Power cable performance measurement method, device, storage medium and program product

Abstract

The present application provides a performance measurement method, device, storage medium and program product for a power cable, which obtains and processes the electric field sensor measurement signal by setting at least one electric field sensor on the surface and / or inside of the cable body, obtains the electric field strength at the detection position of the electric field sensor, and judges whether the cable has insulation defects based on the electric field strength, thereby evaluating the insulation performance of the cable. It also provides an evaluation index of electric field strength for existing performance detection methods, making the performance evaluation of the cable more comprehensive, more conducive to discovering insulation defects of the cable body, and improving the safety and stability of the power system.

Description

Technical Field

[0001] The present application relates to the technical field of power cable performance measurement, and in particular to a power cable performance measurement method, device, storage medium and program product. Background Art

[0002] Power cables are cables used to transmit and distribute electrical energy. With their large transmission capacity, low power loss, and little impact on the electromagnetic environment, power cables have become the first choice to replace overhead lines (lines based on ultra-high voltage AC and DC transmission systems). The insulation performance of the cable is directly related to the safe and stable operation of the cable, so the insulation performance of the cable is crucial.

[0003] At present, the performance testing methods of power cables include routine tests, type tests and acceptance tests. Among them, routine tests and type tests are carried out before the cable is laid. Routine tests are tests conducted by the manufacturer on all finished cables, including DC resistance test of the conductor, insulation resistance test, withstand voltage test, partial discharge test, etc. Its purpose is to check whether the product quality meets the requirements of technical conditions. Type tests are comprehensive performance tests conducted by manufacturers on products on a regular basis, including thermal aging performance of insulation and sheath, long-term stability test of power cables, etc. Through type tests, it can be tested whether the product can meet the requirements of operation.

[0004] With the in-depth research on cables, the requirements for the assessment of cable materials are getting higher and higher, but the indicators considered in the above-mentioned testing methods are not comprehensive enough, resulting in an incomplete evaluation of the cable performance. Summary of the invention

[0005] The present application provides a performance measurement method, device, storage medium and program product for a power cable, which are used to solve the problem that the indicators considered in the existing cable performance detection method are not comprehensive enough, resulting in incomplete performance evaluation of the cable.

[0006] In a first aspect, the present application provides a method for measuring the performance of a power cable, which is applied to a measuring device, and the method comprises:

[0007] Acquiring a measurement signal of at least one electric field sensor disposed on the cable, wherein the at least one electric field sensor is disposed on the surface and / or inside of the cable body;

[0008] Processing the measurement signal to obtain the electric field strength at the detection position of each electric field sensor;

[0009] According to the electric field strength, it is determined whether the cable at the detection position of the electric field sensor has insulation defects.

[0010] Optionally, the thickness of the insulation layer of the cable body is less than a preset thickness, and the electric field sensors are arranged on the surface of the cable body at a preset distance, and judging whether the cable at the detection position of the electric field sensor has an insulation defect according to the electric field strength includes:

[0011] When the electric field strength corresponding to the first electric field sensor is not within the electric field strength standard range of the cable body, it is determined that the cable at the detection position of the first electric field sensor has an insulation defect;

[0012] Alternatively, when the electric field strength corresponding to the first electric field sensor is within the electric field strength standard range of the cable body, and when the difference in electric field strength between the first electric field sensor and the second electric field sensor is greater than a first preset value, it is determined that there is an insulation defect in the cable portion between the first electric field sensor and the second electric field sensor.

[0013] Optionally, the thickness of the insulation layer of the cable body is greater than or equal to a preset thickness, the cable body includes three structural layers: a core, an insulation layer and a shielding layer, an electric field sensor is provided at a first position of at least two structural layers of the cable, and an electric field sensor is provided at a second position on the same structural layer at a preset distance from the first position, each electric field sensor is connected to the measuring device, and judging whether the cable at the detection position of the electric field sensor has an insulation defect according to the electric field strength includes:

[0014] When the electric field strength corresponding to the electric field sensors located at the first position in each structural layer is within the standard range of the electric field strength corresponding to each structural layer, and the difference in the electric field strength corresponding to the electric field sensors located at the first position in any two structural layers is greater than a preset difference, it is determined that the cable has an insulation defect at the first position;

[0015] Alternatively, when the electric field strength corresponding to the electric field sensor located at the first position in each structural layer is within the standard range of the electric field strength corresponding to each structural layer, and the difference in the electric field strength corresponding to the electric field sensors located at the first position in any two structural layers is less than or equal to the preset difference, and the difference in the electric field strength corresponding to the electric field sensor located at the first position in the same structural layer and the electric field strength corresponding to the electric field sensor located at the second position is greater than a second preset value, it is determined that there is an insulation defect in the portion of the cable between the first position and the second position in the same structural layer.

[0016] Optionally, the test power supply connected to the cable body generates one or more of the following voltages under the operating conditions of the cable: voltages required for different loads, voltages required for different polarities, and voltages required for transient and steady states before and after polarity reversal. The obtaining of the measurement signal of each electric field sensor includes:

[0017] The measurement signal of each electric field sensor under different operating conditions of the cable is obtained.

[0018] Optionally, a signal amplifier is connected between the measuring device and the electric field sensor, and obtaining the measurement signal of each electric field sensor includes:

[0019] A measurement signal amplified by the signal amplifier is obtained.

[0020] Optionally, before processing the measurement signal to obtain the electric field strength at each electric field sensor detection position, the method further includes:

[0021] The measurement signal of each electric field sensor is amplified.

[0022] In a second aspect, the present application provides a measuring device, comprising:

[0023] An acquisition module, which acquires a measurement signal of at least one electric field sensor disposed on the cable, wherein the at least one electric field sensor is disposed on the surface and / or inside of the cable body;

[0024] A processing module, used for processing the measurement signal to obtain the electric field strength at the detection position of each electric field sensor;

[0025] The judging module is used to judge whether there is an insulation defect in the cable at the detection position of the electric field sensor according to the electric field strength.

[0026] In a third aspect, the present application provides a measuring device, comprising: a processor, and a memory communicatively connected to the processor;

[0027] The memory stores computer-executable instructions;

[0028] The processor executes the computer-executable instructions stored in the memory to implement the method according to the first aspect.

[0029] In a fourth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, they are used to implement a performance measurement method for a power cable as described in the first aspect.

[0030] In a fifth aspect, the present application provides a computer program product, including a computer program, which implements the method described in the first aspect when executed by a processor.

[0031] The present application provides a performance measurement method, device, storage medium and program product for a power cable, which obtains the measurement signal of at least one electric field sensor arranged on the cable, the electric field sensor being arranged on the surface and / or inside the cable body, and then processes the measurement signal to obtain the electric field strength at the detection position of the electric field sensor, and judges whether the cable at the detection position has insulation defects according to the electric field strength, thereby realizing the evaluation of the insulation performance of the cable. It also provides the evaluation index of electric field strength for the existing performance detection method, making the performance evaluation of the cable more comprehensive, more conducive to discovering the insulation defects of the cable body, and improving the safety and stability of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0033] Figure 1 A schematic diagram of an application scenario of a performance testing method for a power cable provided in this application;

[0034] Figure 2 A partial schematic diagram of an electric field sensor provided in a cable body 1 provided in the present application;

[0035] Figure 3 A partial schematic diagram of another electric field sensor provided in a cable body 1 provided in the present application;

[0036] Figure 4 A schematic diagram of a flow chart of a method for measuring the performance of a power cable provided in Embodiment 1 of the present application;

[0037] Figure 5 A schematic diagram of a first position and a second position of a cable provided in Embodiment 1 of the present application;

[0038] Figure 6 A schematic diagram of the structure of a measuring device provided in Example 2 of the present application;

[0039] Figure 7 A schematic diagram of the structure of a measuring device provided in Embodiment 3 of the present invention.

[0040] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0041] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0042] At present, the performance testing methods of power cables include routine tests, type tests and acceptance tests. Among them, routine tests and type tests are carried out before the cable is laid. Routine tests are tests conducted by the manufacturer on all finished cables, including DC resistance test of the conductor, insulation resistance test, withstand voltage test, partial discharge test, etc. Its purpose is to check whether the product quality meets the requirements of technical conditions. Type tests are comprehensive performance tests conducted by manufacturers on products on a regular basis, including thermal aging performance of insulation and sheath, long-term stability test of power cables, etc. Through type tests, it can be tested whether the product can meet the requirements of operation.

[0043] In the cable research, it was found that when the insulation of the cable body is defective, the overall electric field strength of the cable body with insulation defects will suddenly increase or be locally distorted. Insulation defects generally refer to defects in insulating materials, including material damage, electron or hole injection impurities, etc. The insulation strength at the defect will decrease, and the electric field strength will change at this location, which is easy to cause local breakdown. The electric field strength is a physical quantity used to indicate the strength and direction of the electric field, and the unit can be kilovolts per millimeter.

[0044] However, with the in-depth research on cables, the requirements for the assessment of cable materials are getting higher and higher. The indicators considered in the above-mentioned detection method are not comprehensive enough, that is, the electric field strength of the cable body is not considered, resulting in an incomplete performance evaluation of the cable.

[0045] Therefore, the present application provides a performance measurement method, device, storage medium and program product for a power cable, by setting an electric field sensor on the surface and / or inside the cable body to detect the electric field strength of the cable body, and then judging whether the cable at the detection position has insulation defects based on the electric field strength, thereby realizing the evaluation of the cable insulation performance, and also providing the electric field strength as an evaluation index for the existing performance detection method, so that the performance evaluation of the cable is more comprehensive, which is more conducive to discovering insulation defects of the cable body and improving the safety and stability of the power system.

[0046] Figure 1A schematic diagram of an application scenario of a performance test method for a power cable provided in the present application, in which the cable body 1 includes three structural layers, a thin shielding layer is provided on the surface of the cable body 1, the insulating layer 2 of the cable body wraps the core 3 of the cable body, one end of the core 3 is connected to the test power supply 4, and the test power supply 4 can generate voltages under various operating conditions: voltages required for different loads, voltages required for different polarities, and voltages required for transient and steady states before and after polarity reversal, etc., so as to achieve measurement of the performance of the cable body under different operating conditions, making the evaluation more accurate. The shielding layer corresponding to the other end of the core 3 is grounded, and the test power supply 4 is grounded to form a loop of the test power supply 4, the cable body 1 and the ground, ensuring the formation of transient and steady-state electric fields to complete the test.

[0047] Taking an electric field sensor as an example, the position of the electric field sensor 5 in the figure is only an example. The setting position of the electric field sensor 5 can be set on any structural layer inside the cable body or on the surface of the cable body 1. The electric field sensor 5 is connected to its independent functional power supply 6, and the output end of the electric field sensor 5 is connected to the signal amplifier 7. When the measurement signal collected by the electric field sensor 5 is weak, the signal amplifier 7 can amplify the signal and then send it to the measuring device 8 connected to it (the measuring device 8 is grounded), so that the measuring device 8 can process according to the measurement signal to determine whether there is an insulation defect in the cable at the detection position of the electric field sensor.

[0048] Optionally, there may be multiple electric field sensors 5. Figure 2 and Figure 3 This is a partial schematic diagram of arranging two electric field sensors in the cable body 1. The position of the electric field sensor 5 in the figure is only an example. Figure 2 As shown, multiple electric field sensors can share the same signal amplifier and measuring device, that is, multiple electric field sensors are connected to the same signal amplifier and measuring device. Figure 3 As shown, multiple electric field sensors can also be connected to their own signal amplifiers and measuring devices respectively. In this connection mode, the signals obtained by multiple measuring devices can be concentrated in one of the measuring devices to determine whether there are insulation defects in the entire cable body.

[0049] It should be noted that the above-mentioned measuring device 8 can be a server, or any electronic device with computing and processing functions, and this application does not impose any limitation on this.

[0050] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments may exist independently or in combination with each other, and the same or similar concepts or processes may not be described in detail in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0051] refer to Figure 4 , Figure 4 A flow chart of a method for measuring the performance of a power cable provided in Embodiment 1 of the present application, the method may be executed by a measuring device, the measuring device may be a server, and the method includes the following steps.

[0052] S401. Acquire a measurement signal of at least one electric field sensor disposed on the cable, wherein the at least one electric field sensor is disposed on the surface and / or inside of the cable body.

[0053] When the detection position where each electric field sensor is located detects the electric field strength, a corresponding signal is output, and the server can obtain the measurement signal of at least one electric field sensor arranged on the cable.

[0054] The measurement signal is that when the electric field sensor is working, due to the piezoelectric effect of the electric field sensor, after the electric field strength is present at the location of the electric field sensor, a small pressure will be generated inside the sensor, and this pressure will cause the current in the sensor circuit to change, and the measurement signal can be the change value of the current, and the change value of the current can reflect the magnitude of the electric field strength. By setting the relevant parameters of the piezoresistance of the electric field sensor, that is, setting the piezoresistance in different directions, the direction of the electric field strength can be determined by the current change caused by the resistance in a certain direction.

[0055] In order to make the performance detection method of the cable more accurate, the test power supply connected to the cable body can generate one or more of the following voltages under operating conditions: the voltage required for different loads, the voltage required for different polarities, and the voltage required for transient and steady states before and after polarity reversal, so as to realize the performance detection of the cable under different operating conditions. Among them, the voltage required for different loads can be understood as the voltage of different magnitudes output by the test power supply, the voltage required for different polarities can be understood as the voltage when the voltage output by the test power supply is negative or the voltage when the voltage output is positive, and the voltage required for transient and steady states before and after polarity reversal is the voltage required for transient and steady states before and after the output voltage of the test power supply changes from positive to negative, or from negative to positive. The transient state can be understood as a temporary state, and the state is unstable. If the voltage output is described as a change curve, the voltage fluctuation presented will show peaks or troughs, while the steady state means that the power supply is stable and there will be no changes in polarity.

[0056] Then, the server can obtain the measurement signal of each electric field sensor under different operating conditions of the cable, thereby realizing performance testing of the cable under different operating conditions.

[0057] When the electric field strength at the detection position where the electric field sensor is located is weak, the measurement signal of the electric field sensor is also relatively weak, which is not conducive to subsequent signal processing. Optionally, a signal amplifier can be set between the measuring device and the electric field sensor, that is, the signal amplifier is connected between the measuring device and the electric field sensor, and the server obtains the measurement signal after amplification by the signal amplifier.

[0058] Optionally, before processing the measurement signal to obtain the electric field strength at the detection position of each electric field sensor, the server may also amplify the measurement signal of each electric field sensor.

[0059] S402: Process the measurement signal to obtain the electric field strength at the detection position of each electric field sensor.

[0060] The server may process the acquired measurement signal to obtain the electric field strength at each detection position of the electric field sensor, that is, input the measurement signal into a signal processing algorithm to obtain the electric field strength.

[0061] S403. Determine whether the cable at the detection position of the electric field sensor has insulation defects based on the electric field strength.

[0062] When the thickness of the insulation layer of the cable body is less than the preset thickness, for example, the preset thickness is 6cm (centimeter), that is, the thickness of the insulation layer of the cable body is relatively thin, each electric field sensor can be set on the surface of the cable body at a preset distance, and optionally, it can also be set in a certain structural layer inside the cable body. Due to the thin thickness of the insulation layer, the signal value measured at the setting position of the electric field sensor can approximately represent the signal value corresponding to all structural layers of the cable at that position. That is to say, for cables with thinner cores, the electric field strength of each structural layer corresponding to that position can be obtained through one electric field sensor. Whether the cable has insulation defects can be judged in the following ways:

[0063] When the electric field strength corresponding to the first electric field sensor is not within the standard range of the electric field strength of the cable body, it can be determined that the cable at the detection position of the first electric field sensor has insulation defects.

[0064] Alternatively, when the electric field strength corresponding to the first electric field sensor is within the electric field strength standard range of the cable body, and when the difference in electric field strength between the first electric field sensor and the second electric field sensor is greater than a first preset value, it is determined that there is an insulation defect in the cable portion between the first electric field sensor and the second electric field sensor.

[0065] Optionally, it is also possible to determine whether the electric field strength corresponding to the second electric field sensor is within the standard range of the electric field strength of the cable body. When the electric field strength corresponding to the second electric field sensor is not within the standard range of the electric field strength of the cable body, it can also be determined that part of the cable corresponding to the preset distance has insulation defects.

[0066] When the thickness of the insulation layer of the cable body is greater than or equal to the preset thickness, that is, the insulation layer of the cable body is thick, the cable body includes the following three structural layers: a core, an insulation layer and a shielding layer. Since the insulation layer is thick, the electric field strength of each structural layer of the cable body is different, and the electric field strength increases from the insulation layer to the shielding layer in a nearly linear relationship from small to large. Therefore, the electric field strength at the same position of any structural layer cannot be approximately expressed as the electric field strength on other structural layers at that position. Therefore, an electric field sensor is provided at a first position of at least two structural layers of the cable, and an electric field sensor is provided at a second position on the same structural layer at a preset distance from the first position. Each electric field sensor is connected to a measuring device, and the first position and the second position can be referenced. Figure 5 By determining the increase in the electric field strength between any two structural layers, it is possible to accurately determine whether the cable has insulation defects. The following methods can be used to determine whether the cable has insulation defects:

[0067] When the electric field strength corresponding to the electric field sensors located at the first position in each structural layer is within the standard range of the electric field strength corresponding to each structural layer, and the difference in the electric field strength corresponding to the electric field sensors located at the first position in any two structural layers is greater than the preset difference, it is determined that the cable has an insulation defect at the first position.

[0068] Alternatively, when the electric field strength corresponding to the electric field sensor located at the first position in each structural layer is within the standard range of the electric field strength corresponding to each structural layer, and the difference in the electric field strength corresponding to the electric field sensors located at the first position in any two structural layers is less than or equal to the preset difference, and the difference in the electric field strength corresponding to the electric field sensor located at the first position in the same structural layer and the electric field strength corresponding to the electric field sensor located at the second position is greater than a second preset value, it can be determined that there is an insulation defect in the portion of the cable between the first position and the second position in the same structural layer, and the second preset value is equal to the first preset value.

[0069] Optionally, it is also possible to determine whether the electric field strength corresponding to the electric field sensors located at the second position of each structural layer is within the standard range of the electric field strength corresponding to each structural layer. When the electric field strength corresponding to the electric field sensors located at the second position of each structural layer is not within the standard range of the electric field strength corresponding to each structural layer, it can also be determined that there is an insulation defect in the portion of the cable between the first position and the second position in the same structural layer.

[0070] In this embodiment, by obtaining the measurement signal of at least one electric field sensor arranged on the cable, the electric field sensor is arranged on the surface and / or inside the cable body, and then the measuring device processes the measurement signal to obtain the electric field strength of the detection position of the electric field sensor, and judges whether the cable at the detection position has insulation defects according to the electric field strength, thereby realizing the evaluation of the insulation performance of the cable. It also provides the evaluation index of electric field strength for the existing performance detection method, making the performance evaluation of the cable more comprehensive, more conducive to discovering the insulation defects of the cable body, and improving the safety and stability of the power system.

[0071] refer to Figure 6 , Figure 6 This is a schematic diagram of the structure of a measuring device provided in Example 2 of this application. Figure 6 As shown, the device 60 includes: an acquisition module 601, a processing module 602 and a judgment module 603.

[0072] The acquisition module 601 is used to acquire a measurement signal of at least one electric field sensor disposed on the cable, wherein the at least one electric field sensor is disposed on the surface and / or inside the cable body.

[0073] The processing module 602 is used to process the measurement signal to obtain the electric field strength at the detection position of each electric field sensor.

[0074] The judgment module 603 is used to judge whether there is an insulation defect in the cable at the detection position of the electric field sensor according to the electric field strength.

[0075] Optionally, the thickness of the insulation layer of the cable body is less than a preset thickness, and the electric field sensors are arranged on the surface of the cable body at preset intervals, and the judgment module 603 is specifically used for:

[0076] When the electric field strength corresponding to the first electric field sensor is not within the standard range of the electric field strength of the cable body, it is determined that the cable at the detection position of the first electric field sensor has an insulation defect.

[0077] Alternatively, when the electric field strength corresponding to the first electric field sensor is within the electric field strength standard range of the cable body, and when the difference in electric field strength between the first electric field sensor and the second electric field sensor is greater than a first preset value, it is determined that there is an insulation defect in the cable portion between the first electric field sensor and the second electric field sensor.

[0078] Optionally, the thickness of the insulation layer of the cable body is greater than or equal to a preset thickness, the cable body includes three structural layers: a core, an insulation layer and a shielding layer, an electric field sensor is provided at a first position of at least two structural layers of the cable, and an electric field sensor is provided at a second position on the same structural layer at a preset distance from the first position, each electric field sensor is connected to a measuring device, and the judgment module 603 is further used to:

[0079] When the difference in electric field strengths corresponding to the electric field sensors of the various structural layers at the first position is greater than a preset difference, it is determined that an insulation defect exists in the cable at the first position.

[0080] Optionally, also include:

[0081] When the electric field strength corresponding to the electric field sensors located at the first position in each structural layer is within the standard range of the electric field strength corresponding to each structural layer, and the difference in the electric field strength corresponding to the electric field sensors located at the first position in any two structural layers is greater than the preset difference, it is determined that the cable has an insulation defect at the first position.

[0082] Alternatively, when the electric field strength corresponding to the electric field sensor located at the first position in each structural layer is within the standard range of the electric field strength corresponding to each structural layer, and the difference in the electric field strength corresponding to the electric field sensors located at the first position in any two structural layers is less than or equal to the preset difference, and the difference in the electric field strength corresponding to the electric field sensor located at the first position in the same structural layer and the electric field strength corresponding to the electric field sensor located at the second position is greater than the second preset value, it is determined that there is an insulation defect in the portion of the cable between the first position and the second position in the same structural layer.

[0083] Optionally, the test power supply connected to the cable body generates one or more of the following voltages under the operating conditions of the cable: voltages required for different loads, voltages required for different polarities, and voltages required for transient and steady states before and after polarity reversal. The acquisition module 601 is specifically used to:

[0084] The measurement signal of each electric field sensor under different operating conditions of the cable is obtained.

[0085] Optionally, a signal amplifier is connected between the measuring device and the electric field sensor, and the acquisition module 601 is further used for:

[0086] Get the measurement signal after being amplified by the signal amplifier.

[0087] Optionally, before processing the measurement signal to obtain the electric field strength at each electric field sensor detection position, the method further includes:

[0088] The measurement signal of each electric field sensor is amplified.

[0089] The measuring device of this embodiment can be used to execute the steps of a method for measuring performance of a power cable in Embodiment 1. The specific implementation method and technical effect are similar and will not be described in detail here.

[0090] Figure 7 A schematic diagram of the structure of a measuring device provided in Embodiment 3 of the present invention is shown in FIG. Figure 7As shown, the device 70 includes: a processor 701, a memory 702, and a transceiver 703. The memory 702 is used to store instructions, the transceiver 703 is used to communicate with other devices, and the processor 701 is used to execute the instructions stored in the memory so that the device 70 performs the steps of a performance measurement method for a power cable as in Example 1. The specific implementation method and technical effect are similar and will not be repeated here.

[0091] Embodiment 4 of the present invention provides a computer-readable storage medium, in which computer execution instructions are stored. When the computer execution instructions are executed by a processor, they are used to implement the steps of a performance measurement method for a power cable as in the above-mentioned embodiment 1. The specific implementation method and technical effect are similar and will not be repeated here.

[0092] Embodiment 5 of the present invention provides a computer program product, including a computer program. When the computer program is executed by a processor, the steps of a method for measuring performance of a power cable as in the above embodiment 1 are implemented. The specific implementation method and technical effect are similar and will not be repeated here.

[0093] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0094] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A method for measuring the performance of a power cable, characterized in that: Applied to a measuring device, the method comprises: Acquire a measurement signal of at least one electric field sensor arranged on the cable, wherein the at least one electric field sensor is arranged on the surface and / or inside of the cable body; wherein, when the thickness of the insulation layer of the cable body is less than a preset thickness, each electric field sensor is arranged on the surface of the cable body at a preset distance interval; when the thickness of the insulation layer of the cable body is greater than or equal to the preset thickness, the cable body comprises three structural layers: a core, an insulation layer and a shielding layer, an electric field sensor is arranged at a first position of at least two structural layers of the cable, and an electric field sensor is arranged at a second position on the same structural layer at a preset distance from the first position, and each electric field sensor is connected to the measuring device; Processing the measurement signal to obtain the electric field strength at the detection position of each electric field sensor; When the thickness of the insulation layer of the cable body is less than the preset thickness, judging whether the cable at the detection position of the electric field sensor has insulation defects according to the electric field strength corresponding to the electric field sensor and the standard range of the electric field strength of the cable body; When the thickness of the insulation layer of the cable body is greater than or equal to the preset thickness, it is determined whether there is an insulation defect in the cable at the detection position of the electric field sensor based on the electric field strength corresponding to the electric field sensor located at the first position in each structural layer and the standard range of electric field strength corresponding to each structural layer, as well as the difference in electric field strength corresponding to the electric field sensor located at the first position in any two structural layers.

2. The method according to claim 1, characterized in that The step of judging whether the cable at the detection position of the electric field sensor has insulation defects according to the electric field strength corresponding to the electric field sensor and the standard range of the electric field strength of the cable body comprises: When the electric field strength corresponding to the first electric field sensor is not within the electric field strength standard range of the cable body, it is determined that the cable at the detection position of the first electric field sensor has an insulation defect; Alternatively, when the electric field strength corresponding to the first electric field sensor is within the electric field strength standard range of the cable body, the difference in electric field strength between the first electric field sensor and the second electric field sensor is used to determine whether there is an insulation defect in the cable at the detection position of the electric field sensor.

3. The method according to claim 2, characterized in that The determining, based on the difference between the electric field strengths of the first electric field sensor and the second electric field sensor, whether the cable at the detection position of the electric field sensor has an insulation defect comprises: When the difference between the electric field strengths of the first electric field sensor and the second electric field sensor is greater than a first preset value, it is determined that an insulation defect exists in a portion of the cable between the first electric field sensor and the second electric field sensor.

4. The method according to claim 1, characterized in that: The method of judging whether the cable at the detection position of the electric field sensor has an insulation defect according to the electric field strength corresponding to the electric field sensor located at the first position in each structural layer and the standard range of the electric field strength corresponding to each structural layer, and the difference between the electric field strengths corresponding to the electric field sensors located at the first position in any two structural layers, comprises: When the electric field strength corresponding to the electric field sensors located at the first position in each structural layer is within the standard range of the electric field strength corresponding to each structural layer, and the difference in the electric field strength corresponding to the electric field sensors located at the first position in any two structural layers is greater than a preset difference, it is determined that the cable has an insulation defect at the first position; Alternatively, when the electric field strength corresponding to the electric field sensors located at the first position in each structural layer is within the standard range of the electric field strength corresponding to each structural layer, and the difference in the electric field strength corresponding to the electric field sensors located at the first position in any two structural layers is less than or equal to the preset difference, it is judged whether there is an insulation defect in the cable at the detection position of the electric field sensor based on the difference in the electric field strength corresponding to the electric field sensor located at the first position in the same structural layer and the electric field strength corresponding to the electric field sensor located at the second position.

5. The method according to claim 4, characterized in that The method of judging whether the cable at the detection position of the electric field sensor has an insulation defect according to the difference between the electric field strength corresponding to the electric field sensor located at the first position and the electric field strength corresponding to the electric field sensor located at the second position in the same structural layer comprises: When the difference between the electric field strength corresponding to the electric field sensor located at the first position in the same structural layer and the electric field strength corresponding to the electric field sensor located at the second position is greater than a second preset value, it is determined that there is an insulation defect in the portion of the cable between the first position and the second position in the same structural layer.

6. The method according to claim 1, characterized in that The test power supply connected to the cable body generates one or more of the following voltages under the operating conditions of the cable: voltages required for different loads, voltages required for different polarities, and voltages required for transient and steady states before and after polarity reversal. The acquisition of the measurement signal of at least one electric field sensor provided on the cable includes: A measurement signal of each electric field sensor of at least one electric field sensor arranged on the cable under different operating conditions of the cable is obtained.

7. The method according to any one of claims 2 to 5, characterized in that: A signal amplifier is connected between the measuring device and the electric field sensor, and obtaining a measurement signal of at least one electric field sensor arranged on the cable includes: The measurement signal amplified by the signal amplifier is obtained.

8. The method according to any one of claims 2 to 5, characterized in that: Before the measurement signal is processed to obtain the electric field strength at each electric field sensor detection position, the method further includes: The measurement signal of each electric field sensor is amplified.

9. A measuring device, characterized in that: include: An acquisition module is provided to acquire a measurement signal of at least one electric field sensor provided on the cable, wherein the at least one electric field sensor is provided on the surface and / or inside of the cable body; wherein, when the thickness of the insulating layer of the cable body is less than a preset thickness, each electric field sensor is provided on the surface of the cable body at a preset distance interval; when the thickness of the insulating layer of the cable body is greater than or equal to the preset thickness, the cable body comprises three structural layers: a core, an insulating layer and a shielding layer, an electric field sensor is provided at a first position of at least two structural layers of the cable, and an electric field sensor is provided at a second position on the same structural layer at a preset distance from the first position, and each electric field sensor is connected to the measuring device; A processing module, used for processing the measurement signal to obtain the electric field strength at the detection position of each electric field sensor; A judgment module is used to judge whether the cable at the detection position of the electric field sensor has insulation defects when the thickness of the insulation layer of the cable body is less than a preset thickness, based on the electric field strength corresponding to the electric field sensor and the standard range of the electric field strength of the cable body; when the thickness of the insulation layer of the cable body is greater than or equal to the preset thickness, judge whether the cable at the detection position of the electric field sensor has insulation defects based on the electric field strength corresponding to the electric field sensor located at the first position in each structural layer and the standard range of the electric field strength corresponding to each structural layer, as well as the difference in electric field strength corresponding to the electric field sensors located at the first position in any two structural layers.

10. A measuring device, characterized in that: include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1 to 8.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, they are used to implement a performance measurement method for a power cable as described in any one of claims 1 to 8.

12. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 1 to 8 when being executed by a processor.

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