Method and system for evaluating aging state of zinc oxide piezoresistor for direct current lightning arrester

Abstract

The invention belongs to the technical field of state evaluation of zinc oxide varistors for direct-current lightning arresters, and discloses an aging state evaluation method and system for a zinc oxide varistor for a direct-current lightning arrestor. According to the method, the single face of the zinc oxide varistor is coated with parallel silver electrodes, and direct-current aging voltage is applied to a channel between the two electrodes; the X-ray diffraction peak position and the Zn2p orbital peak position of the crystal face of the ZnO piezoresistor (002) at the channel are respectively tested under the conditions of no aging and different aging time. The aging state of the zinc oxide varistor is evaluated according to the (002) diffraction peak and the deviation degree of the Zn2p orbital peak, so that the aging state of the zinc oxide varistor for the direct-current lightning arrester is judged on the grain boundary physicochemical level, and the aging state of the zinc oxide varistor for the direct-current lightning arrester can be accurately evaluated. And the reliability of the aging state evaluation result of the zinc oxide piezoresistor for the direct current lightning arrester is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of zinc oxide varistor state evaluation for DC lightning arresters, and in particular to an aging state evaluation method and system for zinc oxide varistor for DC lightning arresters. Background Art

[0002] ZnO varistors have excellent nonlinear volt-ampere characteristics and are the core components of DC lightning arresters. They are widely used in overvoltage protection of power systems and in maintaining the safe and stable operation of power equipment. Since ZnO varistors are connected in parallel with power equipment for a long time, aging is inevitable, which is generally manifested as an increase in power consumption (leakage current), posing a potential threat to the insulation protection level of power equipment. However, with the development of production technology, the power consumption of zinc oxide varistors no longer increases invariably. According to the aging power consumption trend, ZnO varistors can be divided into stable, metastable and unstable types. The power consumption of stable types continues to decrease with the increase of aging time, the power consumption of metastable types first decreases and then continues to increase, and the power consumption of unstable types continues to increase with the increase of aging time.

[0003] At present, the aging status evaluation of DC lightning arresters mainly relies on the Arrhenius formula to analyze the rising power consumption (leakage current). However, the non-Arrhenius aging characteristics of stable ZnO varistors are difficult to evaluate through power consumption; at the same time, the power consumption has a significant voltage dependence characteristic and is significantly affected by the ambient temperature and atmosphere. It is difficult to accurately characterize the aging degree of ZnO varistors, which limits the further development and application of DC lightning arresters. Summary of the invention

[0004] The invention provides a method and system for evaluating the aging state of a zinc oxide varistor for a DC lightning arrester, which solves the technical problem that the evaluation result of the aging resistance of a ZnO varistor for a DC lightning arrester is unreliable.

[0005] To achieve the above object, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for evaluating the aging state of a zinc oxide varistor for a DC lightning arrester, comprising: Obtain a zinc oxide varistor sample for a DC lightning arrester for an aging status evaluation test; wherein a single side of the zinc oxide varistor sample for a DC lightning arrester is covered with parallel silver electrodes, and a test channel is reserved in the middle of the single side; Performing X-ray diffraction spectrum and X-ray photoelectron spectrum tests on the test channel respectively to obtain the ZnO (002) crystal plane and Zn2p orbital binding energy when not aged; Performing accelerated aging tests of zinc oxide varistor samples for DC lightning arresters for different preset time lengths to obtain test channels with different aging degrees; wherein the accelerated aging test includes applying a DC aging voltage to parallel silver electrodes while heating the zinc oxide varistor samples for DC lightning arresters; X-ray diffraction spectra and X-ray photoelectron spectroscopy tests were performed on the test channels with different aging degrees to obtain the binding energies of the ZnO (002) crystal plane and the Zn2p orbital at different aging degrees; the degree of deviation of the binding energies of the ZnO (002) crystal plane and the Zn2p orbital at different aging degrees relative to those of the ZnO (002) crystal plane and the Zn2p orbital when not aged was determined as the aging status evaluation result of the zinc oxide varistor.

[0006] As an optional solution of the present invention, heating a zinc oxide varistor sample for a DC lightning arrester comprises: When heating the zinc oxide varistor sample for DC lightning arrester, the zinc oxide varistor sample for DC lightning arrester is placed on an alumina heating plate, and the zinc oxide varistor sample for DC lightning arrester is heated by the alumina heating plate.

[0007] As an optional solution of the present invention, one side of the zinc oxide varistor sample for DC lightning arrester is covered with parallel silver electrodes; wherein the parallel silver electrodes are obtained by coating one side of the zinc oxide varistor sample for DC lightning arrester by ion sputtering or low-temperature silver paste coating.

[0008] As an optional solution of the present invention, the width of the test channel is 0.5-1 mm.

[0009] As an optional solution of the present invention, when performing X-ray diffraction spectroscopy, it is carried out in the following manner: X-ray diffraction spectrum test was carried out by X-ray diffractometer; wherein, the scanning range of the X-ray diffractometer was 10∼80°, the scanning speed was 4° / min, the step size was less than or equal to 0.02°, Cu target radiation was used, the working voltage was 40 kV, and the diffraction peak of the ZnO (002) crystal plane was obtained.

[0010] As an optional solution of the present invention, when performing X-ray photoelectron spectroscopy testing, it is carried out in the following manner: X-ray photoelectron spectroscopy testing was performed using an X-ray photoelectron spectrometer; the test binding energy range of the X-ray photoelectron spectrometer was 0~1350 eV, with a step size of less than or equal to 0.1 eV, to obtain the orbital peak of Zn2p.

[0011] As an optional solution of the present invention, when a DC aging voltage is applied to the parallel silver electrodes, the DC aging voltage is applied to one side of the parallel silver electrodes, and the other side of the parallel silver electrodes is grounded. The DC aging voltage applied is 0.8-0.9 U 1mA, U 1mA is the voltage corresponding to a current of 1 mA flowing through the channel.

[0012] As an optional solution of the present invention, when the zinc oxide varistor sample for DC lightning arrester is heated, the aging temperature is set to 100°C~180°C.

[0013] As an optional solution of the present invention, the deviation degree of the binding energy of the ZnO (002) crystal plane and the Zn2p orbital under different aging degrees relative to the binding energy of the ZnO (002) crystal plane and the Zn2p orbital when not aged is determined as the aging state evaluation result of the zinc oxide varistor, including: The binding energies of the ZnO (002) crystal plane and Zn2p orbital at different aging levels are compared with those of the corresponding unaged ZnO (002) crystal plane and Zn2p orbital. If the diffraction peak of the ZnO (002) crystal plane and the orbital peak position of the Zn2p orbital binding energy remain unchanged, it is determined that the aging degree of the zinc oxide varistor used in DC lightning arresters is small; If the diffraction peak of the ZnO (002) crystal plane decreases by 0.02° or more, or the orbital peak of the Zn2p orbital binding energy decreases by more than 0.5 eV, it is judged that the aging degree of the zinc oxide varistor used in DC lightning arresters is serious.

[0014] In a second aspect, the present invention provides a system for implementing the above-mentioned method for evaluating the aging state of zinc oxide varistor for DC lightning arrester, comprising: An X-ray diffractometer is used to perform X-ray diffraction spectrum tests on the unaged test channels and the test channels with different aged degrees, so as to obtain the ZnO (002) crystal plane when unaged and the ZnO (002) crystal planes with different aged degrees; X-ray photoelectron spectrometer, used to perform X-ray photoelectron spectroscopy test on the unaged test channels and the test channels with different aged degrees, so as to obtain the Zn2p orbital binding energy when unaged and the Zn2p orbital binding energy with different aged degrees; The comparative evaluation module is used to determine the degree of deviation of the binding energy of the ZnO (002) crystal plane and the Zn2p orbital at different aging degrees relative to the binding energy of the ZnO (002) crystal plane and the Zn2p orbital when not aged, as the aging status evaluation result of the zinc oxide varistor.

[0015] It can be seen from the above technical solutions that the present invention has the following advantages: The present invention covers a single side of a ZnO varistor for a DC lightning arrester with parallel silver electrodes, performs DC aging on the surface channels between the silver electrodes, tests the XRD and XPS spectra of the channel region before aging and at different aging stages, obtains the distribution of the ZnO (002) diffraction peak and the Zn2p orbital peak, thereby determining the offset of the ZnO (002) diffraction peak and the Zn2p orbital peak after aging, and determines the aging state of the ZnO varistor for the DC lightning arrester at the physical and chemical structure level, avoids the influence of inaccurate judgment of the aging state by power consumption (leakage current), can accurately evaluate the aging resistance of the ZnO varistor for the DC lightning arrester, and improves the reliability of the evaluation result of the aging resistance of the ZnO varistor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flow chart of a method for evaluating the aging state of a zinc oxide varistor for a DC lightning arrester according to an embodiment of the present invention; Figure 2 A schematic diagram of an aging test scheme for a zinc oxide varistor for a DC lightning arrester provided in an embodiment of the present invention; Figure 3 A schematic diagram of the diffraction peak spectra of ZnO (002) in different aging states in the XRD test provided in an embodiment of the present invention; Figure 4 Schematic diagram of Zn2p orbital peaks in different aging states tested by XPS according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] The core of DC arrester is ZnO varistor. Under normal working conditions, DC arrester is connected in parallel with power equipment and needs to withstand the system voltage to age. In the past, the aging state of arrester could be judged by monitoring the leakage current flowing through the arrester, that is, the larger the leakage current, the more serious the aging. However, the current stable DC arrester decreases during the aging process, so the physical and chemical testing method of this scheme is given. Aging is judged by microstructural changes.

[0019] Example 1 like Figure 1 As shown, a method for evaluating the aging state of a zinc oxide varistor for a DC lightning arrester comprises: S1. Obtain a zinc oxide varistor sample for a DC lightning arrester for aging status evaluation test; wherein a single side of the zinc oxide varistor sample for a DC lightning arrester is covered with parallel silver electrodes, and a test channel is reserved in the middle of the single side.

[0020] S2. Performing X-ray diffraction spectrum and X-ray photoelectron spectrum tests on the test channel respectively to obtain the ZnO (002) crystal plane and Zn2p orbital binding energy when not aged.

[0021] S3. Performing accelerated aging tests for zinc oxide varistor samples for DC lightning arresters at different preset time lengths to obtain test channels with different aging degrees; wherein the accelerated aging test includes applying a DC aging voltage to parallel silver electrodes while heating the zinc oxide varistor samples for DC lightning arresters.

[0022] S4. Perform X-ray diffraction spectroscopy and X-ray photoelectron spectroscopy tests on the test channels with different aging degrees to obtain the ZnO (002) crystal plane and Zn2p orbital binding energy at different aging degrees; determine the degree of deviation of the ZnO (002) crystal plane and Zn2p orbital binding energy at different aging degrees relative to the ZnO (002) crystal plane and Zn2p orbital binding energy when not aged, as the aging status evaluation result of the zinc oxide varistor.

[0023] As an optional solution, in step S4, heating the zinc oxide varistor sample for DC lightning arrester includes: When heating the zinc oxide varistor sample for DC lightning arrester, the zinc oxide varistor sample for DC lightning arrester is placed on an alumina heating plate, and the zinc oxide varistor sample for DC lightning arrester is heated by the alumina heating plate.

[0024] like Figure 2 As shown, as an optional scheme, in step S1, one side of the zinc oxide varistor sample for DC lightning arrester is covered with parallel silver electrodes; wherein, the surface of the zinc oxide varistor for DC lightning arrester is clean and smooth, and the parallel silver electrodes are obtained by coating one side of the zinc oxide varistor sample for DC lightning arrester by ion sputtering or low-temperature silver paste coating.

[0025] As an optional solution, in step S1, the width of the test channel is 0.5-1 mm.

[0026] As an optional solution, in step S1 and step S4, when performing X-ray diffraction spectroscopy, it is carried out as follows: X-ray diffraction (XRD) tests were performed using an X-ray diffractometer; the scanning range of the X-ray diffractometer was 10∼80°, the scanning speed was 4° / min, the step length was less than or equal to 0.02°, Cu target radiation was used, the operating voltage was 40 kV, and the diffraction peak of the ZnO (002) crystal plane was obtained.

[0027] As an optional solution, in step S1 and step S4, when performing X-ray photoelectron spectroscopy (XPS) testing, the following method is used: X-ray photoelectron spectroscopy testing was performed using an X-ray photoelectron spectrometer; the test binding energy range of the X-ray photoelectron spectrometer was 0~1350 eV, with a step size of less than or equal to 0.1 eV, to obtain the orbital peak of Zn2p.

[0028] As an optional solution, in step S3, when applying a DC aging voltage to the parallel silver electrodes, the DC aging voltage is applied to one side of the parallel silver electrodes, and the other side of the parallel silver electrodes is grounded. The DC aging voltage applied is 0.8-0.9 U 1mA, U 1mA is the voltage corresponding to a current of 1 mA flowing through the channel. U 1mA takes 200V. When heating the zinc oxide varistor sample for DC lightning arrester, the aging temperature is set to 100℃~180℃. The accelerated aging time is selected according to the actual situation, for example, 18h, 232h, etc., or 50h, 100h, 150h, 200h, etc.

[0029] As an optional solution, in step S4, the test position of XRD and XPS of the aged zinc oxide varistor ceramic is the aging channel, which is basically consistent with the test position of the unaged sample; the deviation degree of the binding energy of the ZnO (002) crystal plane and the Zn2p orbital at different aging degrees relative to the ZnO (002) crystal plane and the Zn2p orbital binding energy when not aged is determined as the aging state evaluation result of the zinc oxide varistor, including: The binding energies of the ZnO (002) crystal plane and Zn2p orbital at different aging levels are compared with those of the corresponding unaged ZnO (002) crystal plane and Zn2p orbital. If the diffraction peak of the ZnO (002) crystal plane and the orbital peak position of the Zn2p orbital binding energy remain unchanged, it is determined that the aging degree of the zinc oxide varistor used in DC lightning arresters is small; If the diffraction peak of the ZnO (002) crystal plane decreases by 0.02° or more, or the orbital peak of the Zn2p orbital binding energy decreases by more than 0.5 eV, it is judged that the aging degree of the zinc oxide varistor used in DC lightning arresters is serious.

[0030] In the preferred embodiment, the diffraction peaks and Zn2p orbital peaks of the ZnO (002) crystal plane at different aging times are obtained by XRD and XPS tests, and the diffraction peaks and Zn2p orbital peaks of the ZnO (002) crystal plane without aging and at different aging times are normalized respectively; the normalized ZnO (002) diffraction peaks and Zn2p orbital peaks of the zinc oxide varistor are compared with the peak positions of the unaged ones, as shown in FIG. Figure 3 and Figure 4 As shown; Figure 3 In the figure, the position of the ZnO (002) diffraction peak remains basically unchanged after aging for 18 h, which indicates that the aging degree of the zinc oxide varistor used in DC lightning arresters is relatively small; Figure 3 After aging for 232 h, the ZnO (002) diffraction peak decreased by 0.02°. Figure 4 If the Zn2p orbit peak shows a decrease of more than 0.7 eV after aging for 232 h, it is judged that the aging degree of the zinc oxide varistor used in DC lightning arrester is serious.

[0031] It should be noted that the electrical performance of zinc oxide varistors for DC lightning arresters is controlled by grain boundary barriers, which are composed of depletion layers and grain boundary interface states. The aging of ZnO varistors is mainly due to two physical processes: the spatial rearrangement of the depletion layer by the migration and diffusion of ions inside the grain boundary barrier, and the neutralization of the grain boundary migration ions and grain boundary interface states. When the depletion layer ions migrate significantly, the ZnO lattice will be distorted, resulting in a decrease in the ZnO (002) diffraction peak; at the same time, when the mobile zinc filling in the depletion layer is neutralized with the grain boundary interface states, the grain boundary interface states will be consumed, the corresponding Zn ions will be reduced, and the binding energy of the Zn2p orbital peak will be reduced.

[0032] Therefore, if the position of the ZnO (002) diffraction peak remains basically unchanged, it means that the degree of ion migration is weak; if the position of the Zn2p orbital peak remains basically unchanged, the mobile zinc interstitial ions in the grain boundary depletion layer are basically not neutralized with the grain boundary interface states, and the aging degree of the ZnO varistor is small. On the contrary, if the position of the ZnO (002) diffraction peak moves significantly to the direction of small angles, the binding energy of the Zn2p orbital peak decreases significantly, the degree of ion migration is intense, and there is a significant neutralization phenomenon between the grain boundary interface states and the mobile zinc interstitial ions in the depletion layer. At this time, the ZnO varistor undergoes irreversible degradation, which corresponds to the serious aging of the DC arrester.

[0033] In addition, the more the XRD diffraction peak of the ZnO lattice moves to a smaller angle, the more severe the lattice distortion, the more significant the ion migration behavior, the more the Zn2p orbital binding energy tested by XPS decreases, and the more significant the surface Zn reduction reaction, that is, the more obvious the interface state consumption.

[0034] Example 2 Based on Example 1, this Example 2 provides specific experimental parameters, wherein: In step S1, the width of the test channel is 0.5 mm.

[0035] In step S1 and step S4, when performing X-ray diffraction spectrum, the step size of the X-ray diffractometer is 0.01° and the step size of the X-ray photoelectron spectrometer is 0.05 eV.

[0036] In step S3, the DC aging voltage applied is 160 V. The aging temperature is set to 100°C.

[0037] Example 3 Based on Example 1, this Example 3 provides specific experimental parameters, wherein: In step S1, the width of the test channel is 1 mm.

[0038] In step S1 and step S4, when performing X-ray diffraction spectrum, the step size of the X-ray diffractometer is 0.02° and the step size of the X-ray photoelectron spectrometer is 0.1 eV.

[0039] In step S3, the DC aging voltage applied is 180 V and the aging temperature is set to 180°C.

[0040] Example 4 Based on Example 1, this Example 4 provides specific experimental parameters, wherein: In step S1, the width of the test channel is 0.8 mm.

[0041] In step S1 and step S4, when performing X-ray diffraction spectrum, the step size of the X-ray diffractometer is 0.01° and the step size of the X-ray photoelectron spectrometer is 0.05 eV.

[0042] In step S3, the DC aging voltage applied is 170 V. The aging temperature is set to 150°C.

[0043] Example 5 Based on Example 1, this Example 5 provides specific experimental parameters, wherein: In step S1, the width of the test channel is 0.9 mm.

[0044] In step S1 and step S4, when performing X-ray diffraction spectrum, the step size of the X-ray diffractometer is 0.01° and the step size of the X-ray photoelectron spectrometer is 0.1 eV.

[0045] In step S3, the DC aging voltage applied is 170 V and the aging temperature is set to 170°C.

[0046] Example 6 Based on Example 1, this Example 6 provides specific experimental parameters, wherein: In step S1, the width of the test channel is 0.5 mm.

[0047] In step S1 and step S4, when performing X-ray diffraction spectrum, the step size of the X-ray diffractometer is 0.02° and the step size of the X-ray photoelectron spectrometer is 0.08 eV.

[0048] In step S3, the DC aging voltage applied is 160 V. The aging temperature is set to 130°C.

[0049] Example 7 Based on Example 1, this Example 7 provides specific experimental parameters, wherein: In step S1, the width of the test channel is 0.9 mm.

[0050] In step S1 and step S4, when performing X-ray diffraction spectrum, the step size of the X-ray diffractometer is 0.01° and the step size of the X-ray photoelectron spectrometer is 0.1 eV.

[0051] In step S3, the DC aging voltage applied is 180 V. The aging temperature is set to 180°C.

[0052] Example 8 Based on Example 1, this Example 8 provides specific experimental parameters, wherein: In step S1, the width of the test channel is 1 mm.

[0053] In step S1 and step S4, when performing X-ray diffraction spectrum, the step size of the X-ray diffractometer is 0.02° and the step size of the X-ray photoelectron spectrometer is 0.02 eV.

[0054] In step S3, the DC aging voltage applied is 160 V. The aging temperature is set to 180°C.

[0055] Example 9 Based on Example 1, this Example 9 provides specific experimental parameters, wherein: In step S1, the width of the test channel is 0.7 mm.

[0056] In step S1 and step S4, when performing X-ray diffraction spectrum, the step size of the X-ray diffractometer is 0.01°. The step size of the X-ray photoelectron spectrometer is 0.01 eV.

[0057] In step S3, the DC aging voltage applied is 160 V. The aging temperature is set to 170°C.

[0058] Example 10 This embodiment 10 provides a system for implementing the method for evaluating the aging state of a zinc oxide varistor for a DC lightning arrester described in any of the above embodiments, including: An X-ray diffractometer is used to perform X-ray diffraction spectrum tests on the unaged test channels and the test channels with different aged degrees, so as to obtain the ZnO (002) crystal plane when unaged and the ZnO (002) crystal planes with different aged degrees; X-ray photoelectron spectrometer, used to perform X-ray photoelectron spectroscopy test on the unaged test channels and the test channels with different aged degrees, so as to obtain the Zn2p orbital binding energy when unaged and the Zn2p orbital binding energy with different aged degrees; The comparative evaluation module is used to determine the degree of deviation of the binding energy of the ZnO (002) crystal plane and the Zn2p orbital at different aging degrees relative to the binding energy of the ZnO (002) crystal plane and the Zn2p orbital when not aged, as the aging status evaluation result of the zinc oxide varistor.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for evaluating the aging state of a zinc oxide varistor for a DC lightning arrester, characterized in that: include: Obtain a zinc oxide varistor sample for a DC lightning arrester for an aging status evaluation test; wherein a single side of the zinc oxide varistor sample for a DC lightning arrester is covered with parallel silver electrodes, and a test channel is reserved in the middle of the single side; Performing X-ray diffraction spectrum and X-ray photoelectron spectrum tests on the test channel respectively to obtain the ZnO (002) crystal plane and Zn2p orbital binding energy when not aged; Performing accelerated aging tests of zinc oxide varistor samples for DC lightning arresters for different preset time lengths to obtain test channels with different aging degrees; wherein the accelerated aging test includes applying a DC aging voltage to parallel silver electrodes while heating the zinc oxide varistor samples for DC lightning arresters; X-ray diffraction spectra and X-ray photoelectron spectroscopy tests were performed on the test channels with different aging degrees to obtain the binding energies of the ZnO (002) crystal plane and the Zn2p orbital at different aging degrees; the degree of deviation of the binding energies of the ZnO (002) crystal plane and the Zn2p orbital at different aging degrees relative to those of the ZnO (002) crystal plane and the Zn2p orbital when not aged was determined as the aging status evaluation result of the zinc oxide varistor.

2. The method for evaluating the aging state of a zinc oxide varistor for a DC lightning arrester according to claim 1, characterized in that: Heating of zinc oxide varistor samples for DC lightning arresters, including: When heating the zinc oxide varistor sample for DC lightning arrester, the zinc oxide varistor sample for DC lightning arrester is placed on an alumina heating plate, and the zinc oxide varistor sample for DC lightning arrester is heated by the alumina heating plate.

3. The method for evaluating the aging state of a zinc oxide varistor for a DC lightning arrester according to claim 1, characterized in that: A single side of the zinc oxide varistor sample for DC lightning arrester is covered with parallel silver electrodes; wherein the parallel silver electrodes are obtained by coating a single side of the zinc oxide varistor sample for DC lightning arrester by ion sputtering or low-temperature silver paste coating.

4. The method for evaluating the aging state of a zinc oxide varistor for a DC lightning arrester according to claim 1, characterized in that: The width of the test channel is 0.5-1 mm.

5. The method for evaluating the aging state of a zinc oxide varistor for a DC lightning arrester according to claim 1, characterized in that: When performing X-ray diffraction spectroscopy, proceed as follows: X-ray diffraction spectrum test was carried out by X-ray diffractometer; wherein, the scanning range of the X-ray diffractometer was 10∼80°, the scanning speed was 4° / min, the step size was less than or equal to 0.02°, Cu target radiation was used, the working voltage was 40 kV, and the diffraction peak of the ZnO (002) crystal plane was obtained.

6. The method for evaluating the aging state of a zinc oxide varistor for a DC lightning arrester according to claim 1, characterized in that: When performing X-ray photoelectron spectroscopy testing, proceed as follows: X-ray photoelectron spectroscopy testing was performed using an X-ray photoelectron spectrometer; the test binding energy range of the X-ray photoelectron spectrometer was 0~1350 eV, with a step size of less than or equal to 0.1 eV, to obtain the orbital peak of Zn2p.

7. The method for evaluating the aging state of a zinc oxide varistor for a DC lightning arrester according to claim 1, characterized in that: When a DC aging voltage is applied to the parallel silver electrodes, the DC aging voltage is applied to one side of the parallel silver electrodes, and the other side of the parallel silver electrodes is grounded. The applied DC aging voltage is 0.8~0.9 U 1mA, U 1mA is the voltage corresponding to a current of 1 mA flowing through the channel.

8. The method for evaluating the aging state of a zinc oxide varistor for a DC lightning arrester according to claim 1, characterized in that: When heating the zinc oxide varistor samples for DC lightning arresters, the aging temperature is set to 100℃~180℃.

9. The method for evaluating the aging state of a zinc oxide varistor for a DC lightning arrester according to claim 1, characterized in that: Determine the degree of deviation of the binding energy of the ZnO (002) crystal plane and the Zn2p orbital under different aging degrees relative to the binding energy of the ZnO (002) crystal plane and the Zn2p orbital when not aged, as the aging state evaluation result of the zinc oxide varistor, including: The binding energies of the ZnO (002) crystal plane and Zn2p orbital at different aging levels are compared with those of the corresponding unaged ZnO (002) crystal plane and Zn2p orbital; If the diffraction peak of the ZnO (002) crystal plane and the orbital peak position of the Zn2p orbital binding energy remain unchanged, it is determined that the aging degree of the zinc oxide varistor used in DC lightning arresters is small; If the diffraction peak of the ZnO (002) crystal plane decreases by 0.02° or more, or the orbital peak of the Zn2p orbital binding energy decreases by more than 0.5 eV, it is judged that the aging degree of the zinc oxide varistor used in DC lightning arresters is serious.

10. A system for implementing the method for evaluating the aging state of zinc oxide varistor for DC lightning arrester according to any one of claims 1 to 9, characterized in that: include: An X-ray diffractometer is used to perform X-ray diffraction spectrum tests on the unaged test channels and the test channels with different aged degrees, so as to obtain the ZnO (002) crystal plane when unaged and the ZnO (002) crystal planes with different aged degrees; X-ray photoelectron spectrometer, used to perform X-ray photoelectron spectroscopy test on the unaged test channels and the test channels with different aged degrees, so as to obtain the Zn2p orbital binding energy when unaged and the Zn2p orbital binding energy with different aged degrees; The comparative evaluation module is used to determine the degree of deviation of the binding energy of the ZnO (002) crystal plane and the Zn2p orbital at different aging degrees relative to the binding energy of the ZnO (002) crystal plane and the Zn2p orbital when not aged, as the aging status evaluation result of the zinc oxide varistor.

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