Resistance-capacitance change-based main transformer winding fault diagnosis method

Abstract

The embodiment of the invention discloses a main transformer winding fault diagnosis method based on resistance-capacitance change, and the method comprises the steps: measuring transformer winding injection signals and output signals under different injection resistance-capacitance conditions, and obtaining resistance-capacitance distinguishing amplitudes, including the amplitude of an mth data point of an lth group of frequency response curves when only the resistance is considered, only considering the amplitude of the mth data point of the k-th group of frequency response curves when capacitance is performed, and comprehensively considering the amplitude of the mth data point of the pq-th group of frequency response curves when resistance and capacitance are performed; acquiring weights of different frequency response curves, including weights when only resistors are considered, weights when only capacitors are considered, and weights when the resistors and the capacitors are comprehensively considered; according to the resistance-capacitance distinguishing amplitude and different frequency response curve weights, transformer winding diagnosis characteristic indexes are obtained, transformer winding fault judgment factors are calculated, and transformer winding fault judgment is carried out; according to the method, the transformer winding fault can be accurately and effectively judged, the judgment process is simplified, and non-professionals can easily master the method.

Description

Technical Field

[0001] The invention relates to the technical field of transformer winding fault diagnosis, and in particular to a main transformer winding fault diagnosis method based on resistance and capacitance changes. Background Art

[0002] Transformer is one of the most important equipment in power system and traction power supply system. Any failure will seriously threaten the safety of the whole system and may cause huge economic losses. Among them, transformer winding failure is the main factor leading to transformer failure. Because the transformer winding is under the action of alternating magnetic field, especially under conditions such as overvoltage, series resonance and short circuit, the winding is easily affected by strong electric force and deformed. Although small deformation has little effect on the normal operation of the transformer, deformation has a cumulative effect. Once the winding is permanently deformed, it may significantly reduce its mechanical stability and even damage the inter-turn insulation of the winding, resulting in increased winding loss and increased oil temperature. In severe cases, it may cause fire and other accidents.

[0003] Frequency response analysis (FRA) is a widely used transformer winding fault detection technology. Its core idea is to determine whether there is a fault in the winding by analyzing the response characteristics of the transformer at different frequencies. When there is a problem with the winding, such as insulation failure or ground fault, its response to the applied signal will change. By inputting signals of multiple frequencies and monitoring the amplitude and phase changes of the output signal, potential fault points and their characteristics can be identified. However, existing frequency response analysis often requires users to have professional electrical knowledge, which makes it challenging for non-professionals to understand and apply it. Summary of the invention

[0004] The main purpose of the present invention is to provide a main transformer winding fault diagnosis method based on resistance and capacitance changes, which can accurately and effectively judge transformer winding faults, simplify the judgment process, and make it easy for non-professionals to master it.

[0005] To achieve the above-mentioned object, the first aspect of the present application provides a main transformer winding fault diagnosis method based on resistance-capacitance change, the method comprising:

[0006] Measure the transformer winding injection signal and output signal under different injection resistance and capacitance to obtain the resistance-capacitance distinction amplitude, wherein the resistance-capacitance distinction amplitude includes the amplitude of the mth data point of the lth group frequency response curve when only the resistance is considered, the amplitude of the mth data point of the kth group frequency response curve when only the capacitance is considered, and the amplitude of the mth data point of the pqth group frequency response curve when the resistance and capacitance are comprehensively considered, wherein l, k, p, and q are positive integers;

[0007] Obtain weights of different frequency response curves, including the weight when only resistance is considered, the weight when only capacitance is considered, and the weight when resistance and capacitance are considered comprehensively;

[0008] Obtaining transformer winding diagnostic characteristic indicators according to the resistance-capacitance distinction amplitude and the weights of the different frequency response curves;

[0009] A transformer winding fault judgment factor is calculated according to the transformer winding diagnosis characteristic index, and a transformer winding fault judgment is performed according to the transformer winding fault judgment factor.

[0010] Optionally, the step of measuring the transformer winding injection signal and the output signal under different injection resistance and capacitance to obtain the resistance and capacitance distinction amplitude includes:

[0011] The variable capacitor and the variable resistor are controlled to be in a short-circuit state, and then a computer is used to generate excitation signals of different frequencies through a signal generator. The excitation signals are injected into the transformer windings, flow through the low-voltage winding, the medium-voltage winding, and the high-voltage winding, and then flow out of the transformer. The output response is measured, and the input and output measurements are stopped. The change value of the variable capacitor is controlled to be C va =[c1 c2 … c n ], the change value of the variable resistor is R va =[r1 r2 … r n ], c n and r n Respectively represent the capacitance and resistance values ​​injected by the nth measurement, where c n >c n-1 …>c1,r n >r n-1 …>r1;

[0012] Repeat the above measurement steps to obtain n×n groups of frequency response curves, including the frequency response curves considering only resistance, only capacitance, and comprehensive consideration of resistance and capacitance, respectively. l =[a rl1 a rl2 … a rlm ]、F k =[a ck1 a ck2 … a ckm ]、F pq =[a pq1 a pq2 … a pqm ], where a rlm represents the amplitude of the mth data point of the frequency response curve of the first group when only the resistance is considered, a ckm represents the amplitude of the mth data point of the kth group frequency response curve when only the capacitance is considered, a pqmIt represents the amplitude of the mth data point of the frequency response curve of the pqth group when the resistance and capacitance are comprehensively considered.

[0013] Optionally, obtaining weights of different frequency response curves includes:

[0014] Calculate the resistance and capacitance distinction weights according to the following formula:

[0015]

[0016] Among them, w rl 、w ck 、w pq They respectively represent the weight when only resistance is considered, the weight when only capacitance is considered, and the weight when resistance and capacitance are comprehensively considered, and α and β represent adjustment parameters.

[0017] Optionally, obtaining a transformer winding diagnostic characteristic index according to the resistance-capacitance distinction amplitude and the weights of the different frequency response curves includes:

[0018] The composite RC frequency characteristic curve is calculated according to the following formula:

[0019]

[0020] Among them, A only_rm , A only_cm , A rcm They represent the amplitude of the mth data point of the frequency response curve when only resistance, only capacitance, and resistance and capacitance are considered respectively;

[0021] The linear correlation strength index of the response signal is calculated according to the composite resistance-capacitance frequency characteristic curve.

[0022] Optionally, calculating the linear correlation strength index of the response signal according to the composite resistance-capacitance frequency characteristic curve includes:

[0023] The linear correlation strength index of the response signal is calculated using the following formula:

[0024]

[0025] Optionally, the calculating of the transformer winding fault judgment factor according to the transformer winding diagnosis characteristic index includes:

[0026] The transformer winding fault judgment factor is calculated according to the following formula:

[0027] σ=1.5sin(0.2XR)+2ln(|XC|+1)+0.3e XZ +0.05(XR 2 +XC 2 +XZ2 )。

[0028] Optionally, the determination of the transformer winding fault based on the transformer winding fault determination factor includes:

[0029] If σ≥G, it is determined that there is a fault in the transformer winding;

[0030] If σ<G, it is determined that there is no fault in the transformer winding, where G is a constant related to the transformer model, the winding signal injection method, and external devices.

[0031] The second aspect of the present application provides a main transformer winding fault diagnosis device based on resistance-capacitance change, including:

[0032] A measurement module, configured to measure the injection signal and output signal of the transformer winding under different injected resistances and capacitances, and obtain the resistance-capacitance discrimination amplitude, where the resistance-capacitance discrimination amplitude includes the amplitude of the m-th data point of the l-th group of frequency response curves when only considering the resistance, the amplitude of the m-th data point of the k-th group of frequency response curves when only considering the capacitance, and the amplitude of the m-th data point of the pq-th group of frequency response curves when comprehensively considering the resistance and capacitance, where l, k, p, and q are positive integers;

[0033] A weight calculation module, configured to obtain the weights of different frequency response curves, including the weight when only considering the resistance, the weight when only considering the capacitance, and the weight when comprehensively considering the resistance and capacitance;

[0034] An index calculation module, configured to obtain the transformer winding diagnosis characteristic index according to the resistance-capacitance discrimination amplitude and the weights of different frequency response curves;

[0035] A judgment module, configured to calculate the transformer winding fault judgment factor according to the transformer winding diagnosis characteristic index, and perform the transformer winding fault judgment according to the transformer winding fault judgment factor.

[0036] The third aspect of the present application provides an electronic device, including a memory and a processor. When the computer program stored in the memory is executed by the processor, the processor is caused to execute the steps of the first aspect and any one of its possible implementation manners.

[0037] The fourth aspect of the present application provides a computer-readable storage medium, storing a computer program. When the computer program is executed by a processor, the processor is caused to execute each step in the method described in the first aspect.

[0038] The present application provides a main transformer winding fault diagnosis method based on resistance and capacitance changes. By measuring the transformer winding injection signal and output signal under different injection resistance and capacitance, the resistance and capacitance difference amplitude is obtained, and the resistance and capacitance difference amplitude includes the amplitude of the mth data point of the lth group frequency response curve when only the resistance is considered, the amplitude of the mth data point of the kth group frequency response curve when only the capacitance is considered, and the amplitude of the mth data point of the pqth group frequency response curve when the resistance and capacitance are comprehensively considered, wherein l, k, p, q are positive integers; the weights of different frequency response curves are obtained, including the weight when only the resistance is considered, the weight when only the capacitance is considered, and the weight when the resistance and capacitance are comprehensively considered; according to the resistance and capacitance difference amplitude and the weights of the different frequency response curves, the transformer winding diagnosis characteristic index is obtained; according to the transformer winding diagnosis characteristic index, the transformer winding fault judgment factor is calculated, and the transformer winding fault judgment is performed according to the transformer winding fault judgment factor; the method considers the main transformer winding fault diagnosis based on resistance and capacitance changes, and while improving the fault diagnosis sensitivity, it simplifies the judgment process so that non-professionals can easily master it. In addition, it can accurately identify the status of the winding and determine whether there is a fault, thereby providing effective support for the safe and stable operation of the transformer and power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] in:

[0041] Figure 1 A schematic flow chart of a main transformer winding fault diagnosis method based on resistance-capacitance change provided in an embodiment of the present application;

[0042] Figure 2 A flow chart of another method for diagnosing a main transformer winding fault based on resistance-capacitance changes provided in an embodiment of the present application;

[0043] Figure 3 A schematic diagram of the structure of a main transformer winding fault diagnosis device based on resistance-capacitance change provided in an embodiment of the present application;

[0044] Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0046] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0047] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0048] The resistance and capacitance changes involved in the embodiments of the present application mainly refer to the changes in the resistance and capacitance of the transformer, which can be controlled based on variable resistors and variable capacitors in experiments.

[0049] The method in the embodiment of the present application mainly involves obtaining the frequency response curve of the transformer winding when the outside of the transformer is connected to different resistance and capacitance loads, and then calculating the composite resistance and capacitance frequency response curve by assigning response weights to the frequency response curve when only resistance, only capacitance, and resistance and capacitance are considered comprehensively, and further calculating the response signal linear correlation strength index of the frequency response curve when only resistance, only capacitance, and resistance and capacitance are considered comprehensively, and finally determining whether the transformer winding is faulty by calculating the transformer winding fault judgment factor.

[0050] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0051] See also Figure 1 , is a flow chart of a main transformer winding fault diagnosis method based on resistance-capacitance change provided in an embodiment of the present application, such as Figure 1 As shown, the method includes:

[0052] 101. Measure the transformer winding injection signal and output signal under different injection resistance and capacitance to obtain the resistance-capacitance distinction amplitude, the resistance-capacitance distinction amplitude includes the amplitude of the mth data point of the lth group of frequency response curves when only resistance is considered, the amplitude of the mth data point of the kth group of frequency response curves when only capacitance is considered, and the amplitude of the mth data point of the pqth group of frequency response curves when resistance and capacitance are comprehensively considered, wherein l, k, p, q are positive integers.

[0053] The executor of the method in the embodiment of the present application can be a main transformer winding fault diagnosis device based on resistance and capacitance changes, which can be implemented using terminal equipment, such as a computer, in practical applications, and mainly involves signal control and data analysis and calculation processes.

[0054] Specifically, the transformer winding injection signal and output signal under different injection resistance and capacitance can be measured. During measurement, an oscilloscope or spectrum analyzer can be used at the output end of the transformer to measure the amplitude, frequency, phase and other parameters of the output signal. For each injection resistance and capacitance value, the corresponding injection signal and output signal characteristics can be recorded.

[0055] In an optional implementation, the above step 101 includes:

[0056] The variable capacitor and the variable resistor are controlled to be in a short-circuit state, and then a computer is used to generate excitation signals of different frequencies through a signal generator. The excitation signals are injected into the transformer windings, flow through the low-voltage winding, the medium-voltage winding, and the high-voltage winding, and then flow out of the transformer. The output response is measured, and the input and output measurements are stopped. The change value of the variable capacitor is controlled to be C va =[c1 c2 … c n ], the change value of the variable resistor is R va =[r1 r2 … r n ], c n and r n Respectively represent the capacitance and resistance values ​​injected by the nth measurement, where c n >c n-1 …>c1,r n >r n-1 …>r1;

[0057] Repeat the above measurement steps to obtain n×n groups of frequency response curves, including the frequency response curves considering only resistance, only capacitance, and comprehensive consideration of resistance and capacitance, respectively. l =[a rl1 a rl2 … a rlm ]、F k =[a ck1 a ck2 … a ckm ]、F pq=[a pq1 a pq2 … a pqm ], where a rlm represents the amplitude of the mth data point of the frequency response curve of the first group when only the resistance is considered, a ckm represents the amplitude of the mth data point of the kth group frequency response curve when only the capacitance is considered, a pqm It represents the amplitude of the mth data point of the frequency response curve of the pqth group when the resistance and capacitance are comprehensively considered. Wherein, l, k, p, q ranges from [1, 2, 3, ..., n].

[0058] 102. Obtain weights of different frequency response curves, including the weight when only resistance is considered, the weight when only capacitance is considered, and the weight when resistance and capacitance are considered comprehensively.

[0059] Specifically, the embodiments of the present application are mainly divided into three situations: only considering resistance, only considering capacitance, and considering resistance and capacitance comprehensively. Three types of weights are calculated here accordingly.

[0060] In an optional implementation, the obtaining of weights of different frequency response curves includes:

[0061] Calculate the resistance and capacitance distinction weights according to the following formula:

[0062]

[0063] Among them, w rl 、w ck 、w pq They respectively represent the weight when only resistance is considered, the weight when only capacitance is considered, and the weight when resistance and capacitance are considered comprehensively, and α and β represent adjustment parameters.

[0064] w rl This formula calculates the relative position of a single resistor value among all resistor values. First, it normalizes each resistor value to the range [0,1], and then gets the weight by dividing it by the sum of the normalized results of all resistor values. In this way, the sum of the weights of all resistor values ​​is 1.

[0065] w ck This formula is similar to the calculation for resistor weights, but applied to capacitor values. It also normalizes each capacitor value and calculates its weight among all capacitor values.

[0066] w pq This formula takes into account the effects of resistance and capacitance.

[0067] 103. Obtain transformer winding diagnostic characteristic indicators according to the above resistance-capacitance distinction amplitude and the above different frequency response curve weights.

[0068] Specifically, based on the data obtained in the above steps, the transformer winding diagnostic characteristic index can be calculated. Accordingly, the calculated index is divided into three cases: only considering resistance, only considering capacitance, and considering resistance and capacitance comprehensively. It mainly includes two steps:

[0069] (1) Calculate the composite resistance-capacitance frequency characteristic curve;

[0070] (2) Calculate the linear correlation strength index of the response signal.

[0071] In an optional implementation, the step of obtaining a transformer winding diagnostic characteristic index according to the resistance-capacitance distinction amplitude and the weights of the different frequency response curves includes:

[0072] The above composite RC frequency characteristic curve is calculated according to the following formula:

[0073]

[0074] Among them, A only_rm , A only_cm , A rcm They represent the amplitude of the mth data point of the frequency response curve when only resistance, only capacitance, and resistance and capacitance are considered respectively;

[0075] According to the composite resistance-capacitance frequency characteristic curve, the linear correlation strength index of the response signal is calculated.

[0076] Further optionally, the calculation of the linear correlation strength index of the response signal according to the composite resistance-capacitance frequency characteristic curve includes:

[0077] The linear correlation strength index of the above response signal is calculated using the following formula:

[0078]

[0079]

[0080] The above response signal linear correlation strength index can be used to analyze the linear relationship between two signals. Specifically, the variables and operations involved in the formula are as follows:

[0081] A only_rm Indicates the signal when only the resistance is considered, ARO i is the corresponding response signal. The numerator in the XR formula calculates the covariance, the denominator is the product of the standard deviations of the two sequences, and the entire expression calculates the correlation coefficient between the resistance signal and the response signal.

[0082] XC This formula is similar to the calculation of the resistance correlation strength, but it is applied to the capacitance signal A only_cmand the corresponding response signal ACO i 。

[0083] The signal A calculated by the formula XZ is when comprehensively considering the resistance and capacitance (impedance). rcm and the response signal AO i The correlation strength between them.

[0084] 104. Calculate the transformer winding fault judgment factor according to the above-mentioned transformer winding diagnosis characteristic indexes, and judge the transformer winding fault according to the above-mentioned transformer winding fault judgment factor.

[0085] After obtaining the response signal linear correlation strength indexes in the above three aspects, the transformer winding fault judgment factor can be further calculated for the transformer winding fault judgment. The calculation formula of the transformer winding fault judgment factor can be set according to needs.

[0086] In an alternative embodiment, calculating the transformer winding fault judgment factor according to the above-mentioned transformer winding diagnosis characteristic indexes includes:

[0087] Calculate the above-mentioned transformer winding fault judgment factor according to the following formula:

[0088] σ = 1.5sin(0.2XR) + 2ln(|XC| + 1) + 0.3e XZ + 0.05(XR 2 + XC 2 + XZ 2 ).

[0089] Further optionally, judging the transformer winding fault according to the above-mentioned transformer winding fault judgment factor includes:

[0090] If σ ≥ G, it is judged that the transformer winding has a fault;

[0091] If σ < G, it is judged that the transformer winding has no fault, where G is a constant related to the transformer model, winding signal injection method, and external equipment, and can be set according to needs.

[0092] To more clearly show the method in the embodiments of the present application, reference can be made to Figure 2 , Figure 2 which is the flow chart of another main transformer winding fault diagnosis method based on the change of resistance and capacitance provided by the embodiments of the present application. As Figure 2 shown, the method mainly includes:

[0093] Obtain the transformer winding frequency response curve under different resistance-capacitance loads externally connected to the transformer;

[0094] Calculate the response weight of the frequency response curve when only the resistance is considered, the response weight of the frequency response curve when only the capacitance is considered, and the response weight of the frequency response curve when the resistance and capacitance are considered comprehensively;

[0095] Calculate the optimized frequency response curve when only resistance is considered, the optimized frequency response curve when only capacitance is considered, and the optimized frequency response curve when resistance and capacitance are considered comprehensively;

[0096] Calculate the linear correlation strength index of the response signal when only the resistance is considered, the linear correlation strength index of the response signal when only the capacitance is considered, and the linear correlation strength index of the response signal when the resistance and capacitance are comprehensively considered;

[0097] Calculate the transformer winding fault judgment factor based on the above indicators;

[0098] Whether a transformer winding fault occurs is determined based on the transformer winding fault judgment factor.

[0099] It can be seen that in the embodiment of the present application, first, the frequency response curve of the transformer winding connected to different resistance and capacitance loads on the outside of the transformer can be obtained through computer control; then, by assigning response weights to the frequency response curves when only resistance, only capacitance, and resistance and capacitance are considered comprehensively, the composite resistance and capacitance frequency response curve is calculated; further, the linear correlation strength index of the response signal of the frequency response curves when only resistance, only capacitance, and resistance and capacitance are considered comprehensively is calculated; finally, by calculating the transformer winding fault judgment factor, it is determined whether the winding has a fault.

[0100] The method in the embodiment of the present application particularly considers the fault diagnosis of the main transformer winding based on the change of resistance and capacitance. This method improves the sensitivity of fault diagnosis and simplifies the judgment process, making it easy for non-professionals to master it. In addition, it can accurately identify the state of the winding and determine whether there is a fault, thereby providing effective support for the safe and stable operation of the transformer and the power system.

[0101] Based on the description of the aforementioned method embodiment, an embodiment of the present application also provides a main transformer winding fault diagnosis device based on resistance and capacitance changes.

[0102] Figure 3 The structure diagram of a main transformer winding fault diagnosis device based on resistance and capacitance changes provided by an embodiment of the present application is shown in FIG. Figure 3 As shown, the main transformer winding fault diagnosis device 300 based on resistance and capacitance changes includes:

[0103] The measuring module 310 is used to measure the transformer winding injection signal and the output signal under different injection resistance and capacitance to obtain the resistance and capacitance distinction amplitude, wherein the resistance and capacitance distinction amplitude includes the amplitude of the mth data point of the lth group frequency response curve when only the resistance is considered, the amplitude of the mth data point of the kth group frequency response curve when only the capacitance is considered, and the amplitude of the mth data point of the pqth group frequency response curve when the resistance and capacitance are comprehensively considered, wherein l, k, p, q are positive integers;

[0104] A weight calculation module 320 is used to obtain weights of different frequency response curves, including a weight when only resistance is considered, a weight when only capacitance is considered, and a weight when resistance and capacitance are considered comprehensively;

[0105] An index calculation module 330 is used to obtain a transformer winding diagnostic characteristic index according to the above-mentioned resistance-capacitance distinction amplitude and the above-mentioned different frequency response curve weights;

[0106] The judgment module 340 is used to calculate the transformer winding fault judgment factor according to the above transformer winding diagnosis characteristic index, and perform transformer winding fault judgment according to the above transformer winding fault judgment factor.

[0107] Understandably, this involves Figure 3 The relevant contents of each module in the above method embodiment have been described in detail, and the details can be referred to the contents in the method embodiment; that is, Figure 3 The main transformer winding fault diagnosis device 300 based on resistance and capacitance change can be performed as follows: Figure 1 or Figure 2 Any steps in the illustrated embodiment will not be described in detail here.

[0108] In one embodiment of the present application, an electronic device is also provided. Figure 4 , Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 4 As shown, the electronic device 400 includes a processor 401 and a memory 402, wherein the memory 402 stores a computer program. When the computer program is executed by the processor 401, the following operations are performed: Figure 1 or Figure 2 Any step in the method embodiment shown. The electronic device 400 may also include an input / output device, etc. In a specific implementation, the electronic device may be a terminal device, etc.

[0109] In one embodiment, a computer-readable storage medium is further provided. The computer-readable storage medium stores a computer program. When the computer program is executed by the processor 401, the processor 401 executes any step in the above method embodiment.

[0110] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0111] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A main transformer winding fault diagnosis method based on resistance and capacitance changes, characterized in that: The method includes: Measuring the injection signal and output signal of the transformer winding under different injection resistances and capacitances to obtain the resistance-capacitance discrimination amplitude, where the resistance-capacitance discrimination amplitude includes the amplitude of the m-th data point of the l-th group of frequency response curves when only considering the resistance, the amplitude of the m-th data point of the k-th group of frequency response curves when only considering the capacitance, and the amplitude of the m-th data point of the pq-th group of frequency response curves when comprehensively considering the resistance and capacitance. Here, l, k, p, and q are positive integers; Obtaining different frequency response curve weights, including the weight when only considering the resistance, the weight when only considering the capacitance, and the weight when comprehensively considering the resistance and capacitance; Obtaining the diagnostic characteristic index of the transformer winding according to the resistance-capacitance discrimination amplitude and the different frequency response curve weights; Calculating the transformer winding fault judgment factor according to the diagnostic characteristic index of the transformer winding, and performing the transformer winding fault judgment according to the transformer winding fault judgment factor.

2. The main transformer winding fault diagnosis method based on resistance and capacitance changes according to claim 1 is characterized in that: The measuring the injection signal and output signal of the transformer winding under different injection resistances and capacitances to obtain the resistance-capacitance discrimination amplitude includes: The variable capacitor and the variable resistor are controlled to be in a short-circuit state, and then a computer is used to generate excitation signals of different frequencies through a signal generator. The excitation signals are injected into the transformer windings, flow through the low-voltage winding, the medium-voltage winding, and the high-voltage winding, and then flow out of the transformer. The output response is measured, and the input and output measurements are stopped. The change value of the variable capacitor is controlled to be C va =[c1 c2…c n ], the change value of the variable resistor is R va =[r1 r2…r n ], c n and r n Respectively represent the capacitance and resistance values ​​injected by the nth measurement, where c n >c n-1 …>c1,r n >r n-1 …>r1; Repeat the above measurement steps to obtain n×n groups of frequency response curves, including the frequency response curves considering only resistance, only capacitance, and comprehensive consideration of resistance and capacitance, respectively. l =[a rl1 a rl2 …a rlm ]、F k =[a ck1 a ck2 …a ckm ]、F pq =[a pq1 a pq2 …a pqm ], where a rlm represents the amplitude of the mth data point of the frequency response curve of the first group when only the resistance is considered, a ckm represents the amplitude of the mth data point of the kth group frequency response curve when only the capacitance is considered, a pqm It represents the amplitude of the mth data point of the frequency response curve of the pqth group when the resistance and capacitance are comprehensively considered.

3. The main transformer winding fault diagnosis method based on resistance and capacitance changes according to claim 2 is characterized in that: The obtaining different frequency response curve weights includes: Calculating the resistance-capacitance discrimination weight according to the following formula: Among them, w rl 、w ck 、w pq They respectively represent the weight when only resistance is considered, the weight when only capacitance is considered, and the weight when resistance and capacitance are comprehensively considered, and α and β represent adjustment parameters.

4. The main transformer winding fault diagnosis method based on resistance and capacitance changes according to claim 3 is characterized in that: The obtaining the diagnostic characteristic index of the transformer winding according to the resistance-capacitance discrimination amplitude and the different frequency response curve weights includes: Calculating the composite resistance-capacitance frequency characteristic curve according to the following formula: Among them, A only_rm , A only_cm , A rcm They represent the amplitude of the mth data point of the frequency response curve when only resistance, only capacitance, and resistance and capacitance are considered respectively; Calculating the linear correlation intensity index of the response signal according to the composite resistance-capacitance frequency characteristic curve.

5. The main transformer winding fault diagnosis method based on resistance and capacitance changes according to claim 4 is characterized in that: The calculating the linear correlation intensity index of the response signal according to the composite resistance-capacitance frequency characteristic curve includes: Calculating the linear correlation intensity index of the response signal by using the following formula:

6. The main transformer winding fault diagnosis method based on resistance and capacitance changes according to claim 5 is characterized in that: The calculating the transformer winding fault judgment factor according to the diagnostic characteristic index of the transformer winding includes: Calculating the transformer winding fault judgment factor according to the following formula: σ=1.5sin(0.2XR)+2ln(|XC|+1)+0.3e XZ +0.05(XR 2 +XC 2 +XZ 2 )。 7. The main transformer winding fault diagnosis method based on resistance and capacitance changes according to claim 6 is characterized in that: The performing the transformer winding fault judgment according to the transformer winding fault judgment factor includes: If σ≥G, it is determined that there is a fault in the transformer winding; If σ<G, it is determined that there is no fault in the transformer winding, where G is a constant related to the transformer model, the winding signal injection method, and external equipment.

8. A main transformer winding fault diagnosis device based on resistance and capacitance changes, characterized in that: Includes: A measuring module for measuring the injection signal and output signal of the transformer winding under different injection resistances and capacitances to obtain the resistance-capacitance discrimination amplitude, where the resistance-capacitance discrimination amplitude includes the amplitude of the m-th data point of the l-th group of frequency response curves when only considering the resistance, the amplitude of the m-th data point of the k-th group of frequency response curves when only considering the capacitance, and the amplitude of the m-th data point of the pq-th group of frequency response curves when comprehensively considering the resistance and capacitance. Here, l, k, p, and q are positive integers; A weight calculation module for obtaining different frequency response curve weights, including the weight when only considering the resistance, the weight when only considering the capacitance, and the weight when comprehensively considering the resistance and capacitance; An index calculation module for obtaining the diagnostic characteristic index of the transformer winding according to the resistance-capacitance discrimination amplitude and the different frequency response curve weights; A judgment module for calculating the transformer winding fault judgment factor according to the diagnostic characteristic index of the transformer winding and performing the transformer winding fault judgment according to the transformer winding fault judgment factor.

9. An electronic device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the processor is caused to perform the steps of the method according to any one of claims 1 to 7.

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