Disclosure of Invention
The invention mainly aims to provide a main transformer winding fault diagnosis method based on resistance-capacitance change, which can accurately and effectively judge transformer winding faults, simplifies the judging process and enables non-professional staff to easily grasp the faults.
To achieve the above object, a first aspect of the present application provides a method for diagnosing faults of windings of a main transformer based on resistance-capacitance variation, the method comprising:
Measuring injection signals and output signals of transformer windings under different injection resistance-capacitance to obtain resistance-capacitance distinguishing amplitude values, wherein the resistance-capacitance distinguishing amplitude values comprise the amplitude values of the mth data point of a first group of frequency response curves when only resistance is considered, the amplitude values of the mth data point of a k group of frequency response curves when only capacitance is considered, and the amplitude values of the mth data point of a pq group of frequency response curves when resistance and capacitance are comprehensively considered, wherein l, k, p, q is a positive integer;
Acquiring weights of different frequency response curves, wherein the weights comprise weights only considering resistance, weights only considering capacitance and weights comprehensively considering resistance and capacitance;
Acquiring diagnosis characteristic indexes of the transformer winding according to the resistance-capacitance distinguishing amplitude and the different frequency response curve weights;
and calculating a transformer winding fault judgment factor according to the transformer winding diagnosis characteristic index, and judging and breaking the transformer winding fault according to the transformer winding fault judgment factor.
Optionally, the measuring the injection signal and the output signal of the transformer winding under different injection resistance-capacitance to obtain the resistance-capacitance distinguishing amplitude includes:
The variable capacitor and the variable resistor are controlled to be in a short circuit state, then excitation signals with different frequencies are generated by using a computer and a signal generator, the excitation signals are injected into a transformer winding, flow through a low-voltage winding, a medium-voltage winding and a high-voltage winding and then flow out of the transformer, output response is measured, input and output measurement are stopped, the variable value of the variable capacitor is controlled to be Cva＝[c1 c2 … cn, the variable value of the variable resistor is Rva＝[r1 r2 … rn],cn and Rn which respectively represent the capacitance value and the resistance value of n measurement injection, and Cn>cn-1…>c1,rn>rn-1…>r1;
Repeating the above measurement steps to obtain n×n sets of frequency response curves, where the frequency response curves including only considering resistance, only considering capacitance, and comprehensively considering resistance and capacitance are Fl＝[arl1 arl2 … arlm]、Fk＝[ack1 ack2 … ackm]、Fpq＝[apq1 apq2 … apqm], respectively, where arlm represents the amplitude of the mth data point of the first set of frequency response curves when only considering resistance, ackm represents the amplitude of the mth data point of the kth set of frequency response curves when only considering capacitance, and apqm represents the amplitude of the mth data point of the pq set of frequency response curves when comprehensively considering resistance and capacitance.
Optionally, the acquiring different frequency response curve weights includes:
the resistance-capacitance discrimination weight is calculated according to the following formula:
Wherein wrl、wck、wpq represents 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 alpha and beta represent adjustment parameters.
Optionally, the obtaining the diagnostic characteristic index of the transformer winding according to the resistance-capacitance distinguishing amplitude and the weights of the different frequency response curves includes:
The composite resistance-capacitance frequency characteristic curve is calculated according to the following formula:
Wherein, Aonly_rm、Aonly_cm、Arcm respectively represents the amplitude of the mth data point of the frequency response curve when only resistance, only capacitance and comprehensive resistance and capacitance are considered;
And calculating the response signal linear correlation strength index according to the composite resistance-capacitance frequency characteristic curve.
Optionally, the calculating the response signal linear correlation strength index according to the composite resistance-capacitance frequency characteristic curve includes:
the response signal linear correlation strength index is calculated using the following formula:
Optionally, the calculating the transformer winding fault judging factor according to the transformer winding diagnosis characteristic index includes:
the transformer winding fault judgment factor is calculated according to the following formula:
σ=1.5sin(0.2XR)+2ln(|XC|+1)+0.3eXZ+0.05(XR2+XC2+XZ2)。
optionally, the performing transformer winding fault judgment according to the transformer winding fault judgment factor includes:
if sigma is more than or equal to G, judging that the transformer winding has faults;
If sigma < G, judging that the transformer winding has no fault, wherein G is a constant related to the type of the transformer, the injection mode of a winding signal and external equipment.
A second aspect of the present application provides a fault diagnosis device for a winding of a main transformer based on a resistance-capacitance change, comprising:
the measuring module is used for measuring injection signals and output signals of the transformer windings under different injection resistance-capacitance to obtain resistance-capacitance distinguishing amplitude values, wherein the resistance-capacitance distinguishing amplitude values comprise the amplitude values of the mth data point of the first group of frequency response curves when only resistors are considered, the amplitude values of the mth data point of the k group of frequency response curves when only capacitors are considered, and the amplitude values of the mth data point of the pq group of frequency response curves when the resistors and the capacitors are comprehensively considered, wherein l, k, p, q is a positive integer;
The weight calculation module is used for obtaining 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;
the index calculation module is used for acquiring diagnosis characteristic indexes of the transformer winding according to the resistance-capacitance distinguishing amplitude and the different frequency response curve weights;
And the judging module is used for calculating a transformer winding fault judging factor according to the transformer winding diagnosis characteristic index and judging the transformer winding fault according to the transformer winding fault judging factor.
A third aspect of the application provides an electronic device comprising a memory and a processor, the memory storing a computer program which, when executed by the processor, causes the processor to perform the steps as in the first aspect and any one of its possible implementations.
A fourth aspect of the application provides a computer-readable storage medium storing a computer program which, when executed by a processor, causes the processor to perform the steps of the method according to the first aspect.
The application provides a main transformer winding fault diagnosis method based on resistance-capacitance change, which comprises the steps of obtaining resistance-capacitance distinguishing amplitude values by measuring transformer winding injection signals and output signals under different injection resistance-capacitance conditions, wherein the resistance-capacitance distinguishing amplitude values comprise the amplitude of an mth data point of a first group of frequency response curves when only resistors are considered, the amplitude of an mth data point of a k group of frequency response curves when only capacitors are considered, comprehensively considering the amplitude of an mth data point of a pq group of frequency response curves when resistance-capacitance is considered, obtaining different frequency response curve weights comprising the weight when only resistors are considered, the weight when only capacitors are considered and the weight when only resistors and the weight when the capacitors are considered, obtaining transformer winding diagnosis characteristic indexes according to the resistance-capacitance distinguishing amplitude values and the different frequency response curve weights, calculating transformer winding fault judgment factors according to the transformer winding fault judgment factors, and carrying out transformer winding fault diagnosis based on the transformer winding fault judgment factors. In addition, the state of the winding can be accurately identified, and whether faults exist or not can be judged, so that effective support is provided for safe and stable operation of the transformer and the power system.
Detailed Description
In order to make the present application better understood by those skilled in the art, the following description will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
The terms first, second and the like in the description and in the claims and in the above-described figures are used for distinguishing between different objects and not necessarily for describing a sequential or chronological order. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those listed steps or elements but may include other steps or elements not listed or inherent to such process, method, article, or apparatus.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.
The resistance-capacitance change related in the embodiment of the application mainly refers to the change of the resistance and the capacitance of the transformer, and can be controlled based on the variable resistance and the variable capacitance in an experiment.
The method in the embodiment of the application mainly comprises the steps of obtaining frequency response curves of transformer windings connected to different resistance-capacitance loads on the outer side of a transformer, then calculating a composite resistance-capacitance frequency response curve by giving response weights to the frequency response curves when only resistance is considered, only capacitance is considered and resistance-capacitance is comprehensively considered, further calculating response signal linear correlation strength indexes of the frequency response curves when only resistance is considered, only capacitance is considered and resistance-capacitance is comprehensively considered, and finally judging whether the transformer windings have faults or not by calculating a transformer winding fault judging factor.
Embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application.
Referring to fig. 1, a flow chart of a main transformer winding fault diagnosis method based on resistance-capacitance change according to an embodiment of the present application is shown in fig. 1, and the method includes:
101. And measuring injection signals and output signals of the transformer windings under different injection resistance-capacitance to obtain a resistance-capacitance distinguishing amplitude, wherein the resistance-capacitance distinguishing amplitude comprises the amplitude of the mth data point of the first group of frequency response curves when only resistance is considered, the amplitude of the mth data point of the k group of frequency response curves when only capacitance is considered, and the amplitude of the mth data point of the pq group of frequency response curves when resistance and capacitance are comprehensively considered, wherein l, k, p, q is a positive integer.
The implementation main body of the method in the embodiment of the application can be a main transformer winding fault diagnosis device based on resistance-capacitance change, and the method can be realized by using terminal equipment, such as a computer, in practical application, and mainly relates to signal control and data analysis and calculation processes.
Specifically, the injection signal and the output signal of the transformer winding under different injection resistance-capacitance can be measured. During measurement, parameters such as amplitude, frequency and phase of an output signal can be measured at the output end of the transformer by using an oscilloscope or a spectrum analyzer, and for each injection resistance-capacitance value, the characteristics of the corresponding injection signal and the output signal can be recorded.
In an alternative embodiment, the step 101 includes:
The variable capacitor and the variable resistor are controlled to be in a short circuit state, then excitation signals with different frequencies are generated by using a computer and a signal generator, the excitation signals are injected into a transformer winding, flow through a low-voltage winding, a medium-voltage winding and a high-voltage winding and then flow out of the transformer, output response is measured, input and output measurement are stopped, the variable value of the variable capacitor is controlled to be Cva＝[c1 c2 … cn, the variable value of the variable resistor is Rva＝[r1 r2 … rn],cn and Rn which respectively represent the capacitance value and the resistance value of n measurement injection, and Cn>cn-1…>c1,rn>rn-1…>r1;
Repeating the above measurement steps to obtain n×n sets of frequency response curves, where the frequency response curves including only considering resistance, only considering capacitance, and comprehensively considering resistance and capacitance are Fl＝[arl1 arl2 … arlm]、Fk＝[ack1 ack2 … ackm]、Fpq＝[apq1 apq2 … apqm], respectively, where arlm represents the amplitude of the mth data point of the first set of frequency response curves when only considering resistance, ackm represents the amplitude of the mth data point of the kth set of frequency response curves when only considering capacitance, and apqm represents the amplitude of the mth data point of the pq set of frequency response curves when comprehensively considering resistance and capacitance. Wherein l, k, p, q ranges from [1,2,3, ], n ].
102. Different frequency response curve weights are obtained, wherein the weights comprise weights only considering resistance, weights only considering capacitance and weights comprehensively considering resistance and capacitance.
Specifically, in the embodiment of the application, three conditions of only considering resistance, only considering capacitance and comprehensively considering resistance and capacitance are mainly divided, and three types of weights are correspondingly calculated.
In an alternative embodiment, the obtaining weights of different frequency response curves includes:
the resistance-capacitance discrimination weight is calculated according to the following formula:
wherein wrl、wck、wpq represents the weight when only resistance is considered, the weight when only capacitance is considered, and the weight when resistance and capacitance are considered, respectively, and α and β represent adjustment parameters.
The formula wrl calculates the relative position of the individual resistance values among all resistance values. First, it normalizes each resistance value to within the [0,1] range, and then obtains a weight by dividing by the sum of all the resistance value normalization results. Thus, the sum of the weights of all the resistance values is 1.
The formula wck is similar to the calculation of the resistance weights, but applies to the capacitance values, which also normalizes each capacitance value and calculates its weight among all capacitance values.
The formula wpq considers the effects of resistance and capacitance in combination.
103. And obtaining the diagnosis characteristic index of the transformer winding according to the resistance-capacitance distinguishing amplitude and the weights of the different frequency response curves.
Specifically, the diagnostic characteristic index of the transformer winding can be calculated based on the data obtained in the previous steps, and correspondingly, the calculated index is divided into three cases when only resistance is considered, only capacitance is considered and resistance and capacitance are comprehensively considered. Mainly comprises two steps:
(1) Calculating a composite resistance-capacitance frequency characteristic curve;
(2) And calculating the linear correlation strength index of the response signal.
In an alternative embodiment, the obtaining the diagnostic characteristic index of the transformer winding according to the magnitude of the rc region and the weights of the different frequency response curves includes:
Calculating the composite resistance-capacitance frequency characteristic curve according to the following formula:
Wherein, Aonly_rm、Aonly_cm、Arcm respectively represents the amplitude of the mth data point of the frequency response curve when only resistance, only capacitance and comprehensive resistance and capacitance are considered;
And calculating the linear correlation strength index of the response signal according to the composite resistance-capacitance frequency characteristic curve.
Further optionally, the calculating the response signal linear correlation strength indicator according to the composite rc frequency characteristic curve includes:
The following formula is adopted to calculate the linear correlation strength index of the response signal:
The response signal linear correlation strength index can be used for analyzing the linear relation between two signals. Specifically, the variables and operations involved in the formula are as follows:
aonly_rm denotes a signal when only resistance is considered, and AROi is a 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 whole expression calculates the correlation coefficient between the resistance signal and the response signal.
XC this formula is similar to the calculation of the resistance correlation strength, but applies to the capacitance signal aonly_cm and the corresponding response signal ACOi.
The XZ equation calculates the strength of the correlation between the signal arcm and the response signal AOi when the resistance and capacitance (impedance) are taken into account.
104. And calculating a transformer winding fault judgment factor according to the transformer winding diagnosis characteristic index, and judging the transformer winding fault according to the transformer winding fault judgment factor.
After the response signal linear correlation strength index of the above three aspects is obtained, a transformer winding fault determination factor may be further calculated for transformer winding fault determination. The calculation formula of the fault judgment factor of the transformer winding can be set according to the requirement.
In an alternative embodiment, the calculating the transformer winding fault determination factor according to the transformer winding diagnostic characteristic index includes:
Calculating the transformer winding fault judgment factor according to the following formula:
σ=1.5sin(0.2XR)+2ln(|XC|+1)+0.3eXZ+0.05(XR2+XC2+XZ2)。
Further optionally, the performing transformer winding fault determination according to the transformer winding fault determination factor includes:
if sigma is more than or equal to G, judging that the transformer winding has faults;
If sigma < G, judging that the transformer winding has no fault, wherein G is a constant related to the type of the transformer, the injection mode of a winding signal and external equipment, and can be set according to requirements.
In order to more clearly show the method in the embodiment of the present application, reference may be made to fig. 2, and fig. 2 is a schematic flow chart of another main transformer winding fault diagnosis method based on resistance-capacitance change provided in the embodiment of the present application. As shown in fig. 2, the method mainly includes:
Obtaining a frequency response curve of a transformer winding of the transformer under different external resistance-capacitance loads;
calculating the response weight of the frequency response curve when only the resistor is considered, the response weight of the frequency response curve when only the capacitor is considered, and the response weight of the frequency response curve when the resistor and the capacitor are comprehensively considered;
Calculating an optimized frequency response curve when only resistance is considered, an optimized frequency response curve when only capacitance is considered, and an optimized frequency response curve when resistance and capacitance are comprehensively considered;
Calculating a response signal linear correlation strength index when only resistance is considered, a response signal linear correlation strength index when only capacitance is considered, and a response signal linear correlation strength index when resistance and capacitance are comprehensively considered;
calculating a transformer winding fault judgment factor according to the indexes;
and judging whether the transformer winding has faults or not according to the transformer winding fault judging factors.
Therefore, in the embodiment of the application, the frequency response curve of the transformer winding connected to different resistance-capacitance loads at the outer side of the transformer can be obtained through computer control, then the frequency response curve is calculated by giving response weight to the frequency response curve when only resistance is considered, only capacitance is considered and resistance-capacitance is comprehensively considered, the response signal linear correlation strength index of the frequency response curve when only resistance is considered, only capacitance is considered and resistance-capacitance is comprehensively considered is further calculated, and finally whether the winding fails is judged by calculating the transformer winding failure judgment factor.
The method in the embodiment of the application particularly considers the fault diagnosis of the main transformer winding based on resistance-capacitance change, and simplifies the judging flow while improving the fault diagnosis sensitivity, so that non-professional staff can easily grasp the fault diagnosis. In addition, the state of the winding can be accurately identified, and whether faults exist or not can be judged, so that effective support is provided for safe and stable operation of the transformer and the power system.
Based on the description of the embodiment of the method, the embodiment of the application also provides a main transformer winding fault diagnosis device based on resistance-capacitance change.
Fig. 3 is a schematic structural diagram of a main transformer winding fault diagnosis device based on resistance-capacitance change according to an embodiment of the present application. As shown in fig. 3, the main transformer winding fault diagnosis apparatus 300 based on the resistance-capacitance change includes:
The measurement module 310 is configured to measure injection signals and output signals of the transformer windings under different injection resistance-capacitance conditions, and obtain a resistance-capacitance distinction amplitude, where the resistance-capacitance distinction amplitude includes an amplitude of an mth data point of a first group of frequency response curves when only resistance is considered, an amplitude of an mth data point of a k group of frequency response curves when only capacitance is considered, and an amplitude of an mth data point of a pq group of frequency response curves when resistance and capacitance are comprehensively considered, where l, k, p, q is a positive integer;
the weight calculation module 320 is configured to obtain weights of different frequency response curves, including weights when only resistors are considered, weights when only capacitors are considered, and weights when resistors and capacitors are comprehensively considered;
the index calculation module 330 is configured to obtain a diagnosis feature index of the transformer winding according to the resistance-capacitance difference amplitude and the different frequency response curve weights;
And the judging module 340 is configured to calculate a transformer winding fault judging factor according to the transformer winding diagnostic characteristic index, and perform transformer winding fault judgment according to the transformer winding fault judging factor.
It can be appreciated that the details of the foregoing method embodiments related to the respective modules in fig. 3 have been described in detail, and specific reference may be made to the details of the method embodiments, that is, the main transformer winding fault diagnosis device 300 based on the resistance-capacitance change provided in fig. 3 may perform any step in the embodiments shown in fig. 1 or fig. 2, which is not described herein.
In one embodiment of the application, an electronic device is also presented. Referring to fig. 4, fig. 4 is a schematic structural diagram of an electronic device according to an embodiment of the present application. As shown in fig. 4, the electronic device 400 comprises a processor 401 and a memory 402, said memory 402 storing a computer program which, when executed by said processor 401, will perform any of the steps of the method embodiments as shown in fig. 1 or fig. 2. The electronic device 400 may also include input/output devices and the like. In a specific embodiment, the electronic device may be a terminal device or the like.
In an embodiment, a computer readable storage medium is also proposed, which stores a computer program, which, when executed by the processor 401, causes the processor 401 to perform any of the steps of the method embodiments described above.
Those skilled in the art will appreciate that all or part of the processes in the methods of the above embodiments may be implemented by a computer program for instructing relevant hardware, where the program may be stored in a non-volatile computer readable storage medium, and where the program, when executed, may include processes in the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in embodiments provided herein may include non-volatile and/or volatile memory. The nonvolatile memory can include Read Only Memory (ROM), programmable ROM (PROM), electrically Programmable ROM (EPROM), electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of 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), among others.
The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The foregoing examples illustrate only a few embodiments of the application and are described in detail herein without thereby limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.