CN113960424A - Continuous lightning deterioration evaluation method for valve plate of lightning arrester - Google Patents
Continuous lightning deterioration evaluation method for valve plate of lightning arrester Download PDFInfo
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- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
- G01R31/1236—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of surge arresters
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Abstract
The invention discloses a method for evaluating continuous lightning stroke degradation of a valve plate of a lightning arrester, which comprises the following steps: acquiring a plurality of lightning arrester valve plates, and testing initial electrical appliance parameters of each lightning arrester valve plate; configuring lightning stroke test conditions of each lightning arrester valve plate; each lightning stroke test condition corresponds to a current amplitude, a current impact time interval and a current continuous impact frequency; the lightning stroke test conditions of different lightning arrester valve plates to be tested are different; carrying out simulation lightning stroke test on each lightning arrester valve plate according to the lightning stroke test condition corresponding to each lightning arrester valve plate; and testing the second electrical parameter of each lightning arrester valve plate after the lightning stroke simulation test, comparing the second electrical parameter of each lightning arrester with the initial electrical parameter, and determining the deterioration degree of each lightning arrester valve plate according to the comparison result. By implementing the method, the deterioration degree of the valve plate of the lightning arrester after being subjected to the lightning strike currents with different intensities, different lightning strike time and different lightning strike times of continuous lightning strikes can be evaluated.
Description
Technical Field
The invention relates to the technical field of power grids, in particular to a continuous lightning stroke degradation evaluation method for a valve plate of a lightning arrester.
Background
Zinc oxide arresters are widely used in power distribution networks due to their good non-linear characteristics. However, the power system is subjected to lightning strikes for multiple times in the operation process, and the lightning arrester is degraded to different degrees by different lightning strike times, intervals of the lightning strike times and lightning current amplitude in each lightning strike. The deterioration and even damage of the valve plate of the lightning arrester caused by continuous lightning strike can affect the reliability of power supply of a power grid, so that in order to improve the working stability of the zinc oxide lightning arrester, the deterioration degree of the valve plate of the lightning arrester after the continuous lightning strike needs to be evaluated.
Disclosure of Invention
The embodiment of the invention provides a continuous lightning stroke degradation evaluation method for an arrester valve plate, which can evaluate the degradation degree of the arrester valve plate after continuous lightning stroke.
An embodiment of the invention provides a method for evaluating continuous lightning stroke degradation of a valve plate of a lightning arrester, which comprises the following steps:
acquiring a plurality of lightning arrester valve plates, and testing initial electrical appliance parameters of each lightning arrester valve plate;
configuring lightning stroke test conditions of each lightning arrester valve plate; each lightning stroke test condition corresponds to a current amplitude, a current impact time interval and a current continuous impact frequency; the lightning stroke test conditions of different lightning arrester valve plates to be tested are different;
carrying out simulation lightning stroke test on each lightning arrester valve plate according to the lightning stroke test condition corresponding to each lightning arrester valve plate;
and testing the second electrical parameter of each lightning arrester valve block after the lightning stroke simulation test, comparing the second electrical parameter of each lightning arrester valve block with the initial electrical parameter, and determining the deterioration degree of each lightning arrester valve block according to the comparison result.
Further, the method also comprises the following steps: comparing the micro crystal structure of each lightning arrester valve plate before the lightning simulation test with the micro crystal structure after the lightning simulation test, and determining the deterioration degree of each lightning arrester valve plate according to the comparison result.
Further, compare the second electrical apparatus parameter and the initial electrical apparatus parameter of each arrester valve block, specifically include:
comparing the 1mA reference voltage, the leakage current, the capacitance and the characteristic voltage of each lightning arrester valve block after the lightning stroke simulation test with the initial 1mA reference voltage, the initial leakage current, the initial capacitance and the initial characteristic voltage of each lightning arrester valve block.
Further, the method also comprises the following steps: and comparing the second electrical appliance parameters of the lightning protection valve plates with different current amplitudes and the same current impact time interval and the same current continuous impact times.
Further, the method also comprises the following steps: and comparing the second electrical appliance parameters between the lightning protection valve plates with different current impact time intervals but same current amplitude and current continuous impact times.
Further, the method also comprises the following steps: and comparing the second electrical appliance parameters of the lightning protection valve plates with different current continuous impact times, the current impact time interval and the current amplitude being the same.
The embodiment of the invention has the following beneficial effects:
the embodiment of the invention discloses a continuous lightning stroke degradation evaluation method for a valve plate of a lightning arrester, which sets different lightning stroke test conditions for each valve plate of the lightning arrester, and tests the change of electrical appliance parameters of each valve plate of the lightning arrester under the simulated lightning stroke test of different lightning stroke test conditions, thereby realizing the evaluation of the degradation degree of the valve plate of the lightning arrester after being subjected to the continuous lightning strokes of different intensities of lightning current, different lightning stroke time and different lightning stroke times.
Drawings
Fig. 1 is a schematic flow chart of a method for evaluating continuous lightning strike degradation of an arrester valve plate according to an embodiment of the invention.
Fig. 2 is a view of a structure of a micro-crystal of a valve plate of an arrester before and after a simulated lightning strike test according to an embodiment of the invention.
Fig. 3 is a normalized volt-ampere characteristic curve diagram of a valve plate of an arrester according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1, an embodiment of the present invention provides a method for evaluating degradation of a lightning arrester valve plate by continuous lightning strike, which at least includes:
step S101: and acquiring a plurality of arrester valve plates, and testing initial electrical appliance parameters of the arrester valve plates.
S102, configuring lightning stroke test conditions of each lightning arrester valve plate; each lightning stroke test condition corresponds to a current amplitude, a current impact time interval and a current continuous impact frequency; the lightning stroke test conditions of different lightning arrester valve plates to be tested are different.
And S103, carrying out simulated lightning stroke test on each lightning arrester valve plate according to the lightning stroke test condition corresponding to each lightning arrester valve plate.
And S104, testing the second electrical appliance parameters of the valve plates of the arresters after the lightning stroke simulation test, comparing the second electrical appliance parameters of the valve plates of the arresters with the initial electrical appliance parameters, and determining the deterioration degree of the valve plates of the arresters according to the comparison result.
For step S101, preferably, the obtained initial electrical parameters of each lightning arrester valve plate are the same, and the initial electrical parameters include: the device comprises an initial direct current 1mA reference voltage, an initial leakage current, an initial current amount and an initial characteristic voltage; for the initial characteristic voltage: dividing the current in the initial volt-ampere characteristic curve of the lightning arrester valve plate by the sectional area of the lightning arrester valve plate to obtain the current density (A/cm)2) Dividing the voltage in the initial volt-ampere characteristic curve by the height of the valve plate to obtain a potential gradient (kV/cm) according to the current density (A/cm)2) And potential gradient (kV/cm) to obtain a normalized voltammogram as shown in fig. 3. The normalized voltammogram is subjected to an extraction characteristic value process, illustratively 0.1mA/cm2,1mA/cm2,2mA/cm2The potential gradient value corresponding to the current density is used as the initial characteristic voltage.
For step S102, because in an actual situation, lightning strike conditions are variable, current amplitudes during lightning strikes, interval time between different lightning strikes and different conditions can occur at different times of the lightning strikes, in order to evaluate the deterioration degree of the valve plate of the lightning arrester under different types of lightning strikes, different lightning strike test conditions are set for each valve plate of the lightning arrester to correspond to different lightning strike conditions;
schematically, in the present invention, the set current amplitude (amplitude of current in simulating lightning stroke) includes: 5kA, 10kA, 20kA, 50 kA; the set current surge time interval (the interval time between different lightning strikes when simulating lightning strikes) includes: 10ms, 20ms, 50ms, 100ms, 300ms, 500 ms; the number of continuous current surges (number of simulated lightning strikes) includes: 3 times, 5 times, 8 times and 10 times; and (4) arranging and combining the numerical values of the three aspects to form a plurality of lightning stroke test conditions. For example: a lightning strike test condition may be: the current amplitude is 5kA, the current impact time interval is 10ms, and the current continuous impact times are 3 times; another lightning strike test condition may be: the current amplitude is 5kA, the current impact time interval is 20ms, and the current continuous impact times are 5 times; therefore, each lightning stroke test condition is constructed by analogy.
And S103, carrying out simulated lightning stroke test on each lightning arrester valve plate according to each lightning stroke test condition constructed in the S102.
In step S104, in a preferred embodiment, the micro-crystal structure of each valve plate of the lightning arrester before the lightning strike simulation test is compared with the micro-crystal structure after the lightning strike simulation test, and the degradation degree of each valve plate of the lightning arrester is determined according to the comparison result.
In a preferred embodiment, the comparing the second electrical parameter of each lightning arrester valve plate with the initial electrical parameter specifically includes:
after the lightning stroke simulation test is carried out on each lightning arrester valve block, the reference voltage, the leakage current and the capacitance (for some lightning arrester valve blocks with better tolerance, after the impact current with weaker strength enters, the parameter changes such as the reference voltage of the valve block are possibly unobvious, and the capacitance changes after each impact tolerance, so that the deterioration degree of the lightning arrester valve block can be more comprehensively quantified by measuring the capacitance) and the characteristic voltage are compared with the initial 1mA reference voltage, the initial leakage current, the initial capacitance and the initial characteristic voltage of each lightning arrester valve block.
Specifically, in an actual situation, the deterioration degree of the valve plate of the lightning arrester after continuous lightning stroke can be evaluated in a parameter comparison and structure comparison mode;
the parameter comparison scheme is as follows: comparing the 1mA reference voltage of the lightning arrester valve block subjected to the lightning stroke simulation test with the initial 1mA reference voltage of the lightning arrester valve block, comparing the leakage current of the lightning arrester valve block subjected to the lightning stroke simulation test with the initial leakage current, comparing the capacitance of the lightning arrester valve block subjected to the lightning stroke simulation test with the initial capacitance, comparing the characteristic voltage of the lightning arrester valve block subjected to the lightning stroke simulation test with the initial characteristic voltage, detecting the change characteristic of the electrical appliance parameter, wherein the larger the change degree is, the larger the deterioration degree of the lightning arrester valve block is. Particularly, if the lightning arrester valve plate is subjected to direct current 1mA reference voltage before and after the lightning arrester valve plate is subjected to the lightning stroke simulation test, the leakage current and the capacitance change are not more than 5 percent and 0.1mA/cm2,1mA/cm2And 2mA/cm2And when the variation amplitude of the corresponding characteristic voltage does not exceed 5%, 3.5% and 2%, judging that the valve plate of the lightning arrester has good energy tolerance.
Scheme of structural alignment: the change of the microscopic crystal structure of the valve plate of the lightning arrester before and after the lightning stroke simulation test is observed through the SEM scanning electron microscope, so that the deterioration degree of the valve plate of the lightning arrester under different lightning stroke test conditions can be intuitively obtained. As schematically shown in fig. 2, fig. 2(a) shows an initial micro crystal structure of a valve sheet of an arrester before a simulated lightning strike test, and fig. 2(b) shows a micro crystal structure of the valve sheet of the arrester after the simulated lightning strike test.
In a preferred embodiment, further comprising: and comparing the second electrical appliance parameters of the lightning protection valve plates with different current amplitudes and the same current impact time interval and the same current continuous impact times. In the embodiment, the current amplitude is taken as a variable, the difference between the electrical parameters is compared with the lightning protection valve plate after the lightning protection valve plate is subjected to the simulated lightning stroke test with different current amplitudes, the influence degree of the factor of the current amplitude on each electrical parameter of the lightning protection valve plate is determined according to the change degree of each electrical parameter, and the larger the change degree of each electrical parameter is, the larger the influence degree of the current amplitude on the electrical parameter is.
In a preferred embodiment, further comprising: and comparing the second electrical appliance parameters between the lightning protection valve plates with different current impact time intervals but same current amplitude and current continuous impact times. In the embodiment, the current impact time interval is used as a variable, after the lightning protection valve plate is compared with simulated lightning stroke tests of different current impact time intervals, the influence degree of the factor of the current impact time interval on each electrical parameter of the lightning protection valve plate is determined according to the change degree of each electrical parameter, and the larger the change degree of the electrical parameter is, the larger the influence degree of the current impact time interval on the electrical parameter is.
In a preferred embodiment, further comprising: and comparing the second electrical appliance parameters of the lightning protection valve plates with different current continuous impact times, the current impact time interval and the current amplitude being the same. In the embodiment, the current continuous impact times are used as variables, after the lightning protection valve plate is compared with simulated lightning stroke tests of different current continuous impact times, the influence degree of the factor of the current continuous impact times on each electrical parameter of the lightning protection valve plate is determined according to the change degree of each electrical parameter, and the larger the change degree of the electrical parameter is, the larger the influence degree of the current impact time interval on the electrical parameter is.
In a preferred embodiment, the weight of each electrical parameter used for judging the deterioration performance of the valve plate of the lightning arrester under different simulated lightning stroke tests can be adjusted according to the influence degree of the current amplitude, the current impact time interval and the continuous impact frequency of the current on each electrical parameter of the valve plate of the lightning arrester, so as to obtain the optimal scheme for judging the continuous lightning stroke resistance of the valve plate of the lightning arrester.
While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.
Claims (6)
1. A method for evaluating the continuous lightning stroke degradation of a valve plate of an arrester is characterized by comprising the following steps:
acquiring a plurality of lightning arrester valve plates, and testing initial electrical appliance parameters of each lightning arrester valve plate;
configuring lightning stroke test conditions of each lightning arrester valve plate; each lightning stroke test condition corresponds to a current amplitude, a current impact time interval and a current continuous impact frequency; the lightning stroke test conditions of different lightning arrester valve plates to be tested are different;
carrying out simulation lightning stroke test on each lightning arrester valve plate according to the lightning stroke test condition corresponding to each lightning arrester valve plate;
and testing the second electrical parameter of each lightning arrester valve block after the lightning stroke simulation test, comparing the second electrical parameter of each lightning arrester valve block with the initial electrical parameter, and determining the deterioration degree of each lightning arrester valve block according to the comparison result.
2. The method for evaluating the deterioration of the valve plate of the lightning arrester by continuous lightning stroke according to claim 1, further comprising the following steps: comparing the micro crystal structure of each lightning arrester valve plate before the lightning simulation test with the micro crystal structure after the lightning simulation test, and determining the deterioration degree of each lightning arrester valve plate according to the comparison result.
3. The method for evaluating the continuous lightning stroke degradation of the valve plates of the lightning arrester of claim 1, wherein the step of comparing the second electrical parameter of each valve plate of the lightning arrester with the initial electrical parameter comprises the following steps:
comparing the 1mA reference voltage, the leakage current, the capacitance and the characteristic voltage of each lightning arrester valve block after the lightning stroke simulation test with the initial 1mA reference voltage, the initial leakage current, the initial capacitance and the initial characteristic voltage of each lightning arrester valve block.
4. The method for evaluating the deterioration of the valve plate of the lightning arrester by continuous lightning stroke according to claim 1, further comprising the following steps:
and comparing the second electrical appliance parameters of the lightning protection valve plates with different current amplitudes and the same current impact time interval and the same current continuous impact times.
5. The method for evaluating the deterioration of the valve plate of the lightning arrester by continuous lightning stroke according to claim 1, further comprising the following steps:
and comparing the second electrical appliance parameters between the lightning protection valve plates with different current impact time intervals but same current amplitude and current continuous impact times.
6. The method for evaluating the deterioration of the valve plate of the lightning arrester by continuous lightning stroke according to claim 1, further comprising the following steps:
and comparing the second electrical appliance parameters of the lightning protection valve plates with different current continuous impact times, the current impact time interval and the current amplitude being the same.
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