Cable buffer layer ablation state detection system and detection method

Abstract

The present invention relates to a cable buffer layer ablation state detection system and detection method, the detection system comprises a detection module, a communication module, a state analysis platform and an alarm module, the detection module transmits the detected information to the state analysis platform through the communication module, the state analysis platform is connected to the instruction module, and is used to issue an alarm for abnormal state information. The present invention solves the problem that the ablation of the buffer layer of the in-service cable cannot be effectively detected, has the characteristics of safety, reliability and high efficiency, and is of great significance to ensuring the safety of urban power grid power supply and improving the reliability of power grid operation.

Description

Technical Field

[0001] The present invention relates to the field of electrical detection technology, and more specifically, to a cable buffer layer ablation state detection system and a detection method. Background Art

[0002] The operational reliability of power cables is directly related to the inherent safety of the power grid. In recent years, more than dozens of high-voltage cross-linked polyethylene insulated cable failures caused by buffer layer ablation have occurred in Beijing, Shanghai, Xinjiang and other regions of China. Similar reports have also been reported abroad. In severe cases, the insulation shielding layer may even be completely penetrated, causing cable insulation breakdown and power outages. At present, cable operation and maintenance units have not yet proposed an effective evaluation method to evaluate the buffer layer ablation status of operating cables, resulting in the inability of management units to take measures to prevent the spread and diffusion of defects. Therefore, it is urgent to develop new detection systems and evaluation methods to effectively evaluate buffer layer ablation defects and avoid cable failures. Summary of the invention

[0003] 1. Technical issues to be resolved

[0004] The technical problem to be solved by the present invention is to detect the ablation defects of the buffer layer of the power cable. At the same time, the detection device adopted has the advantages of accurate judgment, intuitive and clear, high efficiency and no influence on the cable body structure. Therefore, the present invention provides a cable buffer layer ablation state detection system and detection method.

[0005] (II) Technical solution

[0006] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0007] A cable buffer layer ablation state detection system is designed, including a detection module, a communication module, a state analysis platform and an instruction module. The detection module is used to detect the state information of the power cable buffer layer, and is composed of an X-ray instrument, a partial discharge tester and a cable leakage current detector, wherein the X-ray instrument is used to measure the contact state between the cable corrugated aluminum sheath and the buffer layer, the partial discharge tester is used to measure the discharge information caused by the non-tight contact between the cable corrugated aluminum sheath and the buffer layer along the length direction, and the leakage current detector is used to measure the current value caused by the non-tight contact between the cable corrugated aluminum sheath and the buffer layer along the length direction. The communication module is used to transmit the state information detected by the detection module to the state analysis platform, which integrates two communication modes, wireless and wired, wherein the wired communication mode provides two communication interfaces, namely a shielded communication cable interface and a communication optical fiber interface, and the wireless communication mode provides wifi and Bluetooth communication modules. The state analysis platform is used to analyze and process the state information and give the analysis results. In an embodiment of the present invention, the state analysis platform can be placed at the detection site or in a remote monitoring room. The analysis results of the state analysis platform include close contact, non-close contact and the length is not enough to damage the cable, non-close contact without discharge and leakage current, and non-close contact with discharge and leakage current. The instruction module is connected to the state analysis platform, and is used to make instructions for the analysis results of the state analysis platform and the next operation, and to issue a warning for abnormal state information. In an embodiment of the present invention, the instruction module is composed of yellow, green and red three-color indicator lights.

[0008] The present invention also provides a method for detecting the ablation state of a cable buffer layer, the method comprising the following steps:

[0009] Step 1: Install the detection module and the command module at relevant parts of the cable to be tested;

[0010] Step 2: Confirm that the cable buffer layer ablation state detection system is correctly wired and in working condition;

[0011] Step 3: The X-ray instrument takes a picture of the contact state between the cable corrugated aluminum sheath and the buffer layer;

[0012] Step 4: The state analysis platform analyzes the image collected in step 3 and feeds back the contact state result between the cable corrugated aluminum sheath and the buffer layer;

[0013] Step 5: When the result of step 4 is close contact, the instruction module issues a stop operation instruction;

[0014] When the result of step 4 is non-tight contact, the length of the non-contact cable is calculated. When the length is not enough to damage the cable, the instruction module issues a stop operation instruction and the detection ends; when the length is enough to damage the cable, the instruction module issues a continue measurement instruction, and the partial discharge tester and the cable leakage current detector measure the cable.

[0015] Step 6: When no partial discharge signal and leakage current are detected in step 5, the instruction module issues a stop operation instruction, and the detection ends;

[0016] When a partial discharge signal and a leakage current are detected in step 5, the instruction module issues an abnormal state instruction.

[0017] Step 7: Remove the system wiring, clean up the site, and the inspection is complete.

[0018] In step 5, whether the separation length of the cable corrugated aluminum sheath and the buffer layer can damage the cable is determined by: whether the separation length in the contact state picture between the cable corrugated aluminum sheath and the buffer layer taken by the X-ray instrument is less than 2L, wherein the expression of the allowable pitch L is:

[0019]

[0020] In formula (1), d1 is the outer diameter of the cable conductor shield, d2 is the outer diameter of the cable insulation, δ is the thickness of the outer semi-conductive layer of the cable, D is the average diameter of the outer semi-conductive layer of the cable, D = d2 + 2δ, ε is the dielectric constant of the cable insulation material, ρ is the resistivity of the cable semi-conductive layer, U0 is the operating voltage, and U s is the allowable longitudinal voltage, and f is the operating power frequency.

[0021] (III) Beneficial effects

[0022] The beneficial effects of the present invention are as follows: in the cable buffer layer ablation state detection system of the present invention, all components are arranged outside the cable, the cable system is not damaged, and the cable detection in the operating state can be realized; the detection module adopted by the present invention is composed of an X-ray device, a partial discharge tester and a cable leakage current detector, which can feedback the cable buffer layer status information in multiple dimensions, making the status analysis result more accurate and reliable; the cable buffer layer ablation state detection method of the present invention standardizes the detection steps and can greatly improve the detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a structural schematic diagram of a cable buffer layer ablation state detection system. DETAILED DESCRIPTION

[0024] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0025] like Figure 1 As shown, the present invention provides a cable buffer layer ablation state detection system, including a detection module, a communication module, a state analysis platform and an instruction module. The detection module is used to detect the state information of the power cable buffer layer, and is composed of an X-ray instrument, a partial discharge tester and a cable leakage current detector, wherein the X-ray instrument is used to measure the contact state between the cable corrugated aluminum sheath and the buffer layer, the partial discharge tester is used to measure the discharge information caused by the non-tight contact between the cable corrugated aluminum sheath and the buffer layer along the length direction, and the leakage current detector is used to measure the current value caused by the non-tight contact between the cable corrugated aluminum sheath and the buffer layer along the length direction. The communication module is used to transmit the state information detected by the detection module to the state analysis platform, which integrates two communication modes, wireless and wired, wherein the wired communication mode provides two communication interfaces, namely a shielded communication cable interface and a communication optical fiber interface, and the wireless communication mode provides wifi and Bluetooth communication modules. The state analysis platform is used to analyze and process the state information and give the analysis results. In an embodiment of the present invention, the state analysis platform can be placed at the detection site or in a remote monitoring room. The analysis results of the state analysis platform include close contact, non-close contact and the length is not enough to damage the cable, non-close contact without discharge and leakage current, and non-close contact with discharge and leakage current. The instruction module is connected to the state analysis platform, and is used to make instructions for the analysis results of the state analysis platform and the next operation, and to issue a warning for abnormal state information. In an embodiment of the present invention, the instruction module is composed of yellow, green and red three-color indicator lights.

[0026] The present invention also provides a method for detecting the ablation state of a cable buffer layer, the method comprising the following steps:

[0027] Step 1: Install the detection module and the command module at relevant parts of the cable to be tested;

[0028] Step 2: Confirm that the cable buffer layer ablation state detection system is correctly wired and in working condition;

[0029] Step 3: The X-ray instrument takes a picture of the contact state between the cable corrugated aluminum sheath and the buffer layer;

[0030] Step 4: The state analysis platform analyzes the image collected in step 3 and feeds back the contact state result between the cable corrugated aluminum sheath and the buffer layer;

[0031] Step 5: When the result of step 4 is close contact, the instruction module issues a stop operation instruction;

[0032] When the result of step 4 is non-tight contact, the length of the non-contact cable is calculated. When the length is not enough to damage the cable, the instruction module issues a stop operation instruction and the detection ends; when the length is enough to damage the cable, the instruction module issues a continue measurement instruction, and the partial discharge tester and the cable leakage current detector measure the cable.

[0033] Step 6: When no partial discharge signal and leakage current are detected in step 5, the instruction module issues a stop operation instruction, and the detection ends;

[0034] When a partial discharge signal and a leakage current are detected in step 5, the instruction module issues an abnormal state instruction.

[0035] Step 7: Remove the system wiring, clean up the site, and the inspection is complete.

[0036] In step 5, whether the separation length of the cable corrugated aluminum sheath and the buffer layer can damage the cable is determined by: whether the separation length in the contact state picture between the cable corrugated aluminum sheath and the buffer layer taken by the X-ray instrument is less than 2L, wherein the expression of the allowable pitch L is:

[0037]

[0038] In formula (1), d1 is the outer diameter of the cable conductor shield, d2 is the outer diameter of the cable insulation, δ is the thickness of the outer semi-conductive layer of the cable, D is the average diameter of the outer semi-conductive layer of the cable, D = d2 + 2δ, ε is the dielectric constant of the cable insulation material, ρ is the resistivity of the cable semi-conductive layer, U0 is the operating voltage, and U s is the allowable longitudinal voltage, and f is the operating power frequency.

[0039] The cable buffer layer ablation state detection system of the present invention has application examples as follows:

[0040] Embodiment 1:

[0041] At a certain cable inspection site, the cable was visually bent. The staff first installed the cable buffer layer ablation state detection module and the command module on the bending part of the cable to be tested. After confirming that the cable buffer layer ablation state detection system was correctly wired and in working condition, an X-ray device was used to take pictures of the contact status between the cable corrugated aluminum sheath and the buffer layer. The picture was sent to the status analysis platform in the remote monitoring room through the communication module. The status analysis platform gave the result of close contact after analysis, and issued a stop operation command to the command module 4 through the communication module. The staff removed the system wiring, cleaned up the site, and completed the inspection.

[0042] Embodiment 2:

[0043] At a certain cable inspection site, the cable was visually bent. The staff first installed the cable buffer layer ablation state detection module and the command module on the bending part of the cable to be tested. After confirming that the cable buffer layer ablation state detection system was correctly wired and in working condition, an X-ray device was used to take pictures of the contact state between the cable corrugated aluminum sheath and the buffer layer. The picture was sent to the state analysis platform at the inspection site through the communication module. After analysis, the state analysis platform gave the result that the contact was not tight and the length was enough to damage the cable. The command module issued a command to continue measuring, and the partial discharge tester and the cable leakage current detector were used to continue measuring the cable. The measurement signal was fed back to the state analysis platform. After analysis, the state analysis platform gave the result that the contact was not tight, there was discharge and leakage current, and an abnormal state command was sent to the command module through the communication module. The staff removed the system wiring, cleaned up the site, and the inspection was completed.

[0044] The accompanying drawings describe the embodiments of the present invention, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all within the protection of the present invention.

Claims

1. A method for detecting ablation status of a cable buffer layer, characterized in that: The cable buffer layer ablation state detection system is used for detection. The cable buffer layer ablation state detection system includes a detection module, a communication module, a state analysis platform and an instruction module. The detection module is used to detect the state information of the power cable buffer layer. The communication module is used to transmit the state information detected by the detection module to the state analysis platform. The state analysis platform is used to analyze and process the state information and give the analysis result. The instruction module is connected to the state analysis platform and is used to give instructions on the analysis result of the state analysis platform and the next operation, and to issue a warning for abnormal state information. The detection module is composed of an X-ray instrument, a partial discharge tester and a cable leakage current detector, wherein the X-ray instrument is used to measure the contact state between the cable corrugated aluminum sheath and the buffer layer, the partial discharge tester is used to measure the discharge information caused by the non-tight contact between the cable corrugated aluminum sheath and the buffer layer along the length direction, and the leakage current detector is used to measure the current value caused by the non-tight contact between the cable corrugated aluminum sheath and the buffer layer along the length direction; The detection method includes the following steps: Step 1: Install the detection module and the command module at relevant parts of the cable to be tested; Step 2: Confirm that the cable buffer layer ablation state detection system is correctly wired and in working condition; Step 3: The X-ray instrument takes a picture of the contact state between the cable corrugated aluminum sheath and the buffer layer; Step 4: The state analysis platform analyzes the image collected in step 3 and feeds back the contact state result between the cable corrugated aluminum sheath and the buffer layer; Step 5: When the result of step 4 is close contact, the instruction module issues a stop operation instruction; When the result of step 4 is non-tight contact, the length of the non-contact cable is calculated. When the length is not enough to damage the cable, the instruction module issues a stop operation instruction and the detection ends; when the length is enough to damage the cable, the instruction module issues a continue measurement instruction, and the partial discharge tester and the cable leakage current detector measure the cable; Step 6: When no partial discharge signal and leakage current are detected in step 5, the instruction module issues a stop operation instruction, and the detection ends; When the partial discharge signal and the leakage current are detected in step 5, the instruction module issues an abnormal state instruction; Step 7: Remove the system wiring, clean up the site, and the inspection is complete.

2. The cable buffer layer ablation state detection method according to claim 1, characterized in that: In step 5, whether the separation length of the cable corrugated aluminum sheath and the buffer layer can damage the cable is determined by: whether the separation length in the contact state picture between the cable corrugated aluminum sheath and the buffer layer taken by the X-ray instrument is less than 2L, wherein the expression of the allowable pitch L is: （1） In formula (1), is the outer diameter of the cable conductor shield, is the outer diameter of the cable insulation, is the thickness of the outer semi-conductive layer of the cable, is the average diameter of the outer semi-conductive layer of the cable, , is the dielectric constant of the cable insulation material, is the resistivity of the cable semi-conductive layer, is the operating voltage, To allow longitudinal voltage, is the operating power frequency.

3. The cable buffer layer ablation state detection method according to claim 1, characterized in that: The communication module integrates two communication modes, wireless and wired. The wired communication mode provides two communication interfaces, namely a shielded communication cable interface and a communication optical fiber interface. The wireless communication mode provides Wi-Fi and Bluetooth communication modules.

4. The cable buffer layer ablation state detection method according to claim 1, characterized in that: The status analysis platform is placed at the detection site or in a remote monitoring room.

5. The cable buffer layer ablation state detection method according to claim 1, characterized in that: The analysis results of the state analysis platform include close contact, non-close contact and the length is not enough to damage the cable, non-close contact without discharge and leakage current, and non-close contact with discharge and leakage current.

6. The cable buffer layer ablation state detection method according to claim 1, characterized in that: The instruction module is composed of three-color indicator lights: yellow, green and red.

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