CN113466749A - Method, device, equipment and storage medium for evaluating aging state of main insulation of transformer - Google Patents
Method, device, equipment and storage medium for evaluating aging state of main insulation of transformer Download PDFInfo
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- CN113466749A CN113466749A CN202110794382.XA CN202110794382A CN113466749A CN 113466749 A CN113466749 A CN 113466749A CN 202110794382 A CN202110794382 A CN 202110794382A CN 113466749 A CN113466749 A CN 113466749A
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- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/62—Testing of transformers
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/26—Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants ; Measuring impedance or related variables
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Abstract
The application relates to a transformer main insulation aging state assessment method, a device, equipment and a storage medium. The method for evaluating the aging state of the main insulation of the transformer comprises the following steps: acquiring a differential time domain dielectric spectrum curve and a frequency domain dielectric spectrum curve of main insulation of a transformer and the current oil temperature of insulating oil, wherein the main insulation comprises solid insulation and the insulating oil; correcting the differential time domain dielectric spectrum curve and the frequency domain dielectric spectrum curve according to the current oil temperature; determining a first polymerization degree of the solid insulation according to the corrected differential time domain dielectric spectrum curve and the current oil temperature, and determining a second polymerization degree of the solid insulation according to the corrected frequency domain dielectric spectrum curve and the current oil temperature; and evaluating the aging state of the main insulation of the transformer according to the first polymerization degree and the second polymerization degree. The method for evaluating the aging state of the main insulation of the transformer can improve the precision of evaluating the aging state of the main insulation of the transformer.
Description
Technical Field
The application relates to the technical field of electrical equipment safety state evaluation, in particular to a transformer main insulation aging state evaluation method, device, equipment and storage medium.
Background
During the operation of power equipment, the oil paper insulation can be gradually degraded under the combined action of factors such as electricity, heat, machinery and environment, and the mechanical strength or the insulation performance of the main insulation of the transformer is reduced.
At present, methods for detecting the primary insulation of the transformer mainly include an aging state evaluation method based on the PDC technology, and most of the methods determine the aging state of the primary insulation by comparing a target curve with PDC curves in other known states.
However, the isolated PDC curve reflects the aging degree of the primary insulation of the transformer in a single method, which results in inaccurate estimation of the aging state of the primary insulation of the transformer.
Disclosure of Invention
In view of the above, it is necessary to provide a method, an apparatus, a device, and a storage medium for evaluating the aging state of a primary insulation of a transformer, which can improve the accuracy of evaluating the aging state of the primary insulation of the transformer.
A transformer main insulation aging state assessment method comprises the following steps:
acquiring a differential time domain dielectric spectrum curve and a frequency domain dielectric spectrum curve of main insulation of a transformer and the current oil temperature of insulating oil, wherein the main insulation comprises solid insulation and the insulating oil;
correcting the differential time domain dielectric spectrum curve and the frequency domain dielectric spectrum curve according to the current oil temperature;
determining a first polymerization degree of the solid insulation according to the corrected differential time domain dielectric spectrum curve and the current oil temperature, and determining a second polymerization degree of the solid insulation according to the corrected frequency domain dielectric spectrum curve and the current oil temperature;
and evaluating the aging state of the main insulation of the transformer according to the first polymerization degree and the second polymerization degree.
In one embodiment, the step of correcting the differential time-domain dielectric spectrum curve according to the current oil temperature includes:
determining a preset time domain temperature corresponding to the current oil temperature;
calling a differential time domain dielectric spectrum database, and acquiring a standard differential time domain dielectric spectrum curve corresponding to the preset time domain temperature through the differential time domain dielectric spectrum database;
correcting the differential time-domain dielectric spectrum curve according to the standard differential time-domain dielectric spectrum curve, and/or;
the step of correcting the frequency domain dielectric spectrum curve according to the current oil temperature comprises the following steps:
determining a preset frequency domain temperature corresponding to the current oil temperature;
calling a frequency domain dielectric spectrum database, and acquiring a standard frequency domain dielectric spectrum curve corresponding to the preset frequency domain temperature through the frequency domain dielectric spectrum database;
and correcting the frequency domain dielectric spectrum curve according to the standard frequency domain dielectric spectrum curve.
In one embodiment, the primary insulation further comprises an oil paper insulation, and the determining a first degree of polymerization of the solid insulation from the corrected differential time-domain dielectric spectroscopy curve and the current oil temperature comprises:
calling a differential time domain dielectric spectrum database;
determining the polarization response time of the oiled paper insulation through the corrected differential time domain dielectric spectrum curve and the differential time domain dielectric spectrum database;
and determining a first polymerization degree of the solid insulation according to the polarization response time of the oilpaper insulation and the current oil temperature.
In one embodiment, the determining the polarization response time of the oilpaper insulation by the rectified differential time-domain dielectric spectrum curve and the differential time-domain dielectric spectrum database includes:
determining a spectrum peak of the corrected differential time-domain dielectric spectrum curve;
determining polarization components and linear parameters of the differential time-domain dielectric spectrum curve according to the differential time-domain dielectric spectrum database;
and determining the polarization response time of the oilpaper insulation according to a preset differential spectrum resolving formula.
In one embodiment, the determining the second degree of polymerization of the solid insulation according to the corrected frequency domain dielectric spectrum curve and the current oil temperature includes:
determining a polarization current curve of the main insulation of the transformer according to the corrected frequency domain dielectric spectrum curve;
and comparing the polarization current curve with any curve corresponding to the current oil temperature and prestored in a polarization current curve database to determine the second polymerization degree of the solid insulation.
In one embodiment, the evaluating the aging state of the primary insulation of the transformer according to the first polymerization degree and the second polymerization degree comprises:
determining a test frequency corresponding to the main insulation of the transformer;
determining a first weight corresponding to the first polymerization degree and a second weight corresponding to the second polymerization degree according to the test frequency;
determining a third degree of polymerization from the first degree of polymerization, the second degree of polymerization, the first weight, and the second weight;
and evaluating the aging state of the main insulation of the transformer according to the third polymerization degree.
In one embodiment, the method further comprises:
when the testing frequency of the transformer main insulation is determined to be lower than a first frequency threshold value, determining the aging state of the transformer main insulation through the first polymerization degree;
and when the testing frequency of the main insulation of the transformer is determined to be higher than a second frequency threshold value, determining the aging state of the main insulation of the transformer through the second polymerization degree.
A transformer main insulation aging state evaluation device comprises:
the system comprises an acquisition module, a control module and a control module, wherein the acquisition module is used for acquiring a differential time domain dielectric spectrum curve and a frequency domain dielectric spectrum curve of main insulation of a transformer and the current oil temperature of insulating oil, and the main insulation comprises solid insulation and the insulating oil;
the correction module is used for correcting the differential time domain dielectric spectrum curve and the frequency domain dielectric spectrum curve according to the current oil temperature;
the determining module is used for determining a first polymerization degree of the solid insulation according to the corrected differential time domain dielectric spectrum curve and the current oil temperature, and determining a second polymerization degree of the solid insulation according to the corrected frequency domain dielectric spectrum curve and the current oil temperature;
and the evaluation module is used for evaluating the aging state of the main insulation of the transformer according to the first polymerization degree and the second polymerization degree.
A computer device comprising a memory storing a computer program and a processor implementing the steps of the method described above when executing the computer program.
A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the above-mentioned method.
The method, the device, the equipment and the storage medium for evaluating the aging state of the main insulation of the transformer are characterized in that the method for evaluating the aging state of the main insulation of the transformer comprises the following steps: acquiring a differential time domain dielectric spectrum curve and a frequency domain dielectric spectrum curve of main insulation of a transformer and the current oil temperature of insulating oil, wherein the main insulation comprises solid insulation and the insulating oil; correcting the differential time domain dielectric spectrum curve and the frequency domain dielectric spectrum curve according to the current oil temperature; determining a first polymerization degree of the solid insulation according to the corrected differential time domain dielectric spectrum curve and the current oil temperature, and determining a second polymerization degree of the solid insulation according to the corrected frequency domain dielectric spectrum curve and the current oil temperature; and evaluating the aging state of the main insulation of the transformer according to the first polymerization degree and the second polymerization degree, wherein the aging state of the main insulation of the transformer is evaluated through the first polymerization degree and the second polymerization degree, namely the aging state of the main insulation of the transformer is evaluated through a time domain and a frequency domain, so that the evaluation precision of the aging state of the main insulation of the transformer is improved. In addition, the differential time domain dielectric spectrum curve and the frequency domain dielectric spectrum curve are corrected through the current oil temperature, so that the interference of the temperature on the differential time domain dielectric spectrum curve and the frequency domain dielectric spectrum curve is reduced, and the evaluation precision is further improved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic flowchart of a method for evaluating a primary insulation aging state of a transformer according to an embodiment;
fig. 2 is a schematic structural diagram of an apparatus for evaluating a primary insulation aging state of a transformer according to an embodiment.
Detailed Description
To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Embodiments of the present application are set forth in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
It will be understood that, as used herein, the terms "first," "second," and the like may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another.
It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or be connected to the other element through intervening elements. Further, "connection" in the following embodiments is understood to mean "electrical connection", "communication connection", or the like, if there is a transfer of electrical signals or data between the connected objects.
As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises/comprising," "includes" or "including," etc., specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Also, as used in this specification, the term "and/or" includes any and all combinations of the associated listed items.
With the increase of the operation life and the influence of factors such as electricity, heat and the like, the insulation condition of the main insulation of the transformer is continuously deteriorated, wherein the insulation paper generates moisture after aging, the moisture is combined with polar molecules and migrates and diffuses under the action of an electric field, and the whole insulation aging is gradually caused; in addition, the equipment is not tightly sealed, so that external substances enter the internal insulation, and the aging of the main insulation of the transformer is also one of important reasons; in addition, equipment failure further contributes to the increased rate of aging of the primary insulation of the transformer. Therefore, the application discloses a method, a device, equipment and a storage medium for evaluating the aging state of the main insulation of the transformer, and the aging degree of the main insulation of the transformer can be accurately evaluated.
In addition, the execution main body of the method for evaluating the aging state of the main insulation of the transformer, which is provided by the embodiment of the application, is a computer device.
The technical solutions proposed in the embodiments of the present application are described in detail below with reference to the accompanying drawings.
Referring to fig. 1, fig. 1 is a schematic flowchart of a method for evaluating a primary insulation aging state of a transformer according to an embodiment. In one embodiment, as shown in fig. 1, a method for evaluating the aging state of a primary insulation of a transformer is provided, which includes steps 110 to 140.
And 110, acquiring a differential time domain dielectric spectrum curve and a frequency domain dielectric spectrum curve of main insulation of the transformer and the current oil temperature of insulating oil, wherein the main insulation comprises solid insulation and the insulating oil.
In this step, data corresponding to the differential time domain dielectric spectrum curve of the main insulation of the transformer can be obtained through a differential time domain node testing instrument, so that the differential time domain dielectric spectrum curve is obtained. In addition, data corresponding to the frequency domain dielectric spectrum curve can be obtained through a frequency domain dielectric test instrument, so that the frequency domain dielectric spectrum curve is obtained. In addition, the oil temperature of the insulating oil may be acquired by a temperature instrument. Wherein the differential time-domain dielectric test instrument may be any feasible device for measuring differential time-domain dielectric spectroscopy data, such as, for example, a DIRANA dielectric response analyzer developed by Omicron corporation; the frequency domain dielectric test instrument may be any feasible device for measuring frequency domain dielectric spectroscopy data, such as, for example, the SFRA45 swept response analyzer developed by Congat; the temperature instrument may be any feasible device for measuring the temperature of the insulating oil and is not limited herein.
In an embodiment, optionally, a differential time-domain dielectric spectrum curve of the primary insulation of the transformer is obtained by a differential time-domain node testing instrument or a frequency-domain dielectric testing instrument, wherein an abscissa of the differential time-domain dielectric spectrum curve is time, and an ordinate of the differential time-domain dielectric spectrum curve is a first polarization current value; and acquiring a frequency domain dielectric spectrum curve by a frequency domain dielectric test instrument, wherein the abscissa of the frequency domain dielectric spectrum curve is time, and the ordinate is a first differential time domain dielectric spectrum.
And 120, correcting the differential time domain dielectric spectrum curve and the frequency domain dielectric spectrum curve according to the current oil temperature.
In this step, the differential time-domain dielectric spectrum curve can be corrected through the differential time-domain dielectric spectrum database and the current oil temperature. In addition, the frequency domain dielectric spectrum curve may be corrected by the frequency domain dielectric spectrum database and the current oil temperature.
It should be noted that the differential time domain dielectric spectrum database includes a corresponding relationship between a temperature interval and a preset time domain temperature, so as to determine the preset time domain temperature corresponding to the oil temperature of the insulating oil according to the temperature interval in which the oil temperature of the insulating oil is located, for example, when the oil temperature of the insulating oil is in a [11 ℃ to 60 ℃ range, and the preset time domain temperature corresponding to the [11 ℃ to 60 ℃ range is 30 ℃, then the preset time domain temperature corresponding to the oil temperature of the insulating oil is also 30 ℃. In addition, the frequency domain dielectric spectrum database includes a corresponding relationship between the temperature intervals and the preset frequency domain temperatures, so as to determine the preset frequency domain temperatures corresponding to the oil temperature of the insulating oil according to the temperature intervals in which the oil temperature of the insulating oil is located, for example, when the oil temperature of the insulating oil is in a [11 ℃ to 65 ℃) interval, and the [11 ℃ to 65 ℃) interval corresponds to the preset frequency domain temperatures of 35 ℃, then the preset frequency domain temperatures corresponding to the oil temperature of the insulating oil are also 35 ℃.
And step 130, determining a first polymerization degree of the solid insulation according to the corrected differential time domain dielectric spectrum curve and the current oil temperature, and determining a second polymerization degree of the solid insulation according to the corrected frequency domain dielectric spectrum curve and the current oil temperature.
In this step, the first polymerization degree and the second polymerization degree are used to determine the aging state of the primary insulation of the transformer. Determining a first degree of polymerization of the solid insulation from the corrected differential time-domain dielectric spectral curve and the current oil temperature, and determining a second degree of polymerization of the solid insulation from the corrected frequency-domain dielectric spectral curve and the current oil temperature. Since the first degree of polymerization is obtained by the corrected differential time-domain dielectric spectrum curve, the obtained first degree of polymerization is more accurate. In addition, the second polymerization degree is obtained through the corrected frequency domain dielectric spectrum curve, so that the obtained second polymerization degree is more accurate.
And 140, evaluating the aging state of the main insulation of the transformer according to the first polymerization degree and the second polymerization degree.
In this step, the aging state of the primary insulation of the transformer is evaluated according to the first polymerization degree and the second polymerization degree together. The aging state may be a high or low degree of aging. The smaller the first polymerization degree and the second polymerization degree, the more severe the aging degree.
In the embodiment, since the aging state of the main insulation of the transformer is evaluated through the first polymerization degree and the second polymerization degree, that is, the aging state of the main insulation of the transformer is evaluated through a time domain and a frequency domain, the evaluation accuracy of the aging state of the main insulation of the transformer is improved. In addition, the differential time domain dielectric spectrum curve and the frequency domain dielectric spectrum curve are corrected through the current oil temperature, so that the interference of the temperature on the differential time domain dielectric spectrum curve and the frequency domain dielectric spectrum curve is reduced, and the evaluation precision is further improved.
The following is a description of how to correct the differential time-domain dielectric spectral curve and how to correct the frequency-domain dielectric spectral curve.
In one embodiment, the step of correcting the differential time-domain dielectric spectrum curve according to the current oil temperature includes:
determining a preset time domain temperature corresponding to the current oil temperature;
calling a differential time domain dielectric spectrum database, and acquiring a standard differential time domain dielectric spectrum curve corresponding to the preset time domain temperature through the differential time domain dielectric spectrum database;
and correcting the differential time-domain dielectric spectrum curve according to the standard differential time-domain dielectric spectrum curve.
Specifically, a preset time domain temperature corresponding to the oil temperature of the insulating oil is obtained from a differential time domain dielectric spectrum database. It should be noted that the differential time-domain dielectric spectrum database further includes a corresponding relationship between a preset time-domain temperature and a standard differential time-domain dielectric spectrum curve, and after the preset time-domain temperature corresponding to the differential time-domain dielectric spectrum curve is obtained, the standard differential time-domain dielectric spectrum curve of the transformer main insulation at the preset time-domain temperature is obtained in the differential time-domain dielectric spectrum database. Then, several first reference points are selected from the standard differential time-domain dielectric spectrum curve, wherein the number of the first reference points may be any feasible data, such as 30, 55, or 107, etc., and the specific number of the first reference points may be determined by a person skilled in the art through many experiments. In addition, the first reference points comprise time and second polarization current values, and the first polarization current values at the same time in the differential time-domain dielectric spectrum curve are modified into the second polarization current values according to the time of the first reference points, so that the correction of the differential time-domain dielectric spectrum curve is completed.
In one embodiment, the step of rectifying the frequency domain dielectric spectrum curve according to the current oil temperature comprises:
determining a preset frequency domain temperature corresponding to the current oil temperature;
calling a frequency domain dielectric spectrum database, and acquiring a standard frequency domain dielectric spectrum curve corresponding to the preset frequency domain temperature through the frequency domain dielectric spectrum database;
and correcting the frequency domain dielectric spectrum curve according to the standard frequency domain dielectric spectrum curve.
Specifically, a preset frequency domain temperature corresponding to the oil temperature of the insulating oil is obtained from a frequency domain dielectric spectrum database. It should be noted that the frequency domain dielectric spectrum database further includes a corresponding relationship between a preset frequency domain temperature and a standard frequency domain dielectric spectrum curve, and after the preset frequency domain temperature corresponding to the frequency domain dielectric spectrum number curve is obtained, the standard frequency domain dielectric spectrum curve of the transformer main insulation at the preset time domain temperature is obtained in the frequency domain dielectric spectrum database. Then, several second reference points are selected from the standard frequency domain dielectric spectrum curve, wherein the number of the second reference points may be any feasible data, such as 31, 50, or 109, etc., and the specific number of the second reference points may be determined by a person skilled in the art through many experiments. In addition, the second reference point comprises time and a second differential time-domain dielectric spectrum, and the first differential time-domain dielectric spectrum with the same time in the differential time-domain dielectric spectrum curve is modified into the second differential time-domain dielectric spectrum according to the time of a plurality of reference points, so that the correction of the frequency-domain dielectric spectrum curve is completed.
And finishing the correction of the differential time domain dielectric spectrum curve and the frequency domain dielectric spectrum curve.
The following is a specific description of how the first polymerization degree and the second polymerization degree are obtained.
In one embodiment, the primary insulation further comprises an oil paper insulation, said determining a first degree of polymerization of said solid insulation from the rectified differential time-domain dielectric spectrum curve and said current oil temperature comprises:
calling a differential time domain dielectric spectrum database;
determining the polarization response time of the oiled paper insulation through the corrected differential time domain dielectric spectrum curve and the differential time domain dielectric spectrum database;
and determining a first polymerization degree of the solid insulation according to the polarization response time of the oilpaper insulation and the current oil temperature.
In the embodiment, the polarization response time of the oilpaper insulation is determined through the differential time domain dielectric spectrum database and the corrected differential time domain dielectric spectrum curve. After the polarization response time of the oil-paper insulation is determined, the differential time domain dielectric spectrum database further comprises the corresponding relation among the oil temperature of the insulating oil, the polarization response time of the oil-paper insulation and the first polymerization degree of the solid insulation, and then the first polymerization degree of the solid insulation is determined. It should be noted that the correspondence relationship between the oil temperature of the insulating oil, the polarization response time of the oilpaper insulation, and the first polymerization degree of the solid insulation can be obtained through many experiments by those skilled in the art.
In one embodiment, the step of determining the polarization response time of the oilpaper insulation from the rectified differential time-domain dielectric spectrum curve and the database of differential time-domain dielectric spectra comprises:
determining a spectrum peak of the corrected differential time-domain dielectric spectrum curve;
determining polarization components and linear parameters of the differential time-domain dielectric spectrum curve according to the differential time-domain dielectric spectrum database;
and determining the polarization response time of the oilpaper insulation according to a preset differential spectrum resolving formula.
In this embodiment, the differential time-domain dielectric spectrum database includes polarization components corresponding to each standard differential time-domain dielectric spectrum curve and linear parameters corresponding to each standard differential time-domain dielectric spectrum curve; and (3) importing the differential time-domain dielectric spectrum curve into MATLAB software, comparing the differential time-domain dielectric spectrum curve with each standard differential time-domain dielectric spectrum curve through the MATLAB, and setting the polarization component and the linear parameter of the standard differential time-domain dielectric spectrum curve with the highest fitting degree as the polarization component and the linear parameter of the differential time-domain dielectric spectrum curve.
After determining the polarization component and the linear parameter of the differential time-domain dielectric spectral curve, according to a differential de-spectroscopy formula:
and
determining the polarization response time of the oilpaper insulation; wherein, tI (t) is a spectrum peak, QnIs a polarization component, anFor a linear parameter, τnPolarization response time for oilpaper insulation.
At this point, the calculation of the first polymerization degree is completed.
In one embodiment, determining a second degree of polymerization of the solid insulation from the rectified frequency domain dielectric spectrum curve and the current oil temperature comprises:
determining a polarization current curve of the main insulation of the transformer according to the corrected frequency domain dielectric spectrum curve;
and comparing the polarization current curve with any curve corresponding to the current oil temperature and prestored in a polarization current curve database to determine the second polymerization degree of the solid insulation.
In the embodiment, a polarization current curve of the main insulation of the transformer can be determined through the corrected frequency domain dielectric spectrum curve. Specifically, the frequency domain dielectric test instrument can be used for measuring the dielectric loss tangent value and the frequency of the current oilpaper insulation, further obtaining a curve of the dielectric loss changing along with the frequency, comparing the curve of the dielectric loss changing along with the frequency with any curve corresponding to the current oil temperature prestored in a dielectric loss database, determining the curve with the highest fitting degree as a polarization current curve corresponding to the main insulation of the transformer, further comparing the polarization current curve of the main insulation of the transformer with any curve in a prestored polarization current curve database, and determining the second fitting degree corresponding to the curve with the highest fitting degree as the second fitting degree of the solid insulation. It should be noted that the curves in the dielectric loss database and the curves in the polarization current curve database can be obtained by a person skilled in the art through a plurality of experiments.
At this point, the calculation of the second polymerization degree is completed.
In this embodiment, the first polymerization degree and the second polymerization degree are obtained by a database, so that the first polymerization degree and the second polymerization degree are prevented from being calculated in real time each time, and the efficiency of calculating the first polymerization degree and the second polymerization degree is improved.
The following is a description of how the aging state of the main insulation of the transformer is evaluated.
In one embodiment, evaluating the aging state of the primary insulation of the transformer according to the first polymerization degree and the second polymerization degree comprises:
determining a test frequency corresponding to the main insulation of the transformer;
determining a first weight corresponding to the first polymerization degree and a second weight corresponding to the second polymerization degree according to the test frequency;
determining a third degree of polymerization from the first degree of polymerization, the second degree of polymerization, the first weight, and the second weight;
and evaluating the aging state of the main insulation of the transformer according to the third polymerization degree.
In this embodiment, the first weight and the second weight may be determined by a preset weight database. It should be noted that the preset weight database includes a first weight corresponding to the first aggregation level in the preset frequency interval, and includes a second weight corresponding to the second aggregation level in the preset frequency interval. The first polymerization degree and the second polymerization degree are used for calculating the aging state of the main insulation of the transformer, wherein the smaller the first polymerization degree and/or the second polymerization degree is, the more serious the aging degree of the main insulation of the transformer is
Specifically, according to the test frequency corresponding to the main insulation of the transformer, determining a weight corresponding to a first polymerization degree and a weight corresponding to a second polymerization degree from a preset weight database; then, a first product of the first polymerization degree and the first weight is calculated, a second product of the second polymerization degree and the second weight is calculated, and then an average of the first product and the second product is calculated, and the average is determined as a third polymerization degree. Wherein the smaller the third polymerization degree, the more severe the degree of aging.
And finishing the detection of the aging state of the main insulation of the transformer.
In the present embodiment, by assigning different weights to the first polymerization degree and the second polymerization degree, the accuracy of the aging state evaluation can be further improved.
In one embodiment, the method for evaluating the aging state of the main insulation of the transformer further comprises the following steps:
when the testing frequency of the transformer main insulation is determined to be lower than a first frequency threshold value, determining the aging state of the transformer main insulation through the first polymerization degree;
and when the testing frequency of the main insulation of the transformer is determined to be higher than a second frequency threshold value, determining the aging state of the main insulation of the transformer through the second polymerization degree.
It should be noted that when the test frequency of the main insulation of the transformer is lower than the first frequency threshold, the frequency domain dielectric spectrum data is not sensitive to the insulation aging defect. At the moment, the first polymerization degree of solid insulation is determined only by a differential time domain dielectric spectrum curve and the oil temperature of insulating oil, and then the first polymerization degree is brought into a polymerization degree-aging database to obtain the aging degree corresponding to the first polymerization degree;
when the test frequency of the main insulation of the transformer is higher than a second frequency threshold value, the difference of the insulation structure cannot be reflected by the differential time domain dielectric spectrum data, and the detection error is large. At the moment, the second polymerization degree of the solid insulation is determined only by the frequency domain dielectric spectrum curve of the main insulation of the transformer and the oil temperature of the insulating oil, and then the second polymerization degree is brought into a polymerization degree-aging database to obtain the aging degree corresponding to the second polymerization degree. Optionally, the second frequency threshold is greater than the first frequency threshold.
In this embodiment, the aging state is evaluated by selecting one of the first polymerization degree and the second polymerization degree according to the test frequency, and the aging state can be accurately evaluated by using a small number of parameters, thereby further improving the efficiency of the aging state evaluation.
In one embodiment, after the aging degree evaluation is completed, the application can display the result in the form of a three-dimensional graph.
Specifically, the aging degree of the main insulation of the transformer is determined through a first polymerization degree and a second polymerization degree, and then the aging degree, the oil temperature of insulating oil and the polarization response time of oil paper insulation are fitted on a three-dimensional curved surface; and performing high-precision three-dimensional fitting on the three-dimensional curved surface image through software TableCURVE 3D, automatically searching the most appropriate objective function, obtaining the optimized three-dimensional curved surface image, and displaying the aging state of the main insulation of the transformer through the optimized three-dimensional curved surface image.
In the embodiment, the aging degree, the oil temperature of the insulating oil and the polarization response time of the oil paper insulation are fitted on a three-dimensional curved surface graph for displaying, so that the aging state becomes visible, and the observation of workers is facilitated.
It should be noted that the databases mentioned in the embodiments of the present application may be the same database or different databases, and are not limited herein. It will be appreciated that by arranging the databases described above as one and the same database, the number of databases may be reduced. In one database, different corresponding relations can be searched through different SQL sentences, so that the searching efficiency of the corresponding relations is improved. If the databases are set as different databases, physical isolation can be achieved for different corresponding relationships.
It should be understood that, although the steps in the flowchart of fig. 1 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a portion of the steps in fig. 1 may include multiple steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, which are not necessarily performed in sequence, but may be performed in turn or alternately with other steps or at least a portion of the other steps or stages.
Referring to fig. 2, fig. 2 is a schematic structural diagram of an apparatus for evaluating a primary insulation aging state of a transformer according to an embodiment, and the apparatus includes an obtaining module 210, a correcting module 220, a determining module 230, and an evaluating module 240, where:
the obtaining module 210 is configured to obtain a differential time-domain dielectric spectrum curve and a frequency-domain dielectric spectrum curve of a main insulation of a transformer, and a current oil temperature of insulating oil, where the main insulation includes solid insulation and the insulating oil;
the correction module 220 is configured to correct the differential time-domain dielectric spectrum curve and the frequency-domain dielectric spectrum curve according to the current oil temperature;
the determining module 230 is configured to determine a first polymerization degree of the solid insulation according to the corrected differential time-domain dielectric spectrum curve and the current oil temperature, and determine a second polymerization degree of the solid insulation according to the corrected frequency-domain dielectric spectrum curve and the current oil temperature;
the evaluation module 240 is configured to evaluate an aging state of the primary insulation of the transformer according to the first polymerization degree and the second polymerization degree.
In one embodiment, the orthotic module 220 comprises:
the first correction unit is used for determining a preset time domain temperature corresponding to the current oil temperature;
calling a differential time domain dielectric spectrum database, and acquiring a standard differential time domain dielectric spectrum curve corresponding to the preset time domain temperature through the differential time domain dielectric spectrum database;
correcting the differential time-domain dielectric spectrum curve according to the standard differential time-domain dielectric spectrum curve, and/or;
the second correction unit is used for determining a preset frequency domain temperature corresponding to the current oil temperature;
calling a frequency domain dielectric spectrum database, and acquiring a standard frequency domain dielectric spectrum curve corresponding to the preset frequency domain temperature through the frequency domain dielectric spectrum database;
and correcting the frequency domain dielectric spectrum curve according to the standard frequency domain dielectric spectrum curve.
In one embodiment, the primary insulation further comprises oiled paper insulation, and the determining module 230 comprises:
the first determining unit is used for calling a differential time domain dielectric spectrum database;
determining the polarization response time of the oiled paper insulation through the corrected differential time domain dielectric spectrum curve and the differential time domain dielectric spectrum database;
and determining a first polymerization degree of the solid insulation according to the polarization response time of the oilpaper insulation and the current oil temperature.
In one embodiment, the first determining unit is further configured to determine a spectral peak of the rectified differential time-domain dielectric spectral curve;
determining polarization components and linear parameters of the differential time-domain dielectric spectrum curve according to the differential time-domain dielectric spectrum database;
and determining the polarization response time of the oilpaper insulation according to a preset differential spectrum resolving formula.
In one embodiment, the determining module 230 includes:
the second determining unit is used for determining a polarization current curve of the main insulation of the transformer according to the corrected frequency domain dielectric spectrum curve;
and comparing the polarization current curve with any curve corresponding to the current oil temperature and prestored in a polarization current curve database to determine the second polymerization degree of the solid insulation.
In one embodiment, the evaluation module 240 is specifically configured to determine a test frequency corresponding to the primary insulation of the transformer;
determining a first weight corresponding to the first polymerization degree and a second weight corresponding to the second polymerization degree according to the test frequency;
determining a third degree of polymerization from the first degree of polymerization, the second degree of polymerization, the first weight, and the second weight;
and evaluating the aging state of the main insulation of the transformer according to the third polymerization degree.
In an embodiment, the evaluation module 240 is further specifically configured to determine an aging state of the transformer primary insulation through the first polymerization degree when it is determined that the test frequency of the transformer primary insulation is lower than a first frequency threshold;
and when the testing frequency of the main insulation of the transformer is determined to be higher than a second frequency threshold value, determining the aging state of the main insulation of the transformer through the second polymerization degree.
For specific limitations of the transformer main insulation aging state evaluation device, reference may be made to the above limitations of the transformer main insulation aging state evaluation method, and details are not repeated here. All or part of each module in the transformer main insulation aging state evaluation device can be realized by software, hardware and a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules. It should be noted that, in the embodiment of the present application, the division of the module is schematic, and is only one logic function division, and there may be another division manner in actual implementation.
In one embodiment, a computer device is provided, comprising a memory and a processor, the memory having stored therein a computer program, the processor implementing the steps of the above-described method embodiments when executing the computer program.
In an embodiment, a computer-readable storage medium is provided, on which a computer program is stored, which computer program, when being executed by a processor, carries out the steps of the above-mentioned method embodiments.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database or other medium used in the embodiments provided herein can include at least one of non-volatile and volatile memory. Non-volatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical storage, or the like. Volatile Memory can include Random Access Memory (RAM) or external cache Memory. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM), among others.
In the description herein, references to the description of "some embodiments," "other embodiments," "desired embodiments," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, a schematic description of the above terminology may not necessarily refer to the same embodiment or example.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A method for evaluating the aging state of main insulation of a transformer is characterized by comprising the following steps:
acquiring a differential time domain dielectric spectrum curve and a frequency domain dielectric spectrum curve of main insulation of a transformer and the current oil temperature of insulating oil, wherein the main insulation comprises solid insulation and the insulating oil;
correcting the differential time domain dielectric spectrum curve and the frequency domain dielectric spectrum curve according to the current oil temperature;
determining a first polymerization degree of the solid insulation according to the corrected differential time domain dielectric spectrum curve and the current oil temperature, and determining a second polymerization degree of the solid insulation according to the corrected frequency domain dielectric spectrum curve and the current oil temperature;
and evaluating the aging state of the main insulation of the transformer according to the first polymerization degree and the second polymerization degree.
2. The method for evaluating the aging state of the primary insulation of the transformer according to claim 1, wherein the step of correcting the differential time-domain dielectric spectrum curve according to the current oil temperature comprises:
determining a preset time domain temperature corresponding to the current oil temperature;
calling a differential time domain dielectric spectrum database, and acquiring a standard differential time domain dielectric spectrum curve corresponding to the preset time domain temperature through the differential time domain dielectric spectrum database;
correcting the differential time-domain dielectric spectrum curve according to the standard differential time-domain dielectric spectrum curve, and/or;
the step of correcting the frequency domain dielectric spectrum curve according to the current oil temperature comprises the following steps:
determining a preset frequency domain temperature corresponding to the current oil temperature;
calling a frequency domain dielectric spectrum database, and acquiring a standard frequency domain dielectric spectrum curve corresponding to the preset frequency domain temperature through the frequency domain dielectric spectrum database;
and correcting the frequency domain dielectric spectrum curve according to the standard frequency domain dielectric spectrum curve.
3. The method of claim 1, wherein the primary insulation further comprises oil paper insulation, and the determining the first degree of polymerization of the solid insulation according to the corrected differential time-domain dielectric spectrum curve and the current oil temperature comprises:
calling a differential time domain dielectric spectrum database;
determining the polarization response time of the oiled paper insulation through the corrected differential time domain dielectric spectrum curve and the differential time domain dielectric spectrum database;
and determining a first polymerization degree of the solid insulation according to the polarization response time of the oilpaper insulation and the current oil temperature.
4. The method for evaluating the aging state of the main insulation of the transformer according to claim 3, wherein the determining the polarization response time of the oilpaper insulation through the corrected differential time-domain dielectric spectrum curve and the differential time-domain dielectric spectrum database comprises:
determining a spectrum peak of the corrected differential time-domain dielectric spectrum curve;
determining polarization components and linear parameters of the differential time-domain dielectric spectrum curve according to the differential time-domain dielectric spectrum database;
and determining the polarization response time of the oilpaper insulation according to a preset differential spectrum resolving formula.
5. The method of claim 1, wherein the determining a second degree of polymerization of the solid insulation from the corrected frequency domain dielectric spectrum curve and the current oil temperature comprises:
determining a polarization current curve of the main insulation of the transformer according to the corrected frequency domain dielectric spectrum curve;
and comparing the polarization current curve with any curve corresponding to the current oil temperature and prestored in a polarization current curve database to determine the second polymerization degree of the solid insulation.
6. The method for evaluating the aging state of the primary insulation of the transformer according to any one of claims 1 to 5, wherein the evaluating the aging state of the primary insulation of the transformer according to the first polymerization degree and the second polymerization degree comprises:
determining a test frequency corresponding to the main insulation of the transformer;
determining a first weight corresponding to the first polymerization degree and a second weight corresponding to the second polymerization degree according to the test frequency;
determining a third degree of polymerization from the first degree of polymerization, the second degree of polymerization, the first weight, and the second weight;
and evaluating the aging state of the main insulation of the transformer according to the third polymerization degree.
7. The method of evaluating the aging state of a primary insulation of a transformer according to claim 6, further comprising:
when the testing frequency of the transformer main insulation is determined to be lower than a first frequency threshold value, determining the aging state of the transformer main insulation through the first polymerization degree;
and when the testing frequency of the main insulation of the transformer is determined to be higher than a second frequency threshold value, determining the aging state of the main insulation of the transformer through the second polymerization degree.
8. A transformer main insulation aging state evaluation device is characterized by comprising:
the system comprises an acquisition module, a control module and a control module, wherein the acquisition module is used for acquiring a differential time domain dielectric spectrum curve and a frequency domain dielectric spectrum curve of main insulation of a transformer and the current oil temperature of insulating oil, and the main insulation comprises solid insulation and the insulating oil;
the correction module is used for correcting the differential time domain dielectric spectrum curve and the frequency domain dielectric spectrum curve according to the current oil temperature;
the determining module is used for determining a first polymerization degree of the solid insulation according to the corrected differential time domain dielectric spectrum curve and the current oil temperature, and determining a second polymerization degree of the solid insulation according to the corrected frequency domain dielectric spectrum curve and the current oil temperature;
and the evaluation module is used for evaluating the aging state of the main insulation of the transformer according to the first polymerization degree and the second polymerization degree.
9. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor, when executing the computer program, implements the steps of the method of any of claims 1 to 7.
10. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method of any one of claims 1 to 7.
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| CN115015684A (en) * | 2022-08-10 | 2022-09-06 | 山东和兑智能科技有限公司 | High-voltage bushing digital evaluation method and system based on time-frequency domain feature fusion |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115015684A (en) * | 2022-08-10 | 2022-09-06 | 山东和兑智能科技有限公司 | High-voltage bushing digital evaluation method and system based on time-frequency domain feature fusion |
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