, the differential current sampling value of the differential protection device, the three-phase phase on the high voltage side, and the three-phase phase on the low voltage side;

[0089] Obtain the basic data of the transformer to be tested; the basic data includes the rated capacity of the transformer, the rated voltage on the high voltage side, the short-circuit impedance, the transformation ratio of the current transformer on the high voltage side, and the phase voltage between phases on the high voltage side of the transformer.

[0090] The preset transformer short-circuit test device refers to a transformer short-circuit test device composed of an intelligent digital phase meter, a current clamp, a test line, a three-phase linkage voltage air switch, a USB charger, and a USB charging cable.

[0091] In the embodiment of the present application, when a current transformer calibration request is received, in response to the current transformer calibration request, the high-voltage side of the transformer to be tested involved is connected to the output end of the transformer short-circuit test device, and the input end of the transformer short-circuit test device is connected to the mains three-phase socket to form a transformer short-circuit test loop. The three-phase linkage voltage air switch is closed to make the transformer short-circuit test loop conduct. The three-phase phase of the high-voltage side and the three-phase phase of the low-voltage side can be read from the intelligent digital phase meter in the short-circuit test device, and the primary current of the high-voltage side of the transformer to be tested, the secondary current of the high-voltage side of the transformer to be tested, and the differential current sampling value on the differential winding current transformer can be read by the current clamp.

[0092] Step 202: Substitute the basic data and measurement data into the high-voltage side primary current calculation formula to calculate the theoretical value of the high-voltage side primary current.

[0093] The high-voltage side primary current calculation formula is specifically:

[0094]

[0095] Where, XT is the transformer impedance, U is the phase voltage between phases of the high-voltage side of the transformer, Ud% is the short-circuit impedance, S e is the rated capacity of the transformer, U he is the rated voltage of the high-voltage side, I h1 is the theoretical value of the high-voltage side primary current.

[0096] The theoretical value of the high-voltage side primary current refers to the current value of the high-voltage side when the transformer to be tested operates under the rated condition.

[0097] In the embodiment of the present application, the theoretical value of the high-voltage primary current cannot be directly obtained from the transformer to be tested. It is necessary to select the phase voltage U between phases of the high-voltage side of the transformer, the short-circuit impedance U d %, the rated capacity S of the transformer e , and the rated voltage U of the high-voltage side he from the obtained measurement data and basic data to determine the theoretical value of the high-voltage primary side current.

[0098] Step 203: Calculate the ratio of the theoretical value of the high-voltage side primary current to the transformation ratio of the high-voltage side current transformer to obtain the theoretical value of the high-voltage side secondary current.

[0099] The transformation ratio of the high-voltage side current transformer refers to the ratio of the primary current to the secondary current of the current transformer under the rated condition.

[0100] The theoretical value of the secondary current on the high-voltage side refers to the current value obtained by converting the primary current on the high-voltage side into the secondary current under the rated state of the current transformer.

[0101] In the embodiment of the present application, after calculating the theoretical value of the primary current on the high-voltage side, the theoretical value of the secondary current on the high-voltage side is determined according to the transformation ratio of the current transformer on the high-voltage side. Since the working principle of the current transformer is to convert the primary current into the secondary current on the high-voltage side, and if the secondary current on the high-voltage side differs from the rated value by more than a certain range, it indicates that the current transformer has a fault. Therefore, the theoretical value of the secondary current on the high-voltage side can be used as one of the judgment factors for determining whether the current transformer is faulty.

[0102] Step 204: Calculate the relative error rate of the measurement data;

[0103] Optionally, step 204 includes the following sub-steps S11-S13:

[0104] S11: Calculate the first difference between the three-phase phase on the high-voltage side and the theoretical value of the three-phase phase on the high-voltage side, and determine the ratio of the first difference to the theoretical value of the three-phase phase on the high-voltage side as the first relative error rate.

[0105] The three-phase phase on the high-voltage side refers to the phase relationship between the three-phase currents. For example, the phase difference between phase A and phase B on the high-voltage side, the phase difference between phase A and phase C on the high-voltage side, and the phase difference between phase B and phase C on the high-voltage side.

[0106] The theoretical value of the three-phase phase on the high-voltage side refers to the phase relationship between the three-phase currents when there is no abnormality in the wiring of the current transformer. For example, if the phase difference between phase A and phase B on the high-voltage side is 120 degrees, then the theoretical value of the phase difference between phase A and phase C on the high-voltage side is 240 degrees, and the theoretical value of the phase difference between phase B and phase C on the high-voltage side is 120 degrees.

[0107] In the embodiment of the present application, the three-phase phase on the high-voltage side is the phase difference I between phase A and phase B on the high-voltage side AB 、the phase difference I between phase A and phase C on the high-voltage side AC 、the phase difference I between phase A and phase C on the high-voltage side BC , when the wiring of the power transformer points to the main transformer, the theoretical value of the phase difference between phase A and phase C on the high-voltage side is equal to (I AB+ 120°), calculate the difference between the phase difference I between phase A and phase C on the high-voltage side AC and the theoretical value of the phase difference between phase A and phase C on the high-voltage side (I AB+ 120°) to obtain the first difference, and determine the ratio of the first difference to the theoretical value of the phase difference between phase A and phase C on the high-voltage side (I AB+ 120°) as the first relative error rate. The first relative error rate is the basis for whether the current transformer points to the main transformer.

[0108] S12. Calculate the second difference between the three-phase phases on the low-voltage side and the theoretical values of the three-phase phases on the low-voltage side, and determine the ratio of the second difference to the theoretical values of the three-phase phases on the low-voltage side as the second relative error rate.

[0109] The three-phase phases on the low-voltage side refer to the phase relationships between the three-phase currents. For example, the phase difference between phase a and phase b on the low-voltage side, the phase difference between phase a and phase c on the low-voltage side, and the phase difference between phase b and phase c on the low-voltage side.

[0110] The theoretical values of the three-phase phases on the low-voltage side refer to the phase relationships between the three-phase currents when there is no abnormality in the wiring of the current transformer. For example, if the phase difference between phase a and phase b on the low-voltage side is 120 degrees, then the theoretical value of the phase difference between phase a and phase c on the low-voltage side is 240 degrees, and the theoretical value of the phase difference between phase b and phase c on the low-voltage side is 120 degrees.

[0111] In the embodiments of the present application, the three-phase phases on the low-voltage side are the phase difference I between phase a and phase b on the low-voltage side ab , the phase difference I between phase a and phase c on the low-voltage side ac , the phase difference I between phase a and phase c on the low-voltage side bc , when the wiring of the power transformer points to the busbar, the theoretical value of the phase difference between phase a and phase c on the low-voltage side is equal to (I ab+ 120°), calculate the phase difference I between phase a and phase c on the low-voltage side AC and the theoretical value of the phase difference between phase a and phase c on the low-voltage side (I ab+ 120°) to obtain the second difference, and determine the ratio of the second difference to the theoretical value of the phase difference between phase a and phase c on the low-voltage side (I ab+ 120°) as the second relative error rate. The second relative error rate is the basis for whether the current transformer points to the busbar.

[0112] S13. Calculate the third difference between the secondary current on the high-voltage side and the theoretical value of the secondary current on the high-voltage side, and determine the ratio of the third difference to the theoretical value of the secondary current on the high-voltage side as the third relative error rate.

[0113] The secondary current on the high-voltage side refers to the secondary current on the high-voltage side obtained by converting the primary current on the high-voltage side through the current transformer.

[0114] The theoretical value of the secondary current on the high-voltage side refers to the value of the secondary current on the high-voltage side obtained by converting the primary current on the high-voltage side through the current transformer when the current transformer is not damaged.

[0115] In the embodiments of the present application, obtain the measured value of the secondary current on the high-voltage side and the theoretical value of the secondary current on the high-voltage side obtained through secondary calculation, calculate the difference between the secondary current on the high-voltage side and the theoretical value of the secondary current on the high-voltage side to obtain the third difference, and determine the ratio of the third difference to the theoretical value of the secondary current on the high-voltage side as the third relative error rate. The third relative error rate is the basis for judging whether the current transformer is working properly.

[0116] Step 205: Determine whether there is an abnormality in the wiring of the current transformer according to the relative error rate and the type of the current transformer;

[0117] Optionally, step 204 includes the following sub-steps S21 - S22:

[0118] S21: Determine whether the current transformer is a differential current transformer;

[0119] When the current transformer is a differential winding current transformer, compare whether the differential current sampling value is less than or equal to a preset differential current threshold;

[0120] Compare whether the differential current sampling value is less than or equal to a preset differential current threshold;

[0121] If not, determine that there is an abnormality in the wiring of the current transformer;

[0122] If so, determine whether the first relative error rate is equal to a preset phase difference threshold;

[0123] If the first relative error rate is equal to the phase difference threshold, determine that the wiring of the current transformer is normal;

[0124] If the first relative error rate is not equal to the phase difference threshold, determine that there is an abnormality in the wiring of the current transformer.

[0125] The differential current threshold refers to the critical value of the wiring abnormality of the differential winding current transformer, which is used to compare with the differential current sampling value to determine whether there is an abnormality in the wiring of the differential winding current transformer, and is specifically set according to actual requirements.

[0126] The phase difference threshold refers to the critical value of the error rate between the actual phase difference and the theoretical phase difference when the current transformer points to the main transformer, which is used to compare with the first relative error rate to determine whether the current transformer points to the main transformer. The phase difference threshold is set to 0.

[0127] In the embodiment of the present invention, when the current transformer is a differential winding current transformer, obtain the differential current sampling value and the first relative error rate, determine whether the differential current sampling value is greater than or equal to the differential current threshold. If the differential current sampling value is greater than or equal to the differential current threshold, the differential winding current transformer is abnormal. If the differential current sampling value is less than the differential current threshold, it is considered that the wiring of the differential winding current transformer is normal. Then, determine whether the current transformer points to the main transformer by determining whether the first relative error rate is greater than 0. If the first relative error rate is greater than 0, it is considered that there is an abnormality in the wiring of the current transformer. If the first relative error rate is equal to 0, the wiring of the current transformer is normal.

[0128] S22: When the current transformer is other current transformers, determine whether the current transformer is a low-voltage side current transformer;

[0129] If the current transformer is a low-voltage side current transformer, determine whether the second relative error rate is equal to the preset phase difference threshold;

[0130] If the second relative error rate is equal to the phase difference threshold, it is determined that the wiring of the current transformer is normal;

[0131] If the second relative error rate is not equal to the phase difference threshold, it is determined that the wiring of the current transformer is abnormal;

[0132] If the current transformer is not a low-voltage side current transformer, determine whether the first relative error rate is equal to the phase difference threshold;

[0133] If the first relative error rate is equal to the phase difference threshold, it is determined that the wiring of the current transformer is normal;

[0134] If the first relative error rate is not equal to the phase difference threshold, it is determined that the wiring of the current transformer is abnormal.

[0135] In the embodiments of the present invention, when the current transformer is other electrical transformers, it is necessary to determine whether the current transformer points to the main transformer or the bus. If the current transformer is a current transformer of the low-voltage side measuring winding, it is considered that the current transformer points to the bus, and it is determined whether the second relative error rate is greater than 0. If the second relative error rate is greater than 0, it is considered that the current transformer is abnormal. If the second relative error rate is less than 0, it is considered that the current transformer points to the bus. If the current transformer is not a current transformer of the low-voltage measuring winding, it is considered that the current transformer points to the main transformer, and it is determined whether the first relative error rate is greater than 0. If the first relative error rate is greater than 0, it is considered that the wiring of the current transformer is abnormal. If the first relative error rate is equal to 0, the wiring of the current transformer is normal.

[0136] It should be noted that the two ends of the transformer are divided into the high-voltage side and the low-voltage side. Only when the current transformer is a current transformer of the low-voltage side measuring winding, the current transformer will point to the bus. In other cases, the current transformer points to the main transformer.

[0137] Step 206: If it is determined that the wiring of the current transformer is abnormal, determine the abnormal wiring position of the current transformer based on the measurement data;

[0138] In the implementation of this application, when it is determined that the wiring of the current transformer is abnormal, the measurement data of the abnormal wiring of the current transformer is output. If the abnormal measurement data is the differential current sampling value, it is determined that the differential winding current transformer is abnormal. If the abnormal measurement data is the three-phase phase of the high-voltage side, it is determined that the current transformer pointing to the main transformer is abnormal. If the abnormal measurement data is the three-phase phase of the low-voltage side, it is determined that the current transformer pointing to the bus is abnormal.

[0139] It should be noted that the differential current sampling value collects the measurement data of the current transformer of the differential winding. If the differential current sampling value is abnormal, it indicates that the secondary wiring on the high-voltage side and the secondary wiring on the low-voltage side of the current transformer of the differential winding are inconsistent, and it is considered that the wiring of the current transformer of the differential winding is abnormal. When the current transformer points to the main transformer, the phase differences between the three phases on the high-voltage side should be 120°. If the phase data of the three phases on the high-voltage side is abnormal, it means that the phase differences between the three phases on the high-voltage side are not equal to 120°, indicating that a certain phase of the current transformer is connected to other lines, making the phase differences between the three phases on the high-voltage side not equal to 120°, and it is considered that the current transformer pointing to the main transformer is abnormal. When the current transformer points to the bus, the phase differences between the three phases on the low-voltage side should be 120°. If the phase data of the three phases on the low-voltage side is abnormal, it means that the phase differences between the three phases on the low-voltage side are not equal to 120°, indicating that a certain phase of the current transformer is connected to other lines, making the phase differences between the three phases on the low-voltage side not equal to 120°, and it is considered that the current transformer pointing to the main transformer is abnormal.

[0140] Furthermore, it is also possible to judge whether the current transformer fails according to the relative error rate;

[0141] Judge whether the third relative error rate is greater than the preset high-voltage current threshold;

[0142] If the third relative error rate is greater than the preset high-voltage current threshold, it is judged that the current transformer fails;

[0143] If the third relative error rate is less than or equal to the preset high-voltage current threshold, it is judged that the current transformer does not fail.

[0144] The high-voltage current threshold refers to the critical value of the error rate between the measured value on the high-voltage secondary side and the theoretical value on the high-voltage secondary side when the current transformer is working normally, and is used to judge whether the current transformer fails. The high-voltage current threshold is 1%.

[0145] In the embodiment of the present application, the difference between the high-voltage secondary current and the theoretical value of the high-voltage secondary current is calculated and determined as the third difference, and the ratio of the third difference to the theoretical value of the high-voltage secondary current is determined as the third relative error rate. Judge whether the third relative error rate is greater than 1%. If the third relative error is greater than 1%, the current transformer fails. If the third relative error list is less than or equal to 1%, it is judged that the current transformer does not fail.

[0146] It should be noted that since the secondary current on the high-voltage side is obtained by the secondary transformation of the primary current on the high-voltage side through a current transformer, when the current transformer is operating normally, the secondary current on the high-voltage side obtained by the secondary transformation of the primary current on the high-voltage side through the current transformer is a stable value. The third-phase relative error rate actually represents the error rate between the secondary current on the high-voltage side and the theoretical value. When the third-phase relative error rate changes significantly, it indicates that the transformation ratio error of the current transformer is large, indicating that the current transformer has a fault.

[0147] In the embodiment of the present invention, when a current transformer calibration request sent by a faulty person is received, the request is read, the position of the current transformer is obtained, the transformer connected to the current transformer is used as the transformer to be tested, and the basic data and measurement data of the transformer to be tested are obtained. According to the current transformer calibration request, the data required for calculation are determined to be the primary current theoretical value on the high-voltage side and the secondary current theoretical value on the high-voltage side. By obtaining the basic data and measurement data, the primary current theoretical value on the high-voltage side and the secondary current theoretical value on the high-voltage side are calculated, and the calculated primary current theoretical value on the high-voltage side and the secondary current theoretical value on the high-voltage side are determined as calibration data. By calculating the difference between the measurement data and the theoretical value, and then calculating the ratio of the difference to the theoretical value, the relative error rate of the measurement data is calculated. The type of the current transformer is judged. After determining the type of the current transformer, the relative error rate corresponding to the wiring category of the current transformer is obtained. Combining the relative error rate when the current transformer is operating normally, it is judged whether the wiring of the current transformer is abnormal. After determining that the wiring of the current transformer is abnormal, the measurement data of the abnormal wiring of the current transformer can be obtained. Different measurement data correspond to current transformers at different wiring positions, and the wiring position of the corresponding current transformer can be matched according to the abnormal measurement data. Thus, the problem that when judging whether the wiring of the current transformer is abnormal, by manually drawing a hexagon diagram to judge the correctness of the secondary circuit wiring of the current transformer, the error is large, resulting in low reliability of the operation of the power system relay protection is solved. The present invention collects the basic data and measurement data of the transformer connected to the current transformer to be tested, calculates the relative error rate of the measurement data, and judges whether there is an abnormality in the wiring of the current transformer according to the relative error rate, effectively improving the accuracy of judging whether the wiring of the current transformer is abnormal, thereby improving the reliability of the operation of the power system relay protection.

[0148] Please refer to Figure 3 , Figure 3 which is the structural block diagram of a current transformer abnormality calibration system provided in Embodiment 3 of the present invention.

[0149] A current transformer abnormality calibration system provided by the present invention includes:

[0150] A data acquisition module 301, configured to receive a current transformer calibration request and acquire basic data and measurement data of a transformer to be tested;

[0151] An acquisition module 302, configured to determine calibration data corresponding to a current transformer calibration request according to basic data and measurement data;

[0152] An automatic calculation module 303, configured to calculate the relative error rate of the measurement data;

[0153] A judgment module 304, configured to judge whether there is an abnormality in the wiring of the current transformer according to the relative error rate;

[0154] An analysis module 305, configured to, if it is determined that the wiring of the current transformer is abnormal, determine the abnormal wiring position of the current transformer based on the measurement data.

[0155] Optionally, the data acquisition module 301 is specifically configured to:

[0156] Receive a current transformer calibration request, connect the output end of a preset transformer short-circuit test device to the high-voltage side of the transformer to be tested, connect the input end of the transformer short-circuit test device to a mains three-phase socket, form a transformer short-circuit test loop and turn it on;

[0157] Obtain measurement data of the transformer to be tested through the transformer test device;

[0158] Obtain basic data of the transformer to be tested.

[0159] Optionally, the acquisition module 302 is specifically configured to:

[0160] Substitute the basic data and the measurement data into the high-voltage side primary current calculation formula to calculate the theoretical value of the high-voltage side primary current;

[0161] The high-voltage side primary current calculation formula is specifically:

[0162]

[0163] Wherein, XT is the transformer impedance, U is the phase voltage of the high-voltage side of the transformer, Ud% is the short-circuit impedance, S e is the rated capacity of the transformer, U he is the rated voltage of the high-voltage side, I h1 is the theoretical value of the high-voltage side primary current;

[0164] Calculate the ratio of the theoretical value of the high-voltage side primary current to the transformation ratio of the high-voltage side current transformer to obtain the theoretical value of the high-voltage side secondary current.

[0165] Optionally, the automatic calculation module 303 is specifically configured to:

[0166] Calculate the first difference between the three-phase phases on the high-voltage side and the theoretical values of the three-phase phases on the high-voltage side, and determine the ratio of the first difference to the theoretical values of the three-phase phases on the high-voltage side as the first relative error rate;

[0167] Calculate the second difference between the three-phase phases on the low-voltage side and the theoretical values of the three-phase phases on the low-voltage side, and determine the ratio of the second difference to the theoretical values of the three-phase phases on the low-voltage side as the second relative error rate;

[0168] Calculate the third difference between the secondary current on the high-voltage side and the theoretical value of the secondary current on the high-voltage side, and determine the ratio of the third difference to the theoretical value of the secondary current on the high-voltage side as the third relative error rate.

[0169] The judgment module 304 is specifically used for:

[0170] Judge whether the current transformer is a differential winding current transformer. If the current transformer is a differential winding current transformer, then compare whether the differential current sampling value is less than or equal to the preset differential current threshold;

[0171] If not, it is determined that the wiring of the current transformer is abnormal;

[0172] If so, judge whether the first relative error rate is equal to the preset phase difference threshold;

[0173] If the first relative error rate is equal to the phase difference threshold, it is determined that the wiring of the current transformer is normal;

[0174] If the first relative error rate is not equal to the phase difference threshold, it is determined that the wiring of the current transformer is abnormal;

[0175] If the current transformer is other current transformers, then judge whether the current transformer is a low-voltage side current transformer;

[0176] If the current transformer is a low-voltage side current transformer, then judge whether the second relative error rate is equal to the preset phase difference threshold;

[0177] If the second relative error rate is equal to the phase difference threshold, it is determined that the wiring of the current transformer is normal;

[0178] If the second relative error rate is not equal to the phase difference threshold, it is determined that the wiring of the current transformer is abnormal;

[0179] If the current transformer is not a low-voltage side current transformer, then judge whether the first relative error rate is equal to the phase difference threshold;

[0180] If the first relative error rate is equal to the phase difference threshold, it is determined that the wiring of the current transformer is normal;

[0181] If the first relative error rate is not equal to the phase difference threshold, it is determined that the wiring of the current transformer is abnormal.

[0182] The analysis module is specifically used for:

[0183] Obtain the measurement data of the abnormal wiring of the output current transformer;

[0184] If the abnormal measurement data is the differential current sampling value, it is determined that the differential winding current transformer is abnormal;

[0185] If the abnormal measurement data is the three-phase phase on the high-voltage side, it is determined that the current transformer pointing to the main transformer is abnormal;

[0186] If the abnormal measurement data is the three-phase phase on the low-voltage side, it is determined that the current transformer pointing to the bus is abnormal.

[0187] An electronic device according to an embodiment of the present invention, the electronic device includes: a memory 401 and a processor 402, and a computer program is stored in the memory 402; when the computer program is executed by the processor 402, the processor 402 is caused to execute the current transformer abnormality verification method according to any of the above embodiments.

[0188] The memory 401 may be an electronic memory such as a flash memory, an EEPROM (electrically erasable programmable read-only memory), an EPROM, a hard disk, or a ROM. The memory 401 has a storage space 403 for the program code 413 for executing any method step in the above method. For example, the storage space 403 for the program code may include respective program codes 413 for implementing various steps in the above method. These program codes may be read from or written to one or more computer program products. These computer program products include program code carriers such as hard disks, compact discs (CDs), memory cards, or floppy disks. The program code may be compressed in an appropriate form. When these codes are run by a computing processing device, the computing processing device is caused to execute the respective steps in the method described above.

[0189] An embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed, the current transformer abnormality verification method according to any embodiment of the present invention is implemented.

[0190] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0191] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0192] In addition, in each embodiment of the present invention, each functional unit can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0193] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present invention. The foregoing storage medium includes: USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs and other various media that can store program codes.

[0194] As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of each embodiment of the present invention.

Claims

1. A method for abnormal calibration of a current transformer, characterized in that, Including a transformer under test, the transformer under test is connected with a current transformer; the method includes: Responding to a current transformer calibration request, collecting basic data and measurement data of the transformer under test; Determining calibration data corresponding to the current transformer calibration request according to the basic data and the measurement data; Calculating the relative error rate of the measurement data; Judging whether there is an abnormality in the wiring of the current transformer according to the relative error rate and the type of the current transformer; If it is determined that the wiring of the current transformer is abnormal, determining the abnormal position of the wiring of the current transformer based on the measurement data; The step of responding to a current transformer calibration request and collecting basic data and measurement data of the transformer under test includes: Responding to a current transformer calibration request, connecting the output end of a preset transformer short-circuit test device to the high-voltage side of the transformer under test, connecting the input end of the transformer short-circuit test device to a mains three-phase socket, forming a transformer short-circuit test loop and conducting it; Obtaining measurement data of the transformer under test through the transformer short-circuit test device; the measurement data includes primary current on the high-voltage side, secondary current on the high-voltage side, differential current sampling value of a differential protection device, three-phase phase on the high-voltage side, and three-phase phase on the low-voltage side; Obtaining basic data of the transformer under test; the basic data includes transformer rated capacity, high-voltage side rated voltage, short-circuit impedance, high-voltage side current transformer ratio, and phase voltage between phases on the high-voltage side of the transformer.

2. The method for abnormal calibration of a current transformer according to claim 1, characterized in that, The calibration data includes a theoretical value of primary current on the high-voltage side and a theoretical value of secondary current on the high-voltage side; The step of determining calibration data corresponding to the current transformer calibration request according to the basic data and the measurement data includes: Substituting the basic data and the measurement data into a high-voltage side primary current calculation formula to calculate the theoretical value of primary current on the high-voltage side; The high-voltage side primary current calculation formula is specifically: Among them, X T is the transformer impedance, U is the phase-to-phase voltage on the high-voltage side of the transformer, U d % is the short-circuit impedance, S e is the rated capacity of the transformer, U he is the rated voltage on the high-voltage side, I h1 is the theoretical value of the primary current on the high-voltage side; Calculating the ratio of the theoretical value of primary current on the high-voltage side to the high-voltage side current transformer ratio to obtain the theoretical value of secondary current on the high-voltage side.

3. The method for abnormal calibration of a current transformer according to claim 2, characterized in that, The step of calculating the relative error rate of the measurement data includes: Calculating a first difference between the three-phase phase on the high-voltage side and the theoretical value of the three-phase phase on the high-voltage side, and determining the ratio of the first difference to the theoretical value of the three-phase phase on the high-voltage side as the first relative error rate; Calculating a second difference between the three-phase phase on the low-voltage side and the theoretical value of the three-phase phase on the low-voltage side, and determining the ratio of the second difference to the theoretical value of the three-phase phase on the low-voltage side as the second relative error rate; Calculating a third difference between the secondary current on the high-voltage side and the theoretical value of the secondary current on the high-voltage side, and determining the ratio of the third difference to the theoretical value of the secondary current on the high-voltage side as the third relative error rate.

4. The method for abnormal calibration of a current transformer according to claim 3, characterized in that, When the current transformer is a differential winding current transformer, the step of judging whether there is an abnormality in the wiring of the current transformer according to the relative error rate and the type of the current transformer includes: Comparing whether the differential current sampling value is less than or equal to a preset differential current threshold; If not, determining that the wiring of the current transformer is abnormal; If so, judging whether the first relative error rate is equal to a preset phase difference threshold; If the first relative error rate is equal to the phase difference threshold, it is determined that the wiring of the current transformer is normal; If the first relative error rate is not equal to the phase difference threshold, it is determined that the wiring of the current transformer is abnormal.

5. The method for abnormal calibration of a current transformer according to claim 3, characterized in that, When the current transformer is not a differential winding current transformer, the step of judging whether there is an abnormality in the wiring of the current transformer according to the relative error rate and the type of the current transformer includes: Judging whether the current transformer is a low-voltage side current transformer; If the current transformer is the low-voltage side current transformer, judging whether the second relative error rate is equal to the preset phase difference threshold; If the second relative error rate is equal to the phase difference threshold, it is determined that the wiring of the current transformer is normal; If the second relative error rate is not equal to the phase difference threshold, it is determined that the wiring of the current transformer is abnormal; If the current transformer is not the low-voltage side current transformer, judging whether the first relative error rate is equal to the phase difference threshold; If the first relative error rate is equal to the phase difference threshold, it is determined that the wiring of the current transformer is normal; If the first relative error rate is not equal to the phase difference threshold, it is determined that the wiring of the current transformer is abnormal.

6. The current transformer anomaly calibration method according to claim 3, wherein, It also includes: Judging whether the third relative error rate is greater than the preset high-voltage current threshold; If so, it is determined that the current transformer has a fault; If not, it is determined that the current transformer is normal.

7. A current transformer anomaly calibration system, wherein, It includes a transformer to be tested, and the transformer to be tested is connected with a current transformer; the system includes: A data acquisition module, configured to receive a current transformer calibration request and acquire the basic data and measurement data of the transformer to be tested; An acquisition module, configured to determine the calibration data corresponding to the current transformer calibration request according to the basic data and the measurement data; An automatic calculation module, configured to calculate the relative error rate of the measurement data; A judgment module, configured to judge whether there is an abnormality in the wiring of the current transformer according to the relative error rate and the type of the current transformer; An analysis module, configured to, if it is determined that the wiring of the current transformer is abnormal, determine the abnormal wiring position of the current transformer based on the measurement data; The data acquisition module is specifically configured to: In response to the current transformer calibration request, connect the output end of a preset transformer short-circuit test device to the high-voltage side of the transformer to be tested, and connect the input end of the transformer short-circuit test device to the mains three-phase socket to form a transformer short-circuit test loop and conduct it; Obtain the measurement data of the transformer to be tested through the transformer short-circuit test device; the measurement data includes the primary current on the high-voltage side, the secondary current on the high-voltage side, the differential current sampling value of the differential protection device, the three-phase phase on the high-voltage side, and the three-phase phase on the low-voltage side; Obtain the basic data of the transformer to be tested; the basic data includes the rated capacity of the transformer, the rated voltage on the high-voltage side, the short-circuit impedance, the transformation ratio of the high-voltage side current transformer, and the phase voltage between phases on the high-voltage side of the transformer.

8. An electronic device, wherein, It includes a memory and a processor. A computer program is stored in the memory. When the computer program is executed by the processor, the processor is caused to execute the steps of a method for abnormal calibration of a current transformer as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, wherein, When the computer program is executed, it implements a method for abnormal calibration of a current transformer as described in any one of claims 1-6.

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