阅读说明：本技术 一种126kV三相共箱盆式绝缘子界面缺陷相控超声检测方法 (126kV three-phase common-box basin-type insulator interface defect phase control ultrasonic detection method ) 是由 杨旭 张长虹 黎卫国 黄忠康 高超 周福升 黄若栋 熊佳明 杨芸 王国利 郑尧 于 2021-09-08 设计创作，主要内容包括：本发明公开了一种126kV三相共箱盆式绝缘子界面缺陷相控超声检测方法,利用超声相控检测系统对被测126kV三相共箱盆式绝缘子的环氧树脂-嵌件界面进行缺陷检测,建立了界面缺陷超声相控阵传播模型,对被测126kV三相共箱盆式绝缘子进行超声相控检测,以归一化回波峰值为缺陷表征量,形成界面区域超声检测图像,判断被测126kV三相共箱盆式绝缘子是否存在界面缺陷,并确定界面缺陷区域。解决了使用X射线成像法进行盆式绝缘子界面缺陷检测存在的对宽度较小的缺陷灵敏度不高,且设备体积庞大,不便于携带,价格昂贵,X射线对人体存在辐射性危害的技术问题,具有检测成本低、检测精度高、体积小、对人体无X射线辐射危害的优点。(The invention discloses an ultrasonic detection method for interface defects of a 126kV three-phase common-box basin-type insulator, which is characterized in that an ultrasonic phase control detection system is utilized to detect the defects of an epoxy resin-insert interface of the 126kV three-phase common-box basin-type insulator to be detected, an interface defect ultrasonic phased array propagation model is established, ultrasonic phase control detection is carried out on the 126kV three-phase common-box basin-type insulator to be detected, an ultrasonic detection image of an interface area is formed by taking a normalized echo peak value as a defect representation quantity, whether the 126kV three-phase common-box basin-type insulator to be detected has interface defects or not is judged, and the interface defect area is determined. The technical problems that the defect detection of the basin-type insulator interface by using an X-ray imaging method is low in defect sensitivity to small width, large in equipment size, inconvenient to carry and high in price, and X-rays have radiation damage to a human body are solved, and the method has the advantages of being low in detection cost, high in detection precision, small in size and free of X-ray radiation damage to the human body.)

1. A126 kV three-phase common-box basin-type insulator interface defect phase control ultrasonic detection method is characterized by comprising the following steps:

constructing a basin-type insulator ultrasonic phase control detection platform, wherein the basin-type insulator ultrasonic phase control detection platform comprises an ultrasonic phase control flaw detector, a PC (personal computer) and a 126kV three-phase common-box basin-type insulator to be detected;

setting detection parameters of an ultrasonic phase control flaw detector, wherein the detection comprises a scanning type, a focusing rule, a scanning range and a gain, and the scanning type comprises S scanning, A scanning and C scanning;

coupling a rubber film water bag on an ultrasonic probe of an ultrasonic phased flaw detector, placing the ultrasonic probe coupled with the rubber film water bag on the upper surface of an epoxy insulation layer of a 126kV three-phase common-box basin-type insulator to be detected, and building an ultrasonic phased array propagation model of a basin-type insulator interface;

carrying out ultrasonic phase control detection on the 126kV three-phase common-box basin-type insulator to be detected to obtain an ultrasonic echo signal of an interface of the 126kV three-phase common-box basin-type insulator to be detected;

carrying out normalization processing on the ultrasonic echo signal peak value to form an ultrasonic detection image of an interface area;

and judging whether the 126kV three-phase common-box basin-type insulator to be detected has interface defects according to the ultrasonic detection image of the interface area, and if so, acquiring the interface defect area in the ultrasonic detection image of the interface area.

2. The 126kV three-phase common-box basin-type insulator interface defect phased ultrasonic detection method according to claim 1, wherein an ultrasonic probe of an ultrasonic phased flaw detector is a linear array probe, the ultrasonic frequency is 4MHz, the number of array elements is 16, the spacing between the array elements is 1.0mm, and the length of the array elements is 10 mm.

3. The 126kV three-phase common-box basin-type insulator interface defect phase-control ultrasonic detection method according to claim 1, wherein a focusing rule is set as full-focusing imaging, and the gain is 50 dB.

4. The 126kV three-phase common-box basin-type insulator interface defect phase-control ultrasonic detection method as claimed in claim 1, wherein the thickness of the rubber thin film water bag is 0.03 mm.

5. The 126kV three-phase common-box basin-type insulator interface defect phase-control ultrasonic detection method according to claim 1, wherein the step of obtaining an interface defect region in an interface region ultrasonic detection image comprises the following steps:

determining the depth information of the interface defect area according to the A scanning image;

and determining the horizontal cross-sectional shape size of the interface defect area according to the C scanning image.

6. The method for phased ultrasonic detection of the interface defect of the 126kV three-phase common-box basin-type insulator according to claim 1, wherein the step of judging whether the 126kV three-phase common-box basin-type insulator to be detected has the interface defect according to the ultrasonic detection image of the interface area comprises the following steps:

and detecting whether the reflection echo peak value corresponding to the epoxy insulation-center insert interface of the 126kV three-phase common-box basin-type insulator to be detected in the ultrasonic detection image of the interface area is greater than a threshold value, if so, detecting that the 126kV three-phase common-box basin-type insulator to be detected has interface defects, otherwise, detecting that the 126kV three-phase common-box basin-type insulator to be detected has no interface defects.

7. The 126kV three-phase common-box basin-type insulator interface defect phase control ultrasonic detection method according to claim 6, further comprising:

and carrying out color marking on the region of the ultrasonic detection image of the interface region, wherein the reflection echo peak value is larger than the threshold value.

Technical Field

The invention relates to the technical field of basin-type insulator interface defect detection, in particular to a 126kV three-phase common-box basin-type insulator interface defect phase-control ultrasonic detection method.

Background

The basin-type insulator is a key part of a gas insulated metal-enclosed switchgear (GIS), is composed of a metal insert, an epoxy insulator and a metal flange, plays roles of electrically insulating, isolating a gas chamber and supporting a conductor, and is the weakest insulating link in the gas insulated metal-enclosed switchgear. The fault caused by the basin-type insulator accounts for a considerable proportion of the insulation fault of the gas insulated metal-enclosed switchgear, wherein the interface defect generated at the interface of the basin-type insulator central conductor and the epoxy insulation material is mainly caused by human error or mechanical movement of the gas insulated metal-enclosed switchgear central conductor and the like in the assembling process, the central conductor-epoxy insulation interface is an area with concentrated electric, thermal and force ratios, the structure is complex, the interface has prominent effect, the interface defect is easy to occur, the partial discharge and the insulation damage of the basin-type insulator are caused, and the normal operation of the gas insulated metal-enclosed switchgear is directly threatened. Therefore, the detection of whether the defect exists at the interface between the basin-type insulator central conductor and the epoxy resin is of great significance for guaranteeing the safe operation of the power system.

The existing methods applied to the detection of the interface defects of the basin-type insulator include an electrical detection method and a non-electrical detection method. The electrical detection method is mainly used for judging the type of a fault defect by detecting an electromagnetic physical signal generated along with partial discharge aiming at the partial discharge phenomenon caused by the defect, but the strength of the detection signal is related to the amount of the partial discharge and is easily interfered by other signals. The non-electric detection method detects the GIS equipment with a non-running object, wherein an X-ray imaging method is mature in technology and high in detection efficiency, but has low sensitivity to defects with small width, the equipment is large in size, inconvenient to carry and high in price, and X-rays have radiation hazard to a human body. Therefore, the invention provides a 126kV three-phase common-box basin-type insulator interface defect phase-control ultrasonic detection method which is used for solving the problem of basin-type insulator interface defect detection by an X-ray imaging method.

Disclosure of Invention

The invention provides a phase-control ultrasonic detection method for interface defects of a 126kV three-phase common-box basin-type insulator, which is used for solving the technical problems of low sensitivity to defects with small width, large equipment size, inconvenience in carrying, high price and radioactive damage of X rays to a human body in the process of detecting the interface defects of the basin-type insulator by using an X-ray imaging method.

In view of the above, the invention provides a 126kV three-phase common-box basin-type insulator interface defect phase-control ultrasonic detection method, which includes:

constructing a basin-type insulator ultrasonic phase control detection platform, wherein the basin-type insulator ultrasonic phase control detection platform comprises an ultrasonic phase control flaw detector, a PC (personal computer) and a 126kV three-phase common-box basin-type insulator to be detected;

setting detection parameters of an ultrasonic phase control flaw detector, wherein the detection comprises a scanning type, a focusing rule, a scanning range and a gain, and the scanning type comprises S scanning, A scanning and C scanning;

coupling a rubber film water bag on an ultrasonic probe of an ultrasonic phased flaw detector, placing the ultrasonic probe coupled with the rubber film water bag on the upper surface of an epoxy insulation layer of a 126kV three-phase common-box basin-type insulator to be detected, and building an ultrasonic phased array propagation model of a basin-type insulator interface;

carrying out ultrasonic phase control detection on the 126kV three-phase common-box basin-type insulator to be detected to obtain an ultrasonic echo signal of an interface of the 126kV three-phase common-box basin-type insulator to be detected;

carrying out normalization processing on the ultrasonic echo signal peak value to form an ultrasonic detection image of an interface area;

and judging whether the 126kV three-phase common-box basin-type insulator to be detected has interface defects according to the ultrasonic detection image of the interface area, and if so, acquiring the interface defect area in the ultrasonic detection image of the interface area.

Optionally, the ultrasonic probe of the ultrasonic phased flaw detector is a linear array probe, the ultrasonic frequency is 4MHz, the number of the array elements is 16, the spacing between the array elements is 1.0mm, and the length of the array elements is 10 mm.

Alternatively, the focus algorithm is set to full focus imaging with a gain of 50 dB.

Optionally, the rubber membrane bladder has a thickness of 0.03 mm.

Optionally, acquiring an interface defect region in the interface region ultrasonic inspection image includes:

determining the depth information of the interface defect area according to the A scanning image;

and determining the horizontal cross-sectional shape size of the interface defect area according to the C scanning image.

Optionally, judging whether the 126kV three-phase common-box basin-type insulator to be tested has an interface defect according to the interface region ultrasonic detection image, including:

and detecting whether the reflection echo peak value corresponding to the epoxy insulation-center insert interface of the 126kV three-phase common-box basin-type insulator to be detected in the ultrasonic detection image of the interface area is greater than a threshold value, if so, detecting that the 126kV three-phase common-box basin-type insulator to be detected has interface defects, otherwise, detecting that the 126kV three-phase common-box basin-type insulator to be detected has no interface defects.

Optionally, the method further comprises:

and carrying out color marking on the region of the ultrasonic detection image of the interface region, wherein the reflection echo peak value is larger than the threshold value.

According to the technical scheme, the embodiment of the invention has the following advantages:

the invention provides an ultrasonic detection method for interface defects of a 126kV three-phase common-box basin-type insulator, which is characterized in that an ultrasonic phase control detection system is utilized to detect the defects of an epoxy resin-insert interface of the 126kV three-phase common-box basin-type insulator to be detected, an interface defect ultrasonic phased array propagation model is established, ultrasonic phase control detection is carried out on the 126kV three-phase common-box basin-type insulator to be detected, an ultrasonic detection image of an interface area is formed by taking a normalized echo peak value as a defect representation quantity, whether the 126kV three-phase common-box basin-type insulator to be detected has interface defects or not is judged, the interface defect area is determined, and the ultrasonic detection method can be used for factory detection of the basin-type insulator and can also be suitable for field assembly detection of the basin-type insulator. The 126kV three-phase common-box basin-type insulator interface defect phase-control ultrasonic detection method solves the technical problems of low sensitivity to defects with small width, large equipment size, inconvenience in carrying and high price in basin-type insulator interface defect detection by using an X-ray imaging method, and X-rays have radiation damage to a human body, and has the advantages of low detection cost, high detection precision, small size and no X-ray radiation damage to the human body.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other related drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic flow chart of a 126kV three-phase common-box basin-type insulator interface defect phase control ultrasonic detection method provided in an embodiment of the present invention;

FIG. 2 is a connection schematic diagram for detecting an interface defect of a 126kV three-phase common-box basin-type insulator in the embodiment of the invention;

FIG. 3 is a schematic diagram of an ultrasonic phased array propagation model of a basin-insulator interface provided in an embodiment of the present invention;

fig. 4 is an ultrasonic phase control S-scan detection imaging diagram of a 126kV three-phase common-box basin-type insulator to be detected provided in the embodiment of the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

For easy understanding, please refer to fig. 1, an embodiment of an ultrasonic detection method for detecting a fault phase of an interface of a 126kV three-phase common-box basin-type insulator is provided in the present invention, which includes:

101, building a basin-type insulator ultrasonic phase control detection platform, wherein the basin-type insulator ultrasonic phase control detection platform comprises an ultrasonic phase control flaw detector, a PC (personal computer) and a 126kV three-phase common-box basin-type insulator to be detected.

The ultrasonic phase control flaw detector is connected with an ultrasonic transmitting phase control probe and an ultrasonic receiving phase control probe through a probe connecting wire, and the ultrasonic phase control flaw detector is connected with a PC through a data transmission line. The probe connecting wire is a special multi-channel input signal wire for matching the phase control ultrasonic flaw detector and the linear probe, has the characteristics of high impedance, strong anti-interference capability and the like, and ensures that signals of the phase control ultrasonic flaw detector can be transmitted and received by the ultrasonic probe in high quality. The ultrasonic phase control flaw detector is provided with 64 detection channels, can be automatically calibrated, has the damping of 50 omega, has the sampling rate of 125MHz, has the delay precision of 2.5ns, has the highest bandwidth of 20MHz and the highest gain of 80dB, and can realize line scanning, A scanning, C scanning and sector scanning (S scanning), wherein the angle range of the sector scanning is-89 degrees, and the maximum scanning movement detection range is 1000 mm. The measurement resolution is 0.5mm and the scanning can be triggered by an encoder or a time base. The image processing has a dynamic depth focusing function and a smoothing function, defects of different depths can achieve good detection resolution and high-quality image display, the image scaling and translation are used for achieving image custom layout, and the gate expansion function is used for achieving fine observation of defect images.

In one embodiment, the ultrasonic transmitting phased probe and the ultrasonic receiving phased probe of the ultrasonic phased flaw detector adopt linear array probes, the probe frequency is 4MHz, the number of array elements is 16, the spacing between the array elements is 1.0mm, and the length of the array elements is 10 mm. The linear array probe is coupled with the rubber film water bag, so that the attenuation of sound waves is reduced.

Step 102, setting detection parameters of the ultrasonic phase-controlled flaw detector, wherein the detection comprises a scanning type, a focusing rule, a scanning range and a gain, and the scanning type comprises S scanning, A scanning and C scanning.

After the basin-type insulator ultrasonic phase control detection platform is built, the detection parameter scanning type, the focusing rule, the scanning range and the gain of the ultrasonic phase control flaw detector need to be set. The scan types include S-scan, a-scan, and C-scan. The focusing rule is defined as full focusing, the gain is adjusted to 50dB, the noise is more due to too large gain, and the defect cannot be identified due to the smaller gain.

And 103, coupling the rubber film water bag with an ultrasonic probe of the ultrasonic phased flaw detector, placing the ultrasonic probe coupled with the rubber film water bag on the upper surface of the epoxy insulation of the 126kV three-phase common-box basin-type insulator to be detected, and building an ultrasonic phased array propagation model of a basin-type insulator interface.

Generally, the outer diameter of a 126kV three-phase common-box basin-type insulator is 665mm, the thickness of the 126kV three-phase common-box basin-type insulator is 50mm, the length of a central conductor insert is 110mm, and the diameter of the central conductor insert is 80mm, as shown in fig. 2, an ultrasonic probe of an ultrasonic phase control flaw detector is coupled with a rubber film water bag, the ultrasonic probe of the coupled rubber film water bag is placed on the upper surface of epoxy insulation of the 126kV three-phase common-box basin-type insulator to be tested, an ultrasonic phase control array propagation model of a basin-type insulator interface is built, namely all interfaces experienced in an ultrasonic wave propagation process are built based on insulator detection positions, and the ultrasonic phase control array propagation model of the basin-type insulator interface is shown in fig. 3 and comprises a probe-water bag interface, a water bag-epoxy insulation interface, an epoxy insulation-central insert interface and the like. The interface defect phase control ultrasonic propagation model requires that a probe is coupled with a water bag and is arranged on the upper surface of an epoxy insulation layer, ultrasonic waves are firstly incident into the water bag, one part of the ultrasonic waves are reflected back to the interior of the probe at the interface of the probe and the water bag, and the other part of the ultrasonic waves enter the water bag; then, the ultrasonic wave reaches the water sac-epoxy insulation interface, one part of the ultrasonic wave is reflected back along the original path, and the other part of the ultrasonic wave is incident from the water sac to the epoxy insulation surface; the ultrasonic waves then reach the epoxy insulation-center insert interface, at which time a portion is reflected back along the way and another portion enters the center insert. The epoxy insulation-center insert interface has an air gap defect, ultrasonic waves are totally reflected on the defect and the epoxy surface, and the amplitude of an ultrasonic echo is larger than that of an echo without the defect. That is, the reflection echo peak value of the epoxy insulation-central insert interface can distinguish whether the interface has defects or not.

In one embodiment, the thickness of the rubber film water bag is 0.03mm, the attenuation of the film to sound waves is reduced, no bubble exists in the water bag, the defect detection result is prevented from being influenced by the bubble, the water bag is soft in shape, and the detection of the probe in multiple angles and any directions can be realized.

And step 104, carrying out ultrasonic phase control detection on the 126kV three-phase common-box basin-type insulator to be detected to obtain an ultrasonic echo signal of an interface of the 126kV three-phase common-box basin-type insulator to be detected.

And adjusting an ultrasonic phase control flaw detector to perform ultrasonic phase control detection on the 126kV three-phase common-box basin-type insulator interface to be detected, and recording and detecting an S scanning detection result, an A scanning detection result and a C scanning detection result.

And 105, carrying out normalization processing on the ultrasonic echo signal peak value to form an ultrasonic detection image of the interface area.

Based on an ultrasonic phased array propagation model of a basin-type insulator interface, the ultrasonic echo peak value of the epoxy insulation-insert interface is subjected to normalization processing to form an ultrasonic detection image of an interface area.

And 106, judging whether the 126kV three-phase common-box basin-type insulator to be detected has interface defects or not according to the ultrasonic detection image of the interface area, and if so, acquiring the interface defect area in the ultrasonic detection image of the interface area.

Analyzing the ultrasonic detection image of the interface region, and if the color of a part of the interface image is different from other colors of the interface (generally, the color depth of the interface defect region is greater than that of the defect-free region), indicating that the part is the interface defect region; the shape and size of the interface defect can be determined by analyzing the length and width of the part. Specifically, the depth information of the interface defect region may be determined from the a-scan image, and the horizontal sectional shape size of the interface defect region may be determined from the C-scan image.

As shown in fig. 4, which is an ultrasonic phased S scan detection imaging diagram of a defect on a certain 126kV three-phase common-box basin-type insulator interface to be detected, compared with the schematic diagram of the ultrasonic phased array propagation model of the basin-type insulator interface in fig. 3, it can be seen that most areas of the epoxy-insert interface (sector 1/4 circles) are light (generally marked as blue), but a dark area (generally marked as red) exists in the middle, the dark area is the position of the defect, and the defect can be seen from the boundary of the dark area.

According to the 126kV three-phase common-box basin-type insulator interface defect phased ultrasonic detection method provided by the embodiment of the invention, an ultrasonic phased detection system is utilized to carry out defect detection on an epoxy resin-insert interface of a 126kV three-phase common-box basin-type insulator to be detected, an interface defect ultrasonic phased array propagation model is established, ultrasonic phased detection is carried out on the 126kV three-phase common-box basin-type insulator to be detected, an interface area ultrasonic detection image is formed by taking a normalized echo peak value as a defect representation quantity, whether the 126kV three-phase common-box basin-type insulator to be detected has interface defects or not is judged, and an interface defect area is determined. The 126kV three-phase common-box basin-type insulator interface defect phase-control ultrasonic detection method solves the technical problems of low sensitivity to defects with small width, large equipment size, inconvenience in carrying and high price in basin-type insulator interface defect detection by using an X-ray imaging method, and X-rays have radiation damage to a human body, and has the advantages of low detection cost, high detection precision, small size and no X-ray radiation damage to the human body.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.