System for monitoring and evaluating ablation state of buffer layer of high-voltage cable

Abstract

The invention relates to a high-voltage cable buffer layer ablation state monitoring and evaluating system, which is characterized in that a terahertz spectrometer can scan point by point and record continuous terahertz wave intensity information of a cable after transmission or reflection in a terahertz continuous wave imaging mode; the image generation module can form a cable digital image according to the intensity information of the terahertz waves; the image intelligent identification module can respectively carry out preprocessing, identification analysis and storage backup on the cable digital image; the feature extraction module can perform feature extraction on the cable digital image which is preprocessed, identified and analyzed by the image intelligent identification module, and the state evaluation module can compare image features transmitted by the feature extraction module with cable buffer layer ablation state feature images pre-stored in the state evaluation module. Therefore, the severity of the actual cable ablation state is evaluated. The method has the advantages of being safe and reasonable in design, accurate and efficient.

Description

Technical Field

[0001] The invention belongs to the technical field of power cable monitoring, and in particular relates to a high-voltage cable buffer layer ablation state monitoring and evaluation system. Background Art

[0002] High-voltage power cable is an important power transmission equipment in the power grid. It plays an important role in the safe and stable operation of power loads. At the same time, it has the characteristics of small line path width, easy line path selection, concealed burial, not easily affected by the surrounding environment and pollution, and high power transmission reliability. Therefore, it is necessary to ensure the safe, stable and efficient operation of high-voltage power cables; however, during the long-term use of high-voltage cables, the electrode material, the degree of moisture in the buffer layer, the current size, and the contact state between the electrode and the buffer layer will cause white spots to form on the buffer layer. The main components of the white spots are NaHCO3, Na2CO3 and Al2O3. These insulating substances will destroy the electrical connection between the insulating shielding layer and the aluminum sheath, thereby causing electrical contact between the buffer layer and the aluminum sheath. Poor, which in turn causes the electric field at that location to be distorted. When the field strength is greater than the breakdown voltage of the air, local discharge will occur, leading to buffer layer ablation. As the discharge continues, the insulating shielding layer will continue to ablate, and eventually the cable body will be broken down. In recent years, there have been reports of buffer layer ablation failures of XPLE cables with voltage levels of 110kV and above. According to statistics, between 2010 and 2019, a total of 11 cable failures with voltage levels of 110kV and above occurred in Beijing, of which 6 were caused by cable buffer layer ablation, accounting for as high as 54.5%, seriously endangering the safe operation of the cable system. Therefore, in order to solve the above problems, it is necessary to develop a safe, reasonable, accurate and efficient high-voltage cable buffer layer ablation status monitoring and evaluation system. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a high-voltage cable buffer layer ablation state monitoring and evaluation system that is safe, reasonable, accurate and efficient in design.

[0004] The object of the present invention is achieved as follows: a high-voltage cable buffer layer ablation state monitoring and evaluation system, including a terahertz spectrometer, a data transmission module, an image generation module, an image intelligent recognition module, a feature extraction module and a state evaluation module, wherein the terahertz spectrometer can emit terahertz waves, and use terahertz continuous wave imaging to scan and record point by point the intensity information of the continuous terahertz waves of the analyte after transmission or reflection; the data transmission module can transmit the intensity information of the continuous terahertz waves recorded by the terahertz spectrometer to the image generation module in the form of a current signal; the image generation module can form a cable digital image according to the intensity information of the continuous terahertz waves, thereby completing the monitoring of the ablation state of the cable buffer layer; the image intelligent recognition module is internally provided with a preprocessing unit, an intelligent recognition unit and a storage unit, and the preprocessing unit can perform preprocessing operations on the cable digital image generated by the image generation module to remove While removing additive noise, multiplicative noise and quantization noise, the grayscale of the image is transformed to make the image clearer, the contrast is enhanced and the edge features are prominent; the intelligent recognition unit can recognize and analyze the cable digital image after preprocessing, so as to observe the changes in the morphology of each layer inside the cable, and then mark the differences in the morphology changes of each layer inside the cable; the storage unit can integrate and package the cable digital image before preprocessing, the cable digital image after preprocessing and the cable digital image marked by the intelligent recognition unit and store them for backup; the feature extraction module can extract features from the marked cable digital image, and after the feature extraction is completed, it is amplified and transmitted to the status evaluation module; the status evaluation module compares the image features transmitted by the feature extraction module with the cable buffer layer ablation state feature image pre-stored in it, so as to complete the evaluation of the severity of the actual cable ablation state and generate an evaluation grade.

[0005] Furthermore, the intelligent recognition unit can establish an intelligent recognition model for cable buffer layer defects, and use the model to identify and analyze the digital image of the cable after preprocessing, so as to observe the morphological change characteristics of each layer inside the cable.

[0006] Furthermore, the status assessment module can generate three assessment levels of A, B, and C according to the severity of the cable ablation status, where level A indicates that the cable buffer layer has no ablation defects, level B indicates that the cable buffer layer has ablation defects, but the range of the ablation defects is small, and subsequent regular re-inspection and observation is required, and level C indicates that the cable buffer layer has a large area of ​​ablation defects, and the cable needs to be replaced in time.

[0007] Furthermore, a warning unit is provided inside the status assessment module, and the warning unit is externally connected to a warning light, wherein the warning light consists of a green warning light, a yellow warning light and a red warning light respectively, wherein when the status assessment module issues a status assessment information of level A, the green warning light is on, when the status assessment module issues a status assessment information of level B, the yellow warning light is on, and when the status assessment module issues a status assessment information of level C, the red warning light is on.

[0008] The beneficial effects of the present invention are as follows: by setting a terahertz spectrometer, the present invention can utilize the terahertz continuous wave imaging method to scan point by point and record the intensity information of the continuous terahertz wave of the analyte after transmission or reflection; by setting an image generation module, a cable digital image can be formed according to the intensity information of the terahertz wave; by setting a preprocessing unit, an intelligent recognition unit and a storage unit, wherein the preprocessing unit can perform a preprocessing operation on the cable digital image generated by the image generation module, the intelligent recognition unit can recognize and analyze the cable digital image after the preprocessing is completed, and the storage unit can uniformly integrate, package and store the cable digital image before the preprocessing, the cable digital image after the preprocessing and the cable digital image annotated by the intelligent recognition unit; by setting a feature extraction module, the feature extraction module can be utilized to extract the features of the annotated cable digital image, and by setting a state evaluation module, the feature extraction module can be utilized to compare the image features transmitted by the feature extraction module with the cable buffer layer ablation state feature image pre-stored therein, thereby completing the evaluation of the severity of the actual cable ablation state; in general, the present invention has the advantages of safe and reasonable design, precision and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a structural flow chart of the present invention. DETAILED DESCRIPTION

[0010] The present invention will be further described below in conjunction with the accompanying drawings.

[0011] Example: Figure 1 As shown, a high-voltage cable buffer layer ablation state monitoring and evaluation system includes a terahertz spectrometer, a data transmission module, an image generation module, an image intelligent recognition module, a feature extraction module and a state evaluation module. The terahertz spectrometer can emit terahertz waves, and use terahertz continuous wave imaging to scan and record the intensity information of the continuous terahertz waves of the analyte after transmission or reflection point by point; the data transmission module can transmit the intensity information of the continuous terahertz waves recorded by the terahertz spectrometer to the image generation module in the form of current signals; the image generation module can form a cable digital image according to the intensity information of the continuous terahertz waves, thereby completing the monitoring of the ablation state of the cable buffer layer; The image intelligent recognition module is internally provided with a preprocessing unit, an intelligent recognition unit and a storage unit. The preprocessing unit can perform preprocessing operations on the cable digital image generated by the image generation module, remove additive noise, multiplicative noise and quantization noise, and transform the grayscale of the image to make the image clear, enhance the contrast and highlight the edge features; the intelligent recognition unit can establish an intelligent recognition model for cable buffer layer defects, and use the model to identify and analyze the cable digital image after preprocessing, so as to observe the morphological change characteristics of each layer inside the cable, and then mark the differences in the morphological changes of each layer inside the cable; the storage unit can uniformly integrate, package and store the cable digital image before preprocessing, the cable digital image after preprocessing and the cable digital image marked by the intelligent recognition unit; the feature extraction module can extract features from the marked cable digital image, and after the feature extraction is completed, amplify it and transmit it to the status evaluation module; The state assessment module evaluates the severity of the actual cable ablation state and generates an assessment grade according to the image features transmitted by the feature extraction module and the pre-stored cable buffer layer ablation state feature image, wherein the state assessment module can generate three assessment grades of A, B and C according to the severity of the cable ablation state, wherein grade A indicates that the cable buffer layer has no ablation defect, grade B indicates that the cable buffer layer has ablation defect, but the ablation defect range is small, and subsequent regular re-inspection and observation are required, and grade C indicates that the cable buffer layer has a large area of ​​ablation defects, and the cable needs to be replaced in time, and a warning unit is provided inside the state assessment module, and the warning unit is externally connected to a rear warning light, and the warning light is composed of a green warning light, a yellow warning light and a red warning light, wherein when the state assessment module sends out a state assessment information of grade A, the green warning light is on, when the state assessment module sends out a state assessment information of grade B, the yellow warning light is on, and when the state assessment module sends out a state assessment information of grade C, the red warning light is on.

[0012] When the present invention is used, firstly, the terahertz wave emitted by the terahertz spectrometer is used to scan and record the intensity information of the continuous terahertz wave of the cable after transmission or reflection point by point by using the terahertz continuous wave imaging method, then, the recorded continuous terahertz wave intensity information is transmitted to the inside of the image generation module by using the data transmission module in the form of a current signal, and finally, the image generation module generates a cable digital image according to the intensity information of the continuous terahertz wave, thereby completing the monitoring of the ablation state of the cable buffer layer; and after the cable digital image is generated, it can be preprocessed by the preprocessing unit in the image intelligent recognition module. Thus, additive noise, multiplicative noise and quantization noise are removed, and the grayscale of the image is transformed to make the image clearer, the contrast enhanced and the edge features prominent; the intelligent recognition unit in the image intelligent recognition module can establish an intelligent recognition model for cable buffer layer defects, and the model can be used to recognize and analyze the cable digital image after preprocessing, so as to observe the morphological change characteristics of each layer inside the cable and mark the differences in the morphological changes of each layer inside the cable; the storage unit in the image intelligent recognition module can be used to uniformly integrate the cable digital image before preprocessing, the cable digital image after preprocessing and the cable digital image marked by the intelligent recognition unit. The cable digital image is packaged and stored for backup to facilitate subsequent data review; after the above operations are completed, the feature extraction module is used to extract features of the marked cable digital image, and after the feature extraction is completed, it is enlarged and transmitted to the status evaluation module. Finally, the status evaluation module is used to compare the image features transmitted by the feature extraction module with the pre-stored cable buffer layer ablation state feature image, so as to complete the evaluation of the severity of the actual cable ablation state and generate an evaluation grade, wherein the evaluation grades include A, B, and C. Among them, grade A indicates that there is no ablation defect in the cable buffer layer, and an A-grade evaluation is generated. At the same time, the green warning light in the warning unit in the status assessment module will be triggered to send out a warning signal. Grade B indicates that ablation defects have occurred in the cable buffer layer, but the range of the ablation defects is small, and subsequent regular re-inspection and observation are required. At the same time, the B-level evaluation is generated, the yellow warning light in the warning unit in the status assessment module will be triggered to send out a warning signal. Grade C indicates that a large area of ​​ablation defects have occurred in the cable buffer layer, and the cable needs to be replaced in time. At the same time, the C-level evaluation is generated, the red warning light in the warning unit in the status assessment module will be triggered to send out a warning signal. In general, the present invention has the advantages of safe and reasonable design, precision and efficiency.

[0013] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the specific implementation modes of the present invention can still be modified or replaced by equivalents, and any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A high-voltage cable buffer layer ablation state monitoring and evaluation system, comprising a terahertz spectrometer, a data transmission module, an image generation module, an image intelligent recognition module, a feature extraction module and a state evaluation module, characterized in that: The terahertz spectrometer can emit terahertz waves, and use terahertz continuous wave imaging to scan and record the intensity information of the continuous terahertz waves of the analyte after transmission or reflection point by point; The data transmission module can transmit the intensity information of the continuous terahertz wave recorded by the terahertz spectrometer to the image generation module in the form of a current signal; The image generation module can form a digital image of the cable according to the intensity information of the continuous terahertz wave, thereby completing the monitoring of the ablation state of the cable buffer layer; The image intelligent recognition module is internally provided with a preprocessing unit, an intelligent recognition unit and a storage unit. The preprocessing unit can perform preprocessing operations on the cable digital image generated by the image generation module, remove additive noise, multiplicative noise and quantization noise, and transform the grayscale of the image to make the image clearer, enhance the contrast and highlight the edge features; The intelligent recognition unit can identify and analyze the cable digital image after preprocessing, so as to observe the changes in the morphology of each layer inside the cable, and then mark the differences in the morphology of each layer inside the cable; the storage unit can uniformly integrate, package and store the cable digital image before preprocessing, the cable digital image after preprocessing and the cable digital image marked by the intelligent recognition unit for backup; The feature extraction module can extract features from the marked cable digital image, and after the feature extraction is completed, it is magnified and transmitted to the status assessment module; The state assessment module evaluates the severity of the actual cable ablation state based on the image features transmitted by the feature extraction module and compares it with the cable buffer layer ablation state feature image pre-stored therein, thereby completing the evaluation of the severity of the actual cable ablation state and generating an evaluation grade.

2. A high-voltage cable buffer layer ablation state monitoring and evaluation system as claimed in claim 1, characterized in that: The intelligent recognition unit can establish an intelligent recognition model for cable buffer layer defects, and use the model to identify and analyze the cable digital image after preprocessing, so as to observe the morphological change characteristics of each layer inside the cable.

3. A high-voltage cable buffer layer ablation state monitoring and evaluation system as claimed in claim 1, characterized in that: The status assessment module can generate three assessment levels of A, B, and C according to the severity of the cable ablation status. Level A indicates that the cable buffer layer has no ablation defects, level B indicates that the cable buffer layer has ablation defects, but the range of the ablation defects is small, and regular re-inspection and observation are required in the future, and level C indicates that the cable buffer layer has a large area of ​​ablation defects, and the cable needs to be replaced in time.

4. A high-voltage cable buffer layer ablation state monitoring and evaluation system as claimed in claim 3, characterized in that: The status assessment module is internally provided with a warning unit, and the warning unit is externally connected to a rear warning light, wherein the warning light consists of a green warning light, a yellow warning light and a red warning light, respectively. When the status assessment module issues a status assessment information of level A, the green warning light is on, when the status assessment module issues a status assessment information of level B, the yellow warning light is on, and when the status assessment module issues a status assessment information of level C, the red warning light is on.

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