Limit energy tolerance test method for resistor disc of lightning arrester of direct current transfer switch
Technical Field
The invention relates to high-voltage maintenance equipment, in particular to a method for testing the limit energy tolerance of a resistor disc of a lightning arrester of a direct-current transfer switch.
Background
Because the energy absorption of the lightning arrester of the change-over switch is large, the number of used resistance cards is large, the resistance cards have certain dispersibility, and the limit energy of the resistance cards is found to be related to the designed energy margin and the operation reliability of the lightning arrester. The energy limit absorption capacity of the conventional lightning arrester is checked according to 2ms square waves, and is completely different from the impact current waveform on an actual change-over switch, and the actual energy equivalence is different, so that the test result cannot ensure that the energy absorption capacity of the lightning arrester of the direct current change-over switch meets the engineering requirement, and the lightning arrester of the direct current change-over switch fails due to insufficient energy configuration.
Disclosure of Invention
The invention provides a method for testing the ultimate energy tolerance of a resistor disc of a lightning arrester of a direct-current transfer switch, aiming at solving the technical problem that the ultimate energy tolerance test result of the existing resistor disc of the lightning arrester of the direct-current transfer switch is inaccurate.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a method for testing the limit energy tolerance of a resistor disc of a lightning arrester of a direct current transfer switch comprises the following steps:
an initial value measuring step: selecting no less than 30 new resistance sheets as test articles, measuring the direct current 1mA reference voltage, the leakage current under 0.75 time of the reference voltage and the residual voltage under the impact current of 500A operation of all the test articles, and recording the residual voltages as initial values;
energy injection test step: respectively carrying out energy injection tests on the N test samples, wherein each test sample test totals 67 groups, each group comprises 3 energy injection tests, the test interval between each group is subject to the condition that the test samples are cooled to the ambient temperature, and the test interval does not exceed the set time; after the energy injection of a plurality of groups is finished, measuring the direct current 1mA reference voltage and the leakage current of a test sample under 0.75 time of the reference voltage, operating the residual voltage under 500A impact current, and recording; completing the 1 st test;
in the 1 st round of test, the injection energy of the resistor disc is Q1(ii) a In the 2 nd round test, the injection energy of the resistor disc is Q2By analogy, in the nth round of test, the injected energy of the resistor disc is Qn;
And (3) test judgment:
if the n-th round of test is failed and the number of failed test samples exceeds 1, skipping the step of measuring the initial value, carrying out the n + 1-th round of energy tolerance test, injecting energyIs Qn+1=(1-10%)Qn;
If the n-th round of test is failed and the number of failed test samples is only 1, skipping the step of measuring the initial value, carrying out the n + 1-th round of energy tolerance test, wherein the injection energy is Qn+1=Qn;
If the nth run passes, and | (Q)n-Qn-1)/Qn-1|>5%, skipping the step of measuring the initial value, and carrying out the n +1 round energy tolerance test with the injection energy of Qn+1=(1+10%)Qn;
If the nth run passes, and | (Q)n-Qn-1)/Qn-1If the absolute value is less than or equal to 5 percent, the test is finished, and the resistance card limiting energy tolerance capacity Q is confirmed to be (Q)n+Qn-1)/2;
Wherein N and N are both positive integers;
the energy injection test step is respectively carried out under test waveforms with more than two wavelengths.
Further, the energy injection test step is sequentially performed under 7 test waveforms of 10ms, 40ms, 70ms, 100ms, 150ms, 200ms, and 300ms wavelengths.
Further, the test waveforms include voltage and current waveforms.
Further, the value of Q1 is selected from the following table:
wavelength time ms
|
10
|
40
|
70
|
100
|
150
|
200
|
300
|
Estimated rated energy Q1
|
65kJ
|
90kJ
|
105kJ
|
115kJ
|
125kJ
|
135kJ
|
150kJ |
Further, the failure of the test includes:
in the test process, any test article generates flashover or breakdown phenomena;
in the test process, the change of the direct current 1mA reference voltage of any test article and the residual voltage under the impact current of 500A operation exceeds +/-5% from the initial value; the leakage current at 0.75 times the reference voltage is greater than the initial value of 20 muA.
Further, the condition that the test passes comprises:
in the test process, any test article does not have flashover or breakdown phenomenon;
in the test process, the change of the direct current 1mA reference voltage of any test article and the residual voltage under the impact current of 500A operation is not more than +/-5 percent; leakage current of not more than 20 μ A at 0.75 times reference voltage
Compared with the prior art, the invention has the beneficial effects that:
according to the lightning arrester resistance card limit energy tolerance test method, test voltage and current waveforms consistent with actual working conditions are adopted, test operation steps of different times are carried out according to different test results, the direct current transfer switch lightning arrester limit energy tolerance value is obtained, energy design basis can be provided for the direct current transfer switch lightning arrester, the energy absorption capacity of the direct current transfer switch lightning arrester is guaranteed to meet engineering requirements, and faults of the direct current transfer switch lightning arrester caused by insufficient energy configuration are reduced.
Drawings
Fig. 1 is a flowchart of a method for testing the ultimate energy tolerance of a resistor disc of a lightning arrester of a direct current transfer switch according to an embodiment of the invention;
FIG. 2 is a schematic diagram of voltage and current waveforms for a wavelength of 100 ms.
Detailed Description
Example (b):
the technical solution of the present invention is further described below with reference to the accompanying drawings and examples.
The method for testing the ultimate energy tolerance of the resistor disc of the direct-current transfer switch arrester mainly comprises an initial value measuring step, an energy injection testing step and a test judging step, and the ultimate energy tolerance Q of the resistor disc can be accurately and effectively determined through the three steps of operation and can be used as an arrester energy design basis to ensure that the energy absorption capacity of the transfer switch arrester meets different engineering requirements.
Specifically, referring to fig. 1, the method for testing the ultimate energy tolerance of the resistor disc of the lightning arrester of the dc transfer switch provided in this embodiment specifically includes the following steps:
an initial value measuring step: confirming the model and the size of a test article, selecting 30 new resistance cards as the test article, measuring the direct current 1mA reference voltage, the leakage current under 0.75 time of the reference voltage and the residual voltage under the impact current of 500A operation of all the resistance cards, and recording the residual voltages as initial values;
energy injection test step: the energy injection test was performed on 30 samples, respectively: 67 groups of tests are counted in each test sample, each group comprises 3 energy injection tests, the test interval between each group is based on the test sample cooled to the ambient temperature, and the test interval does not exceed 1 min. After the 1 st group, the 2 nd group, the 3 rd group, the 5 th group, the 10 th group, the 20 th group, the 30 th group, the 40 th group, the 50 th group, the 60 th group and the 67 th group are respectively subjected to energy injection, measuring the direct current 1mA reference voltage of a test article and the leakage current under 0.75 time of the reference voltage, operating the residual voltage under 500A impact current, and recording to finish the 1 st round of test;
in the 1 st round of test, the injection energy of the resistor disc is Q1(ii) a In the 2 nd round test, the injection energy of the resistor disc is Q2By analogy, in the nth round of test, the injected energy of the resistor disc is Qn。
The energy injection test step is sequentially carried out under 7 test waveforms with the wavelengths of 10ms, 40ms, 70ms, 100ms, 150ms, 200ms and 300ms, wherein the test waveforms comprise voltage waveforms and current waveforms, and typical waveforms are shown in fig. 2.
And (3) test judgment:
if the n-th round of test is failed and the number of failed test samples exceeds 1, skipping to the second step to carry out the n + 1-th round of energy tolerance test, wherein the injection energy is Qn+1=(1-10%)Qn。
If the n-th round of test is failed and the number of the failed test samples is only 1, skipping to the second step to carry out the n + 1-th round of energy tolerance test, wherein the injection energy is Qn+1=Qn。
If the nth run passes, and | (Q)n-Qn-1)/Qn-1|>5 percent, skipping to the second step to carry out the n +1 round energy tolerance test, wherein the injection energy is Qn+1=(1+10%)Qn。
If the nth run passes, and | (Q)n-Qn-1)/Qn-1If the absolute value is less than or equal to 5 percent, the test is finished, and the resistance card limiting energy tolerance capacity Q is confirmed to be (Q)n+Qn-1)/2。
Specifically, the value of Q1 is selected from the following table,
the test fails, and the conditions comprise:
1) in the test process, any test article generates flashover or breakdown phenomena;
2) in the test process, the change of the direct current 1mA reference voltage of any test article and the residual voltage under the impact current of 500A operation exceeds +/-5% from the initial value; the leakage current at 0.75 times the reference voltage is greater than the initial value of 20 muA.
The test passes, the conditions of which include:
1) in the test process, any test article does not have flashover or breakdown phenomenon;
2) in the test process, the change of the direct current 1mA reference voltage of any test article and the residual voltage under the impact current of 500A operation is not more than +/-5 percent; the leakage current at 0.75 times the reference voltage is not more than the initial value of 20 μ A.
According to the lightning arrester resistance card limit energy tolerance test method provided by the invention, test voltage and current waveforms consistent with actual working conditions are adopted, and test operation steps of different rounds are carried out according to different test results, so that the direct current transfer switch lightning arrester limit energy tolerance value is obtained, an energy design basis can be provided for the direct current transfer switch lightning arrester, the energy absorption capacity of the direct current transfer switch lightning arrester is ensured to meet engineering requirements, and faults of the direct current transfer switch lightning arrester caused by insufficient energy allocation are reduced.
The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention accordingly, and not to limit the protection scope of the present invention accordingly. All equivalent changes or modifications made in accordance with the spirit of the present disclosure are intended to be covered by the scope of the present disclosure.