Method for evaluating space charge injection characteristics of polypropylene elastomer blend materials for cables

Abstract

The application relates to a method for evaluating space charge injection characteristics of a polypropylene elastomer blend material for cables. The method comprises: obtaining current information in a to-be-tested sample made of a polypropylene elastomer blend material and sensor signal information of a piezoelectric sensor corresponding to the to-be-tested sample under a preset test condition; determining space charge distribution information according to the sensor signal information; and determining a space charge injection characteristic evaluation result according to the current information and the space charge distribution information. The method can accurately analyze the real injected current based on the current in the to-be-tested sample under the preset test condition, obtain an accurate charge injection rate, accurately analyze the charge transport in the to-be-tested sample by using the charge injection rate, and thus improve the accuracy of the space charge injection characteristic evaluation result.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power equipment insulating material performance monitoring, and particularly relates to a polypropylene elastomer blend material space charge injection characteristic evaluation method and device for cables, computer equipment, a computer readable storage medium and a computer program product. BACKGROUND

[0002] Polymers are widely used as insulating materials in power equipment and electronic devices. The insulating properties (conduction, breakdown voltage, electrical aging life) of polymers under direct current voltage are closely related to the space charge in the polymer and the metal / polymer interface, because the accumulation of space charge will distort the electric field distribution in the polymer and the electrode. The accumulation of space charge depends on the rate of charge transport processes, including charge injection / extraction at the metal / polymer interface and charge migration in the polymer.

[0003] Traditional technology mainly studies the charge injection at the metal / insulation interface based on the Schottky theory or tunnel effect, however, the traditional technology has the problem of low accuracy of charge injection rate, which is not conducive to improving the accuracy of the space charge injection characteristic evaluation result. SUMMARY

[0004] Therefore, it is necessary to provide a polypropylene elastomer blend material space charge injection characteristic evaluation method, device, computer equipment, computer readable storage medium and computer program product for cables, which can improve the accuracy of the space charge injection characteristic evaluation result.

[0005] In a first aspect, the present application provides a polypropylene elastomer blend material space charge injection characteristic evaluation method for cables, comprising:

[0006] In the case that a to-be-tested sample made of a polypropylene elastomer blend material is in a preset test condition, obtaining current information in the to-be-tested sample and sensor signal information of a piezoelectric sensor corresponding to the to-be-tested sample;

[0007] According to the sensor signal information, determining space charge distribution information;

[0008] According to the current information and the space charge distribution information, determining a space charge injection characteristic evaluation result.

[0009] In one of the embodiments, the preset test condition includes a first sub-test condition and a second sub-test condition, and the method further comprises:

[0010] In the case that the to-be-tested sample is in the first sub-test condition, taking the conductive current information in the to-be-tested sample as the current information in the to-be-tested sample;

[0011] In a case where the to-be-tested sample is in the second sub-test condition, the depolarization current information in the to-be-tested sample is taken as the current information in the to-be-tested sample.

[0012] According to the conductive current information, the depolarization current information and the space charge distribution information, the space charge injection characteristic evaluation result is determined.

[0013] In one of the embodiments, the first sub-test condition includes: applying a pulse voltage with a pulse amplitude of 1V-1500V and a pulse width of 20ns to the to-be-tested sample by a nanosecond pulse source; and applying a direct current voltage with a voltage amplitude of 0-20kV to the to-be-tested sample by a high-voltage direct current source.

[0014] In one of the embodiments, the second sub-test condition includes: applying a pulse voltage with a pulse amplitude of 1V-1500V and a pulse width of 20ns to the to-be-tested sample by a nanosecond pulse source.

[0015] In one of the embodiments, one side of the to-be-tested sample is provided with a lower electrode; the other side of the to-be-tested sample is provided with an upper electrode; the to-be-tested sample and the upper electrode are sequentially provided with a blocking layer and a semi-conductive layer; the blocking layer is used for blocking the transmission of a preset type of carrier; and the semi-conductive layer is used for transmitting the carrier.

[0016] In one of the embodiments, the upper electrode and the lower electrode are used for applying a step voltage and a pulse voltage to the to-be-tested sample; the step voltage includes at least two voltage values; and the difference between the voltage values is a preset value.

[0017] In one of the embodiments, the material of the blocking layer includes E-51 epoxy resin, and the thickness of the blocking layer is 160um.

[0018] In one of the embodiments, the material of the upper electrode includes aluminum, the material of the lower electrode includes aluminum, the diameter of the upper electrode is 25mm, and the diameter of the lower electrode is 25mm.

[0019] In one of the embodiments, the to-be-tested sample is in a preset electric field environment; the electric field strength corresponding to the preset electric field environment includes ±30kV / mm and ±50kV / mm.

[0020] In one of the embodiments, the thickness of the to-be-tested sample is 0.2mm, and the diameter of the to-be-tested sample is 85mm.

[0021] In a second aspect, the application further provides a space charge injection characteristic evaluation device for a polypropylene elastomer blend material for cables, including:

[0022] The acquisition module is configured to acquire current information in the to-be-tested sample and sensor signal information of a piezoelectric sensor corresponding to the to-be-tested sample under the condition that the to-be-tested sample made of the polypropylene elastomer blend material is in a preset test condition.

[0023] The determination module is configured to determine spatial charge distribution information according to the sensor signal information.

[0024] The evaluation module is configured to determine a spatial charge injection characteristic evaluation result according to the current information and the spatial charge distribution information.

[0025] In a third aspect, the present application further provides a computer device. The computer device comprises a memory and a processor, and the memory stores a computer program. When the computer program is executed by the processor, the steps of the above method are implemented.

[0026] In a fourth aspect, the present application further provides a computer readable storage medium. The computer readable storage medium stores a computer program. When the computer program is executed by a processor, the steps of the above method are implemented.

[0027] In a fifth aspect, the present application further provides a computer program product. The computer program product comprises a computer program. When the computer program is executed by a processor, the steps of the above method are implemented.

[0028] The above method, device, computer device, computer readable storage medium and computer program product for evaluating spatial charge injection characteristics of a polypropylene elastomer blend material for cables, by acquiring current information in a to-be-tested sample and sensor signal information of a piezoelectric sensor corresponding to the to-be-tested sample under the condition that the to-be-tested sample made of the polypropylene elastomer blend material is in a preset test condition, thereby accurately monitoring sound waves caused by charge vibration due to pulse high voltage in the to-be-tested sample under the preset test condition by the piezoelectric sensor and converting the sound waves into sensor signals; determining spatial charge distribution information according to the sensor signal information, thereby analyzing the sensor signal information to obtain accurate spatial charge distribution; determining a spatial charge injection characteristic evaluation result according to the current information and the spatial charge distribution information, thereby analyzing the conduction characteristics and charge injection mechanism of the to-be-tested sample in combination with the current and the spatial charge distribution, obtaining an accurate spatial charge injection characteristic evaluation result, accurately analyzing the real injected current based on the current in the to-be-tested sample under the preset test condition, obtaining an accurate charge injection rate, and accurately analyzing charge transport in the to-be-tested sample by using the charge injection rate, thereby improving the accuracy of the spatial charge injection characteristic evaluation result. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the present application or the related art. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0030] Figure 1 A flowchart of a method for evaluating space charge injection characteristics of a polypropylene elastomer blend material for a cable in an embodiment;

[0031] Figure 2 A schematic diagram of a double-layer structure in an embodiment;

[0032] Figure 3 A schematic diagram of double-layer space charges under a 6kV voltage in an embodiment;

[0033] Figure 4 A schematic diagram of double-layer currents under a 6kV voltage in an embodiment;

[0034] Figure 5 A structural block diagram of an evaluation device for space charge injection characteristics of a polypropylene elastomer blend material for a cable in an embodiment;

[0035] Figure 6 An internal structure diagram of a computer device in an embodiment. DETAILED DESCRIPTION

[0036] In order to make the purposes, technical solutions and advantages of the present application clearer, the following will further describe the present application in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0037] In an exemplary embodiment, as shown in Figure 1 , a method for evaluating space charge injection characteristics of a polypropylene elastomer blend material for a cable is provided. The method is described by taking an end terminal as an example, and includes the following steps S102 to S106. Wherein:

[0038] Step S102, under the condition that the to-be-tested sample made of the polypropylene elastomer blend material is in a preset test condition, obtaining current information in the to-be-tested sample and sensor signal information of a piezoelectric sensor corresponding to the to-be-tested sample.

[0039] Wherein, the polypropylene elastomer blend material can refer to a composite material composed of polypropylene (PP) and elastomer (Elastomer).

[0040] The to-be-tested sample can be a sample made of a polypropylene elastomer blend material. In actual applications, the to-be-tested sample can be used to prepare a cable.

[0041] The preset test condition can be an experimental condition that is set in advance and used to test the space charge injection characteristics of the to-be-tested sample made of the polypropylene elastomer blend material under high-voltage direct current. In actual applications, the preset test condition can be used to describe the electric field strength in which the to-be-tested sample is located, the voltage applied to the to-be-tested sample, and the like.

[0042] The current information can be information representing the value and / or direction of a conduction current, a depolarization current, an external current, and the like in the to-be-tested sample.

[0043] The piezoelectric sensor can be a device that converts mechanical energy (such as pressure, vibration, acceleration, and the like) into an electrical signal by using the piezoelectric effect.

[0044] The sensor signal information can be information representing the signal output by the piezoelectric sensor. In actual applications, the sensor signal information can include, but is not limited to, amplitude, period, and the like.

[0045] As an example, the polypropylene elastomer blend material can be used to prepare a high-voltage direct current cable. In order to test and evaluate the space charge injection characteristics of the polypropylene elastomer blend material, a test personnel can first make a to-be-tested sample from the polypropylene elastomer blend material, set an experimental environment for the to-be-tested sample according to a preset test condition, and directly / indirectly connect a galvanometer, a piezoelectric sensor, and the like to the to-be-tested sample. When the to-be-tested sample made of the polypropylene elastomer blend material is in the preset test condition, the charge distribution inside the to-be-tested sample will be disturbed and change accordingly. In this process, the terminal can obtain current information in the to-be-tested sample through a current detection device such as a galvanometer, and when the acoustic wave generated by the charge vibration reaches the piezoelectric sensor, the piezoelectric sensor can convert the acoustic wave into an electrical signal. At this time, the terminal can also obtain sensor signal information output by the piezoelectric sensor through the piezoelectric sensor.

[0046] In step S104, the space charge distribution information is determined according to the sensor signal information.

[0047] The space charge distribution information can be information describing the spatial position and concentration of charges (such as free charges, bound charges, trapped charges, and the like) inside or on the interface of the to-be-tested sample.

[0048] As an example, when the to-be-tested sample made of the polypropylene elastomer blend material is in the preset test condition, the charge distribution inside the to-be-tested sample will be disturbed and change accordingly. When the acoustic wave generated by the charge vibration reaches the piezoelectric sensor, the piezoelectric sensor can convert the acoustic wave into an electric signal. Therefore, the sensor signal information output by the piezoelectric sensor can be used to indirectly represent the spatial charge distribution in the to-be-tested sample. Specifically, the terminal can perform time domain analysis on the sensor signal information, analyze the time domain characteristics of the sensor signal, such as the amplitude of the signal, the peak time, etc. The terminal can also perform frequency domain analysis on the sensor signal information, convert the time domain signal into a frequency domain signal using Fourier transform, analyze the frequency components of the signal, and perform waveform recognition on the sensor signal, identify and classify different types of waveforms, such as reflected waves, transmitted waves, etc. Then, the terminal can establish a propagation model of the acoustic wave in the sample based on the time domain analysis result, the frequency domain analysis result, and the waveform recognition result, and iteratively back-propagate to obtain the spatial charge distribution information in the to-be-tested sample.

[0049] In step S106, the spatial charge injection characteristic evaluation result is determined according to the current information and the spatial charge distribution information.

[0050] The spatial charge injection characteristic evaluation result can refer to information representing the formation mechanism and transport mechanism of charges in the to-be-tested sample. In actual applications, the spatial charge injection characteristic evaluation result can include, but is not limited to, carrier injection mechanism, carrier transport mechanism, carrier trapping mechanism, carrier recombination mechanism, and carrier extraction mechanism.

[0051] As an example, the terminal can analyze the injection, transport, trapping, recombination, and extraction processes of carriers in the to-be-tested sample in combination with the current information and the spatial charge distribution information, determine the formation mechanism and transport mechanism of charges in the to-be-tested sample, and obtain the spatial charge injection characteristic evaluation result.

[0052] In the method for evaluating space charge injection characteristics of the polypropylene elastomer blend material for cables, the current information in the to-be-tested sample and the sensor signal information of the piezoelectric sensor corresponding to the to-be-tested sample are obtained under the condition that the to-be-tested sample made of the polypropylene elastomer blend material is in the preset test condition, so that the sound waves generated by the charge vibration caused by the pulse high voltage in the to-be-tested sample under the preset test condition are accurately monitored by the piezoelectric sensor and converted into sensor signals; the space charge distribution information is determined according to the sensor signal information, so that the accurate space charge distribution is obtained by analyzing the sensor signal information; and the space charge injection characteristic evaluation result is determined according to the current information and the space charge distribution information, so that the conduction characteristics and the charge injection mechanism of the to-be-tested sample are analyzed in combination with the current and the space charge distribution, the accurate space charge injection characteristic evaluation result is obtained, the real injected current in the to-be-tested sample under the preset test condition can be accurately analyzed based on the current, the accurate charge injection rate is obtained, the charge transport in the to-be-tested sample is accurately analyzed by using the charge injection rate, and the accuracy of the space charge injection characteristic evaluation result is improved.

[0053] In one exemplary embodiment, the preset test condition includes a first sub-test condition and a second sub-test condition, and the method further includes: in the case that the to-be-tested sample is in the first sub-test condition, taking the conduction current information in the to-be-tested sample as the current information in the to-be-tested sample; in the case that the to-be-tested sample is in the second sub-test condition, taking the depolarization current information in the to-be-tested sample as the current information in the to-be-tested sample; and determining the space charge injection characteristic evaluation result according to the conduction current information, the depolarization current information and the space charge distribution information.

[0054] The first sub-test condition can refer to an experimental condition in which a direct current voltage and a pulse voltage are applied to the to-be-tested sample at the same time.

[0055] The second sub-test condition can refer to an experimental condition in which only a pulse voltage is applied to the to-be-tested sample.

[0056] The conduction current information can refer to information representing a current formed by the directional movement of free charges (usually electrons or holes) in the material under the action of an applied electric field in the to-be-tested sample.

[0057] The depolarization current information can refer to a current generated by the redistribution or disappearance of the polarization charges in the material in the to-be-tested sample after the applied electric field is removed.

[0058] As an example, the initial peak of the depolarization current can reflect the total amount of polarization charges inside the sample, the terminal can calculate the total amount of polarization charges by integrating the depolarization current information, the decay rate of the depolarization current can reflect the release rate of the polarization charges, and the terminal can analyze the decay rate of the depolarization current information to determine the depth and density of the charge traps. If the depolarization current represented by the depolarization current information presents multi-stage decay, the terminal can determine that there are multiple types of charge traps in the sample under test. The terminal can analyze the conductive current and the voltage applied to the sample under test, draw a current-voltage curve, and analyze the conductive characteristics of the sample under test according to the current-voltage curve. The terminal can also determine the trend of the current with respect to the voltage based on the current-voltage curve, especially the difference between the linear region and the nonlinear region, the linear region indicating Ohmic conduction, and the nonlinear region possibly involving other conduction mechanisms such as trap-assisted conduction. The terminal can evaluate the polarization mechanism of the sample based on the initial peak and decay characteristics of the depolarization current, such as electronic dipoles, ionic dipoles, etc., and the terminal can also analyze the multi-stage decay of the depolarization current and the charge density distribution map to evaluate the type and distribution of the charge traps, thereby determining the formation mechanism of the charges in the sample under test. The terminal can also calculate the migration speed of the charges inside the sample by combining the conductive current and the electric field distribution data, and analyze the charge density distribution map based on the spatial charge distribution information to evaluate the main migration path and concentration area of the charges. If the current-voltage curve presents a nonlinear relationship, the terminal can also evaluate the trap-assisted conduction mechanism by combining the multi-stage decay of the depolarization current, thereby determining the transport mechanism of the charges in the sample under test. Then the terminal can determine the spatial charge injection characteristic evaluation result of the sample under test by combining the formation mechanism and transport mechanism of the charges in the sample under test.

[0059] In this embodiment, by taking the conductive current information in the sample under test as the current information in the sample under test when the sample under test is in the first sub-test condition, and taking the depolarization current information in the sample under test as the current information in the sample under test when the sample under test is in the second sub-test condition, and determining the spatial charge injection characteristic evaluation result based on the conductive current information, the depolarization current information and the spatial charge distribution information, the spatial charge injection characteristic evaluation result can be accurately determined based on the current information under different test conditions combined with the spatial charge distribution information, thereby improving the accuracy of the spatial charge injection characteristic evaluation result.

[0060] In some embodiments, the first sub-test condition includes: applying a pulse voltage with a pulse amplitude of 1V-1500V and a pulse width of 20ns to the sample under test by a nanosecond pulse source; and applying a direct current voltage with a voltage amplitude of 0-20kV to the sample under test by a high-voltage direct current source.

[0061] As an example, the DC voltage with the voltage amplitude of 0-20kV applied to the sample to be tested by the high-voltage DC source can establish a stable electric field environment inside the material, so that the charges can move along the electric field direction to form an initial charge distribution. The pulse voltage with the pulse amplitude of 1V-1500V and the pulse width of 20ns applied to the sample to be tested by the nanosecond pulse source can change the electric field distribution inside the material in a short time and disturb the existing charge distribution. The disturbance can excite the charge vibration inside the material, so that the charges move or redistribute near the original position. The DC voltage can be used to provide the charge distribution information of the material under the stable electric field, and the pulse voltage can be used to provide the behavior information of the charges under the dynamic disturbance, so as to comprehensively understand the charge formation and transport mechanism inside the material.

[0062] In the embodiment, the pulse voltage with the pulse amplitude of 1V-1500V and the pulse width of 20ns is applied to the sample to be tested by the nanosecond pulse source, and the DC voltage with the voltage amplitude of 0-20kV is applied to the sample to be tested by the high-voltage DC source. The test conditions of the sample to be tested can be accurately defined, so as to accurately analyze the charge formation and transport mechanism inside the material, thereby improving the accuracy of the space charge injection characteristic evaluation result.

[0063] In some embodiments, the second sub-test condition comprises: applying, by the nanosecond pulse source, the pulse voltage with the pulse amplitude of 1V-1500V and the pulse width of 20ns to the sample to be tested.

[0064] As an example, the second sub-test condition is equivalent to removing the DC voltage applied to the sample to be tested by the high-voltage DC source. When the DC voltage is removed, the background electric field inside the material disappears, which is helpful to observe the natural behavior of the charges without the action of the external electric field, so that the depolarization current measurement is more accurate. By monitoring the depolarization current, the release process of the charges can be evaluated, and the trapping and release characteristics of the charges inside the material can be understood.

[0065] In the embodiment, the pulse voltage with the pulse amplitude of 1V-1500V and the pulse width of 20ns is applied to the sample to be tested by the nanosecond pulse source, so as to accurately define the test conditions of the sample to be tested, accurately analyze the charge formation and transport mechanism inside the material, and improve the accuracy of the space charge injection characteristic evaluation result.

[0066] In some embodiments, one side of the sample to be tested is provided with a lower electrode, and the other side of the sample to be tested is provided with an upper electrode. A blocking layer and a semi-conductive layer are sequentially arranged between the sample to be tested and the upper electrode. The blocking layer is used to block the transmission of the preset type of charge carriers. The semi-conductive layer is used to transmit the charge carriers.

[0067] As an example, when evaluating the space charge injection characteristics of a sample under test, the sample under test is arranged in an experimental structure with a double-layer structure, as shown in Figure 2 A schematic diagram of a double-layer structure is provided, one side of the sample under test is provided with a lower electrode, the other side of the sample under test is provided with an upper electrode, and a blocking layer and a semiconductive layer are arranged between the sample under test and the upper electrode in sequence, wherein the blocking layer is used to block the transmission of a preset type of carrier, and the semiconductive layer is used to transmit the carrier, and the double-layer structure formed by the blocking layer and the semiconductive layer can create a quasi-unipolar carrier transport environment.

[0068] In this embodiment, one side of the sample under test is provided with a lower electrode; the other side of the sample under test is provided with an upper electrode; a blocking layer and a semiconductive layer are arranged between the sample under test and the upper electrode in sequence; the blocking layer is used to block the transmission of a preset type of carrier; and the semiconductive layer is used to transmit the carrier, which can analyze the space charge injection characteristics based on the electric field and the current under quasi-unipolar conditions, avoid the problem that the accuracy of the charge injection rate is not high due to the use of the steady-state current to analyze the space charge injection characteristics, and thus improve the accuracy of the evaluation results of the space charge injection characteristics.

[0069] In some embodiments, the upper electrode and the lower electrode are used to apply a step voltage and a pulse voltage to the sample under test; the step voltage includes at least two voltage values; and the difference between the voltage values is a preset value.

[0070] As an example, under the condition that other experimental conditions such as temperature remain unchanged, a series of step voltages are applied to the sample under test through the upper electrode and the lower electrode, which is conducive to judging the space charge accumulation condition.

[0071] In this embodiment, a step voltage and a pulse voltage are applied to the sample under test through the upper electrode and the lower electrode; the step voltage includes at least two voltage values; and the difference between the voltage values is a preset value, which can accurately analyze the space charge accumulation condition, so as to evaluate the space charge injection characteristics in combination with the space charge accumulation condition, thereby improving the accuracy of the evaluation results of the space charge injection characteristics.

[0072] In some embodiments, the material of the blocking layer includes E-51 epoxy resin, the thickness of the blocking layer is 160 um, the material of the upper electrode includes aluminum, the material of the lower electrode includes aluminum, the diameter of the upper electrode is 25 mm, the diameter of the lower electrode is 25 mm, and the sample under test is in a preset electric field environment; the electric field strength corresponding to the preset electric field environment includes ±30 kV / mm and ±50 kV / mm, the thickness of the sample under test is 0.2 mm, and the diameter of the sample under test is 85 mm.

[0073] As an example, the terminal can analyze the voltage value of the direct current voltage applied to the to-be-tested sample based on the electric field intensity corresponding to the preset electric field environment in which the to-be-tested sample is located. For example, if the to-be-tested sample is located in the preset electric field environment, and the electric field intensity corresponding to the preset electric field environment is ±30 kV / mm, the terminal can calculate the direct current voltage applied to the to-be-tested sample as ±6 kV in combination with the electric field intensity, and if the electric field intensity corresponding to the preset electric field environment is ±50 kV / mm, the terminal can calculate the direct current voltage applied to the to-be-tested sample as ±10 kV in combination with the electric field intensity.

[0074] In one of the example embodiments, from the physical process of charge transport, the space charge accumulation and transport in the polymer insulation material forms a conductive current in the external circuit, and the conductive current also contains the characteristic information of the space charge. Therefore, analyzing the correlation between the polymer space charge and the conductive current characteristics, revealing the space charge formation and charge transport mechanism, is of great significance for analyzing the space charge injection characteristic mechanism. In order to evaluate the space charge injection characteristics of the polypropylene elastomer blend material for high-voltage direct-current cables, a quasi-unipolar carrier transport environment can be created by using a double-layer structure with a barrier layer, and the charge extraction on the metal / polymer interface can be ignored. Based on the pulsed electro-acoustic (PEA) method, the space charge and the injection current of the to-be-tested sample made of the polypropylene elastomer blend material are measured simultaneously during the charging process, the quantitative relationship between the interfacial electric field (calculated according to the space charge distribution) and the injection current is studied, the correlation between the space charge distribution and the conductive current characteristics is analyzed, the space charge formation and charge transport mechanism are revealed, and thus the space charge injection characteristics are analyzed to obtain the space charge injection characteristic evaluation results. In practical applications, the process of joint measurement of material space charge distribution and current injection includes: keeping the temperature and other external conditions unchanged, continuously measuring the change curve of the conductive current in the sample with time under the step voltage (the step voltage is more conducive to judging the space charge accumulation), and evaluating the space charge accumulation according to the change curve. After the experiment is completed, the high-voltage source is turned off, and the short-circuit space charge and the depolarization current are collected. As shown in Figure 3 As shown in Figure 4 , a schematic diagram of double-layer current under a 6kV voltage is provided.

[0075] The calculation expression of the external current of the lower electrode corresponding to the to-be-tested sample in the double-layer structure with a barrier layer can be expressed as:

[0076] .

[0077] wherein, J d may refer to the displacement current density, the conduction current density J c is the injection current J iand the extraction current J e The terminal can determine the accumulation of space charges in the material and the type of space charges that dominate according to the change trend of the conductive current when the direct current voltage is applied and the voltage value is changed, and the corresponding relationship between the conductive current and the space charge, so as to distinguish between positive charge injection and negative charge injection. The double-layer structure of the to-be-blocked layer can be used to manufacture a quasi-unipolar carrier transport environment. Based on the dynamic electric field and current under the quasi-unipolar condition, rather than the current under the steady state, the influence of the blocking layer on the extraction current is excluded, and the change of the electric field at the electrode is considered, the displacement current is eliminated, and the calculated current is the real injection current, rather than the conduction current with extraction components inside; thereby distinguishing between positive charge injection and negative charge injection, which is helpful to further understand the charge transport of the metal / insulation interface. By simultaneously measuring the current and space charge under the unipolar carrier environment, the metal / polymer interface charge injection characteristic evaluation result is determined, which can indicate that the square root of the electrode electric field and the logarithm of the injection current are linearly related, which conforms to the trend of the Schottky theory or the Poole-Frenkel effect; both the electron injection and the hole injection on the metal / polymer interface conform to the mathematical relationship of the Poole-Frenkel effect.

[0078] In this embodiment, by the dynamic electric field and current under the quasi-unipolar condition, rather than the current under the steady state; the influence of the blocking layer on the extraction current is excluded, and the change of the electric field at the electrode is considered, the displacement current is eliminated, and the accurate real injection current is obtained, so as to accurately analyze the charge transport process of the metal / insulation interface, so as to obtain the accurate space charge injection characteristic evaluation result and improve the accuracy of the space charge injection characteristic evaluation result.

[0079] It should be understood that, although each step in the flowchart involved in each of the above embodiments is displayed in sequence according to the arrow, these steps are not necessarily executed in sequence according to the order of the arrow. Unless otherwise stated herein, the execution of these steps is not strictly limited in sequence, and these steps can be executed in other orders. Moreover, at least part of the steps in the flowchart involved in each of the above embodiments can include multiple steps or stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be alternately executed with at least part of other steps or steps or stages in other steps.

[0080] Based on the same inventive concept, the application further provides a device for evaluating the space charge injection characteristics of a polypropylene elastomer blend material for cables, which is used to implement the method for evaluating the space charge injection characteristics of a polypropylene elastomer blend material for cables as described above. The device provides a solution to the problem in a similar manner to the implementation described in the method above, and therefore the specific limitations in one or more device embodiments for evaluating the space charge injection characteristics of a polypropylene elastomer blend material for cables provided below can be seen in the limitations for the method for evaluating the space charge injection characteristics of a polypropylene elastomer blend material for cables described above, and will not be described here again.

[0081] In one exemplary embodiment, as shown in Figure 5 a device for evaluating the space charge injection characteristics of a polypropylene elastomer blend material for cables is provided, comprising: an acquisition module 502, a determination module 504, and an evaluation module 506, wherein:

[0082] The acquisition module 502 is configured to acquire current information in a sample to be tested made of a polypropylene elastomer blend material and sensor signal information of a piezoelectric sensor corresponding to the sample to be tested, under a preset test condition.

[0083] The determination module 504 is configured to determine space charge distribution information according to the sensor signal information.

[0084] The evaluation module 506 is configured to determine a space charge injection characteristic evaluation result according to the current information and the space charge distribution information.

[0085] In one exemplary embodiment, the preset test condition includes a first sub-test condition and a second sub-test condition, and the device further comprises an analysis module, which is specifically configured to: in a case where the sample to be tested is in the first sub-test condition, acquire conductive current information in the sample to be tested as the current information in the sample to be tested; in a case where the sample to be tested is in the second sub-test condition, acquire depolarization current information in the sample to be tested as the current information in the sample to be tested; and determine the space charge injection characteristic evaluation result according to the conductive current information, the depolarization current information, and the space charge distribution information.

[0086] Each of the modules in the device for evaluating the space charge injection characteristics of a polypropylene elastomer blend material for cables described above can be implemented in whole or in part by software, hardware, and combinations thereof. Each of the modules described above can be embedded in or independent of a processor in a computer device in hardware form, or can be stored in a memory in a computer device in software form, so as to be called and executed by a processor to perform the operations corresponding to each of the modules.

[0087] In an exemplary embodiment, a computer device, which can be a terminal, is provided, and an internal structure diagram of the computer device can be as shown in FIG. 1. Figure 6 The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output interface. The processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for running the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is configured to exchange information between the processor and external devices. The communication interface of the computer device is configured to perform wired or wireless communication with external terminals. The wireless communication can be achieved through WIFI, mobile cellular network, Near Field Communication (NFC) or other technologies. The computer program is executed by the processor to implement a method for evaluating space charge injection characteristics of a polypropylene elastomer blend material for cables. The display unit of the computer device is configured to form a visually visible picture, which can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer overlaid on the display screen, or a key, a trackball or a touchpad arranged on the shell of the computer device, or an external keyboard, a touchpad or a mouse, etc.

[0088] Those skilled in the art can understand that Figure 6 The structure shown in the above embodiment is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device can include more or fewer components than those shown in the diagram, or combine certain components, or have a different arrangement of components.

[0089] In an embodiment, a computer device is also provided, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0090] In an embodiment, a computer readable storage medium is provided, which stores a computer program. The computer program is executed by a processor to implement the steps in the above method embodiments.

[0091] In an embodiment, a computer program product is provided, which includes a computer program. The computer program is executed by a processor to implement the steps in the above method embodiments.

[0092] It should be noted that the user information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or authorized by all parties, and the collection, use and processing of related data need to comply with relevant regulations.

[0093] It can be understood by those skilled in the art that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing related hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments of each method. In the embodiments provided in the present application, any reference to memory, database or other medium can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (Read-Only Memory, ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive random access memory (Resistive Random Access Memory, ReRAM), magnetoresistive random access memory (Magnetoresistive Random Access Memory, MRAM), ferroelectric memory (Ferroelectric Random Access Memory, FRAM), phase change memory (Phase Change Memory, PCM), graphene memory, etc. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, etc. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), etc. The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., without being limited thereto. The processor involved in the embodiments provided in the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (Artificial Intelligence, AI) processor, etc., without being limited thereto.

[0094] Any technical features in the above embodiments can be combined, and for the sake of brevity, not all possible combinations are described above, however, any combination of these technical features is deemed to be within the scope of the present application.

[0095] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be pointed out that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method for evaluating space charge injection characteristics of a polypropylene elastomer blend material for cables, characterized by, The method comprises: In the case that the to-be-tested sample made of a polypropylene elastomer blend material is in a preset test condition, acquiring current information in the to-be-tested sample and sensor signal information of a piezoelectric sensor corresponding to the to-be-tested sample; the preset test condition comprises a first sub-test condition and a second sub-test condition, comprising: in the case that the to-be-tested sample is in the first sub-test condition, taking conductive current information in the to-be-tested sample as the current information in the to-be-tested sample; in the case that the to-be-tested sample is in the second sub-test condition, taking depolarization current information in the to-be-tested sample as the current information in the to-be-tested sample; According to the sensor signal information, determining spatial charge distribution information; According to the current information and the spatial charge distribution information, determining a spatial charge injection characteristic evaluation result, comprising: according to the conductive current information, the depolarization current information and the spatial charge distribution information, determining the spatial charge injection characteristic evaluation result.

2. The method of claim 1, wherein, The first sub-test condition comprises: applying, by a nanosecond pulse source, a pulse voltage with a pulse amplitude of 1-1500V and a pulse width of 20ns to the to-be-tested sample; applying, by a high-voltage direct current source, a direct current voltage with a voltage amplitude of 0-20kV to the to-be-tested sample.

3. The method of claim 1, wherein, The second sub-test condition comprises: applying, by a nanosecond pulse source, a pulse voltage with a pulse amplitude of 1-1500V and a pulse width of 20ns to the to-be-tested sample.

4. The method of claim 1, wherein, One side of the to-be-tested sample is provided with a lower electrode; the other side of the to-be-tested sample is provided with an upper electrode; a blocking layer and a semiconductive layer are sequentially arranged between the to-be-tested sample and the upper electrode; the blocking layer is used for blocking the transmission of a preset type of carrier; the semiconductive layer is used for transmitting a carrier.

5. The method of claim 4, wherein, The upper electrode and the lower electrode are used for applying a step voltage and a pulse voltage to the to-be-tested sample; the step voltage comprises at least two voltage values; the difference between the voltage values is a preset value.

6. The method of claim 4, wherein, The material of the blocking layer comprises E-51 epoxy resin, and the thickness of the blocking layer is 160μm.

7. The method of claim 4, wherein, The material of the upper electrode comprises aluminum, and the material of the lower electrode comprises aluminum; the diameter of the upper electrode is 25mm, and the diameter of the lower electrode is 25mm.

8. The method of claim 4, wherein, The to-be-tested sample is in a preset electric field environment; the electric field strength corresponding to the preset electric field environment comprises at least one of ±30kV / mm or ±50kV / mm.

9. The method of claim 1, wherein, The thickness of the to-be-tested sample is 0.2mm, and the diameter of the to-be-tested sample is 85mm.

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