Lightning arrester power frequency reference voltage test device and method

Abstract

The invention provides a lightning arrester power frequency reference voltage test device and method. The lightning arrester power frequency reference voltage test device comprises a boosting transformer, a coarse adjustment voltage regulator and a fine adjustment voltage regulator. The coarse adjustment voltage regulator, the fine adjustment voltage regulator and the input end of the boosting transformer form a series loop; the output end of the boosting transformer and the lightning arrester to be tested form a series loop, and the output voltages of the coarse adjustment voltage regulator and the fine adjustment voltage regulator are adjustable; the tester is used for measuring the real-time resistive current and the power frequency reference voltage of the lightning arrester to be tested. According to the invention, the precision of the voltage applied to the lightning arrester is improved, and the safety of the lightning arrester experiment process is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of power frequency reference voltage test of lightning arresters for distribution network lines, and in particular relates to a power frequency reference voltage test device and method for lightning arresters. Background Art

[0002] In the process of lightning arrester design, development, production to final use and delivery, the power frequency reference voltage test is an important part of the many lightning arrester tests. It needs to be tested frequently. In addition, lightning arresters are used in large quantities. Usually, only single-branch testing can be carried out, and the testing time is long, which seriously affects the detection efficiency.

[0003] The usual test method is to prepare a lightning arrester sample and matching power frequency voltage regulating components, power frequency boost components, and zinc oxide lightning arrester live tester. Ground one end of the sample and connect the other end to the power frequency boost output terminal. Control the output voltage of the voltage regulator and detect the voltage applied to the lightning arrester sample and the power frequency current flowing through the lightning arrester at the same time. When it is detected that the current flowing through the lightning arrester is close to 1mA, it is necessary to slowly apply the voltage value until it reaches 1mA. At the same time, read the voltage and current values ​​applied to the lightning arrester. If the step amount of the applied voltage is too large, the applied voltage will exceed the voltage value corresponding to the actual 1mA, making the test result larger and reducing the measurement accuracy of the equipment.

[0004] According to the properties of zinc oxide arresters, when the leakage current flowing through the arrester reaches 1mA, the current curve will have an "inflection point". If the applied voltage continues to increase by a small amplitude, the current flowing through the arrester will increase exponentially. The large current flowing through the arrester will generate heat inside the arrester in a short period of time, which will reduce the service life of the arrester and even damage the arrester body. At the same time, the sudden increase in current will cause the system voltage to drop sharply, causing the control system to lose control, and will also cause overcurrent alarms and even burn out the equipment, and the test personnel will also be injured. Summary of the invention

[0005] The purpose of the present invention is to solve the deficiencies of the above-mentioned background technology and to provide a lightning arrester power frequency reference voltage test device and method to improve the accuracy of the voltage applied to the lightning arrester and ensure the safety of the lightning arrester test process.

[0006] The technical solution adopted by the present invention is: a lightning arrester power frequency reference voltage test device, including a step-up transformer, a coarse voltage regulator and a fine voltage regulator;

[0007] The coarse voltage regulator, the fine voltage regulator and the input end of the step-up transformer form a series circuit;

[0008] The output end of the step-up transformer forms a series circuit with the arrester to be tested.

[0009] The output voltage of the coarse and fine voltage regulators is adjustable;

[0010] The tester is used to measure the power frequency reference voltage of the arrester under test.

[0011] In the above technical solution, the lightning arrester to be tested is connected to a current-limiting resistor, and the current-limiting resistor is electrically connected to the output end of the step-up transformer to form a test branch.

[0012] In the above technical solution, the coarse voltage regulator includes a first voltage regulator; the two ends of the first voltage regulator serve as input ends of the coarse voltage regulator, which are used to be electrically connected to an external power supply; a slidable contact point is provided on the first voltage regulator, and one end of the first voltage regulator is connected to the slidable contact point; one end of the first voltage regulator is connected to the contact point, serving as the output end of the coarse voltage regulator.

[0013] In the above technical solution, the fine-tuning voltage regulator includes a second voltage regulator and a step-down transformer; the two ends of the second voltage regulator serve as input ends of the fine-tuning voltage regulator, which are used to be electrically connected to an external power supply; a sliding contact point is provided on the second voltage regulator, and one end of the second voltage regulator is connected to the sliding contact point, serving as the input end of the step-down transformer; the output end of the step-down transformer serves as the output end of the fine-tuning voltage regulator.

[0014] In the above technical solution, the input end of the fine-adjusting voltage regulator and the input end of the coarse-adjusting voltage regulator are connected to the same external power supply.

[0015] In the above technical solution, the lightning arrester to be tested includes several ones, each of which is connected in series with the corresponding current limiting resistor to form multiple test branches, and all the test branches are connected to the output end of the step-up transformer; at the same time, the current passing through each test branch and the voltage signal at the input end of the step-up transformer are all connected to the tester, and the tester is used to detect the resistive current and the power frequency reference voltage of the lightning arrester.

[0016] In the above technical solution, the high voltage tail ends of the tester and the step-up transformer are both grounded.

[0017] The present invention also provides a lightning arrester power frequency reference voltage test method, which is implemented based on the lightning arrester power frequency reference voltage test device described in the above technical solution, and includes the following steps:

[0018] The initial output voltage of the coarse and fine regulators is zero;

[0019] First, gradually increase the output voltage of the coarse voltage regulator;

[0020] According to the phase angle of the current voltage at the input end of the step-up transformer and the current peak value of the arrester to be tested, the resistive current value of the arrester to be tested under the voltage is calculated in real time;

[0021] When it is detected that the resistive current value of the arrester to be tested reaches the first set value, the pressure-increasing operation of the coarse-adjusting voltage regulator is stopped; the output action of the fine-adjusting voltage regulator is started to gradually increase its output voltage;

[0022] When it is detected that the resistive current value of the arrester to be tested reaches the second set value, the current voltage of the arrester to be tested is calculated according to the voltage at the input end of the current step-up transformer and the resistive current value of the arrester to be tested as the power frequency reference voltage value of the arrester to be tested.

[0023] The beneficial effects of the present invention are as follows: the device design of the present invention realizes precise voltage control of the lightning arrester through a step-up transformer and an adjustable voltage regulator, can flexibly adjust the output voltage, is suitable for lightning arresters of different specifications, and improves the accuracy and reliability of the test.

[0024] Furthermore, the present invention can effectively limit the power frequency current flowing through the arrester by adding a current limiting resistor between the arrester to be tested and the step-up transformer, thereby avoiding damage to the arrester due to excessive current, thereby protecting the safety of equipment and test personnel.

[0025] Furthermore, the design of the coarse voltage regulator of the present invention uses a slidable contact point, which can achieve precise voltage regulation, improve operational flexibility, and can quickly adjust to a desired voltage value.

[0026] Furthermore, the design of the fine-tuning voltage regulator of the present invention uses a sliding contact point, which, in conjunction with a corresponding step-down transformer, can achieve more precise voltage regulation near the current voltage value, thereby improving operational flexibility, enhancing the precision control of the output voltage, and achieving precise regulation within a lower voltage range, thereby improving test accuracy.

[0027] Furthermore, the coarse voltage regulator and the fine voltage regulator of the present invention share the same external power supply, which simplifies equipment wiring, reduces overall costs, and ensures power supply stability, thereby improving test efficiency.

[0028] Furthermore, the present invention allows multiple arresters to be tested to be tested simultaneously, and the current limiting resistor corresponding to each arrester can prevent overcurrent, ensuring that each arrester can safely and reliably perform power frequency reference voltage measurement, thereby improving the flexibility and efficiency of the test.

[0029] Furthermore, the present invention grounds the high-voltage tails of the tester and the step-up transformer, thereby enhancing the safety of the system, preventing damage caused by static electricity or other electrical faults, and ensuring safety and stability during the test.

[0030] Furthermore, the present invention can accurately control the working state of the arrester to be tested by gradually increasing the voltage, and monitor the peak value of the power frequency current passing through each arrester in real time, thereby improving the safety and accuracy of the test.

[0031] Furthermore, the present invention can effectively prevent the arrester from being damaged by overcurrent during the test process by setting the first set value of 0.9mA. When this value is reached, the voltage is stopped from being increased substantially, and accurate voltage regulation is started to ensure that the arrester is within a safe voltage range, thereby reducing the risk of equipment failure. The present invention uses 1mA as the second set value, which is generally considered to be the working current standard of the arrester. By testing under this specific resistive current, it can be ensured that the measured voltage is more representative and reflects the performance of the arrester under normal working conditions. The present invention uses the same set value for multiple tests, which helps to improve the consistency of the test results and ensure that the test results of different batches of arresters can be compared with each other, thereby enhancing the reliability of the data. The present invention sets a clear resistive current value as the target of adjustment, so that the tester has clear guidance during the operation, reduces human errors, and improves the test efficiency. In practical applications, by recording the voltage values ​​at 0.9mA and 1mA, important data can be provided for subsequent performance analysis to help evaluate the long-term stability and reliability of the arrester. This set value design can adapt to different types of arresters, facilitate application in multiple test scenarios, and improve the versatility of the device. Testing based on this set value can provide feedback to R&D personnel, helping to identify performance bottlenecks of lightning arresters in actual applications, thereby promoting technological progress and product improvement.

[0032] Furthermore, the present invention is designed for multiple lightning arresters to be tested, and the voltage regulation is stopped when all lightning arresters reach the industrial frequency reference current, thereby ensuring the overall stability of the system, avoiding test unevenness caused by a single lightning arrester reaching the resistive current threshold, and improving the comprehensiveness of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the circuit structure of the device of the present invention;

[0034] Figure 2 It is a schematic diagram of the distribution of the arresters to be tested in a specific embodiment.

[0035] Among them, 1-external power switch, 2-first voltage regulator, 3-second voltage regulator, 4-step-down transformer, 5-step-up transformer, 6-current limiting resistor, 7-lightning arrester to be tested. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments to facilitate a clear understanding of the present invention, but they do not constitute a limitation on the present invention.

[0037] Example 1

[0038] like Figure 1As shown, a lightning arrester power frequency reference voltage test device of the present invention includes a step-up transformer 5, a coarse voltage regulator and a fine voltage regulator;

[0039] The coarse voltage regulator, the fine voltage regulator and the input end of the step-up transformer 5 form a series loop;

[0040] The output end of the step-up transformer 5 forms a series circuit with the arrester 7 to be tested.

[0041] The output voltage of the coarse and fine voltage regulators is adjustable;

[0042] The tester is used to measure the power frequency reference voltage of the arrester 7 to be tested.

[0043] Specifically, the lightning arrester 7 to be tested is electrically connected to the output end of the step-up transformer 5 via the current limiting resistor 6 to form a test branch.

[0044] Preferably, the resistance of the current limiting resistor 6 is 1 MΩ. If the resistive current flowing through the current limiting resistor 6 is 1 mA, the voltage across the protective resistor is 1 kV.

[0045] Specifically, the coarse-adjusting voltage regulator includes a first voltage regulator 2; two ends of the first voltage regulator 2 serve as input ends of the coarse-adjusting voltage regulator, and are used to be electrically connected to an external power supply; a slidable contact point is provided on the first voltage regulator 2, one end of the first voltage regulator 2 is connected to the slidable contact point, and the output voltage change of the coarse-adjusting voltage regulator is achieved by adjusting the position of the slidable contact point; one end of the first voltage regulator 2 is connected to the contact point, and serves as the output end of the coarse-adjusting voltage regulator.

[0046] Specifically, the fine-tuning voltage regulator includes a second voltage regulator 3 and a step-down transformer 4; both ends of the second voltage regulator 3 serve as input ends of the fine-tuning voltage regulator, and are used to be electrically connected to an external power supply; a sliding contact point is provided on the second voltage regulator 3, and one end of the second voltage regulator 3 is connected to the sliding contact point, serving as the input end of the step-down transformer 4; the output voltage change of the fine-tuning voltage regulator is achieved by adjusting the position of the sliding contact point; the output end of the step-down transformer 4 serves as the output end of the fine-tuning voltage regulator.

[0047] Preferably, the transformation ratio of the step-down transformer 4 is 220 / 10V, which can reduce the step voltage value input by the fine-adjustment voltage regulator by 22 times again, effectively improving the voltage adjustment accuracy applied to the arrester. The output step voltage of the fine-adjustment voltage regulator is basically consistent with the coarse-adjustment voltage regulator.

[0048] Specifically, the input end of the fine-adjusting voltage regulator and the input end of the coarse-adjusting voltage regulator are connected to the same external power supply.

[0049] Preferably, the input end of the fine-adjustment voltage regulator and the input end of the coarse-adjustment voltage regulator are electrically connected to the external power supply through an external power switch. The present invention can also set the rated voltage value of the lightning arrester, and the system will automatically call the real-time voltage detection value of the lightning arrester and automatically set the maximum protection voltage value to prevent unlimited voltage boost from causing system damage. That is, when the system determines that the real-time voltage detection value of the lightning arrester reaches the maximum protection voltage value, the voltage regulator is disconnected from the external power supply by controlling the external power switch 1.

[0050] like Figure 2 As shown, the lightning arrester 7 to be tested includes several ones, each of which is connected in series with the corresponding current limiting resistor 6 to form multiple test branches, and all the branches are connected to the output end of the step-up transformer 5. At the same time, the current passing through each test branch and the input voltage end voltage of the step-up transformer are respectively connected to the corresponding input port of the tester for detecting the resistive current and the power frequency reference voltage of the lightning arrester to be tested.

[0051] In this specific embodiment, there are 6 arresters 7 to be tested, including D1-D6. Each arrester is connected in series with a corresponding current limiting resistor 6R1-R6. The lower end of each arrester 7 to be tested is directly grounded or grounded through a zinc oxide live tester through a single-pole double-cut switch.

[0052] When conducting a DC reference voltage test, select direct grounding, and switch the step-up transformer to a DC high voltage generator to conduct a DC reference voltage test directly.

[0053] When measuring the power frequency reference voltage, choose to ground after passing through the zinc oxide live tester. The arrester to be tested is connected to the current limiting resistor, and the current limiting resistor is connected to the step-up transformer 5. The zinc oxide live tester has six current input ports and one voltage input port; the current flowing through the arrester and the input voltage signal of the step-up transformer are respectively connected to the corresponding ports of the tester.

[0054] The zinc oxide live tester calculates and processes the resistive current value of the arrester to be tested based on the input peak current of each branch and the phase angle data of the input voltage of the step-up transformer, and then calculates the test result of the power frequency reference voltage value based on the resistive current value of the arrester and the converted output voltage of the step-up transformer and the resistance value of the current limiting resistor. The resistive current value and the power frequency reference voltage value reading of the arrester to be tested can be displayed in real time through the program interface. The internal program is a conventional prior art.

[0055] The zinc oxide arrester live tester calculates the current voltage and resistive current of the arrester according to the output voltage of the step-up transformer and the current flowing through the arrester, and displays them through the program interface. Therefore, the operator can intuitively see the power frequency reference voltage value of the arrester when the resistive current value of the arrester to be tested is 1mA.

[0056] Specifically, the zinc oxide lightning arrester live tester and the high voltage tail end of the step-up transformer 5 are both grounded.

[0057] Example 2

[0058] The present invention also provides a lightning arrester power frequency reference voltage test method, which is implemented based on the lightning arrester power frequency reference voltage test device described in the above technical solution, and includes the following steps:

[0059] The initial output voltage of the coarse and fine regulators is zero;

[0060] First, gradually increase the output voltage of the coarse voltage regulator;

[0061] Real-time detection of the peak current flowing through the arrester to be tested, and calculation of the resistive current value of the arrester to be tested under the voltage according to the phase angle of the current voltage at the input end of the step-up transformer and the peak current of the arrester to be tested;

[0062] When it is detected that the resistive current value of the arrester to be tested reaches the first set value, the pressurization operation of the coarse-adjusting voltage regulator is stopped; the output action of the fine-adjusting voltage regulator is started to gradually increase its output voltage, and the resistive current value of the arrester to be tested is calculated in real time;

[0063] When it is detected that the resistive current value of the arrester to be tested reaches the second set value, the current voltage of the arrester to be tested is calculated according to the current voltage at the input end of the step-up transformer and the resistive current value of the arrester to be tested as the power frequency reference voltage value of the arrester to be tested.

[0064] The first set value is 0.9 mA, and the second set value is 1 mA.

[0065] Preferably, it is detected whether the positions of the two voltage regulators are at zero position, and the voltage regulators are controlled to return to zero. At the beginning of the test, both voltage regulators are at zero position, and the initial boost is carried out by the coarse voltage regulator, which is controlled to boost the voltage, and at the same time, the power frequency voltage value applied to the test piece and the resistive current value flowing through the arrester are detected. When the resistive current value reaches 0.9mA, the coarse voltage regulator is stopped from boosting, and the control system automatically switches to the fine voltage regulator to boost slowly. Due to the presence of the step-down transformer 4 between the fine voltage regulator and the boost test transformer, the step voltage is reduced by 22 times, and the power frequency voltage can be applied to the arrester more accurately, so that the resistive current value flowing through the arrester is 1mA.

[0066] Specifically, if the number of the lightning arresters 7 to be tested is greater than 1, the output voltage of the fine-tuning voltage regulator is stopped from being adjusted after the resistive current values ​​of all the lightning arresters 7 to be tested reach the second set value.

[0067] In this specific embodiment, the number of arresters 7 to be tested is 6. In the process of controlling the coarse voltage regulator to boost the voltage and monitoring the resistive current value flowing through the six arresters in real time, when it is detected that the resistive current value flowing through any arrester reaches 0.9mA, the boost control of the coarse voltage regulator is stopped, and the fine voltage regulator is automatically switched to slowly boost the voltage. Due to the presence of the step-down transformer 4 between the fine voltage regulator and the step-up test transformer, the step voltage is reduced by 22 times, and the power frequency voltage can be applied to the arrester more accurately, so that the resistive current value flowing through one of the arresters reaches 1mA first. The voltage when the resistive current value of the arrester reaches 1mA is measured by the tester as its power frequency reference voltage.

[0068] At this time, the resistive current flowing through other lightning arresters has not yet reached 1mA. Continue to adjust the fine-tuning voltage regulator to boost the voltage. First, due to the effect of the upper-end current limiting resistor 6, the continuously increasing output voltage of the step-up transformer 5 makes the resistive current flowing through the lightning arrester not increase significantly.

[0069] The output voltage of the step-up transformer 5 continues to rise, and finally the resistive current flowing through all the arresters reaches 1 mA, and then the external power supply is disconnected to stop the measurement. The tester measures the voltage of each arrester when the resistive current value reaches 1 mA as its power frequency reference voltage.

[0070] The voltage of the measuring system will not collapse due to the existence of the current limiting resistor 6, thus ensuring the stable operation of the system and the safety of the test personnel.

[0071] Since the present embodiment tests multiple lightning arresters in parallel, the same voltage is applied to the high-voltage end of the six lightning arresters. Due to the differences in the main bodies, the voltage value corresponding to the 1mA resistive current of the lightning arresters is different, that is, the "inflection points" of the lightning arresters are different. Therefore, during the voltage application process, the applied voltage will reach the "inflection point" voltage of the six lightning arresters in advance.

[0072] The resistive currents of the six arresters will reach 1mA successively, and the system will read the voltage value corresponding to the arrester resistive current of 1mA as its power frequency reference voltage. Since the resistive current flowing through other arresters has not yet reached 1mA, the system will continue to increase the voltage, with the goal of making the resistive current flowing through all arresters reach 1mA, and record the voltage value at the moment when the resistive current of each branch reaches 1mA. In this way, the voltage value of all arresters when the resistive current reaches 1mA is obtained.

[0073] Since the resistive current value flows through the current limiting resistor 6 at the same time, the voltage value actually applied to the arrester is subtracted from the voltage value divided by the high-voltage current limiting resistor 6. It is known that the resistance value of the high-voltage current limiting resistor 6 is 1MΩ, and the resistive current flowing through the current limiting resistor is 1mA, then the voltage drop across the current limiting resistor is 1kV. The voltage value actually applied to the arrester is the voltage value output by the step-up transformer 5 at this time minus the voltage drop of 1kV.

[0074] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A lightning arrester power frequency reference voltage test device, characterized in that: It includes a step-up transformer, a coarse voltage regulator and a fine voltage regulator; The coarse voltage regulator, the fine voltage regulator and the input end of the step-up transformer form a series circuit; The output end of the step-up transformer forms a series circuit with the arrester to be tested. The output voltage of the coarse and fine voltage regulators is adjustable; The tester is used to measure the power frequency reference voltage of the arrester under test.

2. The power frequency reference voltage test device for lightning arrester according to claim 1, characterized in that: The lightning arrester to be tested is electrically connected to the output end of the step-up transformer via a current limiting resistor to form a test branch.

3. The power frequency reference voltage test device for lightning arrester according to claim 1, characterized in that: The coarse voltage regulator includes a first voltage regulator; two ends of the first voltage regulator serve as input ends of the coarse voltage regulator and are used to be electrically connected to an external power supply; a slidable contact point is provided on the first voltage regulator, and one end of the first voltage regulator is connected to the slidable contact point; one end of the first voltage regulator is connected to the contact point and serves as an output end of the coarse voltage regulator.

4. The power frequency reference voltage test device for lightning arrester according to claim 3, characterized in that: The fine-tuning voltage regulator includes a second voltage regulator and a step-down transformer; the two ends of the second voltage regulator serve as input ends of the fine-tuning voltage regulator and are used to be electrically connected to an external power supply; a sliding contact point is provided on the second voltage regulator, and one end of the second voltage regulator is connected to the sliding contact point and serves as the input end of the step-down transformer; the output end of the step-down transformer serves as the output end of the fine-tuning voltage regulator.

5. A lightning arrester power frequency reference voltage test device according to claim 4, characterized in that: The input end of the fine-adjusting voltage regulator and the input end of the coarse-adjusting voltage regulator are connected to the same external power supply.

6. A lightning arrester power frequency reference voltage test device according to claim 2, characterized in that: The arresters to be tested include several ones, each of which is connected in series with a corresponding current-limiting resistor to form multiple test branches, and all the test branches are connected to the output end of the step-up transformer; at the same time, the current passing through each test branch and the voltage signal at the input end of the step-up transformer are all connected to the tester, and the tester is used to detect the resistive current and the power frequency reference voltage of the arrester.

7. A lightning arrester power frequency reference voltage test device according to claim 2, characterized in that: The high voltage tails of the tester and the step-up transformer are both grounded.

8. A lightning arrester power frequency reference voltage test method, characterized in that: The lightning arrester power frequency reference voltage test device according to any one of claims 1 to 7 is implemented, comprising the following steps: The initial output voltage of the coarse and fine regulators is zero; First, gradually increase the output voltage of the coarse voltage regulator; According to the phase angle of the current voltage at the input end of the step-up transformer and the current peak value of the arrester to be tested, the resistive current value of the arrester to be tested under the voltage is calculated in real time; When it is detected that the resistive current value of the arrester to be tested reaches the first set value, the pressure-increasing operation of the coarse-adjusting voltage regulator is stopped; the output action of the fine-adjusting voltage regulator is started to gradually increase its output voltage; When it is detected that the resistive current value of the arrester to be tested reaches the second set value, the current voltage of the arrester to be tested is calculated according to the voltage at the input end of the current step-up transformer and the resistive current value of the arrester to be tested as the power frequency reference voltage value of the arrester to be tested.

9. A lightning arrester power frequency reference voltage test method according to claim 8, characterized in that: The first set value is 0.9 mA, and the second set value is 1 mA.

10. A lightning arrester power frequency reference voltage test method according to claim 8, characterized in that: If the number of lightning arresters to be tested is greater than 1, the output voltage of the fine-tuning voltage regulator is stopped from being adjusted after the resistive current values ​​of all lightning arresters to be tested reach the second set value.

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