RU2749338C1 - Method for monitoring technical condition of electric power equipment - Google Patents

Abstract

FIELD: electric power equipment.SUBSTANCE: invention relates to methods for noise diagnostics of electric power equipment (EPE). Essence: according to the control method, the defectiveness of the equipment is determined by its electromagnetic radiation. First of all, informative frequency bands are determined that characterize the technical condition of the main structural elements of the controlled EPE. Then, the energy spectra of radiation of vertical polarization from the controlled EPE are recorded and filtered from high-Q radiation. On the basis of the registered and filtered spectra, the energy spectra of the reference EPE emissions are compiled by separating among the available spectra the lowest intensities of electromagnetic oscillations for each measured frequency. A conclusion is formed on the degree of defectiveness of each element of the controlled EPE and on the complete defectiveness by comparing with the standards of the qualification properties of quasi-harmonic electromagnetic oscillations within the informative frequency bands characterizing the main structural elements of the controlled EPE. In this case, to assess the degree of defectiveness of the external structural elements of the EPE, the energy spectra of low-quality radiation are used.EFFECT: increased accuracy and reliability of EPE defectiveness diagnostics.1 cl, 5 dwg

Description

The invention relates to methods of noise diagnostics of electric power equipment (EEE) and is intended to create industrial information and measurement systems for remote non-destructive testing of the technical condition (TS) of such equipment.

There is a known method for monitoring the technical condition of electrical power equipment [1], in which the defectiveness of the monitored equipment under voltage is determined by the electromagnetic radiation (EMI) of this equipment, and the external vertical parts of the EEE bushings, isolated from the grounded metal case, are taken as antennas. To assess the TS of the equipment being inspected, it is proposed to first calculate the resonant frequencies of the radiation of the antennas, then calculate the informative frequency bands of radiation associated with the values of the resonant frequencies, and then fix in equivalent conditions the integral powers of quasi-harmonic electromagnetic oscillations in the informative frequency bands of the energy spectra of radiation of vertical polarization from the same type of controlled and reference EEE. The conclusion about TS EEE is proposed to be made on the basis of comparison of the above integral powers of quasi-harmonic electromagnetic oscillations in informative frequency bands recorded in equivalent conditions for the same type of controlled and reference electric power equipment.

The disadvantages of this method are low depth, accuracy and reliability of diagnosing the defectiveness of the controlled EEE.

The low accuracy of diagnosing defectiveness is due to the strong dependence of the method on the number of radiation spectra of vertical polarization of the same type of equipment recorded in equivalent conditions, which especially negatively affects the diagnostic results in the case of an initial examination of a small amount of the same type of equipment, or in the case of a regular examination, but under conditions that are very different from working conditions during previous examinations.

The low depth of diagnosing defectiveness is due to the lack of determining the defectiveness of the internal structural elements of the examined equipment, among which the main ones are windings and voltage regulators with their tanks. Determination of defectiveness of these elements of equipment is important for making a responsible decision on partial shutdown, repair or timely replacement of a defective EEE, and therefore the mentioned method cannot provide sufficient reliability in determining the technical state of the monitored EEE.

It follows from this that the mentioned method does not have sufficient depth, accuracy and reliability in diagnosing the defectiveness of the monitored EEE.

There is also known a method for monitoring the technical condition of electric power equipment [2], in which, as in the analogue method [1], the defectiveness of the monitored equipment under voltage is determined by the electromagnetic radiation of this equipment, and the external vertical parts of the EO inputs are taken as antennas isolated from a grounded metal case. To assess the TS of the equipment being inspected, it is proposed to first calculate the resonant frequencies of the radiation of the antennas, then calculate the informative frequency bands of radiation associated with the values of the resonant frequencies, and then fix in equivalent conditions the integral powers of quasi-harmonic electromagnetic oscillations in the informative frequency bands of the energy spectra of radiation of vertical polarization from the same type of controlled and reference EEE. Based on the obtained values of the integral powers, based on a comparison of the indicated powers in the same informative bands for the same type and reference equipment, it is proposed to make a conclusion about the defectiveness of each input of the controlled equipment. Further, based on the use of known ratios and computer programs, the resonant frequencies of the radiation of the structural elements of the examined EEE, located inside its metal case, including the metal case itself, are calculated. Allocate in the energy spectra of vertical polarization measured in equivalent conditions from the monitored and reference equipment for each internal structural element of the EEE, including the metal body of this EEE itself, its optimal informative frequency band located inside one or several adjacent informative frequency bands of radiation of the above-mentioned antennas of vertical polarization ... The conclusion about the defectiveness of each internal structural element of the EEE is made on the basis of comparing the maximum intensities of the peaks of electromagnetic oscillations in the same optimal information frequency bands of the energy spectra of radiation of vertical polarization from the same type of controlled and reference equipment, measured in equivalent conditions. The conclusion about the complete defectiveness of the monitored equipment is made on the basis of the obtained data on the defectiveness of each of the voltage inputs, the metal case of this equipment and each of the structural elements located inside it.

The specified method for monitoring the technical condition of electric power equipment is the closest to the claimed technical solution, and is adopted as a prototype.

However, the known prototype method, as well as the analogue method, does not have sufficient diagnostic accuracy, and therefore does not have sufficient reliability in determining the defectiveness of the controlled EEE, which is associated with a significant dependence of the applicability of the method on the number of vertical polarization radiation spectra recorded in equivalent conditions equipment of the same type. This disadvantage especially negatively affects the diagnostic results in the case of an initial examination of a small amount of the same type of equipment, as well as in the case of the next examination, but under working conditions that are very different from the working conditions during previous examinations.

Another disadvantage of the prototype method is the use as qualification properties of energy spectra of radiation, characterizing the degree of defectiveness of external structural elements of the controlled EEE, integral power values, depending on the degree of defectiveness of internal structural elements. Thus, the degree of defectiveness of the external structural elements of the controlled EEE when using the prototype method can be set falsely.

The task to be solved by the claimed invention is to create a method for monitoring the EEE TS, which provides the possibility of establishing the defectiveness of a small amount of the same type of EEE during its initial examination, as well as in the case of the next examination, but under working conditions that are very different from previous examinations of the controlled EEE, which, in comparison with the prototype and other analogs, has increased accuracy and increased diagnostic reliability.

The technical result achieved when solving the problem is expressed in increased accuracy and increased reliability of diagnosing the defectiveness of this equipment, including the possibility of establishing the defectiveness of a small amount of the same type of EEE during its initial examination, as well as in the case of a regular examination, but under operating conditions that are very different from the previous ones. controlled EEE surveys.

To solve the problem, a method is proposed for monitoring the technical condition of electrical power equipment, in which the defectiveness of the controlled equipment under voltage is determined by the electromagnetic radiation of this equipment, and first the resonant frequencies are calculated and informative frequency bands of radiation of the main structural elements of this equipment are recorded, the energy spectra of quasi-harmonic electromagnetic oscillations of vertical polarization from the same type of monitored equipment, located in equivalent conditions, and determine the defectiveness of each main structural element based on a comparison of the qualification properties of the energy spectra of radiation in the same informative frequency bands for the main structural elements of the monitored and reference equipment, and the conclusion about weak or increased total defectiveness of the monitored equipment is made on the basis of the received data The data on defectiveness of each of the main structural elements of this equipment differs in that to determine the degree of defectiveness of external structural elements of the controlled equipment, the energy spectra of low-Q radiation are used, obtained by filtering the recorded energy spectra of quasi-harmonic electromagnetic oscillations of vertical polarization, and the energy spectra of the radiation of the reference equipment themselves, used to determine the defectiveness of the main structural elements of the monitored equipment, are composite and are formed on the basis of the available energy spectra of radiation of vertical polarization from the same type of monitored equipment, recorded under equivalent conditions, by separating among the mentioned spectra the lowest intensities of electromagnetic oscillations for each measured frequency and forming from these intensities uniform energy spectra of radiation vertical polarization of the reference equipment while maintaining the correspondence between the selected intensities and the frequencies belonging to them.

Comparative analysis of the set of essential features of the proposed technical solution and the set of essential features of the prototype and analogues indicates its compliance with the criterion of "novelty".

In this case, the features of the distinctive part of the claims of the invention provide the solution to the following functional problems.

The sign indicating that "to determine the degree of defectiveness of external structural elements of the controlled equipment, the energy spectra of low-quality radiation are used" allows assessing the degree of defectiveness of the external structural elements of the controlled EEE according to data that does not depend on the degree of defectiveness of the internal structural elements of this equipment. This is due to the fact that the internal structural elements of the EEE, in contrast to the external structural elements, are part of high-quality oscillatory systems. Electromagnetic vibrations associated with their defectiveness, radiating into the external space, form high-Q sections on the energy spectra of quasi-harmonic electromagnetic vibrations of vertical polarization against the background of low-Q radiation of external structural elements. Thus, the use of this feature makes it possible to avoid establishing a false degree of defectiveness of the external structural elements of the controlled EEE due to the presence in its energy spectrum of radiation of information about the degree of defectiveness of the internal structural element. This improves the accuracy and reliability of diagnostics.

The sign “… obtained by filtering the registered energy spectra of quasi-harmonic electromagnetic oscillations of vertical polarization…” explains the process of forming the energy spectra of low-Q radiation.

The sign "... the energy spectra of the radiation of the reference equipment used to determine the defectiveness of the main structural elements of the monitored equipment are composite ..." allows using as a reference not a weakly defective sample with minimum radiation intensities in the allocated informative frequency band, or a new sample from a batch of similar samples of the monitored EEE , or the controlled sample itself at the initial stage of its operation, as it was in the prototype method [2], and use a composite energy spectrum, thus expanding the number of available spectra of the same type of equipment, which makes it possible to facilitate the process of identifying signs of defects and increase the diagnostic accuracy. This, in turn, makes it possible to establish the defectiveness of a small amount of the same type of EEE during its initial examination, as well as in the case of the next examination, but under working conditions that are very different from previous examinations of the controlled EEE.

The sign “... and are formed on the basis of the available energy spectra of radiation of vertical polarization from the same type of controlled equipment, recorded in equivalent conditions, by separating among the mentioned spectra the lowest intensities of electromagnetic oscillations for each measured frequency and forming from these intensities uniform energy spectra of radiation of vertical polarization of the reference equipment with maintaining the correspondence between the selected intensities and the frequencies belonging to them ”explains the process of forming composite reference energy spectra of radiation of vertical polarization, which are used to assess the degree of defectiveness of the main structural elements of the controlled EEE.

Isolation of the reference spectrum from the available energy spectra makes it possible to achieve a lower sensitivity of the proposed method to the effects of parasitic external radiation, which makes it possible to increase the accuracy and increase the reliability in comparison with the prototype. This effect is achieved by using the lowest radiation intensities throughout the entire reference spectrum, which is extremely rare when using as a reference the informative frequency bands of the actually existing energy spectra of vertical polarization radiation from a monitored EEE of the same type.

FIG. 1 shows the device of a high-voltage power autotransformer;

in fig. 2 - energy spectra of radiation of vertical polarization at frequencies of 5-35 MHz of three autotransformers of the same type and their composite reference energy spectrum:

a) AT-1 phase A;

b) AT-1 phase B;

c) AT-1 phase C;

d) standard;

in fig. 3 - energy spectra of radiation of vertical polarization at frequencies 108-198 MHz of three autotransformers of the same type and their composite reference energy spectrum:

a) AT-1 phase A;

b) AT-1 phase B;

c) AT-1 phase C;

d) standard;

in fig. 4 - energy spectra of low-quality radiation of vertical polarization at frequencies of 5-35 MHz of three autotransformers of the same type and their composite reference energy spectrum:

a) AT-1 phase A;

b) AT-1 phase B;

c) AT-1 phase C;

d) low-quality standard

and in FIG. 5 - energy spectra of radiation of vertical polarization at frequencies 108-198 MHz of three autotransformers of the same type and their composite reference energy spectrum:

a) AT-1 phase A;

b) AT-1 phase B;

c) AT-1 phase C;

d) low-quality standard.

где n - число натурального ряда, определяющее номер резонанса, h_i - высота излучающей части i-го конструктивного элемента, с - скорость света; а также программы для расчета и моделирования антенн, такие как MMANA-GAL, Altair FEKO, COMSOL Multiphysics, MATLAB и др.), резонансные частоты и информативные частотные полосы излучений основных конструктивных элементов этого оборудования.In the claimed method for monitoring the technical state of the EEE, the defectiveness of the monitored equipment under voltage is determined by the electromagnetic radiation of this equipment. To do this, first calculate using known ratios and computer programs (for example, ratios for calculating the resonance frequencies of whip antenna antennas, such as

where n is the natural number that determines the resonance number, h _i is the height of the emitting part of the i-th structural element, c is the speed of light; as well as programs for calculating and modeling antennas, such as MMANA-GAL, Altair FEKO, COMSOL Multiphysics, MATLAB, etc.), resonant frequencies and informative frequency bands of radiation of the main structural elements of this equipment.

Further, with the help of a measuring receiver, which allows registering the spectra of electromagnetic radiation of vertical polarization in previously defined informative frequency bands, the mentioned informative frequency bands are distinguished, characterizing the defectiveness of external and internal structural elements controlled by the EEE.

The procedure for filtering the available energy spectra of radiation of vertical polarization, recorded from the same type of monitored equipment, under equivalent conditions is carried out. Since the external structural elements of the EEE have a relatively low quality factor (Q≈3.5), the elimination of high-quality radiation from the energy spectra makes it possible to increase their information content for assessing the degree of defectiveness of external structural elements.

On the basis of the available energy spectra of radiation of vertical polarization, recorded from the same type of controlled equipment, located in equivalent conditions, the energy spectra of the radiation of the reference equipment are compiled. For this, it is advisable to use computer programs that allow for the automated allocation of the lowest EMP intensities for each measured frequency that occur at the corresponding frequencies of the energy spectra of all monitored equipment of the same type, which is in equivalent conditions, and from the resulting array of frequencies and the corresponding intensities to form the energy spectrum of the radiation of the reference equipment.

When performing this stage using computer programs (for example, using PTC Mathcad, Microsoft Office Excel, etc.), the procedure for constructing a composite energy spectrum will take much less time than registering an experimental energy spectrum of vertical polarization radiation from one unit of the surveyed equipment.

Values of qualification properties of quasi-harmonic electromagnetic oscillations in informative frequency bands of energy spectra of radiation of vertical polarization are determined, criteria are formed and defectiveness of each main structural element of the controlled equipment is established.

The procedure for determining the values of the integrated powers of electromagnetic oscillations of vertical polarization, emitted in each of the selected informative frequency bands Δf _νi , can be performed in various ways.

To determine the values of the integrated powers of electromagnetic oscillations of vertical polarization, these powers can be calculated directly by integrating the energy spectra of low-Q radiation within each of the selected informative frequency bands Δf _νi . It is advisable to carry out this procedure using computer programs (for example, using PTC Mathcad, Microsoft Office Excel, etc.) in order to obtain maximum accuracy with minimum time consumption.

Taking into account the data obtained on the defects of external and internal structural elements of the same type of monitored equipment, which is in equivalent conditions, criteria for determining complete defects are developed and, applying these criteria, the total defectiveness of the monitored equipment is determined.

The conclusion about the degree of defectiveness of the main structural elements of the monitored equipment is formed on the basis of a comparison of the qualification properties of quasi-harmonic electromagnetic oscillations in the same informative frequency bands for the main structural elements of the monitored and reference equipment. The values of integral powers, maximum peak intensities, amplitudes of individual spectral lines, polymodality, pulse shape, etc. can be used as qualifying properties of electromagnetic oscillations. The conclusion about the complete defectiveness of the monitored equipment is formed on the basis of the obtained data on the defectiveness of each of the main structural elements of this equipment.

We will demonstrate the practical implementation of the proposed method for monitoring EES TS using the example of diagnosing the defectiveness of three high-voltage single-phase autotransformers of the AODTsTN-167000/500/220 type, registration of the energy spectra of vertical polarization radiation from which occurred for the first time, in the absence of energy spectra of vertical polarization radiation recorded from equipment of the same type under similar operating conditions.

FIG. 1 schematically shows the device of the autotransformer AODTsTN-167000/500/220, corresponding to the analytical emitting model of the EEO [3, 4], shows the structural elements located outside and inside the metal body of the autotransformer: 1, 2 - high-voltage (HV) bushings; 3, 4, 5 - low-voltage (LV) bushings; 6 - main metal tank of the autotransformer (metal case): 7 - metal tank of the voltage regulator; 8 - high-voltage winding S ₁ (S _{11 *} , S _{11 **} - upper and lower parts of the winding S ₁ ); 9 - high-voltage winding S ₂ (main); 10 - high-voltage winding S ₃ (adjusting); 11, 12 - low-voltage windings S ₄ (right) and S ₅ (left); 13, 14 - high-voltage power lines; 15 - low-voltage power line; 16 - high-voltage voltage regulator R.

FIG. 2a, 2b, 2c, 3a, 3b, 3c show the results of measurements of the energy spectra of radiation of vertical polarization for three autotransformers of the indicated type, recorded in the frequency ranges of 5-35 MHz and 108-198 MHz. Registration of energy spectra of radiation of vertical polarization from equipment of this type under conditions equivalent to this case, i.e. in similar atmospheric conditions, the same modes of operation of the EEE and with the use of common metric means, has not been previously produced.

In controlled autotransformers HV inputs 1, 2 have a height H ₁ = h ₁ + h ₁₁ , H ₂ = h ₂ + h ₂₁ , HB inputs 3, 4, 5 - H ₃ = h ₃ + h ₃₁ , H ₄ = H ₅ = h ₄ + h ₄₁ = h ₅ + h ₅₁ , where h ₁ , h ₂ , h ₃ , h ₄ , h ₅ - external and h ₁₁ , h ₂₁ , h ₃₁ , h ₄₁ , h ₅₁ - internal parts of inputs 1 , 2, 3, 4, 5. Bushings 1, 2 have external polymer insulation and internal RIP insulation. Bushings 3, 4, 5 have external porcelain insulation, internal oil insulation and solid insulation applied to the surface of the conductive rod.

HV bushings 1 and 2, which do not have oil filling, are _{connected to external HV transmission lines 13, 14 by means of drop wires with vertical projections h 01} and h ₀₂ , passing at a 20-meter height from the earth's surface.

HB inputs 3, 4, 5 have an oil filling in common with the autotransformer tank 6. In this case, inputs 4, 5 are connected to the LV transmission line 15, and input 3 is grounded outside the autotransformer using a metal wire, the length of which is more than 10 meters.

The main electrical power is supplied to the autotransformer through HV bushings 1, 2 and NV grounded bushing 3, the effective voltage value between which is U ₁₃ = 500 / √3 kV (between inputs 1 and 3) and U ₂₃ = 220 / √3 kV (between inputs 2 and 3).

NV inputs 4, 5 are intended for servicing local consumers, and the effective voltage value between them is U ₄₅ = 11 kV.

Inside the main metal tank of autotransformer 6 filled with oil, the following main structural elements are located: three HV electrical windings (serial - S ₁ , main - S ₂ and control S ₃ ), two HB electrical windings (right - S ₄ , left - S ₅ ) and cylindrical metal tank 7, in which there is an explosive voltage regulator R. Electric windings S ₁ , S ₂ , S ₃ , S ₄ , S ₅ are connected in pairs by electromagnetic links M ₁₂ , M ₂₅ , M ₃₄ .

Internal structural elements of the autotransformer, windings S ₁ , S ₂ , S ₃ , S ₄ , S ₅ with the main tank 6 and the voltage regulator R with its tank 7, together with parts of inputs 1, 2, 3, 4, 5 located outside and inside the tank 6, and the sections of the connecting conductors are a set of internal and external-internal high-frequency and ultra-high-frequency oscillatory circuits. In this case, the screen for the windings S ₁ , S ₃ and the internal parts h ₁₁ , h ₂₁ , h ₃₁ , h ₄₁ , h _{51 of the} voltage inputs 1, 2, 3, 4, 5 is the metal case of the main rectangular tank of the autotransformer 6. The screen for the winding S ₂ is the winding S ₁ (winding S ₂ is arranged inside the winding S _1), a screen for winding S ₄ serves winding S ₃ (winding S ₄ is arranged inside the winding S _3), a screen for winding S ₅ is the winding S ₂ (winding S ₅ located inside the winding S ₂ ). The screen for the HV voltage regulator R is the metal body of the cylindrical tank 7 with oil filling, isolated from the oil filling of the main tank of the autotransformer 6.

где n - число натурального ряда, определяющее номер резонанса, h_i - высота излучающей части i-го конструктивного элемента, с - скорость света; а также программу для расчета и моделирования антенн MMANA-GAL, резонансные частоты и информативные частотные полосы излучений антенн вертикальной поляризации, состоящих из наружных вертикальных частей, изолированных от металлического корпуса контролируемого ЭЭО, проводов вводов этого оборудования, а также резонансные частоты и оптимальные информативные частотные полосы каждого внутреннего конструктивного элемента контролируемого ЭЭО, включая и сам металлический корпус, расположенные внутри одной или нескольких соседних информативных частотных полос излучений вышеуказанных антенн вертикальной поляризации.At the first stage of the implementation of the proposed method for monitoring the TS, the EEE is calculated using the ratios for calculating the resonance frequencies of the whip antenna

where n is the natural number that determines the resonance number, h _i is the height of the emitting part of the i-th structural element, c is the speed of light; as well as a program for calculating and modeling MMANA-GAL antennas, resonant frequencies and informative frequency bands of radiation of antennas of vertical polarization, consisting of external vertical parts isolated from the metal case of the controlled EEE, wires of the inputs of this equipment, as well as resonant frequencies and optimal informative frequency bands of each internal structural element of the controlled EEE, including the metal body itself, located inside one or more adjacent informative frequency bands of radiation of the above-mentioned antennas of vertical polarization.

The following results were obtained for the main structural elements of controlled autotransformers.

The values of the informative frequency bands of the main (first) resonances of the radiation of the antennas of vertical polarization formed by the vertical parts of the bushings with the height h ₁ , h ₂ , h ₃ , h ₄ , h ₅ :

Δf _ν1 = 15.2 - 20.2 MHz;

Δf _ν2 = 23.6 - 31.6 MHz;

Δf _ν3 = 109 - 145 MHz;

Δf _ν4.5 = 145.5 - 194.5 MHz.

Quasi-harmonic electromagnetic vibrations of internal structural elements are brought out into the external space by antennas of vertical polarization, formed by the inputs of autotransformers and descents to them. The values of the optimal informative frequency bands of radiation of the internal structural elements of the controlled autotransformers, including the windings S ₁ , S ₂ , S ₃ , S ₄ , S ₅ with the main tank 6 and the voltage regulator R with its tank 7:

Δf _S1 = 8-10.8 MHz;

Δf _S2 = 10.8-13.2 MHz;

Δf _S3 = 13.2-14.4 MHz;

Δf _S4 = 14.4 - 17.4 MHz;

Δf _S5 = 17.9 - 20.5 MHz;

Δf _H = 31.6 - 33 MHz;

Δf _R = 176 - 187 MHz.

The obtained values are similar to those given in the prototype method [2], which indicates the proximity of the geometric dimensions of the controlled autotransformers in the claimed method and the prototype method.

At the second stage, using a measuring receiver consisting of an NS-30a spectrum analyzer and a Delta N311-01 log-periodic antenna, which allows registering the spectra of electromagnetic radiation of vertical polarization in previously defined informative frequency bands, the mentioned informative frequency bands characterizing the defectiveness of external and internal structural elements are distinguished. controlled autotransformers.

FIG. 2a, 2b, 2c, 3a, 3b, 3c show the experimental energy spectra of radiation of vertical polarization for three autotransformers AT-1 f.A, AT-1 f.V, AT-1 f.C, recorded in the frequency ranges 5-35 MHz and 108-198 MHz, respectively.

In the upper portions of FIG. 2a, 3a mark the informative frequency bands of radiation of external and internal structural elements of controlled autotransformers.

At the third stage, the procedure of filtering the available energy spectra of radiation of vertical polarization, recorded from the autotransformers AT-1 f.A, AT-1 f.V, AT-1 f.S in equivalent conditions, is carried out. Since the external structural elements of the EEE have a relatively low quality factor (Q≈3.5), the elimination of high-quality radiation from the energy spectra makes it possible to increase their information content for assessing the degree of defectiveness of external structural elements.

In the case of FIG. 2 and 3, it is advisable to use the following second-order recursive filter:

и

- i-е значения исходного и низкодобротного энергетических спектров соответственно;Where

and

- i-th values of the initial and low-quality energy spectra, respectively;

A is the coefficient corresponding to the settings of the measuring equipment when registering EMP at a certain frequency section;

- частотный интервал между соседними значениями спектра, МГц;

- frequency interval between adjacent spectrum values, MHz;

n = 2 - filter order.

The obtained energy spectra of low-Q radiation are shown in Fig. 4a, 4b, 4c, 5a, 5b, 5c.

At the fourth stage, based on the available energy spectra of radiation of vertical polarization, recorded from autotransformers AT-1 f.A, AT-1 f.B, AT-1 f.C in equivalent conditions, the energy spectra of the radiation of the reference equipment are compiled

As an example, consider the process of constructing the energy spectrum of the radiation of reference equipment at a frequency of 50 MHz. Among the available energy emission spectra of autotransformers AT-1 f.A, AT-1 f.V, AT-1 f.C (Fig.2a, 2b, 2c, 3a, 3b, 3c), the following EMR intensities correspond to a frequency of 50 MHz:

- AT-1 ph.A: minus 154.077 dBW / Hz;

- AT-1 ph.V: minus 153.078 dBW / Hz;

- AT-1 f.S: minus 154.516 dBW / Hz.

The lowest for this frequency is the intensity of the EMR of the AT-1 f.S. autotransformer. Consequently, the energy spectrum of the reference equipment at a frequency of 50 MHz will have an EMP intensity value minus 154.516 dBW / Hz.

FIG. 2d, 3d show the composite energy spectra of the radiation of the reference autotransformer (reference), and in Fig. 4d, 5d show the composite energy spectra of low-quality emissions from a reference autotransformer (low-quality standard), plotted in the frequency ranges of 5-35 MHz and 108-198 MHz.

At the fifth stage, the values of the qualification properties of quasi-harmonic electromagnetic oscillations in the informative frequency bands of the energy spectra of radiation of vertical polarization are determined, criteria are formed and the defectiveness of each main structural element of the controlled autotransformers is determined.

As qualification properties characterizing the defectiveness of the main external structural elements of autotransformers, we will use the values of the integrated powers of electromagnetic oscillations of vertical polarization, emitted in each of the selected informative frequency bands Δf _νi , where i is the serial number of the input.

The procedure for determining the values of the integrated powers of electromagnetic oscillations of vertical polarization, emitted in each of the selected informative frequency bands Δf _νi , can be performed in various ways. In the prototype [2], a method was used that proposes to determine the values of the integral powers by registering the number of peaks of radiation with intensities equal to and above the boundary level γ _al . The choice of the value of the very boundary level γ _{al is} made so that, in relation to the already available experimental data, to obtain at least three distinguishable gradations of defectiveness of the "i" -th inputs of the investigated autotransformers. This method is not suitable for this case, mainly due to the lack of reliable information about the actual defects of controlled autotransformers. In contrast to the case of the prototype [2], all three autotransformers have the same service life and may well have the same level of defect.

To determine the values of the integrated powers of electromagnetic oscillations of vertical polarization, these powers can be calculated directly by integrating the energy spectra of low-Q radiation within each of the selected informative frequency bands Δf _νi . This procedure was performed using the Microsoft Office Excel program in order to obtain maximum accuracy with a minimum amount of time.

As a result of calculations, the following values of the integral powers of the energy spectra of low-Q radiation of vertical polarization, recorded in each of the selected informative frequency bands Δf _{νi, were obtained} .

For the informative frequency band Δf _ν1 , characterizing the technical condition of input 1:

- AT-1 phase A - 8.331⋅10 ^-9 W;

- AT-1 phase B - 1.572⋅10 ^-8 W;

- AT-1 phase C - 5.285⋅10 ^-9 W;

- low-quality standard - 5.009⋅10 ^-9 W.

For the informative frequency band Δf _ν2 , characterizing the technical condition of input 2:

- AT-1 phase A - 5.189⋅10 ^-9 W;

- AT-1 phase B - 4.886⋅10 ^-9 W;

- AT-1 phase C - 3.550⋅10 ^-9 W;

- low-quality standard - 3.031⋅10 ^-9 W.

For informative frequency band Δf _ν3 , characterizing the technical condition of input 3:

- AT-1 phase A - 2.247⋅10 ^-8 W;

- AT-1 phase B - 1.466⋅10 ^-8 W;

- AT-1 phase C - 1.241⋅10 ^-8 W;

- low-quality standard - 1.107⋅10 ^-8 W.

For the informative frequency band Δf _ν4.5 , characterizing the technical condition of inputs 4 and 5:

- AT-1 phase A - 1.441⋅10 ^-8 W;

- AT-1 phase B - 1.336⋅10 ^-8 W;

- AT-1 phase C - 1.325⋅10 ^-8 W;

- low-quality standard - 1.234⋅10 ^-8 W.

Taking into account the data obtained and the accumulated experience in the application of the proposed method for monitoring the technical condition of electric power equipment, the following criteria can be formulated for determining the defects of the "i" -x inputs of controlled autotransformers by their low-quality radiation of vertical polarization in informative frequency bands Δf _νi :

- weak defectiveness of the input - the integrated power of low-quality radiation of vertical polarization in the informative frequency band of the "i" -th input of the controlled autotransformer exceeds the similar integrated power of the low-quality standard by less than 3 times;

- Moderate defectiveness of the input - the integrated power of low-quality radiation of vertical polarization in the informative frequency band "i" -th input of the controlled autotransformer exceeds the similar integrated power of the low-quality standard by 3-8 times;

- strong defectiveness of the input - the integrated power of low-quality radiation of vertical polarization in the informative frequency band of the "i" -th input of the controlled autotransformer exceeds the analogous integrated power of the low-quality standard by more than 8 times.

To determine the defectiveness of the "i" -th inputs of the investigated autotransformers, we will write down the multiplicity of the integral powers of electromagnetic oscillations of vertical polarization in the informative frequency bands Δf _νi .

For the informative frequency band Δf _ν1 , characterizing the technical condition of input 1:

- AT-1 phase A - exceeding the reference value by 1.66 times;

- AT-1 phase B - exceeding the reference value by 3.14 times;

- AT-1 phase C - exceeding the reference value by 1.06 times.

For the informative frequency band Δf _ν2 , characterizing the technical condition of input 2:

- AT-1 phase A - exceeding the reference value by 1.71 times;

- AT-1 phase B - exceeding the reference value by 1.61 times;

- AT-1 phase C - exceeding the reference value by 1.17 times.

For informative frequency band Δf _ν3 , characterizing the technical condition of input 3:

- AT-1 phase A - exceeding the reference value by 2.03 times;

- AT-1 phase B - exceeding the reference value by 1.32 times;

- AT-1 phase C - exceeding the reference value by 1.12 times.

For the informative frequency band Δf _ν4.5 , characterizing the technical condition of inputs 4 and 5:

- AT-1 phase A - exceeding the reference value by 1.17 times;

- AT-1 phase B - exceeding the reference value by 1.08 times;

- AT-1 phase C - exceeding the reference value by 1.07 times.

Applying the formed criteria to the experimental data, we obtain the following estimates for the defectiveness of the bushings of the investigated autotransformers of the same type:

- AT-1 phase A: defectiveness of all inputs - weak;

- AT-1 phase B: the defectiveness of bushing 1 is moderate, the defectiveness of other bushings is weak;

- AT-1 phase C: defectiveness of all inputs - weak.

Note that a comparison of the multiplicities of the integrated powers of electromagnetic oscillations of vertical polarization emitted in each of the selected informative frequency bands Δf _νi , without filtering the spectra from high-Q radiation and in the absence of a composite reference spectrum, as implied in the prototype [2], would inevitably make for the standard, the section of the EMP spectrum of the available autotransformer with the lowest integrated power within a specific frequency band Δf _νi , and the values of the integrated power themselves would be greater by an amount from 3 to 725 percent.

For example, for the informative frequency band Δf _ν1 characterizing the technical condition of bushing 1, the following values of the integral powers of the energy spectra of radiation of vertical polarization would be obtained:

- AT-1 phase A - 6.877⋅10 ^-8 W;

- AT-1 phase B - 3.834⋅10 ^-8 W;

- AT-1 phase C (standard) - 3.539⋅10 ^-8 W.

In this case, the degree of defectiveness of each bushing of the monitored equipment would be assessed as weak, and the multiplicity of the integral powers of electromagnetic oscillations of vertical polarization in the informative frequency band Δf _ν1 , which characterizes the technical condition of bushing 1, for AT-1 of phase B would be only 1.08. Such a difference in the results is caused by the presence of a significant number of high-Q emissions on the energy spectra of the AT-1 phase C emissions, which are not related to the technical state of the input 1 of the autotransformer.

Thus, the filtering procedure and the use of a composite reference energy spectrum of radiation of vertical polarization made it possible to increase not only the accuracy and reliability, but also the quality of detecting bushing defects using the example of controlled autotransformers.

As qualification properties characterizing the defectiveness of the main internal structural elements of autotransformers, we will use the values of the maximum intensities of the peaks of electromagnetic oscillations in the optimal informative frequency bands Δf _Kj for each K _j -th internal structural element, where K denotes the type of element, j is its serial number.

The maximum intensities of peaks of electromagnetic oscillations in the optimal informative frequency band Δf _S1 , characterizing the technical state of the explosive winding S ₁ (and parts S ₁₁ ^* , S ₁₁ ^{** of} this winding), in the energy spectra of the radiation of vertical polarization of controlled autotransformers are (see Fig. 2 ):

- АТ-1 phase А: minus 136.83 dBW / Hz;

- AT-1 phase B: minus 143.91 dBW / Hz;

- АТ-1 phase С: minus 140.83 dBW / Hz;

- standard: minus 147.22 dBW / Hz.

The maximum peak intensity of electromagnetic waves in an optimal informative frequency band Δf _S2, the technical status of BB winding S _2, the energy spectra of radiation of vertical polarization controlled up autotransformers (see FIG 2..):

- АТ-1 phase А: minus 134.27 dBW / Hz;

- AT-1 phase B: minus 141.69 dBW / Hz;

- АТ-1 phase С: minus 140.66 dBW / Hz;

- standard: minus 145.52 dBW / Hz.

The maximum intensities of the peaks of electromagnetic oscillations in the optimal informative frequency band Δf _S3 , which characterizes the technical condition of the explosives of the winding S ₃ , in the energy spectra of the radiation of vertical polarization of controlled autotransformers are (see Fig. 2):

- АТ-1 phase А: minus 123.18 dBW / Hz;

- AT-1 phase B: minus 139.08 dBW / Hz;

- АТ-1 phase С: minus 141.25 dBW / Hz;

- reference: minus 145.30 dBW / Hz.

The maximum intensities of the peaks of electromagnetic oscillations in the optimal informative frequency band Δf _S4 , which characterizes the technical condition of the NV winding S ₄ , in the energy spectra of the radiation of vertical polarization of controlled autotransformers are (see Fig. 2):

- АТ-1 phase А: minus 121.18 dBW / Hz;

- AT-1 phase B: minus 125.91 dBW / Hz;

- AT-1 phase C: minus 134.15 dBW / Hz;

- standard: minus 137.11 dBW / Hz.

The maximum intensities of the peaks of electromagnetic oscillations in the optimal informative frequency band Δf _S5 , which characterizes the technical condition of the NV winding S ₅ , in the energy spectra of the radiation of vertical polarization of controlled autotransformers are (see Fig. 2):

- АТ-1 phase А: minus 144.13 dBW / Hz;

- AT-1 phase B: minus 139.77 dBW / Hz;

- АТ-1 phase С: minus 140.55 dBW / Hz;

- standard: minus 145.38 dBW / Hz.

The maximum intensities of the peaks of electromagnetic oscillations in the optimal informative frequency band Δf _H , characterizing the technical condition of the main tank 6, in the energy spectra of the radiation of vertical polarization of controlled autotransformers are (see Fig. 2):

- АТ-1 phase А: minus 147.71 dBW / Hz;

- AT-1 phase B: minus 147.27 dBW / Hz;

- АТ-1 phase С: minus 148.96 dBW / Hz;

- standard: minus 150.85 dBW / Hz.

The maximum intensities of the peaks of electromagnetic waves in the optimal informative frequency band Δf _R , which characterizes the technical state of the explosives of the voltage regulator R with tank 7, in the energy spectra of the radiation of vertical polarization of controlled autotransformers are (see Fig. 3):

- АТ-1 phase А: minus 150.21 dBW / Hz;

- AT-1 phase B: minus 150.24 dBW / Hz;

- АТ-1 phase С: minus 150.65 dBW / Hz;

- standard: minus 152.49 dBW / Hz.

Taking into account the data obtained and the accumulated experience in the application of the proposed method for monitoring the technical condition of electric power equipment, the following criteria can be formulated for determining the defects of the internal Kj-x structural elements of monitored autotransformers by their EMP of vertical polarization in informative frequency bands Δf _Kj , similar to the prototype method [2] :

- weak defectiveness - the maximum intensities of the radiation peaks are less than 20 dB higher than those in the spectrum of the reference sample;

- moderate defectiveness - the maximum intensities of the radiation peaks are 20-40 dB higher than those in the spectrum of the reference sample;

- strong defectiveness - the maximum intensities of the radiation peaks are more than 40 dB higher than those in the spectrum of the reference sample.

Using the formed criteria, we will determine the defectiveness of all the main internal structural elements in controlled autotransformers:

- AT-1 phase A: defectiveness of HV windings S ₁ , S ₂ , HB windings S ₄ , S ₅ , grounded main tank of autotransformer 6 and HV voltage regulator R with tank 7 - weak; defectiveness of the explosive winding S ₃ - moderate;

- AT-1 phase B: defectiveness of HV windings S ₁ , S ₂ , S ₃ , HB windings S ₄ , S ₅ , grounded main tank of autotransformer 6 and HV voltage regulator R with tank 7 - weak;

- AT-1 phase C: defectiveness of HV windings S ₁ , S ₂ , S ₃ , HB windings S ₄ , S ₅ , grounded main tank of autotransformer 6 and HV voltage regulator R with tank 7 are weak.

Note that in the absence of a composite reference energy spectrum, as implied in the prototype method [2], the values of the maximum intensities of the radiation peaks of the reference sections of the real energy spectra would be higher:

- for Δf _S1 - by 3.31 dB;

- for Δf _S2 - by 3.83 dB;

- for Δf _S3 - by 4.05 dB;

- for Δf _S4 - by 2.96 dB;

- for Δf _S5 - by 1.25 dB;

- for Δf _Н - by 1.89 dB;

- for Δf _R - by 1.84 dB.

At the same time, the maximum intensity of the peak of electromagnetic oscillations in the optimal informative frequency band Δf _S3 for the explosive winding S ₃ in the energy spectrum of the AT-1 f.A autotransformer would exceed the reference value only by 18.07 dB (and not by 22.12, as in the claimed method), which would characterize the defectiveness of the winding as weak, not moderate.

Thus, the use of a composite reference energy spectrum of radiation of vertical polarization made it possible to increase not only the accuracy and reliability, but also the quality of detecting defects in the internal structural elements of the EEE using the example of controlled autotransformers.

At the sixth stage, taking into account the data obtained on the defects of external and internal structural elements of controlled autotransformers, criteria for determining complete defects are developed and, applying these criteria, the complete defects of controlled autotransformers are determined.

Based on the data obtained above on the defects of external and internal structural elements of controlled autotransformers, the following criteria can be formulated for determining their complete defects, similar to the prototype method [2]:

- weak complete defectiveness of the autotransformer corresponds to weak defectiveness of all its main structural elements;

- moderate complete defectiveness of the autotransformer corresponds to moderate defects 1-12 of its main structural elements with weak defects of other structural elements;

- strong complete defectiveness of the autotransformer corresponds to strong defects 1-6 of its main structural elements with weak and (or) moderate defects of other structural elements;

- dangerous complete defectiveness of the autotransformer corresponds to strong defectiveness of 7-12 of its main structural elements with weak and (or) moderate defectiveness of other structural elements.

Using the obtained criteria, we will determine the total defectiveness of controlled autotransformers.

- АТ-1 phase А: defectiveness of inputs 1, 2, 3, 4, 5, windings S ₁ , S ₂ , S ₄ , S ₅ , the main tank of the autotransformer 6 and BB of the voltage regulator R with tank 7 - weak; defectiveness of the winding S ₃ - moderate; complete defectiveness - moderate;

- AT-1 phase B: defectiveness of inputs 2, 3, 4, 5, windings S ₁ , S ₂ , S ₃ , S ₄ , S ₅ , the main tank of the autotransformer 6 and BB voltage regulator R with tank 7 - weak; input defectiveness 1 - moderate; complete defectiveness - moderate;

- AT-1 phase C: defectiveness of all main structural elements - weak; complete defectiveness is weak.

Note that in the absence of a composite reference energy spectrum, as well as without filtering the energy spectra to assess the technical condition of external structural elements, as implied in the prototype method [2], the complete defectiveness of autotransformers AT-1 f.A and AT-1 W would be judged weak rather than moderate.

Thus, the conclusions drawn on the basis of the analysis of the measured energy spectra of the radiation of vertical polarization and determination, using the proposed method for monitoring the technical condition of electric power equipment, the defects of the main internal and external structural elements and the complete defects of the monitored autotransformers, qualitatively clarify and supplement the conclusions that would be obtained with application of the prototype method [2]. The findings are in good agreement with the results of routine tests to assess the technical condition of the autotransformers considered in this example, carried out according to [5, 6].

The given example of the implementation of the proposed method for monitoring the technical condition of electric power equipment shows its advantages in comparison with the prototype method [2] in terms of improving the reliability of diagnosing the defectiveness of the monitored equipment by increasing the accuracy of assessing the technical state of its structural elements.

From the above it follows that the claimed method for monitoring the technical state of the EEE has, in comparison with the prototype [2] and analogue [1], sufficient novelty, increased accuracy and increased diagnostic reliability, makes it possible to establish the defectiveness of a small amount of the same type of EEE during its initial examination, and also in the case of the next examination, but under very different working conditions from the previous examinations.

Information sources

1. Patent RU 2311652, publ. 11/27/2007 - analog.

2. Patent RU 2426997, publ. 08/20/2011 - prototype.

3. Klokov V., Losev V., Popovich A., Silin N. Emitting model of the power electric equipment. Proceedings of the 8-th International Symposium on Electromagnetic Compatibility and Electromagnetic Ecology. S. Petersburg, June 16-19, 2009 (pp. 36-38).

4. Klokov V., Losev V., Popovich A., Silin N. Diagnostics of power electric equipment according to its parasite electromagnetic radiation. Proceedings of the 8-th International Symposium on Electromagnetic Compatibility and Electromagnetic Ecology. S. Petersburg, June 16-19, 2009 (pp. 36-38).

5. RD 153-34.0-46.302-00. Guidelines for the diagnosis of developing defects in transformer equipment based on the results of chromatographic analysis of gases dissolved in oil. - Moscow, 2001 .-- 42 p.

6. STO 34.01-23.1-001-2017 The scope and standards of testing of electrical equipment. - PJSC Rosseti, 2017 .-- 262 p.

Claims (1)

A method for monitoring the technical condition of electrical power equipment, in which the defectiveness of the controlled equipment under voltage is determined by the electromagnetic radiation of this equipment, and first, the resonant frequencies are calculated and informative frequency bands of radiation of the main structural elements of this equipment are determined, the energy spectra of quasi-harmonic electromagnetic oscillations of vertical polarization from of the same type of monitored equipment in equivalent conditions and determine the defectiveness of each main structural element based on a comparison of the qualification properties of the energy spectra of radiation in the same informative frequency bands for the main structural elements of the monitored and reference equipment, and the conclusion about the weak or increased total defectiveness of the monitored equipment is made on based on the data obtained on the defects of each of the main cons structural elements of this equipment, characterized in that to determine the degree of defectiveness of external structural elements of the monitored equipment, the energy spectra of low-quality radiation are used, obtained by filtering the registered energy spectra of quasi-harmonic electromagnetic oscillations of vertical polarization, and the energy spectra of the radiation of the reference equipment used to determine the defectiveness of the main structural elements of the monitored equipment are composite and are formed on the basis of the available energy spectra of radiation of vertical polarization from the same type of monitored equipment, recorded in equivalent conditions, by separating among the mentioned spectra the lowest intensities of electromagnetic oscillations for each measured frequency and forming from these intensities uniform energy spectra of radiation of vertical polarization reference equipment with maintaining the correspondence between the selected intensities and the frequencies belonging to them.

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