Method and device for acquiring high-temperature PEA experiment space charge reference waveform

Abstract

The invention discloses a method and a device for acquiring a high-temperature PEA experiment space charge reference waveform, and relates to the technical field of electrical materials. The method comprises the following steps: acquiring electron displacement polarization time and dipole steering polarization time of an insulating material sample; applying a single-polarity periodic voltage to the insulating material sample, and superposing a same-phase pulse voltage in each period of the periodic voltage; any trigger signal moment of the pulse voltage is located in a pressurization period of the periodic voltage, and tc is greater than tj and less than DT; the duty ratio D of the periodic voltage is more than 2tj / T and less than 0.05; acquiring a reference waveform signal of the insulating material sample; according to the technical scheme, the problem that the charge injection speed is high under the PEA experiment high temperature condition is effectively solved, and the reference waveform of the PEA experiment can be more accurately obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical materials, and particularly to a method and device for obtaining a reference waveform of space charge in a high-temperature PEA experiment space. Background Art

[0002] In the research and development process of new insulating materials, measuring space charge can help researchers understand the charge transport mechanism and trap characteristics inside the materials; by measuring the space charge of materials under different formulations and preparation processes, and then optimizing the molecular structure and formulation of the materials, it is of great significance for improving the electrical resistance performance and service life of insulating materials; the electroacoustic pulse method (PEA) space charge measurement technology is one of the widely used measurement methods at home and abroad. During measurement, a sheet-shaped specimen is first clamped between the upper and lower measurement electrodes. Under the pressurized state, a nanosecond pulse voltage acts on the specimen. The charges in the specimen cause an electrostatic force under the action of the pulse electric field, generating a pressure wave. The pressure wave then passes through the specimen and the lower electrode, and is detected by a piezoelectric sensor and converted into an electrical signal, which is then amplified by an amplifier and observed by an oscilloscope to obtain real-time data and collected and saved by a computer.

[0003] The waveform obtained by the electroacoustic pulse method measurement is the result of distortion of the real space charge distribution, and a reference waveform of the insulating material without injected charges is required to perform waveform restoration processing and analysis on the measured waveform; the existing method for obtaining the reference waveform of space charge is to measure the charge signal under a relatively low DC voltage, that is, it is considered that there is no charge injection in the dielectric under low voltage conditions, and the charge signal does not contain the signal caused by space charge; however, when the experiment involves high temperature, even under a relatively low DC voltage, charges will inject into the insulating dielectric at a very fast speed, and it is impossible to record the reference waveform without space charge in an extremely short time. Summary of the Invention

[0004] The embodiments of the present invention provide a method and device for obtaining a reference waveform of space charge suitable for high-temperature PEA experiments.

[0005] The method for obtaining the reference waveform of space charge in a high-temperature PEA experiment includes the following steps:

[0006] S1, obtaining the electron displacement polarization time and dipole rotation polarization time of the insulating material specimen;

[0007] S2, applying a single-polarity periodic voltage to the insulating material specimen, and superimposing a pulse voltage with the same phase in each cycle of the periodic voltage; any trigger signal moment of the pulse voltage is located in the pressurization period of the periodic voltage, and satisfies the following relationship:

[0008] t j <t c <DT;

[0009] In the formula, t j is the larger value of the electronic displacement polarization time and the dipole rotation polarization time of the insulating material sample, t c is the trigger signal moment of the pulse voltage, T is the period of the periodic voltage, and D is the duty cycle of the periodic voltage;

[0010] The duty cycle D of the periodic voltage satisfies: 2t j / T < D < 0.05;

[0011] S3. Obtain the reference waveform signal of the insulating material sample.

[0012] Optionally, the frequency of the periodic voltage is 200 Hz - 10 kHz.

[0013] Optionally, the electric field strength applied by the periodic voltage on the insulating material sample is greater than 1 kV / mm and less than the breakdown electric field strength of the insulating material sample.

[0014] Optionally, the voltage application time length for obtaining the reference waveform signal is 10 s - 20 s.

[0015] Optionally, the waveform of the periodic voltage is at least one of a square wave, a trapezoidal wave, a triangular wave, and a sine half wave.

[0016] The device for obtaining the reference waveform of the space charge in the high-temperature PEA experiment includes:

[0017] A measurement module, including a pair of measurement electrodes;

[0018] A periodic voltage generation module, electrically connected to the measurement module, for generating a periodic voltage of a single polarity; the duty cycle D of the periodic voltage satisfies: 2t j / T < D < 0.05, t j is the larger value of the electronic displacement polarization time and the dipole rotation polarization time of the insulating material sample, T is the period of the periodic voltage, and D is the duty cycle of the periodic voltage;

[0019] A pulse generation module, electrically connected to the measurement module, for generating a pulse voltage in the same phase as the periodic voltage; any trigger signal moment of the pulse voltage is located in the pressurization period of the periodic voltage and satisfies the following relationship: t j < t c < DT, t c is the trigger signal moment of the pulse voltage;

[0020] A signal acquisition module, for obtaining the reference waveform signal.

[0021] Optionally, the device for obtaining the reference waveform of space charge in the high-temperature PEA experiment further includes:

[0022] A temperature control module for heating the insulating material sample to be measured and maintaining a preset temperature.

[0023] Optionally, the pulse generation module includes a pulse power supply and a DC-blocking capacitor;

[0024] The DC-blocking capacitor is connected in series between the pulse power supply and the measurement module, and its capacitance value is greater than the equivalent capacitance value of the insulating material sample to be measured.

[0025] Optionally, the periodic voltage generation module includes a signal generator and a protection resistor;

[0026] The protection resistor is connected in series between the signal generator and the measurement module, and its resistance value is greater than 10 kΩ.

[0027] The present invention also provides a computer device, including a memory and a processor; the memory stores a computer program, and when the processor executes the computer program, the method for obtaining the reference waveform of space charge in the high-temperature PEA experiment described above is implemented.

[0028] The present invention has the following beneficial effects:

[0029] When the reference waveform of space charge in the high-temperature PEA experiment of the sample is obtained by using the technical solution of the present invention,

[0030] The trigger signal time of the pulse voltage is located in the voltage application period of the single-polarity periodic voltage, enabling the oscilloscope to find the reference signal waveform. The processes of electronic displacement polarization and dipole rotation polarization of the sample are completed before the pulse voltage is triggered, and the time when the periodic voltage is at a high level is greater than twice the electronic displacement polarization time and dipole rotation polarization time of the sample to ensure normal polarization of the sample at a high level. On this basis, by setting a periodic voltage signal with a duty cycle lower than 0.05 to obtain the reference waveform signal for space charge measurement, the voltage application period of the periodic voltage is significantly reduced compared with the traditional scheme of obtaining the reference waveform signal through a DC voltage, avoiding charge injection into the sample when measuring the reference signal, effectively improving the problem of fast charge injection speed under high-temperature conditions, being able to obtain the reference signal more accurately, and further improving the accuracy of the PEA space charge measurement technology under high-temperature conditions. And because the periodic voltage with a low duty cycle avoids charge injection, only the average signal of the target number of reference waveforms needs to be obtained, so there is no need to consider fast triggering and acquisition, and the reference waveform signal can be obtained under the conditions of high-delay triggering and slow acquisition speed, greatly reducing the requirements for hardware. Description of the Drawings

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0032] Figure 1 It is the timing diagram of the acquisition method of the reference waveform of space charge in the high-temperature PEA experiment of the present invention;

[0033] Figure 2 It is the structural schematic diagram of the acquisition device of the reference waveform of space charge in the high-temperature PEA experiment of the present invention;

[0034] Figure 3 It is the equivalent circuit diagram for acquiring the reference waveform of space charge in the high-temperature PEA experiment of the present invention;

[0035] Figure 4 It is the reference waveform data diagram obtained by using square wave voltage and DC voltage respectively in some embodiments of the present invention. Detailed implementation manners

[0036] To make the objectives, features, and advantages of the present invention more obvious and understandable, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0037] Space charge refers to the charge accumulation formed by the uneven distribution of charges in space due to various reasons in a dielectric; at the interface between the electrode and the dielectric, due to the action of the electric field, the charges in the electrode may be injected into the dielectric to form space charge; there are usually some impurities in the dielectric, and these impurities may be ionized under the action of the electric field, and the generated ions will move and accumulate in the dielectric to form space charge; the dielectric will undergo a polarization phenomenon under the action of the electric field, and polarization charges will be generated during the polarization process. When the distribution of the polarization charges is uneven or cannot respond in time when the electric field changes, space charge may also be formed.

[0038] The existence of space charge will distort the electric field distribution inside the dielectric. The originally uniform electric field will become non-uniform due to the accumulation of space charge, resulting in an increase in the local electric field strength. For example, in high-voltage cables, the accumulation of space charge may make the electric field distribution in the insulation layer non-uniform, with too high a local electric field, accelerating insulation aging. Long-term accumulation of space charge may also lead to the generation of dendritic discharge channels inside the insulating material, further weakening the insulation performance.

[0039] The waveform measured by the pulsed electroacoustic method (PEA) is obtained after distortion of the real space charge distribution, and a reference waveform of the insulating material without injected charge is needed to perform waveform restoration processing and analysis on the measured waveform.

[0040] Current methods for obtaining reference waveforms are all to directly obtain reference signals under DC voltage, and it is difficult to apply to the cases where the electric field threshold for charge injection is low and high temperature. When the experiment involves high temperature, for example, for the silicone elastomer used as the packaging material of power devices, the temperature range during measurement is from room temperature to 200 °C. At higher temperatures (100 °C to 200 °C), even at a relatively low DC voltage, charges will be injected into the insulating medium at a very fast speed, and it is impossible to record a reference waveform without space charge in an extremely short time. Therefore, the embodiments of the present invention propose a method for obtaining a reference waveform of space charge in a high-temperature PEA experiment for this problem.

[0041] The method for obtaining a reference waveform of space charge in a high-temperature PEA experiment proposed by the embodiments of the present invention includes the following steps:

[0042] S1, obtain the electron displacement polarization time and the dipole rotation polarization time of the insulating material sample.

[0043] Among them, electron displacement polarization and dipole rotation polarization are two polarization phenomena that occur in the dielectric under the action of an electric field. The electron displacement polarization time refers to the time required for the electron cloud of atoms or molecules in the dielectric to displace relative to the atomic nucleus under the action of an electric field to form an induced electric dipole moment. The dipole rotation polarization time refers to the time required for molecules with inherent dipole moments in the dielectric to turn from a disordered state to an arrangement in the direction of the electric field under the action of an electric field to form a macroscopic polarization intensity. Generally, theoretical models such as the Debye relaxation model and the Havriliak-Negami model can be used, and experimental methods such as the dielectric spectroscopy method, the pulsed electric field method, and the thermally stimulated current method can be used to obtain the electron displacement polarization time and the dipole rotation polarization time of the insulating material sample.

[0044] S2, apply a periodic voltage of a single polarity to the insulating material sample, and superimpose a pulsed voltage with the same phase within each period of the periodic voltage; any trigger signal moment of the pulsed voltage is located in the voltage application period of the periodic voltage.

[0045] In this step, it is necessary to ensure that the trigger signal of the pulsed voltage is located in the voltage application period of the periodic voltage, so that the oscilloscope can find the reference signal waveform; and the processes of electronic displacement polarization and dipole rotation polarization of the insulating material need to be completed before the pulsed voltage is triggered; therefore, the trigger signal time of the pulsed voltage satisfies the following relationship:

[0046] t j <t c <DT;

[0047] In the formula, t j is the larger value of the electronic displacement polarization time and the dipole rotation polarization time of the insulating material sample, t c is the trigger signal time of the pulsed voltage, T is the period of the periodic voltage, and D is the duty cycle of the periodic voltage.

[0048] Meanwhile, the charge accumulation amount in the insulating material is proportional to the duty cycle of the periodic voltage. Therefore, the duty cycle D is required to be as small as possible to ensure that no charge is injected when obtaining the reference signal; but the time at the high level needs to be greater than twice the electronic displacement polarization time and the dipole rotation polarization time of the insulating material to ensure normal polarization of the sample at the high level; therefore, in the embodiment of the present invention, the duty cycle D of the periodic voltage satisfies: 2t j / T < D < 0.05; preferably, the closer the duty cycle D is to the minimum value within this range, the more accurate the obtained reference waveform signal is.

[0049] In the embodiment of the present invention, the frequency of the periodic voltage can be selected within the range of 200 Hz - 10 kHz; considering that the waveforms measured by the electroacoustic pulse method experiment need to be averaged to improve the signal-to-noise ratio, the frequency of the periodic voltage can be increased as much as possible to reduce the time for the oscilloscope to calculate the average waveform; according to the frequency, the voltage application time length for obtaining the reference waveform signal is 10 s - 20 s.

[0050] In the embodiment of the present invention, the amplitude of the periodic voltage is determined according to the sample thickness and the charge accumulation starting electric field threshold of the sample; generally, the electric field strength applied to the insulating material sample is greater than 1 kV / mm and less than the breakdown electric field strength of the insulating material sample.

[0051] In the embodiment of the present invention, the waveform of the periodic voltage can be selected from any one or a combination of single-polarity periodic waveforms such as square wave, trapezoidal wave, triangular wave, sine half-wave, etc.

[0052] Referring to Figure 1 , in some feasible embodiments, the periodic voltage adopts a square wave voltage; Figure 1 It can intuitively reflect the phase relationship between the trigger signal of the pulsed voltage and the periodic voltage. Compared with the traditional scheme of continuously applying a DC voltage, the voltage application period of the square wave voltage is much smaller.

[0053] In the embodiment using a square wave voltage, the amplitude of the square wave voltage can be selected as a voltage value equal to the square wave voltage or DC voltage used in the subsequent formal measurement of space charge in the PEA experiment.

[0054] S3. Obtain the reference waveform signal of the insulating material specimen through signal acquisition modules such as a signal amplifier and an oscilloscope.

[0055] After obtaining the reference waveform of the space charge of the insulating material specimen in the high-temperature PEA experiment by the above method, waveform restoration processing and analysis can be performed on the subsequent space charge signal measurement signal of the insulating material specimen. The measurement signal is deconvolved through the system transfer function to eliminate the distortion effect of the system on the signal and restore a more real space charge distribution signal.

[0056] Refer to Figure 4 , Figure 4 shows the reference waveform data graph obtained by using a square wave voltage and the reference waveform data graph obtained by using a DC voltage in the traditional scheme. The two are the results measured at the same temperature and after applying pressure for the same time; the reference signal is a signal without space charge injection. Theoretically, under the condition of no charge injection, the position of the peak is fixed; Figure 4 The results of show that compared with the reference waveform obtained by using a square wave voltage, the peaks on both the left and right sides of the reference waveform obtained by using a DC voltage move inward, indicating that the reference waveform obtained by using a DC voltage has obvious distortion due to space charge accumulation; in addition, Figure 4 also shows that the peak value of the left negative peak of the reference waveform obtained by using a DC voltage is significantly smaller than that of the reference waveform obtained by using a square wave voltage, which is also due to the reduction of the peak value caused by the accumulation of space charge in the medium under DC voltage application.

[0057] It can be seen from this that in the embodiment of the present invention, a square wave voltage signal with a low duty cycle is set to obtain the reference waveform signal for space charge measurement. The pressurization period of the square wave voltage is significantly reduced compared with the traditional scheme of obtaining the reference waveform signal through a DC voltage, avoiding charge injection into the medium when measuring the reference signal, effectively improving the problem of fast charge injection speed under high-temperature conditions, and being able to obtain the reference signal more accurately, thereby improving the accuracy of the space charge measurement technology of the electroacoustic pulse method (PEA) under high-temperature conditions.

[0058] In addition, for the traditional scheme of obtaining a reference waveform signal through a DC voltage, under high-temperature conditions, usually at the moment of additional voltage application, hundreds of signal triggers and signal acquisitions need to be performed on the time scales of seconds and microseconds to ensure that the reference signal is acquired without charge injection, which requires very high hardware requirements. However, the method proposed in the embodiments of the present invention avoids charge injection as much as possible through a periodic voltage with a low duty cycle, and only needs to obtain the average signal of the target number of reference waveforms. Therefore, there is no need to consider fast triggering and acquisition, and the reference waveform signal can be obtained under the conditions of high-delay triggering and slow acquisition speed, greatly reducing the hardware requirements.

[0059] It should be noted that the method proposed in the embodiments of the present invention is not only applicable to obtaining the reference signal of insulating materials under high temperature, but also applicable to obtaining the reference signal of media with fast charge accumulation. Of course, the method proposed in the embodiments of the present invention can also be used to obtain the space charge reference signal under normal working conditions.

[0060] Based on the above method embodiments, referring to Figure 2 , the present invention also proposes an apparatus for obtaining a reference waveform of space charge in a high-temperature PEA experiment, which includes a measurement module 100, a periodic voltage generation module 200, a pulse generation module 300, and a signal acquisition module 400.

[0061] Among them, the measurement module 100 includes a pair of measurement electrodes. During measurement, the sheet specimen is clamped between the upper and lower measurement electrodes.

[0062] The periodic voltage generation module 200 is electrically connected to the measurement module 100 and is used to generate a periodic voltage of a single polarity; the duty cycle D of the periodic voltage satisfies: 2t j / T < D < 0.05, where t j is the larger value of the electron displacement polarization time and the dipole rotation polarization time of the insulating material specimen, T is the period of the periodic voltage, and D is the duty cycle of the periodic voltage.

[0063] The waveform of the periodic voltage can be selected from any one or a combination of single-polarity periodic waveforms such as square wave, trapezoidal wave, triangular wave, and sine half-wave.

[0064] Specifically, the periodic voltage generation module 200 may include a signal generator and a protection resistor. The signal generator is used to generate a periodic voltage, and the protection resistor is connected in series between the signal generator and the measurement module, and its resistance value is greater than 10 kΩ.

[0065] The pulse generation module 300 is electrically connected to the measurement module 100 and is used to generate a pulse voltage in the same phase as the periodic voltage; any trigger signal moment of the pulse voltage is located in the voltage application period of the periodic voltage and satisfies the following relationship: t j < tc <DT, t c is the trigger signal time of the pulsed voltage.

[0066] The pulse generation module 300 may include a pulse power supply and a DC-blocking capacitor; the DC-blocking capacitor is connected in series between the pulse power supply and the measurement module, and its capacitance value is greater than the equivalent capacitance value of the insulating material sample to be measured.

[0067] The signal acquisition module 400 generally includes a signal amplifier and an oscilloscope, and is used to obtain a reference waveform signal.

[0068] In some embodiments, the apparatus for obtaining a reference waveform of space charge in a high-temperature PEA experiment space further includes a temperature control module for heating the insulating material sample to be measured and maintaining a preset temperature. The temperature control module may include a heating device, a thermostat, a temperature sensor, and a cooling system.

[0069] Refer to Figure 3 , Figure 3 shows an equivalent circuit for obtaining a reference waveform of space charge in an embodiment of the apparatus of the present invention; wherein, C sa is the equivalent capacitance of the insulating material sample; the pulse generation module includes a pulse power supply and a DC-blocking capacitor C c ; the DC-blocking capacitor C c is connected in series between the pulse power supply and the equivalent capacitance C sa , and its capacitance value is greater than the capacitance value of the equivalent capacitance C sa ; preferably, the capacitance value of the DC-blocking capacitor C c is much greater than the capacitance value of the equivalent capacitance C sa to ensure that the pulse power supply voltage is basically applied to the sample; the periodic voltage generation module includes a signal generator and a protection resistor R SW ; the protection resistor R SW is connected in series between the signal generator and the equivalent capacitance C sa , and its resistance value is greater than 10 kΩ to prevent equipment damage caused by electrical breakdown of the sample.

[0070] The apparatus for obtaining a reference waveform of space charge in a high-temperature PEA experiment space proposed in an embodiment of the present invention is used to implement the technical solutions of the foregoing method embodiments. All the technical effects that can be achieved by the foregoing method embodiments can be achieved by this apparatus, and will not be elaborated herein.

[0071] The present invention also proposes a computer device, including a memory and a processor; the memory stores a computer program, and when the processor executes the computer program, it implements the method for obtaining a reference waveform of space charge in a high-temperature PEA experiment space proposed in the foregoing method embodiments.

[0072] Those of ordinary skill in the art can understand that implementing all or part of the processes in the foregoing method embodiments can be accomplished by instructing relevant 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 foregoing method embodiments. Among them, any reference to a memory, storage, database, or other medium used in the various embodiments provided by the present invention can include at least one of non-volatile and volatile memories. The technical effects achievable by the foregoing method embodiments can all be achieved by this computer device, and will not be elaborated herein.

[0073] The above-described embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

1. A method for obtaining a reference waveform of space charge in a high-temperature PEA experimental space, characterized in that, It includes the following steps: S1. Obtain the electronic displacement polarization time and dipole rotation polarization time of the insulating material sample; S2. Apply a periodic voltage with a single polarity to the insulating material sample, and superimpose a pulse voltage with the same phase within each period of the periodic voltage; any trigger signal moment of the pulse voltage is located in the voltage application period of the periodic voltage, and satisfies the following relationship: t j <t c <DT; where t j is the larger value of the electronic displacement polarization time and the dipole rotation polarization time of the insulating material sample, t c is the trigger signal time of the pulse voltage, T is the period of the periodic voltage, and D is the duty cycle of the periodic voltage; The duty cycle D of the periodic voltage satisfies: 2t j / T < D < 0.05; S3. Obtain the reference waveform signal of the insulating material sample.

2. The method for obtaining the reference waveform of space charge in the high-temperature PEA experimental space according to claim 1, characterized in that, The frequency of the periodic voltage is 200 Hz - 10 kHz.

3. The method for obtaining the reference waveform of space charge in the high-temperature PEA experimental space according to claim 1, wherein, The electric field strength applied by the periodic voltage on the insulating material sample is greater than 1 kV / mm and less than the breakdown electric field strength of the insulating material sample.

4. The method for obtaining the reference waveform of space charge in a high-temperature PEA experimental space according to claim 1, wherein The voltage application time length for obtaining the reference waveform signal is 10 s - 20 s.

5. The method for obtaining the reference waveform of space charge in a high-temperature PEA experimental space according to claim 1, wherein The waveform of the periodic voltage is at least one of a square wave, a trapezoidal wave, a triangular wave, and a sine half wave.

6. An acquisition device for the reference waveform of space charge in a high-temperature PEA experimental space, characterized in that, It includes: A measurement module, including a pair of measurement electrodes; A periodic voltage generation module, electrically connected to the measurement module, for generating a periodic voltage with a single polarity; The duty cycle D of the periodic voltage satisfies: 2t j / T < D < 0.05, where t j is the larger value of the electronic displacement polarization time and the dipole rotation polarization time of the insulating material sample, T is the period of the periodic voltage, and D is the duty cycle of the periodic voltage; A pulse generation module, electrically connected to the measurement module, for generating a pulse voltage with the same phase as the periodic voltage; Any triggering signal moment of the pulse voltage is located in the voltage application period of the periodic voltage and satisfies the following relationship: t j <t c <DT, where t c is the triggering signal moment of the pulse voltage; A signal acquisition module, for obtaining the reference waveform signal.

7. The acquisition device for the reference waveform of space charge in the high-temperature PEA experiment according to claim 6, characterized in that, It further includes: A temperature control module, for heating the insulating material sample to be measured and maintaining a preset temperature.

8. The device for obtaining the reference waveform of space charge in the high-temperature PEA experiment according to claim 6, wherein, The pulse generation module includes a pulse power supply and a DC-blocking capacitor; The DC-blocking capacitor is connected in series between the pulse power supply and the measurement module, and its capacitance value is greater than the equivalent capacitance value of the insulating material sample to be measured.

9. The acquisition device for the reference waveform of space charge in a high-temperature PEA experiment according to claim 6, characterized in that, The periodic voltage generation module includes a signal generator and a protective resistor; The signal generator is used for generating a periodic voltage; the protective resistor is connected in series between the signal generator and the measurement module, and its resistance value is greater than 10 kΩ.

10. A computer device, characterized in that, It includes a memory and a processor; the memory stores a computer program, and when the processor executes the computer program, it implements the method for obtaining the reference waveform of the space charge in the high-temperature PEA experiment according to any one of claims 1 - 5.

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