Fault diagnosis and positioning method and system for lead assembly of iron core clamp of converter transformer

Abstract

The invention provides a fault diagnosis positioning method and system for a converter transformer core clamp lead assembly. The method comprises the steps that 1, converter transformer core fundamental wave grounding current, clamp fundamental wave grounding current, the gas content in converter transformer insulating oil and the partial discharge amount of a converter transformer core are collected; 2, encoding based on the converter transformer iron core fundamental wave grounding current data and the clamp fundamental wave grounding current data to obtain a grounding current code, and encoding based on the gas content in the converter transformer insulating oil to obtain a gas content code; and step 3, based on the iron core fundamental wave grounding current, the clamp fundamental wave grounding current, the gas content, the iron core partial discharge amount, the grounding current code and the gas content code, diagnosing the fault of the iron core clamp lead assembly, and positioning the fault according to a diagnosis result to obtain a fault positioning result. According to the invention, a user can observe fault positioning and maintenance suggestions of the iron core clamp lead assembly more visually, and the operation and maintenance efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power equipment operation and maintenance, and more specifically, relates to a method and system for diagnosing and locating faults of a core clamp lead assembly of a converter transformer. Background Art

[0002] The core is one of the important components of the converter transformer. It is a closed magnetic circuit composed of stacked silicon steel sheets with good magnetic conductivity. The operating status of the core clamp lead assembly will directly affect the safe and stable operation of the transformer. During the operation of the converter transformer, the core clamp lead is prone to defects such as abnormal insulation of the core or clamp, suspended discharge, and abnormal heating. However, the core is located in the oil tank of the converter transformer, and the operating status of the core clamp lead cannot be directly observed without returning to the factory.

[0003] Prior art document 1 (CN111650451A) discloses a method and system for identifying the cause of a converter transformer fault in a server storing a historical fault data set and a normal data set of a converter transformer. The disadvantage is that the fault diagnosis model only relies on online monitoring data, ignoring state data such as offline monitoring and power outage test data, and the diagnosis result lacks interpretability, the accuracy of the fault diagnosis result is low, and the operation and maintenance efficiency is low. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the present invention provides a method and system for diagnosing and locating faults of core clamp lead assemblies of converter transformers, which combines online monitoring, offline monitoring, power outage test data, digital twins, and artificial intelligence methods to perform defect diagnosis, fault location, and maintenance suggestions, and construct a fault reasoning flowchart.

[0005] The present invention adopts the following technical solution.

[0006] A first aspect of the present invention provides a method for diagnosing and locating a fault of a core clamp lead assembly of a converter transformer, comprising the following steps:

[0007] Step 1, collecting the fundamental grounding current of the converter transformer core, the fundamental grounding current of the clamp, the gas content in the converter transformer insulating oil and the partial discharge of the converter transformer core; wherein the gas content includes C2H2 content, C2H4 content, CH4 content, H2 content and C2H6 content;

[0008] Step 2: Encode based on the fundamental ground current data of the converter transformer core and the fundamental ground current data of the clamp to obtain the ground current code, and encode based on different combinations of C2H2 content, C2H4 content, CH4 content, H2 content and C2H6 content in the converter transformer insulating oil to obtain the gas content code;

[0009] Step 3: Based on the core fundamental wave grounding current, the clamp fundamental wave grounding current, the gas content, the core partial discharge, the grounding current code and the gas content code, the core clamp lead assembly fault is diagnosed, and the fault is located according to the diagnosis result to obtain the fault location result;

[0010] Among them, the core clamp lead assembly failures include: abnormal insulation of the core or clamp, suspended discharge of the core assembly and abnormal heating of the core assembly.

[0011] Preferably, in step 2, encoding the core fundamental wave grounding current and the clamp fundamental wave grounding current comprises:

[0012] When I core,f / D1≤1, its encoding value is 0; I clamp,f / D2≤1, its coding value is 0;

[0013] When I core,f / D1>1, its coding value is 1; I clamp,f / D2>1, its coding value is 1;

[0014] in,

[0015] I core,f is the core fundamental ground current,

[0016] I clamp,f is the fundamental ground current of the clamp,

[0017] D1 is the first threshold,

[0018] D2 is the second threshold,

[0019] Among them, the first bit of the ground current code is I core,f / D1 code, the second digit is I clamp,f / D2 coding;

[0020] The first threshold and the second threshold are obtained by analyzing transformer parameters and sensor data using digital twins.

[0021] Preferably, in step 2, encoding based on the gas content in the converter transformer insulating oil includes:

[0022] When C2H2 / C2H4<0.1, its coding value is 0; CH4 / H2<0.1, its coding value is 1; C2H4 / C2H6<0.1, its coding value is 0;

[0023] When 0.1≤C2H2 / C2H4<1, its code is assigned to 1; 0.1≤CH4 / H2<1, its code is assigned to 0; 0.1≤C2H4 / C2H6<1, its code is assigned to 0;

[0024] When 1≤C2H2 / C2H4<3, its code is assigned to 1; 1≤CH4 / H2<3, its code is assigned to 2; 1≤C2H4 / C2H6<3, its code is assigned to 1;

[0025] When C2H2 / C2H4≥3, its coding value is 2; CH4 / H2≥3, its coding value is 2;

[0026] C2H4 / C2H6≥3, its coding value is 2;

[0027] Among them, the first digit of the gas content code is C2H2 / C2H4 code, the second digit is CH4 / H2 code, and the third digit is C2H4 / C2H6 code.

[0028] Preferably, step 3 comprises:

[0029] Step 3.1, based on the obtained ground current code, diagnose whether the core or the clamp insulation is abnormal, and obtain a first diagnosis result;

[0030] Step 3.2, based on the obtained partial discharge and gas content codes of the core, diagnose the suspended discharge defect of the core assembly to obtain a second diagnosis result;

[0031] Step 3.3: Based on the gas content code, diagnose abnormal heating of the core assembly to obtain a third diagnosis result.

[0032] Preferably, in step 3.1, when at least one bit of the ground current code is set to 1, the core clamp lead assembly fault is determined to be abnormal insulation of the core or clamp, and the core clamp lead assembly insulation fault is in an abnormal state. The core assembly evaluation status is displayed in the first color as a reminder, and the ground current is monitored in real time.

[0033] Preferably, if the ground current code is 11, the fault is located at insulation damage or overlap between core clamps;

[0034] If the ground current code is 10, the fault is located in the core itself or the insulation between the core and the oil tank is damaged or there is a foreign object overlapping;

[0035] If the ground current code is 01, the fault is located as insulation damage or foreign matter overlap in the clamp itself or between the clamp and the oil tank;

[0036] If at least one digit of the ground current code is set to 1, and the total hydrocarbon weekly increment exceeds the seventh threshold, and the first and third digits of the gas content code are set to 0 and 2 respectively or the gas content code is 021, the fault is located as a core heating fault.

[0037] Preferably, if the ground current code is 11 and the core fundamental current is greater than the third threshold value, the core assembly is in a serious state, and its evaluation state is displayed in a second color; and / or,

[0038] If the ground current code is 11 and the insulation resistance is less than the fourth threshold value, the core assembly is in a serious state, and its evaluation state is displayed in a second color; and / or,

[0039] If the ground current code is 10 and the core fundamental ground current is greater than the fifth threshold, the core assembly is in a serious state, and its evaluation state is displayed in a second color; and / or,

[0040] If the ground current code is 01 and the fundamental ground current of the clamp is greater than the sixth threshold value, the core assembly is in a serious state, and its evaluation state is displayed in a second color; and / or,

[0041] In the case where the fault is located as a core heating fault, the core assembly is in a serious state, and its evaluation state is displayed in a second color;

[0042] Among them, the third threshold and the fifth threshold are both greater than the first threshold, and the sixth threshold is greater than the second threshold.

[0043] Preferably, step 3.2 comprises:

[0044] Step 3.2.1, if the gas content code is 010 or the first digit of the gas content code is 1 or the first digit of the gas content code is 2, and the acetylene content is greater than the first attention value and / or the acetylene weekly increment is greater than the second attention value, it is determined that the core clamp lead assembly failure is suspended discharge of the core assembly, and the core assembly is in an abnormal state. Its evaluation status is displayed in the first color as a reminder, and chromatographic monitoring is strengthened.

[0045] Step 3.2.2. On the basis of step 3.2.1, when the partial discharge of the core exceeds the eighth threshold value, and / or the acetylene content exceeds the first alarm value, and / or the acetylene increment exceeds the second alarm value, the fault is located as discharge of the equipotential line, shielding line, or fastener, and the core assembly is in a serious state, and its evaluation status is displayed in the second color.

[0046] Preferably, step 3.3 includes:

[0047] Step 3.3.1. When the total hydrocarbon increment is higher than the third attention value or the total hydrocarbon content exceeds the fourth attention value, and the first digit of the gas content code is 0 and does not include the gas content code 010, it is determined that the core clamp lead assembly failure is abnormal heating of the core assembly, and the core assembly is in an abnormal state. Its evaluation status is displayed in the first color as a reminder, and chromatographic monitoring is strengthened.

[0048] Step 3.3.2. Based on step 3.3.1, when the total hydrocarbon content exceeds the fifth attention value, and / or the acetylene content increment exceeds the third alarm value, the fault is located as local core circulating current overheating, clamps, pull straps, pull plates, shielding plates, and insulating isolation circulating current overheating, and its evaluation status is displayed in the second color.

[0049] Preferably, the method further comprises:

[0050] Step 3.4: Based on the first diagnostic result and / or the second diagnostic result and / or the third diagnostic result, output maintenance suggestions and display the formed core clamp lead assembly fault defect reasoning flowchart, wherein the core clamp lead assembly fault defect reasoning flowchart is used to display the fault reasoning process to the user.

[0051] The second aspect of the present invention provides a fault diagnosis and positioning system for a core clamp lead assembly of a converter transformer, comprising an acquisition module, an encoding module and a fault positioning module. The acquisition module is used to collect the fundamental grounding current data of the core of the converter transformer, the fundamental grounding current data of the clamp, the gas content data in the insulating oil of the converter transformer and the partial discharge data of the core of the converter transformer. The encoding module is used to encode based on the fundamental grounding current data of the core of the converter transformer and the fundamental grounding current data of the clamp to obtain the grounding current code, and to encode based on the gas content in the insulating oil of the converter transformer to obtain the gas content code. The fault positioning module is used to diagnose the fault of the core clamp lead assembly based on the fundamental grounding current of the core, the fundamental grounding current of the clamp, the gas content, the partial discharge of the core, the grounding current code and the gas content code, and locate the fault according to the diagnosis result to obtain the fault positioning result.

[0052] The third aspect of the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the computer program is loaded into the processor, the method for diagnosing and locating the fault of the core clamp lead assembly of the converter transformer described above is implemented.

[0053] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the above-mentioned method for diagnosing and locating faults of a core clamp lead assembly of a converter transformer.

[0054] Compared with the prior art, the beneficial effects of the present invention include at least:

[0055] (1) Based on the state quantity data such as online monitoring, offline monitoring, and power outage test data of the converter transformer, the present invention gradually derives the state evaluation, fault diagnosis, and fault location of the core assembly through digital twins and artificial intelligence models, and puts forward further maintenance suggestions, thereby forming an inference flow chart of the core clamp lead assembly of the converter transformer.

[0056] (2) The present invention obtains online monitoring data such as the core fundamental grounding current and the clamp fundamental grounding current and power outage test data through digital twin or artificial intelligence technology, gradually infers the occurrence of core or clamp insulation abnormalities, evaluates the operating status of the converter transformer when the defect occurs, and further realizes fault location, and gives reasonable maintenance suggestions based on the operating status of the converter transformer, forming a core or clamp insulation abnormality defect fault reasoning flow chart.

[0057] (3) The present invention combines an artificial intelligence model to gradually infer the occurrence of suspended discharge in the core assembly of the converter transformer based on online monitoring data such as the dissolved gas content in the oil and the amount of local discharge, evaluates the operating status of the converter transformer when the defect occurs, and further explores the fault location. In combination with the operating status of the converter transformer, reasonable maintenance suggestions are given to form a flow chart for reasoning about the suspended discharge defect of the core clamp lead assembly.

[0058] (4) The present invention utilizes online monitoring data such as the dissolved gas content in oil and gas content coding to deduce the abnormal heating defect of the core clamp lead assembly of the converter transformer, evaluates and codes the operating status of the converter transformer, and simultaneously locates the fault, thereby providing reasonable maintenance suggestions and forming a fault reasoning flow chart for the abnormal heating defect of the core clamp lead assembly.

[0059] (5) The present invention enables users to more intuitively observe the fault location and maintenance suggestions of the core clamp lead assembly, enhances the accuracy and interpretability of the fault diagnosis results, and further improves the operation and maintenance efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0061] Figure 1 It is a flowchart schematic diagram of a method for diagnosing and locating a fault of a core clamp lead assembly of a converter transformer provided by an embodiment of the present invention;

[0062] Figure 2 The present invention provides a flow chart for inferring defect faults of a core clamp lead assembly of a converter transformer. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only part of the embodiments of the present invention, not all of them. Based on the spirit of the present invention, other embodiments obtained by ordinary technicians in this field without creative work are all within the scope of protection of the present invention.

[0064] The present invention proposes a method and system for diagnosing and locating the fault of a core clamp lead assembly for a converter transformer. Based on the state quantity data such as online monitoring, offline monitoring, and power outage test data of the converter transformer, combined with digital twins and artificial intelligence means, the state evaluation, fault diagnosis, and fault location of the core clamp lead assembly can be achieved without returning the transformer to the factory, and further maintenance suggestions can be made.

[0065] like Figure 1 and Figure 2 As shown, embodiment 1 of the present invention provides a method for diagnosing and locating a fault of a core clamp lead assembly of a converter transformer, comprising the following steps:

[0066] Step 1: Collect the fundamental grounding current of the converter transformer core, the fundamental grounding current of the clamp, the gas content in the converter transformer insulating oil and the partial discharge of the converter transformer core; wherein the gas content includes C2H2 content, C2H4 content, CH4 content, H2 content and C2H6 content.

[0067] Specifically, step 1 includes:

[0068] Step 1.1: Collect the core grounding current and the clamp grounding current of the converter transformer and calculate the core fundamental grounding current I core,f and the clamp fundamental ground current I clamp,f data.

[0069] Step 1.2, collecting the gas content in the converter transformer insulating oil, including: C2H2 (acetylene), C2H4 (ethylene), CH4 (methane), H2 (hydrogen) and C2H6 (ethane), preferably but not limited to, obtained by online oil chromatography monitoring of the converter transformer. The total hydrocarbon content is the sum of the contents of C2H2, C2H4, CH4 and C2H6.

[0070] Step 1.3, collect partial discharge spectra of the core clamp lead assembly of the converter transformer, preferably but not limited to, analyze the partial discharge spectra through an artificial intelligence model, extract information such as partial discharge frequency and peak value, and obtain partial discharge amount. Artificial intelligence models include but are not limited to LeNet-5, AlexNet, VGGNet, SeNet, Transformer, ConViT and other image recognition algorithm models.

[0071] The collected data and their types are shown in Table 1.

[0072] Table 1

[0073] data type Core grounding current Online monitoring Clamp grounding current Online monitoring C2H6 Online monitoring C2H4 Online monitoring C2H2 Online monitoring CH4 Online monitoring H2 Online monitoring Total hydrocarbons Online monitoring Partial discharge frequency Online monitoring Partial discharge peak Online monitoring Insulation resistance Power failure test

[0074] As can be seen from Table 1, the online monitoring data include core grounding current, clamp grounding current, C2H6, C2H4, C2H2, CH4, H2, total hydrocarbons, partial discharge frequency and partial discharge peak, and the power outage test data is insulation resistance. By combining multi-source data to analyze the fault of the core clamp lead assembly, the accuracy of fault analysis can be improved.

[0075] Step 2: Encode based on the fundamental grounding current data of the converter transformer core and the fundamental grounding current data of the clamp to obtain the grounding current code, and encode based on different combinations of C2H2 content, C2H4 content, CH4 content, H2 content and C2H6 content in the converter transformer insulating oil to obtain the gas content code.

[0076] Step 2 specifically includes:

[0077] Step 2.1: Based on the fundamental ground current I of the converter transformer core core,f and the clamp fundamental ground current I clamp,f to encode.

[0078] Specifically, as shown in Table 2,

[0079] When I core,f / D1≤1, its encoding value is 0; I clamp,f / D2≤1, its coding value is 0;

[0080] When I core,f / D1>1, its coding value is 1; I clamp,f / D2>1, its coding value is 1;

[0081] in,

[0082] I core,f is the core fundamental ground current,

[0083] I clamp,f is the fundamental ground current of the clamp,

[0084] D1 is the first threshold,

[0085] D2 is the second threshold,

[0086] Among them, the first digit of the ground current code is the code, and the second digit is I clamp,f / D2 encoding.

[0087] Table 2

[0088]

[0089] It can be seen from Table 2 that the core fundamental wave grounding current I core,f Is it greater than the first threshold D1, and the clamp fundamental ground current I clamp,f Is it greater than the second threshold D2? Encode the comparison result to obtain the ground current code, where if the core fundamental wave ground current I core,f If the clamp fundamental ground current I clamp,f If the ground current is greater than the second threshold D2, it is encoded as 1, otherwise it is 0. Therefore, the ground current encoding includes four encoding combinations, namely 00, 01, 10 and 11.

[0090] Preferably, but not limited to, the operation status and fault condition of the commutation transformer core clamp are obtained by comprehensive analysis through digital twin computing or artificial intelligence. Artificial intelligence technology, such as BP neural network, long short-term memory network (LSTM), deep belief network (DBN), convolutional neural network (CNN), support vector machine (SVM), random forest, Transformer and other models, uses the commutation transformer core fundamental ground current I core,f and the clamp fundamental ground current I clamp,f Evaluate the operating status of the converter transformer core clamp lead components, and perform fault diagnosis and location.

[0091] At the same time, digital twin technology can be used to simulate the complex situation inside the transformer, and based on the various parameters of the transformer and various sensor data, the most appropriate thresholds (such as the first threshold and the second threshold) of the core fundamental grounding current and the clamp fundamental grounding current in different operating states can be analyzed in real time.

[0092] Preferably, the first threshold is 300 mA, and the second threshold is 300 mA.

[0093] Step 2.2: Encode based on the gas content in the converter transformer insulating oil to obtain the gas content code, as shown in Table 3:

[0094] Table 3

[0095]

[0096] It can be seen from Table 3 that when C2H2 / C2H4<0.1, its code is assigned to 0; CH4 / H2<0.1, its code is assigned to 1; C2H4 / C2H6<0.1, its code is assigned to 0; when 0.1≤C2H2 / C2H4<1, its code is assigned to 1; 0.1≤CH4 / H2<1, its code is assigned to 0; 0.1≤C2H4 / C2H6<1, its code is assigned to 0; when 1≤C2H2 / C2H4<3, its code is assigned to The code is assigned to 1; 1≤CH4 / H2<3, its code is assigned to 2; 1≤C2H4 / C2H6<3, its code is assigned to 1; when C2H2 / C2H4≥3, its code is assigned to 2; CH4 / H2≥3, its code is assigned to 2; C2H4 / C2H6≥3, its code is assigned to 2; among them, the first digit of the gas content code is the C2H2 / C2H4 code, the second digit is the CH4 / H2 code, and the third digit is the C2H4 / C2H6 code.

[0097] Step 3: Based on the core fundamental grounding current, the clamp fundamental grounding current, the gas content, the core partial discharge, the grounding current code and the gas content code, diagnose the core clamp lead assembly fault, locate the fault according to the diagnosis result, and obtain the fault location result.

[0098] Among them, the core clamp lead assembly failures include: abnormal insulation of the core or clamp, suspended discharge of the core assembly and abnormal heating of the core assembly.

[0099] Step 3 specifically includes:

[0100] Step 3.1: Based on the obtained ground current code, diagnose whether the insulation of the core or the clamp is abnormal, and obtain a first diagnosis result.

[0101] If at least one bit of the ground current code is set to 1, it indicates that if the core fundamental ground current I core,f Greater than the first threshold D1 or the clamp fundamental ground current I clamp,f If it is greater than the second threshold value D2, it is judged that the insulation of the core or the clamp is abnormal, the core assembly is in an abnormal state, and the state evaluation is "yellow code". At this time, the grounding current monitoring should be strengthened, and live grounding current measurement and comparison should be carried out. If necessary, a current limiting resistor cabinet should be installed live.

[0102] Furthermore, if the ground current code is 11, it indicates that the core fundamental ground current I core,f and the clamp fundamental ground current I clamp,f When the core fundamental wave current is greater than the third threshold D3 or the power failure test monitors the insulation resistance R irWhen it is less than the fourth threshold value D4, the insulation fault of the core clamp lead assembly is in a serious state, and the status evaluation is "red code". Relevant personnel should pay attention to the operating status of the transformer in time.

[0103] Furthermore, if the ground current code is 10, it means that by simulating the operation status of the commutation transformer core clamp lead wire through the digital twin, the ground current data is obtained, and the commutation transformer current change is calculated. It is found that only the core fundamental ground current I core,f If there is an increase in the core ground current I, it can be inferred that the fault is located in the core itself or the insulation between the core and the oil tank is damaged or there is a foreign body bridging. core,f If it is greater than the fifth threshold D5, the transformer status needs to be adjusted to the "red code" status, and relevant personnel should pay attention to the transformer operating status in a timely manner.

[0104] Furthermore, if the ground current code is 01, it indicates that the ground current data is obtained by simulating the operation status of the commutation transformer core clamp lead wire through the digital twin simulation, and the commutation transformer current change is calculated. It is found that only the clamp fundamental ground current I clamp,f If the clamp itself or the clamp and the oil tank are damaged, it means that the insulation is damaged or foreign matter is connected. clamp,f If it is greater than the sixth threshold D6, it means that the insulation fault of the core assembly is in a serious state, and the status evaluation is "red code". Relevant personnel should pay attention to the operating status of the transformer in time.

[0105] Furthermore, based on the gas content code, the nature of the transformer fault is judged and expressed in the following table:

[0106] Table 4

[0107]

[0108]

[0109] Preferably but not restrictively, at least one digit of the grounding current code is set to 1, that is, when an insulation abnormality occurs in the core or the clamp, if the total hydrocarbon weekly increment exceeds the seventh threshold value D7 at the same time, and the first and third digits of the gas content code are set to 0 and 2 respectively, or the gas content code is 021, then based on the gas content code, the transformer fault nature is judged to be medium and high temperature overheating, and it can be judged that a core heating fault has occurred. At this time, the transformer status assessment is "red code" and is in a serious state. Relevant personnel should pay attention to the transformer operating status in time.

[0110] Preferably, the third threshold D3 is 1A, the fourth threshold D4 is 500 MΩ, the fifth threshold D5 is 1A, the sixth threshold D6 is 1A, and the seventh threshold D7 is 40 μL / L.

[0111] Step 3.2: Based on the obtained partial discharge and gas content codes of the core, diagnose the suspended discharge defect of the core assembly to obtain a second diagnosis result.

[0112] Step 3.2 specifically includes:

[0113] If the gas content code is 010 or the first digit of the gas content code is set to 1 or 2, that is, when a discharge fault occurs in the converter transformer, if the acetylene content is greater than the first attention value or the acetylene weekly increment is greater than the second attention value, it can be judged that the converter transformer core component has a suspended discharge defect. At this time, the converter transformer status assessment is "yellow code" and is in an abnormal state. The converter transformer can continue to operate, but chromatographic monitoring needs to be strengthened and intensive care should be installed if necessary.

[0114] Furthermore, if the partial discharge of the core exceeds the eighth threshold D8 at the same time, it means that there is a stable and continuous discharge in a fixed phase in the partial discharge spectrum; or if the acetylene content exceeds the first alarm value or the acetylene increment exceeds the second alarm value at the same time, the fault is located as the discharge of the equipotential line, shielding line, and fastener. The transformer status assessment is "red code" and is in a serious state. Relevant personnel should pay attention to the operation status of the transformer in time.

[0115] Preferably, the eighth threshold D8 is 100 pc, the first attention value is 1 μL / L, the second attention value is 0.3 μL / L, the first warning value is 3 μL / L, and the second warning value is 1.2 μL / L.

[0116] Step 3.3: Based on the gas content code, diagnose abnormal heating of the core assembly to obtain a third diagnosis result.

[0117] Step 3.3 specifically includes:

[0118] If the total hydrocarbon increment is higher than the third attention value or the total hydrocarbon content exceeds the fourth attention value, and the first digit of the gas content code is 0 and does not include the gas content code 010, it is inferred that the core component has an abnormal heating defect, the transformer is in an abnormal operating state, and the state assessment code is "yellow code". The converter transformer can continue to operate, but chromatographic monitoring needs to be strengthened, and intensive care should be installed if necessary.

[0119] Furthermore, if the total hydrocarbon content exceeds the fifth attention value or the acetylene content increment exceeds the third alarm value, and the load correlation is low, it can be judged that the fault is local core circulation overheating, clamps, pull straps, pull plates, shielding plates, and insulation isolation circulation overheating. The transformer status needs to be adjusted to the "red code" status, and relevant personnel should pay attention to the transformer operation status in a timely manner.

[0120] Preferably, the third attention value is 5 μL / L, the fourth attention value is 40 μL / L, and the third warning value is 3 μL / L.

[0121] Step 3.4: Based on the first diagnostic result and / or the second diagnostic result and / or the third diagnostic result, output maintenance suggestions and display the formed core clamp lead assembly fault defect reasoning flowchart, wherein the core clamp lead assembly fault defect reasoning flowchart is used to display the fault reasoning process to the user.

[0122] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0123] Embodiment 2 of the present invention provides a converter transformer core clamp lead assembly fault diagnosis and positioning system, including: a collection module, a coding module and a fault positioning module.

[0124] The acquisition module is used to collect the fundamental grounding current data of the converter transformer core, the fundamental grounding current data of the clamp, the gas content data in the insulating oil of the converter transformer and the partial discharge data of the converter transformer core.

[0125] The encoding module is used to encode based on the fundamental grounding current data of the converter transformer core and the fundamental grounding current data of the clamp to obtain the grounding current code, and to encode based on the gas content in the insulating oil of the converter transformer to obtain the gas content code.

[0126] The fault location module is used to diagnose the core clamp lead assembly fault based on the core fundamental grounding current, the clamp fundamental grounding current, the gas content, the core partial discharge, the grounding current code and the gas content code, and locate the fault according to the diagnosis result to obtain the fault location result.

[0127] Embodiment 3 of the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the computer program is loaded into the processor, the method for diagnosing and locating faults of a converter transformer core clamp lead assembly described in Embodiment 1 is implemented.

[0128] Embodiment 4 of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for diagnosing and locating faults of a converter transformer core clamp lead assembly according to Embodiment 1 is implemented.

[0129] Embodiment 5 of the present invention provides a verification embodiment of a method for diagnosing and locating faults of a core clamp lead assembly of a converter transformer, wherein the first attention value is 1 μL / L, the second attention value is 0.3 μL / L, the first alarm value is 3 μL / L, and the second alarm value is 1.2 μL / L.

[0130] The acetylene content in a converter transformer oil exceeds the first attention value and the acetylene weekly growth exceeds the second attention value. The gas content code is 202, which is a low-energy discharge. In addition, on that day, the acetylene content exceeded the first warning value and the acetylene weekly growth exceeded the second warning value. According to the core clamp lead assembly fault reasoning flow chart, the defect diagnosis is inferred to be suspended discharge, and the fault location is equipotential line, shielding line, and fastener discharge.

[0131] After draining the oil and conducting internal inspection, the operation and maintenance personnel found that the threads of the aluminum shielding plate of the converter transformer were loose, which caused the bolts fixing the shielding tube to loosen and the shielding tube to be unable to be reliably grounded, resulting in bare metal suspended discharge and the generation of characteristic gases such as acetylene. This is consistent with the reasoning results of the converter transformer core clamp lead assembly fault reasoning flow chart.

[0132] It is worth noting that the outstanding essential features of the present invention and the significant progress brought to the prior art include at least:

[0133] (1) The present invention gradually derives the status evaluation, fault diagnosis, and fault location of the core clamp lead assembly based on the state quantity data such as online monitoring, offline monitoring, and power outage test data of the converter transformer through digital twins and artificial intelligence models, and puts forward further maintenance suggestions to form a converter transformer core clamp lead assembly fault reasoning flow chart.

[0134] (2) The present invention obtains online monitoring data such as the core fundamental grounding current and the clamp fundamental grounding current and power outage test data through digital twin or artificial intelligence technology, gradually infers the occurrence of core or clamp insulation abnormalities, evaluates the operating status of the converter transformer when the defect occurs, and further realizes fault location, and gives reasonable maintenance suggestions based on the operating status of the converter transformer, forming a core or clamp insulation abnormality defect fault reasoning flow chart.

[0135] (3) The present invention combines an artificial intelligence model to gradually infer the occurrence of suspended discharge in the core assembly of the converter transformer based on online monitoring data such as the dissolved gas content in the oil and the amount of local discharge, evaluates the operating status of the converter transformer when the defect occurs, and further explores the fault location. In combination with the operating status of the converter transformer, reasonable maintenance suggestions are given to form a flow chart for reasoning about the suspended discharge defect of the core clamp lead assembly.

[0136] (4) The present invention utilizes online monitoring data such as the dissolved gas content in oil and gas content coding to deduce the abnormal heating defect of the core clamp lead assembly of the converter transformer, evaluates and codes the operating status of the converter transformer, and simultaneously locates the fault, thereby providing reasonable maintenance suggestions and forming a fault reasoning flow chart for the abnormal heating defect of the core clamp lead assembly.

[0137] (5) The present invention enables users to more intuitively observe the fault location and maintenance suggestions of the core clamp lead assembly, enhances the accuracy and interpretability of the fault diagnosis results, and further improves the operation and maintenance efficiency.

[0138] The present disclosure may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for diagnosing and locating faults of a core clamp lead assembly of a converter transformer, characterized in that: The following steps are involved: Step 1, collecting the fundamental grounding current of the converter transformer core, the fundamental grounding current of the clamp, the gas content in the converter transformer insulating oil and the partial discharge of the converter transformer core; wherein the gas content includes C2H2 content, C2H4 content, CH4 content, H2 content and C2H6 content; Step 2: Encode based on the fundamental wave grounding current data of the converter transformer core and the fundamental wave grounding current data of the clamp to obtain the grounding current code, and encode based on different combinations of C2H2 content, C2H4 content, CH4 content, H2 content and C2H6 content in the converter transformer insulating oil to obtain the gas content code; Step 3: Based on the core fundamental wave grounding current, the clamp fundamental wave grounding current, the gas content, the core partial discharge, the grounding current code and the gas content code, the core clamp lead assembly fault is diagnosed, and the fault is located according to the diagnosis result to obtain the fault location result; Among them, the core clamp lead assembly failures include: abnormal insulation of the core or clamp, suspended discharge of the core assembly and abnormal heating of the core assembly.

2. The method for diagnosing and locating faults of a core clamp lead assembly of a converter transformer according to claim 1, characterized in that: In step 2, encoding the core fundamental wave grounding current and the clamp fundamental wave grounding current includes: When I core,f / D1≤1, its encoding value is 0; I clamp,f / D2≤1, its coding value is 0; When I core,f / D1>1, its coding value is 1; I clamp,f / D2>1, its coding value is 1; in, I core,f is the core fundamental ground current, I clamp,f is the fundamental ground current of the clamp, D1 is the first threshold, D2 is the second threshold, Among them, the first bit of the ground current code is I core,f / D1 code, the second digit is I clamp,f / D2 coding; The first threshold and the second threshold are obtained by analyzing transformer parameters and sensor data using digital twins.

3. The method for diagnosing and locating faults of a converter transformer core clamp lead assembly according to claim 2, characterized in that: In step 2, encoding based on the gas content in the converter transformer insulating oil includes: When C2H2 / C2H4<0.1, its coding value is 0; CH4 / H2<0.1, its coding value is 1; C2H4 / C2H6<0.1, its coding value is 0; When 0.1≤C2H2 / C2H4<1, its code is assigned to 1; 0.1≤CH4 / H2<1, its code is assigned to 0; 0.1≤C2H4 / C2H6<1, its code is assigned to 0; When 1≤C2H2 / C2H4<3, its code is assigned to 1; 1≤CH4 / H2<3, its code is assigned to 2; 1≤C2H4 / C2H6<3, its code is assigned to 1; When C2H2 / C2H4≥3, its code is assigned to 2; CH4 / H2≥3, its code is assigned to 2; C2H4 / C2H6≥3, its code is assigned to 2; Among them, the first digit of the gas content code is C2H2 / C2H4 code, the second digit is CH4 / H2 code, and the third digit is C2H4 / C2H6 code.

4. The method for diagnosing and locating faults of a core clamp lead assembly of a converter transformer according to claim 3, characterized in that: Step 3 includes: Step 3.1, based on the obtained ground current code, diagnose whether the core or the clamp insulation is abnormal, and obtain a first diagnosis result; Step 3.2, based on the obtained partial discharge and gas content codes of the core, diagnose the suspended discharge defect of the core assembly to obtain a second diagnosis result; Step 3.3: Based on the gas content code, diagnose abnormal heating of the core assembly to obtain a third diagnosis result.

5. The method for diagnosing and locating faults of a core clamp lead assembly of a converter transformer according to claim 4, characterized in that: In step 3.1, when at least one bit of the ground current code is set to 1, it is determined that the core clamp lead assembly fault is abnormal core or clamp insulation, the core clamp lead assembly is in an abnormal state, the core assembly evaluation status is displayed in the first color as a reminder, and the ground current is monitored in real time.

6. The method for diagnosing and locating faults of a core clamp lead assembly of a converter transformer according to claim 5, characterized in that: If the ground current code is 11, the fault is located at the insulation damage or overlap between the core clamps; If the ground current code is 10, the fault is located in the core itself or the insulation between the core and the oil tank is damaged or there is a foreign object overlapping; If the ground current code is 01, the fault is located as insulation damage or foreign matter overlap in the clamp itself or between the clamp and the oil tank; If at least one digit of the ground current code is set to 1, and the total hydrocarbon weekly increment exceeds the seventh threshold, and the first and third digits of the gas content code are set to 0 and 2 respectively or the gas content code is 021, the fault is located as a core heating fault.

7. The method for diagnosing and locating faults of a core clamp lead assembly of a converter transformer according to claim 6, characterized in that: If the ground current code is 11 and the core fundamental current is greater than the third threshold value, the core assembly is in a serious state, and its evaluation state is displayed in a second color; and / or, If the ground current code is 11 and the insulation resistance is less than the fourth threshold value, the core assembly is in a serious state, and its evaluation state is displayed in a second color; and / or, If the ground current code is 10 and the core fundamental ground current is greater than the fifth threshold, the core assembly is in a serious state, and its evaluation state is displayed in a second color; and / or, If the ground current code is 01 and the fundamental ground current of the clamp is greater than the sixth threshold value, the core assembly is in a serious state, and its evaluation state is displayed in a second color; and / or, In the case where the fault is located as a core heating fault, the core assembly is in a serious state, and its evaluation state is displayed in a second color; Among them, the third threshold and the fifth threshold are both greater than the first threshold, and the sixth threshold is greater than the second threshold.

8. The method for diagnosing and locating faults of a core clamp lead assembly of a converter transformer according to claim 4, characterized in that: Step 3.2 includes: Step 3.2.1, if the gas content code is 010 or the first digit of the gas content code is 1 or the first digit of the gas content code is 2, and the acetylene content is greater than the first attention value and / or the acetylene weekly increment is greater than the second attention value, it is determined that the core clamp lead assembly failure is suspended discharge of the core assembly, and the core assembly is in an abnormal state. Its evaluation status is displayed in the first color as a reminder, and chromatographic monitoring is strengthened. Step 3.2.

2. On the basis of step 3.2.1, when the partial discharge of the core exceeds the eighth threshold value, and / or the acetylene content exceeds the first alarm value, and / or the acetylene increment exceeds the second alarm value, the fault is located as discharge of the equipotential line, shielding line, or fastener, and the core assembly is in a serious state, and its evaluation status is displayed in the second color.

9. The method for diagnosing and locating faults of a core clamp lead assembly of a converter transformer according to claim 4, characterized in that: Step 3.3 includes: Step 3.3.

1. When the total hydrocarbon increment is higher than the third attention value or the total hydrocarbon content exceeds the fourth attention value, and the first digit of the gas content code is 0 and does not include the gas content code 010, it is determined that the core clamp lead assembly failure is abnormal heating of the core assembly, and the core assembly is in an abnormal state. Its evaluation status is displayed in the first color as a reminder, and chromatographic monitoring is strengthened. Step 3.3.

2. Based on step 3.3.1, when the total hydrocarbon content exceeds the fifth attention value, and / or the acetylene content increment exceeds the third alarm value, the fault is located as local core circulation overheating, and its evaluation status is displayed in the second color.

10. The method for diagnosing and locating faults of a core clamp lead assembly of a converter transformer according to any one of claims 4 to 9, characterized in that: The method further comprises: Step 3.4: Based on the first diagnostic result and / or the second diagnostic result and / or the third diagnostic result, output maintenance suggestions and display the formed core clamp lead assembly fault defect reasoning flowchart, wherein the core clamp lead assembly fault defect reasoning flowchart is used to display the fault reasoning process to the user.

11. A fault diagnosis and positioning system for a converter transformer core clamp lead assembly, characterized in that: include: The acquisition module is used to collect the data of the fundamental grounding current of the converter transformer core, the fundamental grounding current of the clamp, the gas content in the insulating oil of the converter transformer, and the partial discharge data of the converter transformer core; The encoding module is used to encode based on the fundamental wave grounding current data of the converter transformer core and the fundamental wave grounding current data of the clamp to obtain the grounding current code, and to encode based on the gas content in the insulating oil of the converter transformer to obtain the gas content code; The fault location module is used to diagnose the core clamp lead assembly fault based on the core fundamental grounding current, the clamp fundamental grounding current, the gas content, the core partial discharge, the grounding current code and the gas content code, and locate the fault according to the diagnosis result to obtain the fault location result.

12. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the computer program is loaded into a processor, the method for diagnosing and locating faults of a core clamp lead assembly of a converter transformer according to any one of claims 1 to 10 is implemented.

13. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for diagnosing and locating faults of a converter transformer core clamp lead assembly according to any one of claims 1 to 10 is implemented.

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