A method and device for flaw detection of electric power equipment

Abstract

The present invention relates to the field of ultrasonic flaw detection technology, and specifically to a method and device for flaw detection of power equipment, including: obtaining ultrasonic signals of power equipment in several directions and depths; obtaining the strength of ultrasonic signals of power equipment at each depth in each direction; obtaining the strength change index of ultrasonic signals of power equipment at each depth in each direction; screening several suspected defect positions according to the magnitude of the strength change index; obtaining the attenuation of ultrasonic signals of power equipment at each depth in each direction; weighting the significance of the strength of ultrasonic signals of each suspected defect position corresponding to different directions according to the attenuation, and obtaining several defect positions of power equipment. The present invention reduces the influence of the attenuation of ultrasonic signals on the inaccurate flaw detection results of power equipment, and improves the accuracy and efficiency of flaw detection of power equipment.

Description

Technical Field

[0001] The invention relates to the technical field of ultrasonic flaw detection, and in particular to a flaw detection method and device for electric power equipment. Background Art

[0002] In the power system, due to long-term operation under high voltage, high current and different environmental conditions, power equipment may have hidden faults, which may lead to serious safety accidents if not detected and handled in time. Therefore, it is necessary to conduct regular flaw detection on power equipment.

[0003] The existing method only uses ultrasonic flaw detection devices to detect power equipment in different directions when detecting power equipment, and then analyzes the changes in ultrasonic signals to determine whether the power equipment has defects. When using ultrasonic flaw detection devices to detect power equipment, the power equipment will absorb part of the ultrasonic waves, and the uneven microstructure inside the material of the power equipment itself will cause the ultrasonic waves to scatter, thereby reducing the intensity of the ultrasonic waves propagating along a straight line, causing the ultrasonic signal to attenuate and the penetration ability to decrease, resulting in inaccurate flaw detection results for the power equipment, and it is difficult to accurately determine the defect location. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a method and device for flaw detection of electric equipment.

[0005] A method and device for flaw detection of electric power equipment of the present invention adopts the following technical scheme:

[0006] An embodiment of the present invention provides a method for flaw detection of electric power equipment, the method comprising the following steps:

[0007] Acquire ultrasonic signals of the power equipment at several directions and depths, wherein each direction corresponds to several depths;

[0008] According to the change of the extreme value in the ultrasonic signal and the frequency of the ultrasonic signal, the strength of the ultrasonic signal at each depth of the power equipment in each direction is obtained; according to the change of the strength of the ultrasonic signal, the strength change index of the ultrasonic signal at each depth of the power equipment in each direction is obtained; according to the size of the strength change index, several suspected defect locations are screened;

[0009] According to the intensity change index and the intensity of the ultrasonic signal of the power equipment at the first depth in each direction, the attenuation of the ultrasonic signal of the power equipment at each depth in each direction is obtained; according to the attenuation, the significance of the intensity of the ultrasonic signal in different directions corresponding to each suspected defect position is weighted to obtain several defect positions of the power equipment, and the significance is obtained by a significance detection algorithm.

[0010] Furthermore, the method of obtaining the strength of the ultrasonic signal of the power equipment at each depth in each direction according to the change of the extreme value in the ultrasonic signal and the frequency of the ultrasonic signal includes the following specific steps:

[0011] Any direction of the power equipment is recorded as the target direction, and any depth in the target direction is recorded as the target depth; the number of maximum values ​​and the number of minimum values ​​in the ultrasonic signal of the target depth in the target direction are obtained; the average value of the absolute value of the difference between all the maximum values ​​and minimum values ​​of the same order in the ultrasonic signal of the target depth in the target direction and the product of the main frequency of the ultrasonic signal of the target depth in the target direction are taken as the intensity of the ultrasonic signal of the power equipment at the target depth in the target direction.

[0012] Furthermore, the step of obtaining the intensity change index of the ultrasonic signal of the power equipment at each depth in each direction according to the intensity change of the ultrasonic signal includes the following specific steps:

[0013] For any depth in any direction of the power equipment, the depth before the depth is recorded as the first adjacent depth, and the depth before the first adjacent depth is recorded as the second adjacent depth; the absolute value of the difference between the intensity of the ultrasonic signal at the depth and the intensity of the ultrasonic signal at the first adjacent depth is recorded as the first intensity change parameter; the ratio of the intensity of the ultrasonic signal at the depth to the intensity of the ultrasonic signal at the first adjacent depth is recorded as the first intensity change factor, and the ratio of the intensity of the ultrasonic signal at the first adjacent depth to the intensity of the ultrasonic signal at the second adjacent depth is recorded as the second intensity change factor; the absolute value of the difference between the first intensity change factor and the second intensity change factor is recorded as the second intensity change parameter;

[0014] An intensity change index of the ultrasonic signal of the electric equipment at the depth in the direction is obtained according to the first intensity change parameter and the second intensity change parameter.

[0015] Furthermore, the step of obtaining the intensity change index of the ultrasonic signal of the power equipment at the depth in the direction according to the first intensity change parameter and the second intensity change parameter includes the following specific steps:

[0016] The first intensity change parameter and the second intensity change parameter are multiplied to obtain an intensity change index of the ultrasonic signal of the electric equipment at the depth in the direction.

[0017] Furthermore, the specific steps of screening a number of suspected defect locations according to the magnitude of the strength change index are as follows:

[0018] The intensity change index of the ultrasonic signal at all depths in all directions is detected using a significance detection algorithm, and the position corresponding to the depth where the intensity change index changes greatly is taken as the suspected defect position.

[0019] Furthermore, the attenuation of the ultrasonic signal of the power equipment at each depth in each direction is obtained according to the intensity change index and the intensity of the ultrasonic signal of the power equipment at the first depth in each direction, and the specific steps include the following:

[0020] Obtain the intensity of the ultrasonic signal of the power equipment at the first depth in any direction; obtain the cumulative value of the intensity change index of the ultrasonic signal of the power equipment at any depth in the same direction and all depths after the depth; input the ratio of the intensity of the ultrasonic signal at the first depth to the cumulative value of the intensity change index into the gain calculation formula, and use the output result of the gain calculation formula as the attenuation of the ultrasonic signal of the power equipment at the depth in the direction.

[0021] Furthermore, the significance of the intensity of the ultrasonic signal in different directions corresponding to each suspected defect position is weighted according to the attenuation degree to obtain several defect positions of the power equipment, including the following specific steps:

[0022] For any suspected defect position, obtain the attenuation of the ultrasonic signal and the significance of the intensity of the ultrasonic signal corresponding to the nearest depth in each direction of the suspected defect position, weight the significance of the intensity of the corresponding ultrasonic signal by the inverse normalized value of the attenuation of the ultrasonic signal corresponding to the nearest depth in each direction, and obtain the initial defect manifestation degree of the suspected defect position in each direction; the cumulative value of the initial defect manifestation degree of the suspected defect position in all directions is used as the defect manifestation degree of the suspected defect position;

[0023] According to the severity of the defect, several defect locations of the power equipment are screened out.

[0024] Furthermore, the method of screening out several defect locations of the power equipment according to the degree of defect manifestation includes the following specific steps:

[0025] The suspected defect position with a defect manifestation degree greater than the preset first threshold is regarded as the defect position of the power equipment, and the suspected defect position with a defect manifestation degree less than or equal to the preset first threshold is not regarded as the defect position of the power equipment.

[0026] Furthermore, the preset first threshold is specifically 0.7.

[0027] The present invention also proposes a flaw detection device for electric equipment, which includes an absorption block, a chip, a delay block, a damping block, a housing, an electrical adapter, a probe line, a probe and a data processor, wherein the absorption block is used to absorb and attenuate reflected noise generated on the back of the chip; the chip is used as a transducer to convert electrical signals into ultrasonic signals, and convert the received ultrasonic echoes into electrical signals again; the delay block is used to delay the time for ultrasonic waves to enter the electric equipment; the damping block is used to reduce the duration of chip vibration; the housing is used to protect the internal piezoelectric chip and related circuits; the electrical adapter is used to connect the probe and the data processor to drive the probe to emit and receive ultrasonic waves; the probe line is used to transmit electrical signals and connect the probe and the data processor; the probe is used to obtain ultrasonic signals of the electric equipment in several directions and depths; and the data processor is used to implement the above steps.

[0028] The beneficial effects of the technical solution of the present invention are as follows: after obtaining the ultrasonic signals of the power equipment in several directions and depths, the present invention obtains the intensity of the ultrasonic signal by analyzing the changes in the extreme values ​​in the ultrasonic signal and the frequency of the ultrasonic signal; then, by analyzing the intensity changes of the ultrasonic signal, the intensity change index of the ultrasonic signal of the power equipment at each depth in each direction is obtained, and according to the size of the intensity change index, several suspected defect positions are screened, so that the defect position can be determined more quickly; then, the attenuation of the ultrasonic signal is better analyzed by combining the intensity of the ultrasonic signal and the intensity change index, and finally the significance of the intensity of the ultrasonic signal in different directions corresponding to each suspected defect position is weighted by the attenuation degree to obtain several defect positions of the power equipment, thereby reducing the influence of the attenuation of the ultrasonic signal on the inaccurate flaw detection results of the power equipment and improving the accuracy and efficiency of the flaw detection of the power equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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 or the description of the prior art 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 work.

[0030] Figure 1 A flowchart of the steps of a method for flaw detection of electric equipment provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of a method and device for flaw detection of electric equipment proposed by the present invention, its specific implementation, structure, features and effects, in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0032] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0033] The specific scheme of a method and device for flaw detection of electric power equipment provided by the present invention is described in detail below with reference to the accompanying drawings.

[0034] See also Figure 1 , which shows a flow chart of a method for flaw detection of electric equipment provided by an embodiment of the present invention, the method comprising the following steps:

[0035] Step S001: Acquire ultrasonic signals of power equipment in several directions and depths, wherein each direction corresponds to several depths.

[0036] It should be noted that the main purpose of this embodiment is to determine the attenuation of ultrasonic signals of power equipment at different depths in different directions, and then analyze the defect location of the power equipment in combination with the attenuation, so as to reduce the influence of the attenuation of ultrasonic signals on the inaccurate flaw detection results of the power equipment, thereby improving the accuracy and efficiency of flaw detection of the power equipment. Before starting the analysis, first obtain the required data.

[0037] Specifically, ultrasonic signals of the power equipment in several directions and depths are obtained, wherein each direction corresponds to several depths, as follows:

[0038] An ultrasonic flaw detection device is used to detect the six surface directions and eight oblique directions of the power equipment respectively. When detecting in each direction, it is necessary to detect ultrasonic signals of different depths. The depth changes from the surface of the power equipment by 1 cm each time until it passes through the power equipment, thereby obtaining ultrasonic signals at each depth of the power equipment in each direction.

[0039] At this point, ultrasonic signals of the power equipment at different directions and depths are obtained.

[0040] Step S002: Obtain the strength of the ultrasonic signal of the power equipment at each depth in each direction according to the change of the extreme value in the ultrasonic signal and the frequency of the ultrasonic signal; obtain the intensity change index of the ultrasonic signal of the power equipment at each depth in each direction according to the intensity change of the ultrasonic signal; and select several suspected defect locations according to the size of the intensity change index.

[0041] It should be noted that when using ultrasonic flaw detection devices to detect power equipment, the power equipment will absorb part of the ultrasonic wave, and the uneven microstructure inside the material of the power equipment itself will cause the ultrasonic wave to scatter, thereby reducing the intensity of the ultrasonic wave propagating along a straight line, causing the ultrasonic signal to attenuate and the penetration ability to decrease, making it difficult to detect the deep defects of the power equipment, or causing the reflected signal intensity from the deep defects to weaken and be close to the noise level, making it more difficult to identify the defects of the power equipment, resulting in inaccurate flaw detection results for the power equipment. Therefore, it is necessary to first analyze the intensity of the ultrasonic signal of the power equipment at different depths in different directions, so as to facilitate the subsequent better analysis of the attenuation of the ultrasonic signal, so as to more accurately determine the defects of the power equipment. Since the intensity of the ultrasonic signal is mainly related to the extreme value change in the signal and the frequency of the signal itself, when the extreme value change of the signal is large and the frequency is also high, it means that the signal intensity is relatively large. Therefore, by analyzing the extreme value change in the ultrasonic signal and the frequency of the ultrasonic signal, the intensity of the ultrasonic signal in different directions and depths is obtained.

[0042] Preferably, in one embodiment of the present invention, the intensity of the ultrasonic signal of the power equipment at each depth in each direction is obtained according to the change of the extreme value in the ultrasonic signal and the frequency of the ultrasonic signal, as follows:

[0043] Any direction of the power equipment is recorded as the target direction, and any depth in the target direction is recorded as the target depth; the number of maximum values ​​and the number of minimum values ​​in the ultrasonic signal of the target depth in the target direction are obtained, and the smallest value among the number of maximum values ​​and the number of minimum values ​​is used as the number of common extreme values ​​in the ultrasonic signal of the target depth in the target direction; the average value of the absolute values ​​of the differences between all the maximum values ​​and minimum values ​​of the same order in the ultrasonic signal of the target depth in the target direction and the product of the main frequency of the ultrasonic signal of the target depth in the target direction are used as the intensity of the ultrasonic signal of the power equipment at the target depth in the target direction.

[0044] As a specific example, the specific method for obtaining the intensity of the ultrasonic signal is as follows:

[0045]

[0046] In the formula, is the number of common extreme values ​​in the ultrasonic signal of the power device at the target depth in the target direction; The ultrasonic signal of the power equipment at the target depth in the target direction is Minimum value; The ultrasonic signal of the power equipment at the target depth in the target direction is A maximum value; To take the absolute value; is the main frequency of the ultrasonic signal of the power equipment at the target depth in the target direction. It should be noted that obtaining the main frequency of a signal is an existing method and will not be described in detail in this embodiment; The intensity of the ultrasonic signal at the target depth in the target direction of the power device.

[0047] It should be noted that since the strength of the ultrasonic signal is mainly related to the extreme value change in the signal and the frequency of the signal itself, when the extreme value change of the signal is large and the frequency is also high, it means that the signal strength is relatively large. Therefore, the above formula obtains the strength of the ultrasonic signal in different directions and depths by analyzing the extreme value change in the ultrasonic signal and the frequency of the ultrasonic signal. It represents the change of extreme value in ultrasonic signal. The larger the value, the greater the amplitude of the signal change, and the greater the strength of the ultrasonic signal. is the main frequency of the ultrasonic signal. Since the ultrasonic signal may be disturbed by the structure of the power equipment itself, causing the frequency to change, the main frequency of the ultrasonic signal is selected for analysis in this embodiment. The larger it is, the higher the frequency of the ultrasonic signal is and the greater the corresponding intensity is.

[0048] It should be noted that the intensity of ultrasonic signals mainly changes in two ways. One is due to the absorption characteristics of the materials of the power equipment, which weakens the signal strength, which is also the main reason for signal attenuation. The other is when encountering internal defects, the ultrasonic waves interact with these defects, causing the ultrasonic signal to change. In order to better analyze the attenuation of ultrasonic signals, it is first necessary to obtain the intensity change index of the ultrasonic signal of the power equipment at each depth in each direction, so as to better analyze the attenuation of ultrasonic signals.

[0049] Preferably, in one embodiment of the present invention, according to the intensity change of the ultrasonic signal, the intensity change index of the ultrasonic signal of the power equipment at each depth in each direction is obtained, which is specifically as follows:

[0050] For any depth in any direction of the power equipment, the depth before the depth is recorded as the first adjacent depth, and the depth before the first adjacent depth is recorded as the second adjacent depth; the absolute value of the difference between the intensity of the ultrasonic signal at the depth and the intensity of the ultrasonic signal at the first adjacent depth is recorded as the first intensity change parameter; the ratio of the intensity of the ultrasonic signal at the depth to the intensity of the ultrasonic signal at the first adjacent depth is recorded as the first intensity change factor, and the ratio of the intensity of the ultrasonic signal at the first adjacent depth to the intensity of the ultrasonic signal at the second adjacent depth is recorded as the second intensity change factor; the absolute value of the difference between the first intensity change factor and the second intensity change factor is recorded as the second intensity change parameter; the first intensity change parameter and the second intensity change parameter are multiplied to obtain the intensity change index of the ultrasonic signal of the power equipment at the depth in the direction.

[0051] As a specific example, the specific method for obtaining the intensity change index is as follows:

[0052]

[0053] In the formula, The first The strength of the ultrasonic signal at a depth; The first The strength of the ultrasonic signal at a depth; To take the absolute value; The first The intensity of the ultrasonic signal at the first depth is The ratio of the intensities of ultrasonic signals at different depths; The first The intensity of the ultrasonic signal at the first depth is The ratio of the intensities of ultrasonic signals at different depths; is the total depth of the power equipment in the target direction; The first The intensity change indicator of the ultrasonic signal at a certain depth.

[0054] It should be noted that The larger the The intensity of the ultrasonic signal at the first depth is compared with that at the The intensity of the ultrasonic signal at each depth varies greatly. The greater the intensity change index of the ultrasonic signal at each depth; The larger the The intensity of the ultrasonic signal at the depth is different from that of the previous depth. The greater the difference between the intensity of the ultrasonic signal at a depth and the intensity of the ultrasonic signal at the previous depth, the The greater the depth, the greater the intensity change index of the ultrasonic signal.

[0055] It should be noted that the above-mentioned intensity change index of the ultrasonic signal of the power equipment at each depth in each direction can be obtained. The suspected defect position can be determined by the size of the intensity change index. The larger the intensity change index, the more likely the position corresponding to the depth is the defect position.

[0056] Specifically, according to the size of the strength change index, several suspected defect locations are screened, as follows:

[0057] The intensity change index of the ultrasonic signal at all depths in all directions is detected using a significance detection algorithm, and the position corresponding to the depth where the intensity change index changes greatly is taken as the suspected defect position.

[0058] So far, several suspected defect locations have been obtained.

[0059] Step S003: According to the intensity change index and the intensity of the ultrasonic signal of the power equipment at the first depth in each direction, the attenuation of the ultrasonic signal of the power equipment at each depth in each direction is obtained; according to the attenuation, the significance of the intensity of the ultrasonic signal in different directions corresponding to each suspected defect position is weighted to obtain several defect positions of the power equipment, and the significance is obtained by a significance detection algorithm.

[0060] It should be noted that the above-mentioned acquired ultrasonic signal intensities at different directions and depths and ultrasonic signal intensity variation indexes can be used to calculate the attenuation of ultrasonic signals of power equipment at each depth in each direction by combining these two indexes.

[0061] Preferably, in one embodiment of the present invention, the attenuation of the ultrasonic signal of the power equipment at each depth in each direction is obtained according to the intensity change index and the intensity of the ultrasonic signal of the power equipment at the first depth in each direction, as follows:

[0062] Obtain the intensity of the ultrasonic signal of the power equipment at the first depth in any direction; obtain the cumulative value of the intensity change index of the ultrasonic signal of the power equipment at any depth in the same direction and all depths after the depth; input the ratio of the intensity of the ultrasonic signal at the first depth to the cumulative value of the intensity change index into the gain calculation formula, and use the output result of the gain calculation formula as the attenuation of the ultrasonic signal of the power equipment at the depth in the direction.

[0063] As a specific example, the specific method for obtaining the attenuation degree is as follows:

[0064]

[0065] In the formula, is a logarithmic function with base 10; The first The strength of the ultrasonic signal at a depth; The first The depth and The accumulated value of the intensity change index of ultrasonic signals at all depths after the depth; The first The attenuation of the ultrasonic signal at the depth. The strength of the ultrasonic signal at a depth is the strength of the ultrasonic signal on the surface of the power equipment in the target direction. The value is less than Therefore, the calculated attenuation value will not be negative.

[0066] It should be noted that the attenuation of the ultrasonic signal is obtained by the intensity of the ultrasonic signal on the surface of the power equipment in the target direction and the cumulative intensity change index in the target direction. The larger the value, the higher the target direction. The deeper the depth, the greater the attenuation of the ultrasonic signal.

[0067] It should be noted that the above-mentioned attenuation of the ultrasonic signal of the power equipment at each depth in each direction reflects the attenuation of the ultrasonic signal only at the depth of a certain angle. Since the power equipment usually has a complex geometric shape and is composed of multiple materials, this may lead to blind spots in single-angle flaw detection. Multi-angle flaw detection can cover all aspects of the equipment more comprehensively, reduce blind spots, and ensure that every corner can be effectively inspected. Some defects (such as cracks) may have a specific direction. If the propagation direction of the ultrasonic wave is parallel to the defect, it may lead to missed detection. Multi-angle flaw detection increases the probability of being perpendicular to the defect, thereby improving the detection rate of defects. The ultrasonic waves of defects at different angles reach different depths and have different signal attenuation. When the defect position at a certain angle is close, its signal attenuation is weak, and the reliability of the flaw detection result is high. By detecting from different angles, the influence of signal attenuation on the detection results can be reduced, and the comprehensiveness and accuracy of the flaw detection results can be improved. Therefore, the significance of the intensity of the ultrasonic signal corresponding to different directions of the suspected defect position is weighted averaged by the attenuation, and the defect manifestation degree of each suspected defect position is obtained, so as to screen the real defect position according to the size of the defect manifestation degree.

[0068] Specifically, the significance of the intensity of the ultrasonic signal in different directions corresponding to each suspected defect position is weighted according to the attenuation degree to obtain several defect positions of the power equipment, and the significance is obtained by a significance detection algorithm, including the steps of:

[0069] First, the significance of the intensity of the ultrasonic signal in different directions corresponding to each suspected defect position is weighted according to the attenuation degree to obtain the defect manifestation degree of each suspected defect position.

[0070] Secondly, according to the severity of the defect, several defect locations of the power equipment are screened out.

[0071] Preferably, in one embodiment of the present invention, the significance of the intensity of the ultrasonic signal in different directions corresponding to each suspected defect position is weighted according to the attenuation degree to obtain the defect manifestation degree of each suspected defect position, which is specifically as follows:

[0072] For any suspected defect location, obtain the attenuation of the ultrasonic signal at the nearest depth corresponding to the suspected defect location in each direction and the significance of the intensity of the ultrasonic signal; weight the significance of the intensity of the corresponding ultrasonic signal by the inverse normalized value of the attenuation of the ultrasonic signal at the nearest depth corresponding to each direction to obtain the initial defect manifestation degree of the suspected defect location in each direction; and take the accumulated value of the initial defect manifestation degrees of the suspected defect location in all directions as the defect manifestation degree of the suspected defect location.

[0073] As a specific example, the specific method for obtaining the defect manifestation degree is as follows:

[0074]

[0075] In the formula, The number of directions for detecting electrical equipment; For the The suspected defect location is in the first The attenuation of the ultrasonic signal in each direction corresponding to the nearest depth; is the softmax function, used for normalization; For the The suspected defect location is in the first The significance of the intensity of the ultrasonic signal corresponding to the nearest depth in each direction. It should be noted that the significance is obtained by a significance detection algorithm, which will not be described in detail in this embodiment; For the The degree of defect manifestation at each suspected defect location.

[0076] It should be noted that by detecting from different angles, the influence of signal attenuation on the detection results can be reduced, and the comprehensiveness and accuracy of the flaw detection results can be improved. Therefore, the above formula uses the attenuation degree to perform a weighted average on the significance of the intensity of the ultrasonic signal in different directions corresponding to the suspected defect position to obtain the degree of defect manifestation of each suspected defect position. Since the greater the attenuation degree, the greater its influence on the degree of defect manifestation, that is, the smaller the attenuation degree, the more reliable the defect detection result in this direction, and the more accurate the result of the defect manifestation degree, it is necessary to take an inverse relationship, and then weight the significance after normalization, and combine the weighted results of multiple directions to obtain the degree of defect manifestation of the suspected defect position; Indicates The suspected defect location is The initial defect manifestation degrees in each direction are accumulated to finally obtain the defect manifestation degree of the suspected defect position.

[0077] It should be noted that the defect manifestation degree of each suspected defect position is obtained above, and the suspected defect positions with a larger defect manifestation degree are screened by setting a suitable threshold to determine the defect position.

[0078] Specifically, according to the degree of defect manifestation, several defect locations of power equipment are screened out, as follows:

[0079] The suspected defect position with a defect manifestation degree greater than the preset first threshold is regarded as the defect position of the power equipment, and the suspected defect position with a defect manifestation degree less than or equal to the preset first threshold is not regarded as the defect position of the power equipment. This embodiment is described with the first threshold being 0.7.

[0080] Through the above steps, a method for flaw detection of electric power equipment is completed.

[0081] Another embodiment of the present invention provides a power equipment flaw detection device, the device includes an absorption block, a chip, a delay block, a damping block, a housing, an electrical adapter, a probe line, a probe and a data processor; the absorption block is used to absorb and attenuate the reflected clutter generated on the back of the chip to reduce interference signals and improve the clarity of flaw detection; the chip is used as a transducer to convert electrical signals into ultrasonic signals, and convert the received ultrasonic echoes into electrical signals again; the delay block is used to delay the time for ultrasonic waves to enter the power equipment to avoid surface interference waves and improve the accuracy and sensitivity of flaw detection; the damping block is used to reduce the duration of chip vibration, thereby reducing the pulse width and improving resolution and clarity; the housing is used to protect the internal piezoelectric chip and related circuits to prevent physical damage and environmental influences, and ensure the stability and reliability of the probe; the electrical adapter is used to connect the probe and the data processor to drive the probe to transmit and receive ultrasonic waves; the probe line is used to transmit electrical signals, connect the probe and the data processor, and ensure the effective transmission of signals between the two; the probe is used to obtain ultrasonic signals of the power equipment in several directions and depths; the data processor is used to implement the above steps.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for flaw detection of electric power equipment, characterized in that: The method comprises the following steps: Acquire ultrasonic signals of the power equipment at several directions and depths, wherein each direction corresponds to several depths; According to the change of the extreme value in the ultrasonic signal and the frequency of the ultrasonic signal, the strength of the ultrasonic signal at each depth of the power equipment in each direction is obtained; according to the change of the strength of the ultrasonic signal, the strength change index of the ultrasonic signal at each depth of the power equipment in each direction is obtained; according to the size of the strength change index, several suspected defect locations are screened; According to the intensity change index and the intensity of the ultrasonic signal of the power equipment at the first depth in each direction, the attenuation of the ultrasonic signal of the power equipment at each depth in each direction is obtained; according to the attenuation, the significance of the intensity of the ultrasonic signal of each suspected defect position corresponding to different directions is weighted to obtain several defect positions of the power equipment, and the significance is obtained by a significance detection algorithm; The method for obtaining the strength of the ultrasonic signal of the power equipment at the target depth in the target direction is as follows: record any direction of the power equipment as the target direction, and record any depth in the target direction as the target depth; obtain the number of maximum values ​​and the number of minimum values ​​in the ultrasonic signal at the target depth in the target direction; and take the average value of the absolute value of the difference between all the maximum values ​​and minimum values ​​of the same order in the ultrasonic signal at the target depth in the target direction and the product of the main frequency of the ultrasonic signal at the target depth in the target direction as the strength of the ultrasonic signal of the power equipment at the target depth in the target direction; Among them, the method for obtaining the intensity change index of the ultrasonic signal of the power equipment at each depth in each direction is as follows: for any depth in any direction of the power equipment, the depth before the depth is recorded as the first adjacent depth, and the depth before the first adjacent depth is recorded as the second adjacent depth; the absolute value of the difference between the intensity of the ultrasonic signal at the depth and the intensity of the ultrasonic signal at the first adjacent depth is recorded as the first intensity change parameter; the ratio of the intensity of the ultrasonic signal at the depth to the intensity of the ultrasonic signal at the first adjacent depth is recorded as the first intensity change factor, and the ratio of the intensity of the ultrasonic signal at the first adjacent depth to the intensity of the ultrasonic signal at the second adjacent depth is recorded as the second intensity change factor; the absolute value of the difference between the first intensity change factor and the second intensity change factor is recorded as the second intensity change parameter; according to the first intensity change parameter and the second intensity change parameter, the intensity change index of the ultrasonic signal of the power equipment at the depth in the direction is obtained; Wherein, the method for obtaining the attenuation of the ultrasonic signal of the power equipment at each depth in each direction is as follows: obtaining the intensity of the ultrasonic signal of the power equipment at the first depth in any direction; obtaining the cumulative value of the intensity change index of the ultrasonic signal of the power equipment at any depth in the same direction and all depths after the depth; inputting the ratio of the intensity of the ultrasonic signal at the first depth to the cumulative value of the intensity change index into the gain calculation formula, and using the output result of the gain calculation formula as the attenuation of the ultrasonic signal of the power equipment at the depth in the direction; Among them, the significance of the intensity of the ultrasonic signal in different directions corresponding to each suspected defect position is weighted according to the attenuation, and the method for obtaining several defect positions of the power equipment is as follows: for any suspected defect position, the attenuation of the ultrasonic signal at the nearest depth corresponding to the suspected defect position in each direction and the significance of the intensity of the ultrasonic signal are obtained, and the significance of the intensity of the corresponding ultrasonic signal is weighted by the inverse normalized value of the attenuation of the ultrasonic signal at the nearest depth in each direction to obtain the initial defect manifestation degree of the suspected defect position in each direction; the accumulated value of the initial defect manifestation degree of the suspected defect position in all directions is used as the defect manifestation degree of the suspected defect position; and according to the size of the defect manifestation degree, several defect positions of the power equipment are screened out.

2. A method for flaw detection of electric power equipment according to claim 1, characterized in that: The step of obtaining the intensity change index of the ultrasonic signal of the power equipment at the depth in the direction according to the first intensity change parameter and the second intensity change parameter includes the following specific steps: The first intensity change parameter and the second intensity change parameter are multiplied to obtain an intensity change index of the ultrasonic signal of the electric equipment at the depth in the direction.

3. A method for flaw detection of electric power equipment according to claim 1, characterized in that: The specific steps of screening several suspected defect locations according to the magnitude of the strength change index are as follows: The intensity change index of the ultrasonic signal at all depths in all directions is detected using a significance detection algorithm, and the position corresponding to the depth where the intensity change index changes greatly is taken as the suspected defect position.

4. A method for flaw detection of electric power equipment according to claim 1, characterized in that: The specific steps of screening out several defect locations of the power equipment according to the degree of defect manifestation are as follows: The suspected defect position with a defect manifestation degree greater than the preset first threshold is regarded as the defect position of the power equipment, and the suspected defect position with a defect manifestation degree less than or equal to the preset first threshold is not regarded as the defect position of the power equipment.

5. A method for flaw detection of electric power equipment according to claim 4, characterized in that: The preset first threshold is specifically 0.

7.

6. A flaw detection device for electric power equipment, comprising an absorption block, a wafer, a delay block, a damping block, a housing, an electrical adapter, a probe line, a probe and a data processor, characterized in that: The absorption block is used to absorb and attenuate the reflected noise generated on the back of the chip; the chip is used as a transducer to convert electrical signals into ultrasonic signals, and convert the received ultrasonic echoes into electrical signals again; the delay block is used to delay the time for ultrasonic waves to enter the power equipment; the damping block is used to reduce the duration of chip vibration; the housing is used to protect the internal piezoelectric chip and related circuits; the electrical adapter is used to connect the probe and the data processor to drive the probe to transmit and receive ultrasonic waves; the probe line is used to transmit electrical signals and connect the probe and the data processor; the probe is used to obtain ultrasonic signals of the power equipment in several directions and depths; the data processor is used to implement the steps of a power equipment flaw detection method as described in any one of claims 1-5.

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