A method, device and system for detecting gas insulated switchgear

Abstract

The invention discloses a method for detecting a gas-insulated switchgear, and relates to the technical field of defect detection. The method comprises: gridding a device to be detected to obtain a plurality of grid devices; determining a grid device excited by a first laser as a laser ultrasonic sound source; obtaining the vibration velocity and vibration displacement of each laser ultrasonic sound source by using a second laser; calculating and determining a reconstructed image of each laser ultrasonic sound source according to the vibration velocity of each laser ultrasonic sound source; determining the defects of the device to be detected according to all reconstructed images; calculating the elastic modulus and Poisson's ratio according to the vibration velocity and vibration displacement of all laser ultrasonic sound sources; determining the elastic modulus and Poisson's ratio as mechanical information of the device to be detected; and predicting micro-defects and stress concentration of the device to be detected according to the mechanical information. The invention can determine and predict the defects of the gas-insulated switchgear according to the vibration displacement and vibration velocity, and realizes online detection of defects.

Description

Technical Field

[0001] The present invention relates to the technical field of defect detection, and in particular to a detection method, device and system for gas insulated switchgear. Background Art

[0002] With the continuous acceleration of the construction of UHV and EHV power grids, the status detection and fault diagnosis technology of power equipment has become a technical problem that needs to be overcome urgently, especially the early detection of UHV gas insulated switchgear (GIS) is a bottleneck problem restricting the development of status detection and fault diagnosis technology of power transmission and transformation equipment.

[0003] The pot insulator is an important insulating component in the gas insulated switchgear (GIS), playing an important role in supporting, insulating and isolating the gas chamber. The stress distribution of the epoxy material of the pot insulator is uneven. Under the combined effects of electric field, mechanical load and temperature during operation, stress concentration is prone to produce microcracks, which in severe cases lead to leakage, partial discharge, insulation flashover and ablation. In recent years, rupture failures caused by poor mechanical properties of pot insulators have occurred from time to time, seriously threatening the safe and reliable operation of the power grid. However, at present, for the defect detection and early defect prediction of pot insulators, finite element simulation analysis is mostly used to study the stress and strain distribution of pot insulators, and there is no effective detection method. Through the search of patents in recent years, it is found that the stress detection method has gradually gained attention, such as the "A method and system for ultrasonic detection of subsurface thermal stress of GIS pot insulators" with application number 202111088966.1. The traditional ultrasonic method requires coupling agent coupling, which is difficult to achieve online detection. Summary of the invention

[0004] The object of the present invention is to provide a method, device and system for detecting gas insulated switchgear, so as to realize online detection of defects of gas insulated switchgear.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A method for detecting a gas insulated switchgear, the method comprising:

[0007] Gridding the devices to be detected to obtain multiple grid devices;

[0008] Determine the grid device after the first laser excitation as a laser ultrasonic sound source; one grid device corresponds to one laser ultrasonic sound source;

[0009] Using a second laser to obtain the vibration velocity and vibration displacement of each of the laser ultrasonic sound sources;

[0010] Determine a reconstructed image of each of the laser ultrasonic sound sources by calculating the vibration velocity of each of the laser ultrasonic sound sources;

[0011] Determine the defect of the device to be inspected according to all the reconstructed images;

[0012] Calculate the elastic modulus and Poisson's ratio of the device to be tested according to the vibration speed and vibration displacement of all the laser ultrasonic sound sources;

[0013] Determine the elastic modulus and Poisson's ratio as mechanical information of the device to be tested;

[0014] Defects that will be generated in the device to be inspected are predicted based on the mechanical information.

[0015] Optionally, the calculating and determining the reconstructed image of each of the laser ultrasonic sound sources according to the vibration velocity of each of the laser ultrasonic sound sources specifically includes:

[0016] Calculating a spectrum slope parameter of each of the laser ultrasonic sound sources according to the vibration velocity of each of the laser ultrasonic sound sources;

[0017] The reconstructed image of each of the laser ultrasonic sound sources is determined according to the spectrum slope parameter of each of the laser ultrasonic sound sources.

[0018] A detection device for a gas insulated switchgear, comprising: a first laser, a second laser, and a reference channel, a signal processing module, and an imaging module connected in sequence;

[0019] The first laser is used to emit a first laser, and the first laser is used to excite the device to be detected;

[0020] The second laser is used to emit a second laser, and the second laser is used to detect the device to be detected;

[0021] The reference channel is used to cause the second laser to interfere with the laser reflected by the device to be detected, so as to obtain an interference signal;

[0022] The signal processing module is used to obtain the vibration speed and the vibration speed and vibration displacement of the imaging area according to the interference signal; the imaging area is the area where the device to be detected is excited by the first laser and detected by the second laser;

[0023] The imaging module is used to execute any of the above methods to detect defects of the device to be inspected.

[0024] A detection system for a gas insulated switchgear, comprising:

[0025] A gridding module, used for gridding the equipment to be detected to obtain multiple grid devices;

[0026] A sound source determination module, used to determine the grid device after the first laser excitation as a laser ultrasonic sound source; one grid device corresponds to one laser ultrasonic sound source;

[0027] A vibration velocity and vibration displacement acquisition module, used to acquire the vibration velocity and vibration displacement of each of the laser ultrasonic sound sources using a second laser;

[0028] A reconstructed image determination module, used to calculate and determine a reconstructed image of each of the laser ultrasonic sound sources according to each of the vibration velocities;

[0029] A first defect determination module, used for determining the defects of the device to be inspected according to all the reconstructed images;

[0030] An elastic modulus and Poisson's ratio determination module, used to calculate the elastic modulus and Poisson's ratio of the device to be detected according to the vibration velocity and vibration displacement of all the laser ultrasonic sound sources;

[0031] A mechanical information determination module, used to determine the elastic modulus and Poisson's ratio as mechanical information of the device to be detected;

[0032] The second defect determination module is used to predict the defects that will be generated in the device to be inspected based on the mechanical information.

[0033] Optionally, the reconstructed image determination module specifically includes:

[0034] Calculating a spectrum slope parameter of each of the laser ultrasonic sound sources according to the vibration velocity of each of the laser ultrasonic sound sources;

[0035] The reconstructed image of each of the laser ultrasonic sound sources is determined according to the spectrum slope parameter of each of the laser ultrasonic sound sources.

[0036] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0037] The present invention discloses a method, device and system for detecting gas insulated switchgear. The method comprises: gridding the device to be detected to obtain a plurality of grid devices; determining the grid devices excited by a first laser as laser ultrasonic sound sources; one grid device corresponds to one laser ultrasonic sound source; using a second laser to obtain the vibration velocity and vibration displacement of each laser ultrasonic sound source; calculating and determining the reconstructed image of each laser ultrasonic sound source according to the vibration velocity of each laser ultrasonic sound source; determining the defects of the device to be detected according to all the reconstructed images; calculating the elastic modulus and Poisson's ratio according to the vibration velocity and vibration displacement of all the laser ultrasonic sound sources; determining the elastic modulus and Poisson's ratio as the mechanical information of the device to be detected; and predicting the defects that will be generated by the device to be detected according to the mechanical information. The present invention can determine and predict the defects of the gas insulated switchgear according to the vibration displacement and vibration velocity, thereby realizing the online detection of defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0039] Figure 1 A flow chart of a detection method for a gas insulated switchgear provided in an embodiment of the present invention;

[0040] Figure 2 A structural diagram of a defect detection device for a gas insulated switchgear provided in an embodiment of the present invention;

[0041] Figure 3 A block diagram of a defect detection system for a gas insulated switchgear provided in an embodiment of the present invention.

[0042] Description of the drawings: 1-computer, 2-first laser controller, 3-laser scanning controller, 4-first laser, 5-pot insulator, 6-second laser, 7-reference channel, 8-signal processing module. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] The purpose of the present invention is to provide a method, device and system for detecting gas insulated switchgear, aiming to realize online detection of defects of gas insulated switchgear, which can be applied to the field of defect detection technology.

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] Figure 1 The following is a flow chart of a method for detecting a gas insulated switchgear according to an embodiment of the present invention. Figure 1 As shown, the detection method of the gas insulated switchgear in this embodiment includes:

[0047] Step 101: grid the devices to be detected to obtain a plurality of grid devices.

[0048] Step 102: Determine the grid device that has been excited by the first laser as a laser ultrasonic sound source; one grid device corresponds to one laser ultrasonic sound source.

[0049] Step 103: Using the second laser, the vibration velocity and vibration displacement of each laser ultrasonic sound source are obtained.

[0050] Step 104: Calculate and determine the reconstructed image of each laser ultrasonic sound source according to the vibration velocity of each laser ultrasonic sound source.

[0051] Step 105: Determine defects of the device to be inspected based on all reconstructed images.

[0052] Step 106: Calculate the elastic modulus and Poisson's ratio of the device to be tested according to the vibration velocity and vibration displacement of all laser ultrasonic sound sources.

[0053] Step 107: Determine the elastic modulus and Poisson's ratio as mechanical information of the device to be tested.

[0054] Step 108: predicting defects that will be generated in the device to be inspected based on the mechanical information. Specifically, predicting micro defects and stress concentrations in the device to be inspected based on the mechanical information.

[0055] As an optional implementation, step 104 specifically includes:

[0056] The spectrum slope parameter of each laser ultrasonic sound source is calculated according to the vibration velocity of each laser ultrasonic sound source.

[0057] The reconstructed image of each laser ultrasonic sound source is determined according to the spectrum slope parameter of each laser ultrasonic sound source.

[0058] Figure 2 This is a structural diagram of a defect detection device for a gas insulated switchgear provided in an embodiment of the present invention. Figure 2As shown, a detection device for a gas insulated switchgear comprises: a first laser 4, a second laser 6, and a reference channel 7, a signal processing module 8 and an imaging module connected in sequence.

[0059] The first laser 4 is used to emit a first laser, and the first laser is used to excite the device to be detected.

[0060] The second laser 6 is used to emit a second laser, and the second laser is used to detect the device to be detected.

[0061] The reference channel 7 is used to cause the second laser to interfere with the laser reflected by the device to be detected, so as to obtain an interference signal.

[0062] The signal processing module 8 is used to obtain the vibration speed and the vibration speed and vibration displacement of the imaging area according to the interference signal; the imaging area is the area where the device to be detected is excited by the first laser and detected by the second laser.

[0063] The imaging module is used to execute the gas insulated switchgear inspection method to detect defects of the equipment to be inspected.

[0064] Figure 3 A block diagram of a defect detection system for a gas insulated switchgear provided in an embodiment of the present invention. Figure 3 As shown, a detection system for a gas insulated switchgear comprises:

[0065] The gridding module 201 is used to grid the devices to be detected to obtain a plurality of grid devices.

[0066] The sound source determination module 202 is used to determine the grid device that has been excited by the first laser as a laser ultrasonic sound source; one grid device corresponds to one laser ultrasonic sound source.

[0067] The vibration velocity and vibration displacement acquisition module 203 is used to acquire the vibration velocity and vibration displacement of each laser ultrasonic sound source by using the second laser.

[0068] The reconstructed image determination module 204 is used to determine the reconstructed image of each laser ultrasonic sound source according to each vibration velocity calculation.

[0069] The first defect determination module 205 is used to determine defects of the device to be inspected according to all reconstructed images.

[0070] The elastic modulus and Poisson's ratio determination module 206 is used to calculate the elastic modulus and Poisson's ratio of the device to be detected according to the vibration speed and vibration displacement of all laser ultrasonic sound sources.

[0071] The mechanical information determination module 207 is used to determine the elastic modulus and Poisson's ratio as the mechanical information of the device to be detected.

[0072] The second defect determination module 208 is used to predict the defects that will be generated in the device to be detected based on the mechanical information. Specifically, the second defect determination module 208 is used to predict the micro defects and stress concentration of the device to be detected based on the mechanical information, and the micro defects and stress concentration will lead to the generation of defects.

[0073] As an optional implementation, the reconstructed image determination module 204 specifically includes:

[0074] The spectrum slope parameter of each laser ultrasonic sound source is calculated according to the vibration velocity of each laser ultrasonic sound source.

[0075] The reconstructed image of each laser ultrasonic sound source is determined according to the spectrum slope parameter of each laser ultrasonic sound source.

[0076] like Figure 3 As shown, when the device to be detected is a pot-type insulator 5: first, under the control of the computer 1, the first laser controller 2 and the laser scanning controller 3 start the first laser 4 after receiving the instruction of the computer 1 (including the imaging module), and the first laser 4 emits a first laser, which is excited on the pot-type insulator 5 of the target body to be detected after beam expansion and collimation (beam expansion and collimation can be realized by setting corresponding components based on this function between the first laser 4 and the pot-type insulator 5 according to actual applications, such as by using a variable-multiple amplifier), and a photoacoustic signal is generated inside the pot-type insulator 5, and the generated photoacoustic signal propagates inside the pot-type insulator 5. At the same time, the second laser 6 emits a second laser under the control of the computer 1, and the second After the laser is collimated and focused (collimated and focused can be achieved by setting a corresponding component based on this function between the first laser and the pot-type insulator according to actual applications), it is divided into two paths by a spectroscope (not shown in the figure). The first laser is used as an emitting light source and is focused to directly irradiate the surface of the pot-type insulator 5 of the target body to be measured. The second laser enters the reference channel 7 as a reference light. The reflected signal reflected back by the pot-type insulator 5 of the target body to be measured by the first laser beam interferes with the second laser in the reference channel 7. The interfered signal is processed by the signal processing module 8 to obtain the vibration displacement and vibration velocity of the laser ultrasonic excitation. The signal processing module 8 sends the vibration displacement and vibration velocity of the laser ultrasonic excitation to the imaging module in the computer 1.

[0077] The laser emitted by the first laser under the control of the laser scanning controller can be distributed linearly or regionally over time. For online detection, each scan can cover a 120° range of the basin insulator. The first laser is a pulsed laser with a wavelength of 532nm or 1064nm. The second laser is a continuous laser with a wavelength of 532nm or 1064nm.

[0078] For micro defect size detection, since the distribution of light absorption coefficients at different positions is random, in order to eliminate the randomness of the detected laser ultrasonic signal, the data acquisition of each laser ultrasonic sound source adopts the method of multiple measurements and averaging. The average number of times can be set arbitrarily from 1 to 1024 times. The first laser scanning excitation and the second laser fixed excitation reception excitation detection method are used to realize signal detection. The vibration speed of each laser ultrasonic sound source is calculated by formula (1) to perform power spectrum:

[0079]

[0080] Where s(f) represents the power spectrum of the laser ultrasonic sound source, f represents the frequency of the laser ultrasonic sound source, N is the average number of the first laser excitation, represents the integral summation, V n (r,f) represents the vibration velocity of the laser ultrasonic sound source, V n * (r,f) represents V n The complex conjugate of (r, f), n represents the total number of times each set of valid data is collected, and r represents the position vector between the first laser excitation position and the second laser detection position.

[0081] When performing imaging detection, the entire basin insulator area of ​​the first laser excitation and the second laser vibration detection is first determined as the imaging area, and the imaging area is divided into a number of grid devices, each of which is used as a laser ultrasonic sound source. Assuming that the coordinates corresponding to the grid device P are (i, j), the spatial coordinates of the sound source of the first laser excitation at the position (i, j) can be expressed as r ij , the spatial coordinate r ij Substituted into the power spectrum calculation formula (1), the signal spectrum slope parameter s(r) at the mth laser ultrasonic sound source collected by the second laser during the first laser excitation is obtained. ij (m),f):

[0082]

[0083] Among them, s(r ij (m), f) represents the spectrum slope parameter of the mth laser ultrasonic sound source; V n (r ij (m), f) represents the vibration velocity of the mth laser ultrasonic sound source; V * n (r ij (m),f) represents V n (r ij (m), the complex conjugate of f).

[0084] Then, the imaging area grid device is set as a time coordinate function. Considering the scanning excitation mode of the first laser, assuming step scanning, the scanning points are M, the excitation position of the first laser is m (m = 1...M), the second laser is the detection laser, the detection is also a step detection mode, the detection points are K, and the detection position of the second laser is k (k = 1...K), and the coordinate (i, j) corresponding to the grid device P is obtained. ij Corresponding relationship with time:

[0085] |r ij |=|r ij -r m |+|r k -r ij |=t ijmk c (3)

[0086] Where c is the surface wave propagation velocity of laser ultrasound in the pot insulator; r ij is the spatial coordinate of the sound source of laser ultrasonic excitation at position (i, j); r m is the spatial coordinate of the scanning excitation position of the first laser (laser ultrasonic sound source); r k is the spatial coordinate of the detection position of the second laser.

[0087] Then, the synthetic aperture method is used to combine formula (2) and formula (3) to obtain a new synthetic aperture calculation algorithm related to the laser excitation detection position and the power spectrum slope:

[0088]

[0089] Among them, s(t ijmk c, f) represent the power spectrum slope parameters collected at the imaging region (i, j) when the first laser ultrasound is excited at position m and the second laser is detected at position k; w mk is the first weight coefficient; R ij is the imaging factor, that is, the reconstructed image of the laser ultrasonic sound source at position (i, j), which can reflect the defect size information.

[0090] Regarding the mechanical information of the pot insulator, the first laser excites the pot insulator. After the first laser disappears, the local particle vibration at the first laser excitation position is in a free vibration state and will vibrate according to the eigenfrequency. Therefore, the value reflecting the eigenfrequency is extracted from the signal measured by the second laser, that is, the eigenfrequency is quantified by the measurement signal, and then the elastic modulus E and Poisson's ratio σ are calculated using the eigenfrequency. The specific implementation method can use the optimal parameter method to solve the eigenfrequency value and define the error function:

[0091]

[0092] where f i (E,σ) is the predicted eigenfrequency value, which is a function of the elastic modulus E and Poisson’s ratio σ, m i is the experimental measurement quantity (including vibration velocity and vibration position) extracted from the second laser measurement signal, w i is the second weight coefficient, M is the number of frequencies used in the inversion calculation, that is, by solving equation (5) to obtain the minimum elastic modulus E and Poisson's ratio σ, the values ​​of which can reflect the mechanical information of the pot insulator.

[0093] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0094] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the device and its core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for detecting a gas insulated switchgear, characterized in that: The method comprises: Gridding the devices to be detected to obtain multiple grid devices; Determine the grid device that has been excited by the first laser as a laser ultrasonic sound source; one grid device corresponds to one laser ultrasonic sound source; Using a second laser to obtain the vibration velocity and vibration displacement of each of the laser ultrasonic sound sources; Determine a reconstructed image of each of the laser ultrasonic sound sources by calculating the vibration velocity of each of the laser ultrasonic sound sources; Determine the defect of the device to be inspected according to all the reconstructed images; Calculate the elastic modulus and Poisson's ratio of the device to be tested according to the vibration speed and vibration displacement of all the laser ultrasonic sound sources; Determine the elastic modulus and Poisson's ratio as mechanical information of the device to be tested; Defects that will be generated in the device to be inspected are predicted based on the mechanical information.

2. The detection method of gas insulated switchgear according to claim 1, characterized in that: The step of calculating and determining the reconstructed image of each of the laser ultrasonic sound sources according to the vibration velocity of each of the laser ultrasonic sound sources specifically includes: Calculating a spectrum slope parameter of each of the laser ultrasonic sound sources according to the vibration velocity of each of the laser ultrasonic sound sources; The reconstructed image of each of the laser ultrasonic sound sources is determined according to the spectrum slope parameter of each of the laser ultrasonic sound sources.

3. A detection device for a gas insulated switchgear, characterized in that: include: A first laser, a second laser, and a reference channel, a signal processing module, and an imaging module connected in sequence; The first laser is used to emit a first laser, and the first laser is used to excite the device to be detected; The second laser is used to emit a second laser, and the second laser is used to detect the device to be detected; The reference channel is used to cause the second laser to interfere with the laser reflected by the device to be detected, so as to obtain an interference signal; The signal processing module is used to obtain the vibration speed and the vibration speed and vibration displacement of the imaging area according to the interference signal; the imaging area is the area where the device to be detected is excited by the first laser and detected by the second laser; The imaging module is used to execute the method according to any one of claims 1 to 2 to detect defects of the device to be inspected.

4. A detection system for a gas insulated switchgear, characterized in that: include: A gridding module, used for gridding the equipment to be detected to obtain multiple grid devices; A sound source determination module, used to determine the grid device that has been excited by the first laser as a laser ultrasonic sound source; one grid device corresponds to one laser ultrasonic sound source; A vibration velocity and vibration displacement acquisition module, used to acquire the vibration velocity and vibration displacement of each of the laser ultrasonic sound sources using a second laser; A reconstructed image determination module, used to calculate and determine a reconstructed image of each of the laser ultrasonic sound sources according to each of the vibration velocities; A first defect determination module, used for determining the defects of the device to be inspected according to all the reconstructed images; An elastic modulus and Poisson's ratio determination module, used to calculate the elastic modulus and Poisson's ratio of the device to be detected according to the vibration velocity and vibration displacement of all the laser ultrasonic sound sources; A mechanical information determination module, used to determine the elastic modulus and Poisson's ratio as the mechanical information of the device to be detected; The second defect determination module is used to predict the defects that will be generated in the device to be inspected based on the mechanical information.

5. The detection system of the gas insulated switchgear according to claim 4, characterized in that: The reconstructed image determination module specifically includes: Calculating a spectrum slope parameter of each of the laser ultrasonic sound sources according to the vibration velocity of each of the laser ultrasonic sound sources; The reconstructed image of each of the laser ultrasonic sound sources is determined according to the spectrum slope parameter of each of the laser ultrasonic sound sources.

Images