GIS disconnector contact multi-state parameter evaluation method

Abstract

The application provides a GIS disconnector contact multi-state parameter evaluation method, and belongs to the technical field of power equipment state evaluation, and comprises the following steps: calculating the difference between the measured value and the empirical value of the shell temperature rise, and taking the difference as a temperature characteristic quantity; calculating the difference between the measured value and the empirical value of the shell vibration amplitude, and the difference between the measured value and the empirical value of the vibration frequency proportion, and taking these quantities as vibration characteristic quantities; calculating the difference between the measured value and the empirical value of the maximum discharge amplitude, and taking the difference as a partial discharge characteristic quantity; after the temperature characteristic quantity, the vibration characteristic quantity and the partial discharge characteristic quantity are subjected to normalization processing, the normalized characteristic quantities are input into a trained classifier, and the classification result of the GIS disconnector contact state is given by the classifier. The method can determine the contact state of the GIS disconnector.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of power equipment state evaluation, and particularly relates to a GIS disconnector contact multi-state parameter evaluation method. BACKGROUND

[0002] A gas insulated metal-enclosed switchgear (GIS) is composed of disconnectors, circuit breakers, busbars, current transformers, voltage transformers, arresters, bushings and other components. Based on the advantages of compact structure, small floor area, not easy to be affected by climate and environmental conditions, flexible and convenient installation and configuration, low noise level, strong anti-seismic ability, no static induction and corona interference, the GIS device is rapidly promoted and used in the power system. In recent years, faults caused by GIS disconnectors have occurred from time to time. As a typical mechanical and electrical hybrid device, the GIS disconnector needs to be frequently opened and closed in the operation and maintenance of the power grid, and therefore its faults are mainly mechanical state deterioration and abnormal contact state of the moving and static contacts. If the contact state of the disconnector cannot be accurately evaluated in time, the contact fault will further develop into a breakdown discharge, or even cause more serious electrical accidents, which seriously affects the stable operation of the power system.

[0003] The GIS disconnector contact state deterioration is a comprehensive process of electricity, machinery and heat. The existing GIS disconnector contact state evaluation methods are mostly based on a single state parameter, and the influence of multiple state parameters is not comprehensively considered, so that the accuracy and effectiveness of the evaluation results need to be improved. SUMMARY

[0004] In order to overcome the deficiencies of the prior art, the application provides a GIS disconnector contact multi-state parameter evaluation method.

[0005] In order to achieve the above purpose, the application provides the following technical scheme:

[0006] A GIS disconnector contact multi-state parameter evaluation method comprises the following steps: measuring the shell surface temperature T1 of the GIS disconnector contact part, the environmental temperature T0 and the current I;

[0007] Calculating the measured value T2 of the shell temperature rise, T2=T1-T0;

[0008] Using experiments or simulation to establish a fitting equation of the empirical value of the shell temperature rise and the current, substituting the measured current I into the fitting equation to calculate the empirical value of the shell temperature rise;

[0009] Calculating the difference between the measured value and the empirical value of the shell temperature rise, and taking it as a temperature characteristic quantity;

[0010] The temperature characteristic quantity, the GIS disconnector vibration characteristic quantity and the GIS disconnector partial discharge characteristic quantity are input into the trained classifier after normalization, and the classification result of the GIS disconnector contact state is given by the classifier.

[0011] Further, the classifier is a weighted naive Bayes classifier, and the classification criterion is a minimum error rate criterion.

[0012] Further, the fitting equation of the shell temperature rise empirical value and the current established by using the experiment comprises:

[0013] An experimental platform comprising a current source, a GIS disconnector and a temperature sensor is constructed.

[0014] The temperature sensor is placed at the shell of the GIS disconnector, and the GIS disconnector contact state is set to normal.

[0015] Different sizes of currents are input into the GIS disconnector, and the shell temperature rise is recorded after the GIS disconnector temperature stabilizes.

[0016] The fitting equation of the shell temperature rise empirical value and the current is established according to the current and the shell temperature rise.

[0017] Further, the fitting equation of the shell temperature rise empirical value and the current established by using the simulation comprises:

[0018] A GIS disconnector geometric model is constructed.

[0019] Material parameters, physical field control equations, boundary conditions and coupling relationships between physical fields are set for the geometric model.

[0020] The geometric model is meshed, and a finite element algorithm is used for solution calculation to obtain the GIS disconnector steady-state temperature field distribution, and the construction of the simulation model is completed.

[0021] On the basis of the simulation model, the disconnector contact is set to normal, different sizes of currents are input into the disconnector, the steady-state temperature distribution of the GIS disconnector is simulated, and the shell temperature rise is recorded.

[0022] The fitting equation of the shell temperature rise empirical value and the current is established according to the current and the shell temperature rise relationship.

[0023] Further, the extraction of the GIS disconnector vibration characteristic quantity comprises:

[0024] The vibration signal and the current of the GIS disconnector shell are measured.

[0025] The vibration signal amplitude is obtained from the vibration signal time domain waveform.

[0026] The component proportion of the 100Hz vibration signal and its multiple frequency components is obtained through spectrum analysis of the vibration signal;

[0027] A fitting equation of the shell vibration amplitude, the vibration frequency proportion and the current is established by experiment or simulation;

[0028] The measured current I is substituted into the fitting equation to calculate the empirical value of the shell vibration amplitude and the empirical value of the component proportion of the 100Hz vibration signal and its multiple frequency components;

[0029] The difference between the measured value and the empirical value of the shell vibration amplitude and the difference between the measured value and the empirical value of the vibration frequency proportion are calculated, and these quantities are used as the vibration characteristic quantity.

[0030] Further, the fitting equation of the shell vibration amplitude, the vibration frequency proportion and the current established by experiment comprises:

[0031] An experimental platform including a current source, a GIS disconnector and a vibration sensor is constructed;

[0032] The vibration sensor is placed at the shell of the disconnector;

[0033] The contact state of the disconnector is set to be normal, different sizes of current are input into the disconnector each time, the vibration amplitude and the vibration frequency proportion at the shell are recorded, and the fitting equation of the shell vibration amplitude, the vibration frequency proportion and the current is established according to the current and the amplitude and the vibration frequency proportion at the shell.

[0034] Further, the fitting equation of the shell vibration amplitude, the vibration frequency proportion and the current established by simulation comprises: a GIS disconnector vibration simulation experiment model is established, which comprises:

[0035] A geometric model is constructed;

[0036] Material parameters, physical field control equations, boundary conditions and coupling relationships between physical fields are set for the geometric model;

[0037] The geometric model is meshed and solved by using the finite element algorithm to obtain the mechanical field distribution of the GIS disconnector and complete the construction of the simulation model;

[0038] On the basis of the simulation model, the contact of the disconnector is set to be normal, different sizes of current are input into the disconnector, the mechanical field distribution of the GIS disconnector is simulated, and the vibration signal at the shell is recorded. According to the current and the amplitude and the vibration frequency proportion at the shell, the fitting equation of the shell vibration amplitude, the vibration frequency proportion and the current is established.

[0039] Further, the extraction of the GIS disconnector partial discharge characteristic quantity comprises:

[0040] The discharge spectrum and voltage U of the GIS disconnector partial discharge are measured, and the maximum discharge amplitude is obtained from the discharge spectrum;

[0041] A fitting equation of the maximum discharge amplitude empirical value and the voltage is established by experiment or simulation;

[0042] The measured voltage is substituted into the fitting equation to calculate the maximum discharge amplitude empirical value;

[0043] The difference between the measured value and the empirical value of the maximum discharge amplitude is calculated as a partial discharge characteristic quantity;

[0044] After normalization, the temperature characteristic quantity, the vibration characteristic quantity and the partial discharge characteristic quantity are input into the trained classifier to give the classification result of the GIS disconnector contact state.

[0045] Further, the fitting equation of the maximum discharge amplitude empirical value and the voltage established by experiment includes:

[0046] An experimental platform including a voltage source, a GIS disconnector and a UHF sensor is constructed;

[0047] The UHF sensor is placed on an insulating basin near the GIS disconnector;

[0048] The disconnector contact state is set to be normal, different voltages are applied to the disconnector each time, the maximum discharge amplitude is recorded, and the fitting equation of the maximum discharge amplitude empirical value and the voltage is established according to the experimental data.

[0049] Further, the fitting equation of the maximum discharge amplitude empirical value and the voltage established by simulation includes:

[0050] A geometric model is constructed;

[0051] Material parameters, physical field control equations, boundary conditions and coupling relationships between physical fields are set for the geometric model;

[0052] The geometric model is meshed and solved by a finite element algorithm to obtain the electromagnetic field distribution of the GIS disconnector and complete the construction of the simulation model;

[0053] On the basis of the simulation model, the disconnector contact is set to be normal, different voltages are loaded in the disconnector, the electromagnetic field distribution of the GIS disconnector is simulated, and the discharge signal amplitude is calculated;

[0054] According to the discharge signal amplitude and the voltage data, the fitting equation of the maximum discharge amplitude empirical value and the voltage is established.

[0055] The GIS disconnector contact multi-state parameter evaluation method provided by the application has the following beneficial effects:

[0056] The application considers abnormal heating, abnormal vibration and partial discharge phenomenon when the disconnector contact is abnormal, and evaluates the disconnector state by comprehensively considering temperature characteristic quantity, vibration characteristic quantity and partial discharge characteristic quantity, thereby solving the problem in the prior art that the GIS disconnector contact state evaluation method is mostly based on a single state parameter and fails to comprehensively consider the influence of multiple state parameters, so that the accuracy and effectiveness of the evaluation result need to be improved. BRIEF DESCRIPTION OF DRAWINGS

[0057] In order to more clearly illustrate the embodiments of the application and the design scheme thereof, the drawings required by the embodiments will be briefly introduced as follows. The drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings.

[0058] Figure 1 A GIS disconnector contact multi-state parameter evaluation method is shown in the figure.

[0059] Figure 2 A GIS disconnector geometric model is shown in the figure.

[0060] Figure 3 A GIS disconnector temperature field distribution is shown in the figure.

[0061] Figure 4 A GIS disconnector vibration signal is shown in the figure.

[0062] Figure 5 A GIS disconnector partial discharge signal discharge spectrum is shown in the figure.

[0063] Figure 6 Three different contact states of a GIS disconnector are shown in the figure. DETAILED DESCRIPTION

[0064] In order to make those skilled in the art better understand the technical scheme of the application and can implement it, the application will be described in detail below in combination with the drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical scheme of the application, and cannot be used to limit the protection scope of the application.

[0065] Embodiment:

[0066] The application provides a GIS disconnector contact multi-state parameter evaluation method, and specifically as shown in the figure, which comprises the following steps: Figure 1 The temperature characteristic quantity of the GIS disconnector is extracted, which comprises the following steps: measuring the surface temperature T1 of the GIS disconnector contact part shell, the environmental temperature T0 and the current I; calculating the measured value T2 of the shell temperature rise, and the algorithm is T2=T1-T0; using experiments or simulation to establish a fitting equation of the empirical value of the shell temperature rise and the current, substituting the measured current I into the fitting equation to calculate the empirical value of the shell temperature rise; and calculating the difference between the measured value and the empirical value of the shell temperature rise, which is taken as the temperature characteristic quantity.

[0067] The vibration characteristic quantity of the GIS disconnector is extracted, which comprises the following steps: measuring the vibration signal of the GIS disconnector shell and the current; obtaining the vibration signal amplitude through the time domain waveform of the vibration signal; obtaining the component proportion of the 100 Hz vibration signal and its multiple frequency components through the frequency spectrum analysis of the vibration signal; using experiments or simulation to establish a fitting equation of the shell vibration amplitude, the vibration frequency proportion and the current; substituting the measured current I into the fitting equation to calculate the empirical value of the shell vibration amplitude and the component proportion of the 100 Hz vibration signal and its multiple frequency components; and calculating the difference between the measured value and the empirical value of the shell vibration amplitude and the difference between the measured value and the empirical value of the vibration frequency proportion, which are taken as the vibration characteristic quantity.

[0068] The partial discharge characteristic quantity of the GIS disconnector is extracted, which comprises the following steps: measuring the discharge spectrum of the GIS disconnector partial discharge and the voltage U, and obtaining the maximum discharge amplitude M through the discharge spectrum; using experiments or simulation to establish a fitting equation of the maximum discharge amplitude empirical value and the voltage; substituting the measured voltage U into the fitting equation to calculate the maximum discharge amplitude empirical value; and calculating the difference between the measured value and the empirical value of the maximum discharge amplitude, which is taken as the partial discharge characteristic quantity; after the temperature characteristic quantity, the vibration characteristic quantity and the partial discharge characteristic quantity are normalized, they are input into the trained classifier, and the classification result of the GIS disconnector contact state is given through the classifier.

[0069] The following are specific implementation details of the application:

[0070] The temperature characteristic quantity extraction process comprises the following steps: detecting the GIS disconnector shell temperature T1, the environmental temperature T0 and the current I.

[0071] Preferably, for the detection of the GIS disconnector shell temperature, the detection of the GIS disconnector contact part shell surface temperature is specifically performed, and the shell vertex is selected here.

[0072] The measured value of the shell temperature rise is T2=T1-T0. The difference between the measured value T2 of the shell temperature rise and the empirical value T2' of the shell temperature rise is obtained as ΔT. Before performing this step, the empirical value T2' of the shell temperature rise is solved first.

[0073] Before solving the empirical value T2' of the shell temperature rise, first, a fitting equation of the shell temperature rise T2' and the current I' is established, that is, T2'=f(I').

[0074] Before establishing the fitting equation of the shell temperature rise and the current T2'=f(I'), first, a physical experiment model or a simulation experiment model of the GIS disconnector temperature rise is established.

[0075] If the physical experiment model of the GIS disconnector temperature rise is established, an experimental platform including a current source, a GIS disconnector, and a temperature sensor needs to be constructed. The temperature sensor is placed at the shell of the disconnector. The contact state of the disconnector is set to be normal, and each time a different size of current I' is input into the inside of the disconnector. After the temperature of the GIS disconnector is stable, the temperature rise T2' at the shell is recorded. According to the current and the temperature rise at the shell, a fitting equation about the two, T2'=f(I'), is established.

[0076] If the simulation experiment model of the GIS disconnector temperature rise is established, a GIS disconnector electromagnetic-thermal-flow multi-physical field simulation model needs to be constructed. The steps of constructing the simulation model are as follows: constructing a geometric model, setting material parameters, setting physical field control equations, boundary conditions, setting the coupling relationship between physical fields, meshing the geometric model, and using the finite element algorithm to solve and calculate to obtain the steady-state temperature field distribution of the GIS disconnector. On the basis of the simulation model, the contact of the disconnector is set to be normal, and different sizes of currents are set to be input into the disconnector. The steady-state temperature distribution of the GIS disconnector is simulated to record the temperature rise at the shell. According to the current and the temperature rise at the shell, a fitting equation about the two, T2'=f(I'), is established. The results of the simulation experiment need to be verified by experiments before being used.

[0077] The measured current I is substituted into the fitting equation T2'=f(I') to calculate the empirical value T2' of the shell temperature rise.

[0078] The difference AT=T2-T2' between the measured value and the empirical value of the shell temperature rise is calculated as a temperature characteristic quantity.

[0079] The vibration characteristic quantity extraction process includes:

[0080] The GIS disconnector shell vibration signal is detected to obtain the time domain waveform of the vibration signal, and the current I is detected.

[0081] Preferably, for the detection of the GIS disconnector shell vibration signal, the detection of the vibration signal on the surface of the GIS disconnector contact part is specifically performed, and the vertex of the shell is selected.

[0082] The measured amplitude A of the vibration signal is obtained through the time domain waveform.

[0083] The vibration signal is subjected to frequency spectrum analysis to obtain component proportion P of the vibration signal 100 Hz and its multiple frequency components 100 ,P 200 ,P 300 ,L. The number of multiple frequency component proportions and the multiple frequency component proportions are determined according to specific conditions.

[0084] The measured amplitude A of the shell vibration signal is subtracted from the empirical value A' of the shell vibration amplitude to obtain ΔA. The measured frequency proportion P of the shell vibration signal is subtracted from the empirical value P1' 100 ,P 200 ,P 300 ,L, respectively, to obtain ΔP 00 ,P2' 00 ,P3' 00 ,L. Before performing the step, the empirical value A' of the shell vibration amplitude and the empirical value P' of the vibration frequency proportion are solved. 100 ,ΔP 200 ,ΔP 300 ,L. Before performing the step, the empirical value A' of the shell vibration amplitude and the empirical value P' of the vibration frequency proportion are solved. 100 ,P' 200 ,P' 300 ,L.

[0085] Before solving the empirical value A' of the shell vibration amplitude and the empirical value P' of the vibration frequency proportion, a fitting equation of the empirical value A' of the shell vibration amplitude and the empirical value P' of the vibration frequency proportion with the current I' is established, that is, A' = f(I'), P' = f(I'), P' = f(I'), and L = f(I'). 100 ,P' 200 ,P' 300 ,L. 100 ,P' 200 ,P' 300 ,L. 100 =f(I′),P′ 200 =f(I′),P′ 300 =f(I′),L。

[0086] Before establishing the fitting equation A' = f(I'), P' = f(I'), P' = f(I'), and L = f(I'), a physical experiment model or a simulation experiment model of GIS disconnector vibration is established. 100 =f(I′),P′ 200 =f(I′),P′ 300 =f(I′),L.

[0087] If a GIS disconnector vibration physical experiment model is established, an experiment platform including a current source, a GIS disconnector, and a vibration sensor is constructed. The vibration sensor is placed at the disconnector shell. The disconnector contact state is set to be normal, different sizes of current I' are input to the disconnector interior each time, and the vibration amplitude A' and the vibration frequency proportion P' at the shell are recorded 100P' 200 P' 300 L. According to the current and the amplitude and the vibration frequency ratio at the shell, a fitting equation A'=f(I'), P' 100 =f(I'), P' 200 =f(I'), P' 300 =f(I'), L.

[0088] In order to establish a GIS disconnector vibration simulation experiment model, an electromagnetic-mechanical multi-physical field simulation model of the GIS disconnector needs to be constructed. The steps of constructing the simulation model are: constructing a geometric model, setting material parameters, setting physical field control equations, boundary conditions, setting the coupling relationship between physical fields, meshing the geometric model, using the finite element algorithm for solving and calculation, and obtaining the mechanical field distribution of the GIS disconnector. On the basis of the simulation model, the contact of the disconnector is normal, different sizes of current are set in the disconnector, the mechanical field distribution of the GIS disconnector is simulated, and the vibration signal at the shell is recorded. According to the current and the amplitude and the vibration frequency ratio at the shell, a fitting equation A'=f(I'), P' 00 =f(I'), P' 00 =f(I'), P' 00 =f(I'), L. The results of the simulation experiment need to be verified by experiments before they can be used.

[0089] The measured current I is substituted into the fitting equation A'=f(I'), P' 00 =f(I'), P' 00 =f(I'), P' 00 =f(I'), L, the empirical value A' of the shell vibration amplitude and the empirical value P' 00 , P' 00 , P' 00 , L of the vibration frequency ratio are calculated.

[0090] The difference ΔA between the measured value and the empirical value of the shell vibration amplitude is calculated, and the difference ΔP 100 , ΔP 100 , ΔP 00 , ΔP 200 , ΔP 200 , ΔP 00 , ΔP 300 , ΔP 300 , ΔP 00 , L, which are used as vibration characteristic quantities.

[0091] The process of extracting the partial discharge characteristic quantities includes:

[0092] Detecting the partial discharge signal of GIS disconnecting switch, obtaining the partial discharge spectrum of the partial discharge signal, and detecting the voltage U.

[0093] Preferably, for the detection of the partial discharge signal of GIS disconnecting switch, specifically, placing the ultra-high frequency sensor on the insulating basin adjacent to the moving and static contacts of the GIS disconnecting switch, and obtaining the ultra-high frequency discharge spectrum.

[0094] Through the ultra-high frequency discharge spectrum, the maximum discharge amplitude M of the partial discharge signal is obtained.

[0095] The difference ΔM between the measured value M of the maximum discharge amplitude of the partial discharge signal and the empirical value M' of the maximum discharge amplitude is obtained. Before performing this step, the empirical value M' of the maximum discharge amplitude is first solved.

[0096] Before solving the empirical value M' of the maximum discharge amplitude, a fitting equation of M' and U' is first established, i.e., M' = f(U').

[0097] Before establishing the fitting equation M' = f(U'), a physical experiment model or a simulation experiment model of the partial discharge of GIS disconnecting switch is first established.

[0098] If a physical experiment model of the partial discharge of GIS disconnecting switch is established, an experiment platform including a voltage source, a GIS disconnecting switch, and an ultra-high frequency sensor needs to be constructed. The ultra-high frequency sensor is placed on the insulating basin adjacent to the disconnecting switch. The contact state of the disconnecting switch is set to be normal, and different sizes of voltage U' are applied to the disconnecting switch each time, and the maximum discharge amplitude M' is recorded. According to the experimental data of multiple times, a fitting equation M' = f(U') about the two is established.

[0099] If a simulation experiment model of the partial discharge of GIS disconnecting switch is established, a GIS disconnecting switch electromagnetic field simulation model needs to be constructed. The steps of constructing the simulation model are: constructing a geometric model, setting material parameters, setting physical field control equations and boundary conditions, meshing the geometric model, and solving and calculating using finite element algorithm to obtain the electromagnetic field distribution of GIS disconnecting switch. On the basis of the simulation model, the contact of the disconnecting switch is set to be normal, and different sizes of voltage are loaded in the disconnecting switch, and the electromagnetic field distribution of the GIS disconnecting switch is simulated to obtain the discharge signal amplitude. According to the simulation calculation data, a fitting equation M' = f(U') about the two is established. The results of the simulation experiment need to be verified by experiments before they can be used.

[0100] The measured voltage U is substituted into the fitting equation M' = f(U') to calculate the empirical value M' of the maximum discharge amplitude.

[0101] The difference ΔM = M - M' between the measured value and the empirical value of the maximum discharge amplitude is calculated, which is used as a characteristic quantity of partial discharge.

[0102] The multi-state parameter evaluation process comprises:

[0103] After the temperature characteristic quantity, the vibration characteristic quantity and the partial discharge characteristic quantity are normalized, they are input into the tested classifier, and the classification result of the contact state of the GIS disconnecting switch is given by the classifier. Before the step is executed, the classifier needs to be designed, trained and tested.

[0104] The design of the classifier comprises selecting a suitable classifier (a Bayesian classifier is selected herein) and selecting a suitable classification criterion (the minimum error rate criterion is adopted herein).

[0105] The training of the classifier comprises establishing a GIS disconnecting switch contact state training set comprising temperature characteristics, vibration characteristics and partial discharge characteristics.

[0106] The GIS disconnecting switch contact state training set comprising temperature characteristics, vibration characteristics and partial discharge characteristics is established. First, a physical experiment model or a simulation experiment model of the GIS disconnecting switch contact state or historical data of on-site operation is established.

[0107] If the GIS disconnecting switch contact state physical experiment model is established to generate the training set, the GIS disconnecting switch contact state should be artificially divided into different conditions (such as normal contact, abnormal contact and dangerous contact). Then, the temperature characteristic value, the vibration characteristic value and the partial discharge characteristic value are obtained by controlling the GIS disconnecting switch in different contact conditions.

[0108] If the GIS disconnecting switch contact state simulation experiment model is established to generate the training set, the GIS disconnecting switch contact state should be artificially divided into different conditions (such as normal contact, abnormal contact and dangerous contact). Then, the temperature characteristic value, the vibration characteristic value and the partial discharge characteristic value are simulated and calculated by controlling the disconnecting switch in different contact conditions in the simulation model. The results of the simulation experiment need to be verified by experiments before being used.

[0109] Based on the classification criterion (the minimum error rate criterion is selected herein), the parameters (weight coefficients in the weighted naive Bayesian classifier) in the classifier (the weighted naive Bayesian classifier is selected herein) are trained by using the GIS disconnecting switch training sample set (the characteristics comprise temperature, vibration and partial discharge; the types comprise normal contact, abnormal contact and dangerous contact). When the accuracy of the classifier reaches a certain value, the training is completed.

[0110] The test of the classifier comprises establishing a GIS disconnecting switch contact state test set comprising temperature characteristics, vibration characteristics and partial discharge characteristics.

[0111] The test set is generated in the same way as the sample set.

[0112] The samples of the test set are classified by using the trained classifier, and when the test accuracy reaches a certain value, the test is passed.

[0113] The measured temperature characteristic quantity, vibration characteristic quantity and partial discharge characteristic quantity are input into the classifier that passes the test, and the classifier gives the corresponding contact state evaluation result.

[0114] The following is a specific embodiment of the method of the application:

[0115] The multi-state parameter evaluation method of the 220kV GIS disconnector in this embodiment includes the following steps:

[0116] (1) Extract the temperature characteristic quantity of the GIS disconnector: measure the shell vertex temperature T1 of the GIS disconnector contact part, measure the environmental temperature T0, and calculate the measured value of the shell temperature rise T2=T1-T0.

[0117] To establish the fitting equation of the shell temperature rise T2' and the current I', first, establish the electromagnetic-thermal-flow multi-physical field simulation model of the GIS disconnector. The geometric model is constructed as shown in Figure 2 The size parameters of the geometric model are shown in Table 1.

[0118] Table 1 Size parameter table of GIS disconnector geometric model

[0119]

[0120] The material parameters are set as shown in Table 2:

[0121] Table 2 GIS disconnector geometric model material parameter setting table

[0122]

[0123] The electromagnetic field control equation of the conductor region is set as:

[0124]

[0125] Where A1 and are the vector potential function and scalar potential function of the conductor region respectively, σ1 is the conductivity of the conductor, J is the external current density, μ0 is the vacuum permeability, is the Hamiltonian operator, j is the imaginary unit, and ω is the angular frequency. The external current density can be expressed as:

[0126]

[0127] Where I and S are the current flowing through the rod and the cross-sectional area of the rod respectively.

[0128] The electromagnetic field control equation of the non-conductor region is:

[0129]

[0130] Among them A2 and Let be the vector potential function and scalar potential function of the non-conductive region, respectively, where σ² is the electrical conductivity of the material in that region, and μ is the scalar potential function. r denoted as , where is the relative magnetic permeability of the material in this region.

[0131] The governing equation for heat transfer in a solid is set as follows:

[0132]

[0133] Where ρ is density, c is specific heat capacity, T is temperature, t is time, k is thermal conductivity, and Q is heat source.

[0134] The governing equation for heat transfer in a fluid is:

[0135]

[0136] Where u is the velocity of the fluid.

[0137] The radiative heat transfer equations between the guide rod and the outer shell, and between the shell and the external environment, are set as follows:

[0138]

[0139] Q f For radiative heat transfer, ε1 is the surface emission coefficient of the guide rod, S1 is the surface area of ​​the guide rod, δ is the blackbody radiation constant, T1 is the surface temperature of the guide rod, and T2 is the surface temperature of the shell.

[0140] The governing equations for the flow field are set as follows:

[0141]

[0142] Where η is the fluid dynamic viscosity and g is the gravitational acceleration.

[0143] The coupling relationship between the electromagnetic field and the temperature field is set as follows:

[0144]

[0145] Where E is the electric field strength, α is the temperature coefficient of resistivity, and σ ref T ref These are the reference conductivity and the reference temperature, respectively.

[0146] The coupling relationship between the flow field and the temperature field is set as follows:

[0147]

[0148] Where P is the fluid pressure, K1 is the molar mass of the fluid, K2 is the universal gas constant, and ρ ref k ref η ref These represent the reference density, reference thermal conductivity, and reference dynamic viscosity, respectively, with S being the Soothelium constant.

[0149] The temperature field distribution of the disconnector switch was obtained by solving the electromagnetic-thermal-fluid multiphysics simulation model using the finite element method. Figure 3 As shown.

[0150] Based on this simulation model, with the disconnecting switch in normal contact, different currents were applied to the disconnecting switch to simulate the steady-state temperature distribution of the GIS disconnecting switch, and the temperature rise at the casing was recorded. Based on the current and the temperature rise at the casing, a fitting equation T2′=f(I′) was established.

[0151] T2′=0.8826I′ 2 +0.9503I′-0.3201

[0152] In the formula: T2′ is in °C and I′ is in kA.

[0153] Substitute the measured current I into the fitting equation T2′=f(I′) to calculate the empirical value T2′ of the shell temperature rise.

[0154] The difference between the measured and empirical values ​​of the shell temperature rise is calculated as ΔT = T2 - T2′, and this difference is used as the temperature characteristic quantity.

[0155] (2) Extracting vibration characteristic quantities of GIS disconnect switches: Measure the vibration signal at the top of the casing of the GIS disconnect switch contact area. The vibration signal is as follows: Figure 4 As shown, the measured amplitude A of the vibration signal is obtained through the time-domain waveform.

[0156] To establish a fitting equation for the vibration amplitude A′ of the casing and the current I′, a physical test model of the GIS disconnector switch vibration was first established. An FCG-2000 / 5 digital high-current generator was used to sequentially supply AC currents of 400A, 800A, and 1200A to the GIS equipment, recording the vibration signal at the top of the casing near the GIS disconnector switch contacts each time. Based on the current and the amplitude at the casing, a fitting equation A′=f(I′) was established.

[0157] A′=0.0391I′ 2 -0.0231I′+0.0125

[0158] In the formula: the unit of A′ is m / s2, and the unit of I′ is kA.

[0159] The measured current I is substituted into the fitting equation A' = f(I') to calculate the empirical value A' of the shell vibration.

[0160] The difference ΔA = A - A' between the measured value and the empirical value of the shell vibration amplitude is calculated and taken as the vibration characteristic quantity.

[0161] (3) Extracting GIS disconnector partial discharge characteristic quantity: A UHF sensor is placed on the insulating pot next to the moving and static contacts of the GIS disconnector to measure the GIS disconnector partial discharge signal. The discharge spectrogram is shown in FIG. 3. The maximum discharge amplitude M of the partial discharge signal is obtained through the UHF discharge spectrogram. Figure 5

[0162] To establish the fitting equation of the maximum discharge amplitude empirical value M' and the voltage U', a GIS disconnector partial discharge physical test model is first established. A YDTW-100 / 200 type power frequency test transformer is used to apply voltage to the GIS disconnector, and the GIS disconnector is sequentially applied with 120 kV, 140 kV and 160 kV voltage, and the maximum discharge amplitude of the GIS disconnector is recorded each time. According to the voltage and the maximum discharge amplitude, the fitting equation M' = f(U') about the two is established as

[0163] M' = 0.0075U' 2 -1.85U' + 116

[0164] In the formula, the unit of M' is m / s2, and the unit of U' is kV.

[0165] The measured voltage U is substituted into the fitting equation M' = f(U') to calculate the empirical value M' of the maximum discharge amplitude.

[0166] The difference ΔM = M - M' between the measured value and the empirical value of the maximum discharge amplitude is calculated and taken as the partial discharge characteristic quantity.

[0167] (4) Multi-state parameter evaluation:

[0168] A GIS disconnector contact state training and test set containing temperature characteristics, vibration characteristics and partial discharge characteristics is established. The GIS disconnector contact state is artificially divided into three different cases: normal contact, abnormal contact and dangerous contact. The schematic diagram of the three different contact states is shown in FIG. 4. Then the GIS disconnector is controlled to be in different contact states, and the temperature characteristic value, the vibration characteristic value and the partial discharge characteristic value are obtained by experiments. Figure 6

[0169] The weighted naive Bayes classifier is selected as the state evaluation model, and the minimum error rate is taken as the classification criterion to train the weight coefficients of each attribute in the weighted naive Bayes classifier. When the training accuracy rate reaches more than 90%, it is considered that the training is passed. ​​

[0170] The trained weighted Naive Bayes classifier is tested by using the data in the test set, and is considered to pass the test when the test accuracy reaches more than 90%.

[0171] The measured temperature characteristic quantity, vibration characteristic quantity and partial discharge characteristic quantity are input into the trained weighted Naive Bayes classifier, and the classifier gives the corresponding contact state evaluation result.

[0172] The above-described embodiments are merely preferred specific embodiments of the present application, and the protection scope of the present application is not limited thereto, and any simple change or equivalent replacement of the technical solutions within the technical range disclosed by the present application can be obtained by those skilled in the art, and all of them belong to the protection scope of the present application.

Claims

1. A method for evaluating multi-state parameters of GIS disconnector switches, characterized in that, include: Measure the surface temperature T1 of the housing of the GIS disconnector switch contact area, the ambient temperature T0, and the current I; Calculate the measured value of the casing temperature rise. ; By using experiments or simulations, a fitting equation is established between the empirical value of the shell temperature rise and the current. The measured current I is substituted into the fitting equation to calculate the empirical value of the shell temperature rise. Calculate the difference between the measured and empirical values ​​of the shell temperature rise, and use it as a temperature characteristic quantity; The temperature characteristics, vibration characteristics, and partial discharge characteristics of the GIS disconnector are normalized and then input into a trained classifier. The classifier then provides the classification result of the contact state of the GIS disconnector. The classifier is a weighted Naive Bayes classifier, and the classification criterion of the classifier is the minimum misclassification rate criterion. Extracting the vibration characteristics of the GIS disconnector includes: measuring the vibration signal and current of the GIS disconnector casing; obtaining the vibration signal amplitude through the time-domain waveform of the vibration signal; obtaining the component proportion of the 100Hz vibration signal and its harmonics through spectral analysis of the vibration signal; establishing a fitting equation between the casing vibration amplitude, vibration frequency proportion, and current using experiments or simulations; substituting the measured current I into the fitting equation to calculate the empirical value of the casing vibration amplitude and the empirical value of the component proportion of the 100Hz vibration signal and its harmonics. Calculate the difference between the measured value and the empirical value of the shell vibration amplitude, and the difference between the measured value and the empirical value of the vibration frequency ratio, and use these quantities as vibration characteristic quantities; Extracting the partial discharge characteristic quantities of the GIS disconnector switch includes: measuring the discharge spectrum and voltage U of the partial discharge of the GIS disconnector switch, obtaining the maximum discharge amplitude through the discharge spectrum; establishing a fitting equation between the empirical value of the maximum discharge amplitude and the voltage using experiments or simulations; substituting the measured voltage into the fitting equation to calculate the empirical value of the maximum discharge amplitude; and calculating the difference between the measured value and the empirical value of the maximum discharge amplitude, using it as the partial discharge characteristic quantity.

2. The method for evaluating multi-state parameters of GIS disconnector switches according to claim 1, characterized in that, The experimentally established fitting equation between the empirical value of the shell temperature rise and the current includes: Construct an experimental platform that includes a current source, a GIS disconnect switch, and a temperature sensor; Place the temperature sensor on the housing of the GIS disconnect switch and set the contact status of the GIS disconnect switch to normal. Different currents were passed through the GIS disconnect switch, and the temperature rise at the outer casing was recorded after the temperature of the GIS disconnect switch stabilized. Based on the current and the temperature rise at the casing, a fitting equation is established between the empirical value of the casing temperature rise and the current.

3. The method for evaluating multi-state parameters of GIS disconnector switches according to claim 1, characterized in that, The method of establishing a fitting equation between the empirical value of the shell temperature rise and the current using simulation includes: Construct a geometric model of the GIS disconnect switch; Set material parameters, physical field control equations, boundary conditions, and physical field coupling relationships for the geometric model; The geometric model is meshed, and the finite element method is used to solve the problem to obtain the steady-state temperature field distribution of the GIS disconnector, thus completing the construction of the simulation model. Based on the simulation model, the disconnecting switch was made to have normal contact, and different currents were passed through the disconnecting switch to simulate the steady-state temperature distribution of the GIS disconnecting switch and record the temperature rise at the outer casing. Based on the relationship between current and temperature rise at the casing, a fitting equation is established between the empirical value of casing temperature rise and current.

4. The method for evaluating multi-state parameters of GIS disconnector switches according to claim 1, characterized in that, The experimentally established fitting equations for the shell vibration amplitude, vibration frequency ratio, and current include: Construct an experimental platform that includes a current source, a GIS disconnect switch, and a vibration sensor; Place the vibration sensors on the housing of the disconnect switch; With the disconnecting switch in normal contact state, different amounts of current are passed into the disconnecting switch each time, and the vibration amplitude and frequency ratio at the outer casing are recorded. Based on the current and the vibration amplitude and frequency ratio at the outer casing, a fitting equation is established between the vibration amplitude and frequency ratio at the outer casing and the current.

5. The method for evaluating multi-state parameters of GIS disconnector switches according to claim 1, characterized in that, The process of establishing fitting equations for the vibration amplitude, vibration frequency ratio, and current using simulation includes: establishing a vibration simulation experimental model for the GIS disconnector switch, which includes: Construct a geometric model; Set material parameters, physical field control equations, boundary conditions, and physical field coupling relationships for the geometric model; The geometric model is meshed, and the finite element method is used to solve the problem to obtain the mechanical field distribution of the GIS disconnector, thus completing the construction of the simulation model. Based on the simulation model, the disconnecting switch is made to have normal contact, and different currents are passed through the disconnecting switch to simulate the mechanical field distribution of the GIS disconnecting switch. The vibration signal at the outer casing is recorded. Based on the current and the amplitude and frequency ratio at the outer casing, a fitting equation is established for the vibration amplitude and frequency ratio of the outer casing with the current.

6. The method for evaluating multi-state parameters of GIS disconnector switches according to claim 1, characterized in that, The experimentally established fitting equation between the empirical value of the maximum discharge amplitude and the voltage includes: Construct an experimental platform that includes a voltage source, a GIS disconnect switch, and an ultra-high frequency sensor; Place the UHF sensor on an insulating basin near the GIS disconnect switch; With the disconnector switch in normal contact condition, apply different voltages to the disconnector switch each time and record the maximum discharge amplitude. Based on the experimental data from multiple tests, establish a fitting equation between the empirical value of the maximum discharge amplitude and the voltage.

7. The method for evaluating multi-state parameters of GIS disconnector switches according to claim 1, characterized in that, The process of establishing a fitting equation between the empirical value of the maximum discharge amplitude and the voltage using simulation includes: establishing a partial discharge simulation experimental model for a GIS disconnector switch, which includes: Construct a geometric model; Set material parameters, physical field control equations, boundary conditions, and physical field coupling relationships for the geometric model; The geometric model is meshed, and the electromagnetic field distribution of the GIS disconnector is obtained by solving the problem using the finite element method, thus completing the construction of the simulation model. Based on the simulation model, the disconnecting switch was made to have normal contact, and different voltages were applied to the disconnecting switch. The electromagnetic field distribution of the GIS disconnecting switch was simulated, and the amplitude of the discharge signal was calculated. Based on the discharge signal amplitude and voltage data, a fitting equation is established between the empirical value of the maximum discharge amplitude and the voltage.

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