RU2589303C1 - Method of controlling technical state of electric power equipment - Google Patents

Abstract

FIELD: metrology.

SUBSTANCE: invention relates to metrology, in particular, to methods of diagnostics of electrical equipment. Method involves determination of peak values of energy spectra of currents, calculation of white noise intensity, comparing parameters with reference sample. All measurements are carried out in same conditions using identical tools. Determination of defects is performed by separate voltage inputs. Then one introduces defects gradation on weak, moderate, strong or dangerous. If intensity of white noise in current of control input branch exceeds reference by value of up to 15 dB, then defect is weak, value from 15 to 30 dB corresponds to moderate defects, value from 30 to 45 dB corresponds to strong defects, value of 45 dB corresponds to dangerous defects. Complete defectiveness is defined as weak if weak white noise intensity is present at all inputs. If at least one of inputs has moderate, strong or dangerous white noise intensity, then conclusion is made about fact that complete defectiveness is moderate, strong or dangerous.

EFFECT: technical result is increased accuracy and efficiency of diagnostics.

1 cl, 3 dwg

Description

The invention relates to methods for diagnosing the defectiveness of electric power (EE) equipment (primarily, discrete EE equipment, i.e. equipment with small and moderate occupied area such as voltage transformers, current transformers, control shunt reactors and other similar devices) and is intended for creation of industrial information-measuring complexes for monitoring the technical condition of this equipment, providing reliable express diagnostics of complete defectiveness to controlled energy efficiency equipment.

A known method of monitoring the technical condition of EE equipment, based on the use of thermal imagers to record the temperature distribution on the surface of the controlled equipment under voltage. In this known manner, the defects of the external, surface parts of the EE equipment are determined (see Khrennikov A.Yu. et al. Power Plants, No. 8, 2001).

The main disadvantages of the known method are that it is complex, has low sensitivity, requires a significant investment of time for the analysis of measurement results (a detailed study of thermal imaging maps) and does not allow to identify defects associated with electrical discharges in the internal parts of EE equipment. Therefore, this method does not provide the required efficiency, sensitivity and reliability of diagnosis and is not suitable for performing reliable express diagnostics of the complete defectiveness of controlled EE equipment, and primarily discrete EE equipment.

There is also a method for monitoring the technical condition of electric power equipment, the defectiveness of which is determined by the intensity of white noise generated by this equipment connected to voltage power lines (see Glukhov O.A., Korovkin N.V., Balagula Yu.M. Method for estimating partial parameters discharges in high-voltage insulation during relative measurements of their pulsed electromagnetic fields. Proceedings of the IV international symposium on electromagnetic compatibility, St. Petersburg, 2001, prototype). This method includes measuring the average intensity of the flow of chaotic (noise) electromagnetic pulses emitted by EE equipment, i.e. essentially the integral power of the white noise emitted by the equipment with a uniform spectrum created by electric discharges in the external and internal parts of this equipment. Measurements in this known method are carried out using a broadband receiving antenna of arbitrary polarization connected to the input of a specially manufactured recorder of average intensity of the flow of electromagnetic pulses emitted by EE equipment. Recommended in this known method, the measurement frequencies exceed f = 150-200 MHz and lie in the high-frequency part of the white noise. Based on the measurement results, the dependence of the average intensity of the stream of emitted pulses on the detection threshold is built, and the diagnostic parameters are used: the slope of the slopes of the segments of the approximating straight lines in the sections of this dependence, the number of intervals necessary for such an approximation, and the coordinates of the inflection points of this dependence. In this case, the complete defectiveness of the EE-controlled equipment is established by the dynamics of changes in the specified diagnostic parameters when performing series of periodic measurements at time intervals separated by months and years of operation of this equipment.

This method of monitoring the technical state of EE equipment belongs to the category of noise and quasi-noise methods and therefore has increased, in comparison with the analogue, sensitivity and reliability of diagnosing the complete defectiveness of the controlled equipment, determined by electric discharges not only in its external, but also in its internal structural elements (which not in analogue).

Nevertheless, this method is not without drawbacks due to the use of the cumbersome procedure for processing measurement results in it, as well as the unsatisfactory sensitivity and reliability of the authors developed by the authors of the meter of the average intensity of the flow of emitted pulses, not able to separate the radiation of the controlled EE equipment from the noise of the measuring equipment. In addition, when diagnosing the defectiveness of EE equipment by this method, it is impossible to unequivocally state the average intensity of the flow of which pulses is recorded by measuring equipment: noise (as the authors themselves believe) or quasi-noise and deterministic, also emitted by EE equipment, i.e. the reliability of the diagnosis of defects must be confirmed by additional measurements of the energy spectra of the radiation of the controlled equipment, which is not provided in the prototype. Therefore, the prototype does not have the required efficiency, sensitivity and reliability of diagnosis, and therefore is not suitable for performing reliable express diagnostics of the complete defectiveness of the specified equipment, and primarily discrete EE equipment.

The problem to which the claimed invention is directed is to create a method for monitoring the technical condition of EE equipment suitable for performing reliable express diagnostics of the complete defectiveness of controlled equipment.

The technical result obtained when solving the problem is expressed in the creation of a method for monitoring the technical condition of EE equipment (and, first of all, discrete EE equipment such as voltage transformers, current transformers, control shunt reactors and other similar devices), quite simple, with increased efficiency and increased reliability of diagnosis, and therefore suitable for performing reliable express diagnostics of the complete defectiveness of the controlled equipment.

To solve this problem, a method for monitoring the technical condition of electric power equipment, the defectiveness of which is determined by the intensity of white noise generated by this equipment connected to voltage power lines, is different in that it is first measured by known methods under equivalent conditions for controlled and standard equipment samples of the same type frequencies of the combined action of white noise and peaks of quasi-harmonic oscillations with resonant frequencies of high-quality oscillations In this case, the energy spectra of the currents of the control branches of the individual voltage inputs of this equipment are then isolated and recorded in these spectra of white noise intensities and, comparing these intensities for the same voltage inputs of the reference and controlled equipment, the defects on the individual voltage inputs in the controlled equipment are established as weak moderate, strong or dangerous if the intensity of white noise in the current of the control branch of this input exceeds th indicator in the reference equipment by respectively up to 15, from 15 to 30, from 30 to 45 and more than 45 dB, while the complete defectiveness of the controlled equipment is defined as weak, moderate, strong or dangerous, if one of the four gradations corresponds to complete defectiveness, for example, weak, or moderate, or strong, or dangerous, if, respectively, weak defects are detected in all voltage inputs in this equipment, if at least one of the voltage inputs is found to be malfunctioning, if at least one of the inputs on arresters revealed strong defects or if at least one of the input voltage is detected dangerous defects.

The restrictive and distinctive features of the claimed invention provide a solution to the problem - the creation of a method for monitoring the technical condition of EE equipment, devoid of the disadvantages of the prototype, i.e. possessing, in comparison with it, sufficient simplicity, increased efficiency, reliability and increased sensitivity of diagnosis, and therefore allowing reliable express diagnostics of the complete defectiveness of controlled equipment.

In the claimed method of monitoring the technical condition of EE equipment common with the prototype, an essential feature is that in it "the defectiveness of the controlled equipment is determined by the intensity of white noise created by this equipment connected to voltage power lines." Those. in the claimed method, as in the prototype, it is proposed to determine the defectiveness of the EE-controlled equipment by the white noise intensity of this equipment, operating in the nominal operating mode, i.e. connected to voltage transmission lines and under the influence of these voltages.

A comparative analysis of the essential features of the proposed method and prototype shows the presence of the following distinctive features:

- “using known methods, measure under equivalent conditions for controlled and homogeneous reference equipment samples at frequencies of joint action of white noise and peaks of quasi-harmonic vibrations with resonant frequencies of high-quality vibrational circuits of the specified equipment, the energy spectra of the currents of the control branches of the individual voltage inputs of this equipment”;

- “isolate and record in these spectra the intensities of white noise and, comparing these intensities for the same voltage inputs of the reference and controlled equipment, establish defects on the individual voltage inputs in the controlled equipment”;

- “the complete defectiveness of the controlled equipment is determined taking into account the received data on defects on individual voltage inputs in this equipment”.

The distinguishing feature “by known methods, is measured under equivalent conditions for controlled and homogeneous reference equipment samples at frequencies of the joint action of white noise and peaks of quasi-harmonic vibrations with resonant frequencies of high-quality vibrational circuits of the specified equipment, energy spectra of the currents of the control branches of the individual voltage inputs of this equipment” indicates that in the inventive method is measured using known methods (for example, using highly sensitive measurement the current noise spectral meter of a known design, which allows to separate the measured noise from the meter’s own noise and therefore provides increased reliability and 10-15 dB increased sensitivity for diagnosing defectiveness, rather than using a meter of average intensity of the flow of noise, quasi-noise and deterministic impulses of arbitrary polarization emitted by EE equipment in the entire operating frequency band of the measuring equipment, as in the prototype) and in equivalent conditions (i.e. under the same operating conditions of the controlled and the same standard EE equipment and using the same metric means) the energy spectra of the currents of the control branches of the individual voltage inputs of the specified equipment at the frequencies of the joint action of white noise and peaks of quasi-harmonic oscillations with resonant frequencies of high-quality vibrational circuits of this equipment. In this case, the main recommended measurement range in the present method is located in the low-frequency part of the field of action of white noise, i.e. at frequencies of 3-300 MHz (a fallback in the high-frequency part of this region at frequencies of 0.3-3.0 GHz), and differs from that in the prototype.

The distinguishing feature “isolate and record white noise intensities in these spectra and, comparing these intensities for the same voltage inputs of the reference and controlled equipment, determine the faults for individual voltage inputs in the controlled equipment” specifies the diagnostic parameter used in the proposed method (white noise intensities in the energy spectra currents of control branches of individual voltage inputs of reference and controlled EE equipment), offers simple ma by mathematical methods (for example, by a linear approximation of a set of experimental points with minimum local spectral densities in the energy spectra of the currents of the control branches of voltage inputs of EE equipment in the areas of joint action of white noise and quasi-harmonic vibrations with resonant frequencies of high-quality vibrational circuits of this equipment) to highlight in the measured energy spectra for controlled and homogeneous reference sample of EE equipment components of white noise c (whose spectral densities are independent of the analysis frequency) and recommends fixing these intensities (i.e. spectral density of white noise), in order to compare the indicated intensities, to develop criteria and, using them, to determine the defects of the controlled equipment by individual voltage inputs in this equipment.

These criteria are formed in such a way as to distinguish several gradations (levels) of defects in the controlled voltage inputs of EE equipment, for example, gradations of weak, moderate, strong and dangerous defects. At the same time, a controlled sample of EE equipment at the initial stage of its operation (or immediately after repair work to restore the working capacity of this sample), or any other equipment of the same type with a minimum white noise intensity in the energy spectrum, which is the same type as a controlled one, can be used as a reference the current of the control branch of the corresponding voltage input among the examined equipment samples.

It is known that before the failure of EE equipment, the intensity of white noise created by it increases by 50-60 dB. Therefore, the criteria for determining defects on individual voltage inputs in EE equipment based on a comparison of the white noise intensities in the energy spectra of the currents of the control branches of the same voltage inputs in the controlled and reference equipment samples can be simple and universal for various types of EE equipment:

- weak defectiveness of the EE-controlled equipment for a separate voltage input in this equipment corresponds to the intensity of white noise in the current of the control branch of the corresponding input, exceeding that in the reference equipment by up to 15 dB;

- moderate defectiveness of the EE-controlled equipment for a separate voltage input in this equipment corresponds to the intensity of white noise in the current of the control branch of the corresponding input, exceeding that in the reference equipment by 15 to 30 dB;

- severe defectiveness of the EE-controlled equipment for a separate voltage input in this equipment corresponds to the intensity of white noise in the current of the control branch of the corresponding input, exceeding that in the reference equipment by 30 to 45 dB;

- the dangerous defect of the EE-controlled equipment for a separate voltage input in this equipment corresponds to the intensity of white noise in the current of the control branch of the corresponding input, exceeding that in the reference equipment by 45 dB or more.

The distinguishing feature "... the complete defectiveness of the controlled equipment is determined taking into account the obtained data on the faults for individual voltage inputs in this equipment ..." indicates the path to the development of criteria and the determination, using these criteria, of the already complete defectiveness of the controlled EE equipment.

These criteria are formed in such a way as to distinguish between the same gradations (levels) of defects in controlled EE equipment as previously introduced for assessing defects in individual voltage inputs in controlled EE equipment, i.e. weak, moderate, severe and dangerous defects:

- weak complete defectiveness of the controlled equipment sample corresponds to weak defects in all voltage inputs in this equipment;

- moderate complete defectiveness of the controlled equipment sample corresponds to moderate defectiveness in at least one of the voltage inputs in it with weak and moderate defects in the remaining investigated inputs;

- severe complete defectiveness of the controlled equipment sample corresponds to severe defectiveness in at least one of the voltage inputs in it with weak, moderate and severe defects in the remaining investigated inputs;

- dangerous complete defectiveness of the controlled equipment sample corresponds to dangerous defectiveness in at least one of the voltage inputs in it for any defects in other inputs.

Due to comparison with the standard, the criteria proposed in the claimed method for individual voltage inputs in the EE equipment and for the complete defectiveness of the controlled sample of EE equipment, as well as the assessments of the defects for individual voltage inputs in the controlled samples of EE equipment and the total defects of these samples obtained using these criteria, exhibit the same low sensitivity to external interference, as in the prototype.

Therefore, in the inventive method for monitoring the technical condition of EE equipment, all the advantages of the prototype are preserved and multiplied. Moreover, due to the use of the highly sensitive current noise meter in the inventive method, which is able to separate the investigated noise from the meter’s own noise, this method has an increased reliability compared to the prototype and an increased sensitivity for diagnosing the complete defectiveness of controlled equipment by 10-15 dB.

In addition, the claimed method is quite simple and not time-consuming, both in terms of performing measurements and in terms of processing their results, and therefore allows reliable express diagnostics of the complete defectiveness of EE equipment with increased efficiency, reliability and increased sensitivity compared to the prototype and analogue.

From the foregoing, it follows that the proposed combination of general and distinctive essential features of the proposed method for monitoring the technical condition of EE equipment provides a solution to the problem and achieving the desired technical result: it improves the efficiency, reliability and sensitivity of diagnosing the defectiveness of this equipment, and therefore makes the inventive method suitable for implementation reliable express diagnostics of the complete defectiveness of EE equipment and, first of all, for performing rapid diagnosis of defects discrete EE type voltage transformer equipment, current transformers, controlled shunt reactors and other similar devices.

The set of essential features of the claimed invention has a causal relationship with the achieved technical result, i.e. thanks to this combination of essential features, the invention solves the problem.

Moreover, the claimed invention is new and has an inventive step, because it does not follow explicitly from known technical solutions and is suitable for practical use.

The practical implementation of the proposed method for monitoring the technical state of EE equipment will be demonstrated by diagnosing the complete defectiveness of a single-phase high-voltage voltage autotransformer type AODTSTN16700 / 500/220, which is widely used in Russian power plants.

This transformer has 5 voltage inputs: high voltage (BB) inputs 1, 2 and low voltage (HB) inputs 3, 4, 5.

Inputs 1, 3 with a voltage between them of 500 kV are connected to the power line (power transmission line) from the power plant, while input 3 is grounded. Inputs 2, 3 with a voltage between them of 220 kV are connected to the power line of the main consumer. NV inputs 4, 5 with a voltage between them of 11 kV are connected to the power lines of the local consumer.

The BB inputs 1, 2 of this voltage transformer have standard built-in control branches, which make it possible to study the energy spectra of the currents of these inputs using a highly sensitive current noise spectra meter of a known design. NV inputs 3, 4, 5 do not have regular built-in control branches. Therefore, in order to realize in full the potential of the proposed method for monitoring the technical state of EE equipment, it is advisable to order the developer of the above transformers in advance to design and manufacture additional control branches for the low-frequency voltage inputs of these transformers.

In the meantime, you can restrict yourself to using the existing standard control branches of the explosive inputs 1, 2 to determine the defects on these inputs and the complete defectiveness of the controlled voltage transformer. This approach was previously applied (see Klokov V., Losev V., Silin Ν., Sheverdin D., Tsepennikov D. Flicker-Noise Diagnostics of Power Electric Equipment. Proceedings of International Symposium on Electromagnetic Theory (EMTS-2010), Berlin , August, 2010) and fully justified itself, since in the considered voltage transformers the most vulnerable from the standpoint of reliability of operation are precisely the voltage input BBs.

The essence of the claimed invention is illustrated by drawings, where in FIG. 1 shows a diagram of the inputs of a transformer; in FIG. 2 shows on a logarithmic scale the vertical-polarized EMR energy spectrum taken on June 3, 2010 for a voltage transformer AT-1 phase B (weak total defectiveness of the reference transformer on 06/03/2010 was confirmed by known methods); in FIG. 3 - a similar spectrum for the same voltage transformer, which became controlled after four years of continuous operation, taken July 23, 2014. The essence of the practical application of the claimed invention is illustrated by drawings, where in FIG. Figure 2 shows on a logarithmic scale the normalized energy spectrum of the current of the control branch of the explosive input 1 of the reference voltage transformer AT-1 phase A, obtained at one of the distribution power plants in Russia 06/03/2010 (weak complete defectiveness of the reference transformer was confirmed by methods known from RU No. 2311652 and Methodological guidelines for the diagnosis of developing defects in transformer equipment based on the results of chromatographic analysis of gases dissolved in oil RD 153-34.0-46.302-00, RAO UES of Russia, Depa Rament of scientific and technical policy and development of the Russian Federation, M., 2001, - further Methodical instructions).

Moreover, in FIG. Figure 3 shows a similar spectrum for the controlled transformer AT-1, standby, phase A, obtained there on July 23, 2014. Both spectra correspond to a frequency range of 3-300 MHz, the nominal operating mode of transformers and are measured using unified metric means (a highly sensitive measuring instrument for current noise spectra of known design).

, $$S_{i2}/I_{ef2}^2$$

- нормированные спектральные плотности токов контрольных ответвлений ВВ вводов 1 эталонного (первого) и контролируемого (второго) трансформаторов в дБ/Гц; S_i1, S_i2 - спектральные плотности токов контрольных ответвлений ВВ вводов 1 для эталонного и контролируемого трансформаторов в ²/Ηz; I_ef1, Ι_ef2 - эффективные значения в токов контрольных ответвлений эталонного и контролируемого трансформаторов с частотой промышленной сети f_c=50 Гц; f - частота анализа спектра в Гц; $${\left(S_{il}\right)}_W/I_{ef1}^2$$

, $${\left(S_{i2}\right)}_W/I_{ef2}^2$$

- нормированные спектральные плотности (интенсивности) белых шумов в дБ/Гц в спектрах токов контрольных ответвлений ВВ вводов 1 эталонного и контролируемого трансформаторов. Благодаря нормировке представленные на фиг. 2, 3 энергетические спектры $$S_{il}/I_{ef1}^2$$

, $$S_{i2}/I_{ef2}^2$$

и интенсивности белых шумов $${\left(S_{il}\right)}_W/I_{ef1}^2$$

, $${\left(S_{i2}\right)}_W/I_{ef2}^2$$

одновременно являются характеристиками полных токов ВВ вводов 1 эталонного и контролируемого трансформаторов.In FIG. 2 and 3, the following notation is used: $$S_{il}/I_{ef\mathrm{one}}^2$$

, $${\mathrm{<figure-callout\; id="2"\; label="S\; i"\; filenames="00000008.png,00000009.png"\; state="\{\{state\}\}">S\; </figure-callout>}}_i/{\mathrm{<figure-callout\; id="2"\; label="I\; e\; f"\; filenames="00000008.png,00000009.png"\; state="\{\{state\}\}">I\; </figure-callout>}}_{ef}^2$$

- normalized spectral current densities of the control branches of the explosive inputs of 1 reference (first) and controlled (second) transformers in dB / Hz; S _i1 , S _i2 are the spectral densities of the currents of the control branches of the explosive inputs 1 for the reference and controlled transformers at ² / Ηz; I _ef1 , Ι _ef2 - effective values in the currents of the control branches of the reference and controlled transformers with a frequency of the industrial network f _c = 50 Hz; f is the frequency of spectrum analysis in Hz; $${\left(S_{il}\right)}_W/I_{ef\mathrm{one}}^2$$

, $${\left(S_{i2}\right)}_W/{\mathrm{<figure-callout\; id="2"\; label="I\; e\; f"\; filenames="00000008.png,00000009.png"\; state="\{\{state\}\}">I\; </figure-callout>}}_{ef}^2$$

- normalized spectral densities (intensities) of white noise in dB / Hz in the current spectra of the control branches of the explosive inputs of 1 reference and controlled transformers. Due to the normalization shown in FIG. 2, 3 energy spectra $$S_{il}/I_{ef\mathrm{one}}^2$$

, $${\mathrm{<figure-callout\; id="2"\; label="S\; i"\; filenames="00000008.png,00000009.png"\; state="\{\{state\}\}">S\; </figure-callout>}}_i/{\mathrm{<figure-callout\; id="2"\; label="I\; e\; f"\; filenames="00000008.png,00000009.png"\; state="\{\{state\}\}">I\; </figure-callout>}}_{ef}^2$$

and white noise intensity $${\left(S_{il}\right)}_W/I_{ef\mathrm{one}}^2$$

, $${\left(S_{i2}\right)}_W/{\mathrm{<figure-callout\; id="2"\; label="I\; e\; f"\; filenames="00000008.png,00000009.png"\; state="\{\{state\}\}">I\; </figure-callout>}}_{ef}^2$$

at the same time are the characteristics of the full currents of the explosive inputs of 1 reference and controlled transformers.

Note that in the normalized current spectrum of the control branch of the explosive input of input 1 of the reference voltage transformer (Fig. 2), peaks of quasi-harmonic components at the resonant frequencies of high-quality oscillatory circuits of the transformer are clearly visible. The approximation by a straight line parallel to the frequency axis f of the set of experimental points A, Υ, Ζ corresponding to the minimum local spectral densities falling in the interval of values equal to twice the statistical measurement error 2β = 2 dB allows us to isolate in the current spectrum of the control branch of the explosive input 1 reference transformer component of white noise (dashed line) and determine its intensity (normalized spectral density of noise current), which at the reference transformer was $${\left(S_{il}\right)}_W/I_{ef\mathrm{one}}^2=-187dB/Gc.$$

т.е. на 21 дБ выше, чем у эталонного трансформатора.In the current spectrum of the controlled voltage transformer (Fig. 3), peaks of quasi-harmonic components at the resonant frequencies of high-quality oscillatory circuits of the transformer are increased in magnitude. The approximation by a straight line parallel to the frequency axis f of the set of experimental points Υ, Ζ corresponding to the minimum local spectral densities falling within the interval of values equal to twice the statistical measurement error 2β = 2 dB allows us to isolate the component white noise and determine its intensity (normalized spectral density of noise current), which at the controlled transformer was equal $${\left(S_{i2}\right)}_W/{\mathrm{<figure-callout\; id="2"\; label="I\; e\; f"\; filenames="00000008.png,00000009.png"\; state="\{\{state\}\}">I\; </figure-callout>}}_{ef}^2=-166dB(\mathrm{AT}t)/Gc,$$

those. 21 dB higher than the reference transformer.

At the same time, it is guaranteed that the obtained 21-dB readout, up to a doubled statistical measurement error of 2β = 2 dB, corresponds to the difference in intensities of precisely white noises, and not peaks of quasi-harmonic oscillations in the current spectra of the control branches of the transformers under consideration. The prototype does not have such a guarantee.

Now, using the criteria (for individual voltage inputs in EE equipment), it is possible to assess the defectiveness of the controlled transformer by BB input 1 as moderate, which was confirmed by methods known from RU No. 2311652 and the “Methodological Instructions”.

In a similar way, the difference in the intensities of white noise in the spectra of the currents of the explosive inputs 2 of the reference and controlled transformers was determined, which amounted to 22 dB. Accordingly, the defectiveness of the controlled transformer by BB input 2, taking into account the criteria (for individual voltage inputs in EE equipment) in our case, was also moderate (the result was also confirmed by methods known from RU No. 2311652 and the “Methodological Instructions”).

Taking into account the obtained assessments of the defects of the controlled voltage transformer by explosive inputs 1, 2, it is now possible to evaluate the complete defects of the controlled transformer with the increased reliability and sensitivity increased by 10-15 dB (compared to the prototype) with the increased reliability of the controlled sample of EE equipment) as moderate (the result is also confirmed by methods known from RU No. 2311652 and the "Guidelines").

It can be noted that it is sufficient for a skilled person to take a quick look at spectra similar to those shown in FIG. 2 and 3, so that without additional processing of the experimental results up to a doubled statistical measurement error of 2β (in our case 2β = 2 dB), to determine the difference in white noise intensities in the current spectra of the control branches of the controlled voltage inputs of the reference and controlled transformers and, applying the criteria for individual voltage inputs in EE equipment and criteria for complete defectiveness of a controlled sample of EE equipment, to quickly determine with increased reliability and with an increase of 10-15 dB by the quality (in comparison with the prototype) of the defectiveness of individual voltage inputs and the complete defectiveness of the EE-controlled equipment.

Therefore, the claimed method of monitoring the technical condition of EE equipment not only provides increased reliability and increased sensitivity for diagnosing the complete defectiveness of the controlled equipment (in comparison with the prototype), but is also quite simple both in terms of performing measurements using standard industrial equipment and in terms of interpretation experimental results obtained. This allows the specialist, using the proposed method, to quickly implement reliable rapid diagnostics of the complete defectiveness of EE equipment (and, first of all, discrete EE equipment) directly at the measurement site without additional processing of the experimental data received by him (which is not in the prototype and in the analogue).

The indicated advantages of the proposed method, including the simplicity and speed of forming a conclusion, are especially important when performing express diagnostics of emergency EE equipment with dangerous defects, when it is urgent to solve the issue of stress relief from this equipment.

The given example of the implementation of the proposed method for monitoring the technical condition of EE equipment shows its advantages in comparison with the prototype and analogue.

Practical application of the proposed method for monitoring the technical condition of EE equipment for attesting the faultiness of a single-phase explosive voltage transformer made it possible to increase the efficiency, reliability and sensitivity of diagnosing the complete defectiveness of this equipment and confirmed the possibility of realizing (using this method) reliable express diagnostics of EE equipment.

From the foregoing, it follows that the claimed method of monitoring the technical condition of EE equipment has, in comparison with the prototype and analogue, sufficient novelty, simplicity, increased responsiveness, reliability and increased by 10-15 dB sensitivity to diagnose the complete defectiveness of the controlled equipment, and first of all, discrete EE equipment such as voltage transformers, current transformers, controlled shunt reactors and other similar devices.

Claims (1)

A method for monitoring the technical condition of electric power equipment, the defectiveness of which is determined by the intensity of white noise generated by this equipment connected to voltage power lines, characterized in that at first it is measured by known methods under equivalent conditions for controlled and homogeneous reference samples of equipment at frequencies of joint action of white noise and peaks of quasi-harmonic oscillations with resonant frequencies of high-quality vibrational circuits of the specified equipment energy spectra of the currents of the control branches of the individual voltage inputs of this equipment, then isolate and record the white noise intensities in these spectra and, comparing these intensities for the same voltage inputs of the reference and controlled equipment, establish the defects on the individual voltage inputs in the controlled equipment as weak, moderate, strong or dangerous if the intensity of white noise in the current of the control branch of this input exceeds such an indicator in the reference speed down to 15, 15 to 30, 30 to 45, and more than 45 dB, respectively, while the complete defectiveness of the equipment under control is defined as weak, moderate, strong, or dangerous if there is one of four gradations of complete defectiveness, for example, weak, moderate, strong, or dangerous if, respectively, weak defect is detected on all voltage inputs in this equipment, if moderate defect is detected on at least one of the voltage inputs, if a strong defect is detected on at least one of the voltage inputs spine or if at least one of the voltage inputs revealed a dangerous defect.

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