CN111352011B

CN111352011B - Tolerance characteristic test method, test circuit and design method of lightning protection insulator

Info

Publication number: CN111352011B
Application number: CN202010433590.2A
Authority: CN
Inventors: 陆佳政; 胡建平; 谢鹏康; 方针; 李波
Original assignee: Xiang-Electric Experiment And Research Technology Co Of Hunan Province
Current assignee: Hunan Disaster Prevention Technology Co ltd; Xiang-Electric Experiment And Research Technology Co Of Hunan Province
Priority date: 2020-05-21
Filing date: 2020-05-21
Publication date: 2020-10-27
Anticipated expiration: 2040-05-21
Also published as: WO2021232549A1; CN111352011A

Abstract

The utility model relates to a test method, a test circuit and a design method for the tolerance characteristic of a lightning protection insulator, wherein the test method comprises the steps of obtaining the impact energy absorbed by the whole lightning protection insulator under a first impact current wave; acquiring impact current and corresponding thermal stress under a second impact current wave; respectively acquiring power frequency reference voltage and leakage current corresponding to the first impulse current wave and the second impulse current wave; adjusting the impact current applied to the whole lightning protection insulator according to the comparison result of the power frequency reference voltage change rate and the leakage current; and circularly executing the steps until the obtained power frequency reference voltage change rates are all less than or equal to the set change rate, and the leakage currents are all less than or equal to the set leakage current, wherein the impact energy tolerance maximum value and the thermal stress tolerance maximum value correspond to the whole lightning protection insulator. Through the technical scheme, the response characteristic of the whole lightning protection insulator subjected to high-current direct lightning is truly simulated.

Description

Tolerance characteristic test method, test circuit and design method of lightning protection insulator

Technical Field

The embodiment of the disclosure relates to the technical field of electrical equipment testing, in particular to a method for testing tolerance characteristics of a lightning protection insulator, a testing circuit and a design method.

Background

With the development of economy, the construction speed of a power grid in China is gradually increased in recent years, and due to the fact that the transmission distance is long and the span range is wide, a power transmission line often passes through high-altitude mountain areas with complex terrains, the problems of lightning damage in summer and ice coating in winter are serious, and accidents such as tripping power failure and equipment damage caused by lightning stroke and ice coating flashover also occur occasionally. In order to improve the capability of the power transmission line for resisting lightning stroke and icing disasters, the lightning protection insulator can be adopted for protecting the lightning stroke and the icing disasters at present, and the lightning protection insulator mainly absorbs and releases lightning current energy by arranging a zinc oxide resistance chip sleeved on a lightning protection section of the lightning protection insulator and limits lightning overvoltage to prevent the power transmission line from tripping.

The method is limited by the output capability and the manufacturing technology of test equipment, the existing lightning protection equipment impulse current test is mainly carried out on a lightning protection equipment proportional unit or a single-chip zinc oxide resistance sheet lightning protection element, and the test result is multiplied by a proportional coefficient to simulate the energy tolerance and thermal stress tolerance characteristics of the whole lightning protection equipment under the lightning current impulse. But theoretical analysis and field operation results show that: during the impulse current test of the single zinc oxide resistor disc, the resistor disc is directly exposed in the air environment, and the multiple series resistor discs are sealed and packaged during the forming of the whole lightning protection device, so that the energy and pressure generated by the large current impact cannot be quickly released, and the impulse current tolerance of the whole lightning protection device is smaller than that of the single resistor disc, therefore, the impulse current tolerance characteristics of the single zinc oxide resistor disc and the proportional unit in the existing lightning protection device test method cannot simulate the actual situation of direct lightning current impact of the whole lightning protection insulator under the operation condition.

Disclosure of Invention

In view of this, the present disclosure provides a method, a circuit and a design method for testing the endurance characteristics of a lightning protection insulator, which truly simulate the response characteristics of the entire lightning protection insulator when subjected to a large-current direct lightning strike under the operation condition, and are beneficial to improving the safety and reliability of the field operation.

In a first aspect, an embodiment of the present disclosure provides a method for testing tolerance characteristics of a lightning protection insulator, including:

step S1, obtaining the impact current flowing through the whole lightning protection insulator under the first impact current wave and the residual voltage at the two ends of the whole lightning protection insulator, and obtaining the impact energy absorbed by the whole lightning protection insulator according to the impact current flowing through the whole lightning protection insulator under the first impact current wave and the residual voltage; acquiring impulse current flowing through the whole lightning protection insulator under the second impulse current wave and corresponding thermal stress;

step S2, respectively obtaining power frequency reference voltage and leakage current of the whole lightning protection insulator corresponding to the first impact current wave and the second impact current wave;

step S3, obtaining a power frequency reference voltage change rate before and after the whole lightning protection insulator impulse current test according to the power frequency reference voltage, and comparing the obtained leakage current with the leakage current corresponding to the whole lightning protection insulator before the impulse current is applied;

step S4, adjusting the impact current applied to the whole lightning protection insulator according to the power frequency reference voltage change rate and the comparison result of the leakage current;

and circularly executing the steps S1 to S4 until the change rates of the power frequency reference voltages are all less than or equal to the set change rate, and the leakage currents are all less than or equal to the impact energy tolerance maximum value and the thermal stress tolerance maximum value corresponding to the whole lightning protection insulator with the set leakage currents.

Optionally, the first shock current wave is 2.6/50

The second rush current is 4.0/10

A surge current wave.

Optionally, obtaining the impact energy absorbed by the integral lightning protection insulator according to the residual voltage and the impact current flowing through the integral lightning protection insulator under the first impact current wave comprises:

acquiring the impact energy absorbed by the whole lightning protection insulator according to the following formula:

wherein, W_{Whole piece}U (t) is a numerical expression of the waveform of the residual voltage under the first impact current wave and satisfies the requirement

I (t) is a numerical expression of the waveform of the first impulse current wave and satisfies

T is the duration of the first surge current wave, I₀Is the amplitude of the first impulse current wave, k is a waveform correction factor,

as a function of the attenuation coefficient of the wavefront,

is the attenuation coefficient of wave tail, c is constant,

the nonlinear coefficient of the zinc oxide resistance card for the whole lightning protection insulator is shown.

Optionally, the thermal stress corresponding to the whole lightning protection insulator under the second impulse current wave is obtained according to the following formula:

wherein, F_{Whole piece}The thermal stress corresponding to the whole lightning protection insulator, E is the elastic modulus of the zinc oxide resistance card for the whole lightning protection insulator,

The linear thermal expansion coefficient of the zinc oxide resistance card,

is Poisson's ratio, T, of the zinc oxide resistor disc_maxAnd T_minThe maximum value and the minimum value of the temperature of the zinc oxide resistance card after the second impact current wave acts are respectively obtained.

Optionally, the power frequency reference voltage change rate before and after the impact current test of the whole lightning protection insulator satisfies the following formula:

wherein,

the change rate of power frequency reference voltage, U, before and after the whole lightning protection insulator impulse current test₀And U_1mAAnd the power frequency reference voltages before and after the impact current test of the whole lightning protection insulator are respectively used.

Optionally, adjusting the impulse current applied to the entire lightning protection insulator according to the comparison result of the power frequency reference voltage change rate and the leakage current includes:

if the power frequency reference voltage change rate is smaller than or equal to a set change rate and the leakage current is smaller than or equal to a set leakage current, judging that the whole lightning protection insulator passes the impact energy and thermal stress test corresponding to the currently applied impact current, and increasing the impact current applied to the whole lightning protection insulator by a set proportion;

if the power frequency reference voltage change rate is greater than the set change rate or the leakage current is greater than the set leakage current, it is determined that the whole lightning protection insulator does not pass the impact energy and thermal stress test corresponding to the currently applied impact current, and the impact current applied to the whole lightning protection insulator is reduced by the set proportion.

In a second aspect, an embodiment of the present disclosure further provides a method for designing a lightning protection insulator, including:

acquiring the maximum impact energy tolerance value and the maximum thermal stress tolerance value according to the tolerance characteristic testing method of the lightning protection insulator in the first aspect;

and designing the number and specification size of the zinc oxide resistance cards for the whole lightning protection insulator according to the maximum impact energy tolerance value and the maximum thermal stress tolerance value.

Optionally, designing the number and the specification size of the zinc oxide resistor discs for the whole lightning protection insulator according to the impact energy tolerance maximum value and the thermal stress tolerance maximum value, wherein the designing comprises the following steps:

obtaining the maximum value of the impact energy of the single zinc oxide resistance card in the whole lightning protection insulator, which can bear the first impact current wave; wherein the maximum value of the impact energy of the single zinc oxide resistance chip enduring the first impact current wave satisfies the following calculation formula:

wherein, W_{Single sheet}For a single zinc oxide resistor disc to withstand the maximum value of the impact energy, W, of said first impact current wave_{Whole piece}Impact energy absorbed by the entire lightning protection insulator, N₀The number of the zinc oxide resistance cards adopted before the test of the whole lightning protection insulator;

the number of the zinc oxide resistance cards for the whole lightning protection insulator meets the following calculation formula:

wherein N is the number of the zinc oxide resistance cards for the whole lightning protection insulator, and W is₀The single zinc oxide resistance chip is corresponding to the impact energy of the first impact current wave;

the area parameters contained in the specification and the size of the zinc oxide resistance card for the whole lightning protection insulator meet the following calculation formula:

wherein S is an area parameter contained in the specification and the size of the zinc oxide resistance card for the whole lightning protection insulator, and S₀Area of the zinc oxide resistor disc adopted before the test of the whole lightning protection insulator, F₀And the thermal stress of the single zinc oxide resistance chip corresponding to the second impact current wave.

In a third aspect, an embodiment of the present disclosure further provides a circuit for testing tolerance characteristics of a lightning protection insulator, including:

the impact current wave output circuit is connected with the whole lightning protection insulator and is used for applying a first impact current wave and a second impact current wave to the whole lightning protection insulator;

the power frequency voltage output circuit is connected with the whole lightning protection insulator and is used for applying power frequency voltage to the whole lightning protection insulator;

the parameter testing circuit is used for testing the impact current flowing through the whole lightning protection insulator under the first impact current wave and the second impact current wave, the residual voltage at two ends of the whole lightning protection insulator, and the power frequency reference voltage and the leakage current of the whole lightning protection insulator corresponding to the first impact current wave and the second impact current wave under the power frequency voltage test;

and the calculation and analysis device is connected with the parameter testing circuit and is used for executing the method for testing the tolerance characteristic of the lightning protection insulator according to the first aspect.

Optionally, the impulse current wave output circuit includes a charging transformer, a rectifier silicon stack, a protection resistor, a spherical gap, a capacitor bank, a wave tail impedance, a wave modulating inductor, and a wave modulating resistor;

the power frequency voltage output circuit comprises a power frequency test transformer, a power frequency protection impedance and a vacuum switch;

the parameter testing circuit comprises a resistance voltage divider, a current transformer and a resistance-capacitance voltage divider, wherein the resistance voltage divider is used for testing the charging voltage of the whole lightning protection insulator under the first impact current wave and the second impact current wave, the current transformer is used for testing the impact current flowing through the whole lightning protection insulator under the first impact current wave and the second impact current wave, the resistance-capacitance voltage divider is used for testing the residual voltage at two ends of the whole lightning protection insulator under the first impact current wave and the second impact current wave, and the power frequency reference voltage and the leakage current of the whole lightning protection insulator under the power frequency voltage test;

and an explosion-proof device is arranged outside the whole lightning protection insulator and is used for blocking fragments generated when the whole lightning protection insulator is cracked.

The embodiment of the disclosure provides a method, a circuit and a design method for testing the tolerance characteristics of a lightning protection insulator, which are used for carrying out an impact heavy current test on the whole lightning protection insulator, obtaining real data of impact energy and thermal stress tolerance when the whole lightning protection insulator is subjected to direct lightning current under the operation condition, truly simulating the response characteristics of the whole lightning protection insulator when the whole lightning protection insulator is subjected to direct lightning current under the operation condition, providing safe and reliable technical support for the design of lightning protection equipment of a power transmission line, and being beneficial to improving the safe reliability of field operation.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure.

In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present disclosure, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

Fig. 1 is a schematic flow chart of a method for testing tolerance characteristics of a lightning protection insulator according to an embodiment of the present disclosure;

FIG. 2 shows that the 10kV integral lightning protection insulator provided by the embodiment of the disclosure is 2.6/50

Current and residual voltage waveforms under the action of lightning current;

FIG. 3 shows that the 10kV integral lightning protection insulator provided by the embodiment of the disclosure is 4.0/10

Current and residual voltage waveforms under the action of impact large current;

fig. 4 is a schematic structural diagram of a circuit for testing tolerance characteristics of a lightning protection insulator according to an embodiment of the present disclosure;

fig. 5 is a schematic flow chart of a method for designing a lightning protection insulator according to an embodiment of the present disclosure;

fig. 6 is a schematic specific flow chart of a method for designing a lightning protection insulator according to an embodiment of the present disclosure.

Detailed Description

In order that the above objects, features and advantages of the present disclosure may be more clearly understood, aspects of the present disclosure will be further described below. It should be noted that the embodiments and features of the embodiments of the present disclosure may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure, but the present disclosure may be practiced in other ways than those described herein; it is to be understood that the embodiments disclosed in the specification are only a few embodiments of the present disclosure, and not all embodiments.

Fig. 1 is a schematic flow chart of a method for testing tolerance characteristics of a lightning protection insulator according to an embodiment of the present disclosure. The method for testing the tolerance characteristic of the lightning protection insulator can be applied to a scene that the impact tolerance characteristic of the whole lightning protection insulator needs to be tested, and can be realized in a software and/or hardware mode. As shown in fig. 1, the method for testing the endurance characteristics of the lightning protection insulator includes:

s1, acquiring the impact current flowing through the whole lightning protection insulator under the first impact current wave and the residual voltage at the two ends of the whole lightning protection insulator, and acquiring the impact energy absorbed by the whole lightning protection insulator according to the impact current flowing through the whole lightning protection insulator under the first impact current wave and the residual voltage; and acquiring the impact current flowing through the whole lightning protection insulator under the second impact current wave and the corresponding thermal stress.

Specifically, a first impact current wave and a second impact current wave are respectively applied to the whole lightning protection insulator, so that impact current flowing through the whole lightning protection insulator under different impact currents and residual voltage at two ends of the whole lightning protection insulator are obtained, and impact energy and corresponding thermal stress absorbed by the whole lightning protection insulator are obtained according to the impact current and the residual voltage.

Illustratively, the first shock current wave may be set to 2.6/50

Impulse current wave, second impulse current is 4.0/10

A surge current wave. At present, in order to simulate the response characteristic of lightning protection equipment under lightning current impact, domestic and foreign electric appliance product detection mechanisms and manufacturers construct impact test devices capable of outputting different current waveforms, and the impact test devices can generate 2ms square wave current and 8/20

Nominal discharge current sum 4/10

High currents are impacted. However, the existing lightning monitoring results show that the waveform of the current flowing through the lightning protection equipment is 2.6/50 of that of the current flowing through the lightning protection equipment when the operation power transmission line is subjected to direct lightning strike

Predominantly, not 8/20

The impact current wave is limited by the output capability and the manufacturing technology of the test equipment, the impact current test of the existing lightning protection equipment is mainly carried out on the lightning protection equipment proportional unit or the single-chip zinc oxide resistance sheet lightning protection element, and the test waveform is also 4/10 which is easy to generate

And 8/20

The surge current wave is dominant.

The first impact current wave is set to be 2.6/50

Impulse current wave, second impulse current is 4.0/10

The impact current wave, namely 2.6/50 of the same waveform as the actual lightning current in the nature is adopted in the impact current impact energy endurance test

The impact current wave can truly simulate the response characteristic when the lightning is directly struck by heavy current under the operation condition, and is beneficial to improving the safety and reliability of the field operation.

Specifically, first 2.6/50 is generated

Lightning current is applied to a 10kV whole lightning protection insulator test sample, 10kV is the rated voltage of the whole lightning protection insulator, and a first impact current wave is obtained, for example, 2.6/50

The impulse current flowing through the entire lightning protection insulator under the impulse current wave and the residual voltage at the two ends of the entire lightning protection insulator, the obtained lightning current and the residual voltage waveform thereof are shown in FIG. 2, where the abscissa in FIG. 2 is time t and the unit is 10^-4s, the left ordinate is the current I in KA and the right ordinate is the voltage U in KV, curve a represents 2.6/50

The surge current flowing through the entire lightning protection insulator under the surge current wave, curve b represents 2.6/50

And residual voltage at two ends of the whole lightning protection insulator under the impact current wave.

Then, a 10kV whole lightning protection insulator sample is selected again to generate 4.0/10

Applying the impact current wave to the reselected 10kV whole lightning protection insulator sample to obtain a second impact current wave, such as 4.0/10

The lightning current and its residual voltage waveform obtained by the impact current flowing through the whole lightning protection insulator under the impact current wave and the residual voltage at the two ends of the whole lightning protection insulator are shown in fig. 3, where the abscissa in fig. 3 is time t and the unit is 10^-6s, the left ordinate is the current I in KA and the right ordinate is the voltage U in KV, the curve c represents 4.0/10

The surge current flowing through the entire lightning protection insulator under the surge current wave, and curve d represents 4.0/10

Optionally, obtaining the impact energy absorbed by the entire lightning protection insulator according to the residual voltage and the impact current flowing through the entire lightning protection insulator under the first impact current wave comprises obtaining the impact energy absorbed by the entire lightning protection insulator according to the following formula:

and applying a first impact current wave to the whole lightning protection insulator, and acquiring the impact energy absorbed by the whole lightning protection insulator according to the following formula. Wherein, W_{Whole piece}U (t) is a numerical expression of the waveform of the residual voltage under the first impact current wave and satisfies the requirement of the impact energy absorbed by the whole lightning protection insulator

And T is the duration of the first shock current wave. u (t) and I (t) in which₀Is the amplitude of the first impulse current wave, k is the waveform correction factor,

as a function of the attenuation coefficient of the wavefront,

is the attenuation coefficient of wave tail, c is constant,

the nonlinear coefficient of the zinc oxide resistance card for the whole lightning protection insulator is disclosed.

Optionally, the thermal stress corresponding to the entire lightning protection insulator is obtained according to the following formula:

and applying a second impact current wave to the whole lightning protection insulator, and obtaining the corresponding thermal stress of the whole lightning protection insulator according to the following formula. Wherein, F_{Whole piece}E is the elastic modulus of the zinc oxide resistance card for the whole lightning protection insulator,

Is the linear thermal expansion coefficient of the zinc oxide resistance card,

poisson ratio, T, of zinc oxide resistor disc_maxAnd T_minThe maximum temperature value and the minimum temperature value of the zinc oxide resistance card after the second impact current wave acts are respectively.

Specifically, before obtaining the impact energy and the corresponding thermal stress absorbed by the entire lightning protection insulator according to the impact current and the residual voltage, the technical parameters of the entire lightning protection insulator to be tested and the zinc oxide resistor thereof may be obtained first, and the technical parameters may specifically include an alternating current 1mA reference voltage U of the entire lightning protection insulator₀Leakage current I_{Leakage of}Volt-ampere characteristic curve, type, structure size and number N of zinc oxide resistance cards₀Elastic modulus, coefficient of thermal expansion and Poisson's ratio, and 2.6/50

Impulse current wave tolerance value I_2.6/50And corresponding energy W₀，4/10

Impact large current tolerance value I_4.0/10And corresponding thermal stress F₀. The technical parameters of the 10kV whole lightning protection insulator to be tested are shown in table 1, and the technical parameters of the zinc oxide resistance card of the 10kV whole lightning protection insulator to be tested are shown in table 2.

Meter 110 kV lightning protection insulator technical parameters

Technical parameters of zinc oxide resistor disc for 210 kV lightning protection insulator

Specifically, according to the waveforms and amplitudes of the impact current flowing through the entire lightning protection insulator under different impact current waves and the residual voltages at the two ends of the entire lightning protection insulator shown in fig. 2 and 3, the corresponding impact current charge amount, impact energy and thermal stress of the entire lightning protection insulator are calculated.

When the impact current waveform is 2.6/50

And then, respectively calculating the impact current charge quantity and the impact energy absorbed by the whole lightning protection insulator:

wherein Q is the current-in-rush waveform of 2.6/50

In time, the whole lightning protectionThe charge quantity of the impact current absorbed by the insulator, Q, can be used as an auxiliary judgment parameter of the endurance characteristic of the whole lightning protection insulator, u (t), i (t) are numerical expressions of impact current and residual voltage waveforms respectively, the impact current i (t) adopts a double-exponential function,

u (t) can be obtained according to the voltammetry characteristic curve of the zinc oxide resistance card shown in Table 1,

. When the impulse current waveform is 4.0/10

s time, the thermal stress, T, corresponding to the whole lightning protection insulator_max、T_minThe maximum value and the minimum value of the resistance card temperature after the impact current measured by an infrared thermometer is acted,

as can be seen from the waveform shown in FIG. 2, 2.6/50 of the voltage applied to the 10kV whole lightning protection insulator

The amplitude of the lightning current is 17.7kA, and the lightning current is fitted by adopting a double-exponential function to obtain a numerical expression of i (t):

2.6/50

the residual voltage of the 10kV lightning protection insulator under the action of the s-lightning current can be obtained according to a Voltan characteristic curve numerical expression in a table 1, 4 in the following formula is the number of the zinc oxide resistance cards for the whole lightning protection insulator test sample, and a waveform numerical expression of the residual voltage under the first impact current wave meets the following calculation formula:

illustratively, a program can be written in MATLAB software, and 2.6/50 of a 10kV integral lightning protection insulator at 17.7kA can be calculated

The absorbed charge under the action of the s-thunder current is as follows:

the absorbed impact current energy is:

the 10kV whole lightning protection insulator is 4.0/10 of 91.7kA

After the heavy current is impacted, the temperature T of the internal resistance card measured by the infrared thermometer_max=54.6℃、T_min=47.1 ℃, and the thermal stress of the 10kV lightning protection insulator is calculated by combining the technical parameters of the zinc oxide resistor disc shown in table 2 as follows:

and S2, respectively obtaining power frequency reference voltage and leakage current of the whole lightning protection insulator corresponding to the first impact current wave and the second impact current wave.

Specifically, after the corresponding impact current waves are applied to the whole lightning protection insulator, power frequency voltage is applied to the whole lightning protection insulator, and power frequency reference voltage and leakage current of the whole lightning protection insulator corresponding to different impact current waves are obtained. Specifically, at 2.6/50

After the s-thunder current is applied for a period of time (the time is less than 100ms, and is required for controlling the switch of power frequency voltage input to be opened and closed), the whole lightning protection insulation is changed to 10kVAnd applying power frequency voltage. When the measured power frequency current is 1mA, recording the power frequency reference voltage U at the moment_(2.6/50)1mA=21.3kV, and the reduction of the U of the power frequency voltage applied to the whole lightning protection insulator by 0.75 times_(2.6/50)1mANamely, the power frequency reference voltage applied to the whole lightning protection insulator is reduced to 15.98kV, and the leakage current I is measured at the moment_(2.6/50)1mA=5.0

A. Similarly, also at 4/10

Applying power frequency voltage to the whole 10kV lightning protection insulator after the lightning current is applied for a period of time, and recording the power frequency reference voltage U when the measured power frequency current is 1mA_(4.0/10)1mA=21.1kV, and the reduction of U by 0.75 times of the power frequency voltage applied to the whole lightning protection insulator_(4.0/10)1mAAt this time, the leakage current I is measured_(4.0/10)1mA=6.0

A。

S3, obtaining the power frequency reference voltage change rate before and after the whole lightning protection insulator impulse current test according to the power frequency reference voltage, and comparing the obtained leakage current with the leakage current corresponding to the whole lightning protection insulator before the impulse current is applied.

wherein,

for the change rate of power frequency reference voltage before and after the impulse current test of the whole lightning protection insulator, U₀And U_1mAThe power frequency reference voltages before and after the impulse current test of the whole lightning protection insulator can be known from table 1U₀Equal to 21.5 kV.

Specifically, the 10kV whole lightning protection insulator is 2.6/50

Lightning current, 4.0/10

Power frequency 1mA reference voltage change rate before and after impact heavy current test

、

Respectively satisfy the following calculation formula:

comparing the obtained leakage current with the leakage current corresponding to the whole lightning protection insulator before the impact current is applied, as can be seen from table 1, the leakage current I corresponding to the whole lightning protection insulator before the impact current is applied_{Leakage of}Equal to 3.0 muA, and comparing the leakage current before and after the impulse current test, it can be seen that:

。

and S4, adjusting the impact current applied to the whole lightning protection insulator according to the comparison result of the power frequency reference voltage change rate and the leakage current.

And S5, obtaining the impact energy tolerance maximum value and the thermal stress tolerance maximum value corresponding to the whole lightning protection insulator, wherein the power frequency reference voltage change rates are all less than or equal to the set change rate, and the leakage currents are all less than or equal to the set leakage current.

Specifically, the steps S1 to S4 are executed in a loop until the obtained power frequency reference voltage change rates are all less than or equal to the set change rate, and the leakage currents are all less than or equal to the impact energy tolerance maximum value and the thermal stress tolerance maximum value corresponding to the whole lightning protection insulator with the set leakage currents.

Specifically, the impact current applied to the entire lightning protection insulator is adjusted according to the comparison result of the power frequency reference voltage change rate and the leakage current, a new entire lightning protection insulator with the same model and the same technical parameters can be selected, and the steps S1 to S4 are repeatedly executed until the power frequency 1mA reference voltage change rate is not more than the set change rate, such as 5%, and the leakage current is not more than the set leakage current, such as 50 ≤

The whole lightning protection insulator A can bear the maximum value of impact current and the corresponding impact energy and thermal stress.

Optionally, adjusting the inrush current applied to the entire lightning protection insulator according to the power frequency reference voltage change rate and the comparison result of the leakage current includes: if the power frequency reference voltage change rate is less than or equal to the set change rate and the leakage current is less than or equal to the set leakage current, judging that the whole lightning protection insulator passes the impact energy and thermal stress test corresponding to the currently applied impact current, and increasing the impact current applied to the whole lightning protection insulator by a set proportion; if the power frequency reference voltage change rate is greater than the set change rate or the leakage current is greater than the set leakage current, it is determined that the whole lightning protection insulator does not pass the impact energy and thermal stress test corresponding to the currently applied impact current, and the impact current applied to the whole lightning protection insulator is reduced by a set proportion, which may be, for example, 5%.

Illustratively, the rate of change of the if-frequency reference voltage can be set

Less than or equal to 5% and leakage current I_1mALess than or equal to 50

A, then deeming to be lightning protectionThe insulator passes the currently applied impact current I₀Corresponding impact energy or thermal stress test, if I₀The impact current applied to the whole lightning protection insulator is increased by 5% instead of the maximum impact current resistance of the lightning protection insulator. If it is not

Greater than 5% or I_1mAGreater than 50

A, the lightning protection insulator is considered not to pass the currently applied impact current I₀And the impact current applied to the whole lightning protection insulator is reduced by 5 percent through a corresponding impact energy or thermal stress test.

For example, according to the above

(2.6/50) and

the calculation results of (4.0/10) show that: after the 10kV whole lightning protection insulator is subjected to an impulse current test,

(2.6/50) and

(4.0/10) are all less than 5%, and I_(2.6/50)1mAIs less than I_(4.0/10)1mALess than 50

A, therefore, the 10kV whole lightning protection insulator can be judged to pass 2.6/50 of 17.7kA

The lightning current impact energy test also passes 4.0/10 of 91.7kA

Impact heavy current thermal stress test。

Then two new 10kV whole lightning protection insulators with the same type and the same technical parameters are selected, and the impact current applied to the whole lightning protection insulator is increased by 5 percent, namely the newly applied impact current is equal to I_0(2.6/50)=17.7×1.05 =18.6kA，I_0(4.0/10)= 91.7 × 1.05 = 96.3kA, and then steps 101 to 104 are repeatedly performed. Through the test, the following results are obtained: when I is_0(2.6/50)When = 18.6kA is applied on 10kV whole lightning protection insulator, the impact current test platform measuring system can measure the impact current and residual voltage waveform, but the power frequency 1mA reference voltage tests U_(2.6/50)1mA=20.3kV，I_(2.6/50)1mA=63

A, calculating to obtain

(2.6/50) = 5.58% greater than 5% and I_(2.6/50)1mAGreater than 50

A, so that the 10kV whole lightning protection insulator does not pass 2.6/50 of 18.6kA

And (4) testing lightning current impact energy. When I is_0(4.0/10)When the = 96.3kA is applied on a 10kV whole lightning protection insulator, the surface of an external insulating umbrella skirt of the lightning protection insulator is cracked, an impact current test platform measurement system does not measure impact current and residual voltage waveforms, and a power frequency 1mA reference voltage U_(2.6/50)1mA=5.7kV、I_(2.6/50)1mA=143

A, so that the 10kV lightning protection insulator does not pass 4.0/10 of 96.3kA

And (4) impact high-current thermal stress test.

Therefore, it can be considered that the 10kV whole lightning protection insulator can endure 2.6/50

The maximum value of lightning current is 17.7kA, corresponding to impact energy W_{Whole piece}=48.60kJ, tolerance 4.0/10

The maximum value of the impact large current is 91.7kA, corresponding to the thermal stress F_{Whole piece}And =8.2MPa, namely the obtained power frequency reference voltage change rate is smaller than or equal to the set change rate, the maximum impact energy tolerance value corresponding to the whole lightning protection insulator with the leakage current smaller than or equal to the set leakage current is 48.60kJ, and the maximum thermal stress tolerance value is 8.2 MPa.

Therefore, the embodiment of the disclosure develops an impact large current test on the whole lightning protection insulator, obtains real data of impact energy and thermal stress tolerance when the whole lightning protection insulator is subjected to direct lightning current under the operation condition, truly simulates the response characteristic of the whole lightning protection insulator when the whole lightning protection insulator is subjected to direct lightning current under the operation condition, provides a safe and reliable technical support for the design of the lightning protection equipment of the power transmission line, and is beneficial to improving the safety and reliability of field operation.

The embodiment of the disclosure also provides a tolerance characteristic test circuit of the lightning protection insulator. Fig. 4 is a schematic structural diagram of a circuit for testing tolerance characteristics of a lightning protection insulator according to an embodiment of the present disclosure. As shown in fig. 4, the circuit for testing the endurance characteristics of the lightning protection insulator comprises an impact current wave output circuit 1, a power frequency voltage output circuit 2, a parameter test circuit 4 and a calculation and analysis device 5, wherein the impact current wave output circuit 1 and the power frequency voltage output circuit 2 are both connected with the whole lightning protection insulator 32, the impact current wave output circuit 1 is used for applying a first impact current wave and a second impact current wave to the whole lightning protection insulator 32, the power frequency voltage output circuit 2 is used for applying a power frequency voltage to the whole lightning protection insulator 32, the parameter test circuit 4 is used for testing the impact current flowing through the whole lightning protection insulator 32 under the first impact current wave and the second impact current wave and the residual voltage at two ends of the whole lightning protection insulator 32, and the power frequency reference voltage and the leakage current of the whole lightning protection insulator 32 corresponding to the first impact current wave and the second impact current wave under the power frequency voltage test. The calculation and analysis device 5 is connected to the parameter testing circuit 4, and the calculation and analysis device 5 is configured to execute the method for testing the tolerance characteristic of the lightning protection insulator according to the above embodiment, so that the circuit for testing the tolerance characteristic of the lightning protection insulator according to the embodiment of the present disclosure has the beneficial effects of the above embodiment, and details are not repeated here.

Optionally, as shown in fig. 4, the inrush current wave output circuit 1 includes a charging transformer 11, a rectifier silicon stack 12, a protection resistor 13, a spherical gap 15, a capacitor bank 14, a wave tail impedance 16, a wave regulation inductor 17, and a wave regulation resistor 18; the power frequency voltage output circuit 2 comprises a power frequency test transformer 21, a power frequency protection impedance 22 and a vacuum switch 23; the parameter testing circuit 4 comprises a resistance voltage divider 41, a current transformer 42 and a resistance-capacitance voltage divider 43, wherein the resistance voltage divider 41 is used for testing the charging voltage of the whole lightning protection insulator 32 under the first impact current wave and the second impact current wave, the current transformer 42 is used for testing the impact current flowing through the whole lightning protection insulator 32 under the first impact current wave and the second impact current wave, the resistance-capacitance voltage divider 43 is used for testing the residual voltage at two ends of the whole lightning protection insulator 32 under the first impact current wave and the second impact current wave, and the power frequency reference voltage and the leakage current of the whole lightning protection insulator 32 under the power frequency voltage test; an explosion-proof device 31 is arranged outside the whole lightning protection insulator 32, and the explosion-proof device 31 is used for blocking fragments generated when the whole lightning protection insulator 32 is cracked.

Specifically, a circuit for testing the impact tolerance characteristics of the whole lightning protection insulator can be set up in a high-voltage test hall with reference to fig. 4, that is, a platform for testing the impact current of the whole lightning protection insulator is set up. The lightning protection insulator tolerance characteristic test circuit is composed of an impact current wave output circuit 1, a power frequency voltage output circuit 2, a test sample support 3 and a measurement system, wherein the test sample support 3 is used for placing a whole lightning protection insulator test sample, and the measurement system comprises a parameter test circuit 4 and a calculation analysis device 5. The surge current wave output circuit 1 is used for generating 4/10

High impact current and 2.6/50

The lightning current and impulse current wave output circuit 1 is composed of a charging transformer 11, a rectifier silicon stack 12, a protective resistor 13, a capacitor bank 14, a spherical gap 15, a wave tail impedance 16, a wave regulating inductor 17 and a wave regulating resistor 18, wherein the charging transformer 11, the rectifier silicon stack 12, the protective resistor 13 and the capacitor bank 14 are sequentially connected through a high-voltage lead and used for charging the capacitor bank 14, and the capacitor bank 14, the wave tail impedance 16, the wave regulating inductor 17 and the wave regulating resistor 18 are sequentially connected and then connected with a high-voltage end of a test sample support 3. The current waveform applied to the sample is 4/10 by changing the values of the wave tail impedance 16, the wave modulation inductor 17 and the wave modulation resistor 18

Or 2.6/50

The magnitude of the surge current can be adjusted by changing the charging voltage of the capacitor bank 14.

The power frequency voltage output circuit 2 consists of a power frequency test transformer 21, a power frequency protection impedance 22 and a vacuum switch 23, and is used for outputting power frequency voltage to the whole lightning protection insulator 32 in the test article bracket 3 after being sequentially connected. An explosion-proof device, such as an explosion-proof box 31, is arranged outside the whole lightning protection insulator 32, namely outside the test sample holder 3, and the explosion-proof device is used for blocking fragments generated when the whole lightning protection insulator 32 is cracked, so as to prevent personnel or equipment from being injured. The measuring system consists of a resistance voltage divider 41, a current transformer 42, a resistance-capacitance voltage divider 43 and a calculation and analysis device 5, wherein the resistance voltage divider 41 is used for testing the amplitude and the waveform of charging voltage during an impulse current test, the current transformer 42 is used for testing the amplitude and the waveform of test article current, the resistance-capacitance voltage divider 43 is used for testing the amplitude and the waveform of test article residual voltage, and 1mA reference voltage and leakage current during a power frequency voltage test.

The lightning protection insulator tolerance characteristic test method and circuit provided by the embodiment of the disclosure are easy to implement, have strong operability, and can be used for the whole lightning protection equipment impact current impact energy and thermal stress tests of various voltage levels and the design of zinc oxide resistance sheets by adjusting the values of the wave tail impedance 16, the wave modulation inductor 17 and the wave modulation resistor 18 or adjusting the charging voltage of the capacitor bank 14.

The embodiment of the disclosure further provides a design method of the lightning protection insulator, and fig. 5 is a schematic flow chart of the design method of the lightning protection insulator provided by the embodiment of the disclosure. The design method of the lightning protection insulator can be applied to scenes needing to design the whole lightning protection insulator, and can be realized in a software and/or hardware mode. As shown in fig. 5, the design method of the lightning protection insulator includes:

s201, acquiring the maximum impact energy tolerance value and the maximum thermal stress tolerance value.

Specifically, according to the method for testing the tolerance characteristics of the lightning protection insulator in the embodiment, the maximum impact energy tolerance value and the maximum thermal stress tolerance value are obtained, and according to the embodiment, for example, the power frequency reference voltage change rate is smaller than or equal to the set change rate, the maximum impact energy tolerance value corresponding to the whole lightning protection insulator with the leakage current smaller than or equal to the set leakage current is 48.60kJ, and the maximum thermal stress tolerance value is 8.2 MPa.

S202, designing the number and the specification size of the zinc oxide resistance cards for the whole lightning protection insulator according to the maximum impact energy tolerance value and the maximum thermal stress tolerance value.

Optionally, the number and the specification size of the zinc oxide resistor discs for the whole lightning protection insulator are designed according to the maximum value of the impact energy and the maximum value of the thermal stress tolerance, and the number and the specification size comprise:

obtaining the maximum value of the impact energy of a single zinc oxide resistor disc in the whole lightning protection insulator, which can bear a first impact current wave; the maximum value of the impact energy of the single zinc oxide resistance chip enduring the first impact current wave meets the following calculation formula:

wherein, W_{Single sheet}Withstanding a first shock current wave for a single zinc oxide resistor discMaximum value of impact energy of, W_{Whole piece}Impact energy absorbed by the entire lightning protection insulator, N₀The number of zinc oxide resistance cards adopted before testing of the whole lightning protection insulator;

wherein N is the number of zinc oxide resistance cards for the whole lightning protection insulator, and W is₀The single zinc oxide resistance chip is corresponding to the impact energy of the first impact current wave;

in particular, N₀The number of the zinc oxide resistance cards W is adopted before the test of the whole lightning protection insulator₀Is a single zinc oxide resistance card 2.6/50

The energy of the impulse wave was obtained from Table 2₀Is equal to 4, W₀Equal to 13.78, redesigning the quantity of the adopted zinc oxide resistance pieces according to the shock current wave energy tolerance of the 10kV whole lightning protection insulator, and calculating the 2.6/50 tolerance of the single zinc oxide resistance piece in the 10kV whole lightning protection insulator

Maximum value W of surge current wave_{Single sheet}：

Redesigning the number N of the zinc oxide resistance cards required by the 10kV whole lightning protection insulator as follows:

wherein S is an area parameter contained in the specification and size of the zinc oxide resistance card for the whole lightning protection insulator, and S₀Area of zinc oxide resistor disc adopted before testing of whole lightning protection insulator, F₀The thermal stress of the single zinc oxide resistance chip corresponding to the second impulse current wave.

Specifically, S₀Area of zinc oxide resistor disc adopted before lightning protection insulator test, F₀Is a monolithic resistor disc 4/10

The thermal stress tolerance value of the impact current wave can be obtained according to the table 2, and the structural size of the zinc oxide resistance card adopted before the lightning protection insulator test is

(32 multiplied by 60) multiplied by 24mm, the zinc oxide resistance sheet is of a circular ring structure, wherein 60mm is the outer diameter of the zinc oxide resistance sheet, 32mm is the inner diameter of the zinc oxide resistance sheet, 24mm is the thickness of the zinc oxide resistance sheet, and F₀Equal to 9.2, area S of zinc oxide resistor disc adopted before lightning protection insulator test₀Then is

，r_{Outer diameter}Equal to 6cm, r_{Inner diameter}Equal to 3.2 cm. The specification size of the zinc oxide resistance card is adopted for the 10kV whole lightning protection insulator, wherein the specification size mainly refers to the area S of the circular ring surface of the zinc oxide resistance card, and the redesign of S is as follows:

therefore, the area of the zinc oxide resistance card is increased by 12.2%, and the zinc oxide resistance card can be realized mainly by increasing the outer diameter of the zinc oxide resistance card. Therefore, the number of zinc oxide resistor sheets is considered in consideration of the impact current energy and the thermal stress tolerance characteristic of the 10kV whole lightning protection insulatorThe quantity is adjusted from 4 pieces to 5 pieces, and the structural size of the resistance card is adjusted from

(32X 60). times.24 mm was adjusted to

(32X 64) X24 mm, corresponding to the structural dimensions

(32X 64) X24 mm, the area S of the zinc oxide resistor disc is equal to 24.12cm²。

Fig. 6 is a schematic specific flowchart of a method for designing a whole lightning protection insulator according to an embodiment of the present disclosure. The design method of the whole lightning protection insulator can also be applied to scenes needing to design the whole lightning protection insulator. As shown in fig. 6, the method for designing the whole lightning protection insulator includes:

s301, building a whole lightning protection insulator impact current test platform in a high-voltage test hall.

Specifically, as shown in fig. 4, the test platform is composed of an impulse current wave output circuit 1, a power frequency voltage output circuit 2, a test sample support 3, a parameter test circuit 4 and a calculation and analysis device 5.

S302, obtaining technical parameters of the whole lightning protection insulator to be tested and the zinc oxide resistance card of the lightning protection insulator to be tested.

Specifically, the technical parameters of the whole lightning protection insulator and the zinc oxide resistor disc thereof are respectively shown in the above table 1 and table 2.

S303, fixing the lightning protection insulator sample to be tested, and setting the wave tail impedance, the wave modulation inductance and the resistance value of the test loop according to the impulse current waveform.

Specifically, as shown in fig. 4, a 10kV lightning protection insulator sample to be tested is fixed in an explosion-proof box 31 of a sample support of an impulse current test platform, wave tail impedance, wave modulation inductance and resistance values corresponding to an impulse current waveform are set, and 2.6/50 is adopted when testing the impulse current energy tolerance

The current waveform is 4.0/10 for testing the thermal stress tolerance

The current waveform. When 2.6/50 of the sample is performed

During the lightning current tolerance test, the wave tail impedance is set to be 0.398 kilo ohm, and the wave regulation inductance is set to be 10.0

H, the wave modulating resistance is 8.7 ohms; when a sample is subjected to 4.0/10

When the impact large current endurance capacity is tested, the wave tail impedance is 1.59 kilo ohm, and the wave regulation inductance is 9.0

H, the wave modulating resistance is 2.1 ohm.

S304, switching on the working power supply of the test device to generate 2.6/50

Or 4.0/10

Rush Current I₀And outputting the lightning protection insulator to the whole lightning protection insulator test sample.

Specifically, a working power supply of a charging transformer is switched on, a charging voltage is controlled through a resistor voltage divider, the distance of a ball gap is adjusted to trigger a capacitor bank to discharge, and an impact current I is generated₀And is applied to the whole lightning protection insulator test sample. As shown in FIG. 4, the working power of the charging transformer 11 is turned on, the charging voltage of the capacitor bank 14 is adjusted, the discharge of the ball gap 15 is triggered, and 2.6/50 of the charge is firstly generated

Lightning current is applied to the whole lightning protection insulator sample of 10kV,the resulting lightning current and its residual voltage waveform are shown in fig. 2. Adjusting the loop impedance parameter of the impulse current test platform, reselecting a 10kV lightning protection insulator sample to be fixed on the test article support, and carrying out 4.0/10

And (3) testing the endurance capability of the impact large current, and obtaining the impact current, the residual voltage waveform and the voltage waveform shown in figure 3.

S305, recording the impact current, residual voltage waveform and amplitude parameter flowing through the lightning protection insulator, and calculating the impact current charge amount, impact energy and thermal stress absorbed by the whole lightning protection insulator.

Specifically, the waveforms and amplitudes of the impact current and the residual voltage flowing through the lightning protection insulator are read and recorded, and the impact current, the impact energy and the thermal stress absorbed by the whole lightning protection insulator are calculated. According to the waveform shown in figure 2, 2.6/50 of the voltage is applied to the 10kV lightning protection insulator

2.6/50

the residual voltage of the 10kV lightning protection insulator under the action of the lightning current can be obtained according to a numerical expression of a Voltan characteristic curve in a table 1, namely:

writing a program in MATLAB software, and calculating to obtain 2.6/50 of the 10kV integral lightning protection insulator at 17.7kA

The amount of charge absorbed under the action of lightning current is:

the impact energy of the absorbed impact current is as follows:

the 10kV whole lightning protection insulator is 4.0/10 of 91.7kA

After the heavy current is impacted, the temperature T of the internal resistance card measured by the infrared thermometer_max=54.6℃、T_min=47.1 ℃, and the thermal stress of the 10kV lightning protection insulator is calculated by combining the technical parameters of the zinc oxide resistor disc in table 2 as follows:

and S306, testing the power frequency 1mA reference voltage and leakage current of the whole lightning protection insulator within a period of time after the impact current is applied.

Specifically, within a period of time (less than 100 ms) after the impact current wave is applied, applying power frequency voltage to the lightning protection insulator through the impact current wave test device platform power frequency voltage output device, and testing the power frequency 1mA reference voltage U of the whole lightning protection insulator_1mAAnd leakage current I at 0.75 times the power frequency reference voltage_1mA. At 2.6/50

After the lightning current is applied for a period of time (less than 100 ms), applying power frequency voltage to the 10kV lightning protection insulator through the power frequency voltage output device of the impact current wave test device platform, and recording the power frequency voltage U when the power frequency current measured by the current transformer 42 of the measurement system is 1mA_(2.6/50)1mA=21.3 kV; the power frequency voltage applied to the lightning protection insulator is reduced to be 0.75 times U_(2.6/50)1mA(15.98 kV), the leakage current I was measured_(2.6/50)1mA=5.0

A. Can obtain U in the same way_(4.0/10)1mA=21.1kV、I_(4.0/10)1mA=6.0

A。

S307, calculating the power frequency 1mA reference voltage change rate before and after the impulse current test

。

Specifically, the 10kV whole lightning protection insulator is calculated to be 2.6/50

Lightning current, 4.0/10

Respectively as follows:

s308, judging

Whether or not 5% or less and whether or not the leakage current is 50% or less

A. If yes, go to step 309; if not, go to step 303 via conditional a.

Specifically, the condition A is a surge current wave I₀Reduced by 5%, rearranged as in step 302The model of the lightning protection insulator. Calculating the power frequency 1mA reference voltage change rate before and after the impact current test of the whole lightning protection insulator

While simultaneously mixing I_1mAAnd the value I before applying the surge current_{Leakage of}A comparison is made.

S309, judgment I₀Whether the lightning protection insulator can bear the maximum impact current or not. If yes, go to step 310; if not, go to step 303 via conditional B.

Specifically, the condition B is a surge current wave I₀And (5) increasing, and rearranging the lightning protection insulator with the same type as the step (2).

S310, obtaining the whole lightning protection insulator 2.6/50 meeting the requirements

、4.0/10

The maximum value of the impact current and the corresponding impact energy and thermal stress.

Specifically, the amplitude of the impact current applied to the whole lightning protection insulator is changed according to the calculation and comparison results, a new lightning protection insulator with the same type and technical parameters as those in the step 302 is selected, and the steps 303 to 309 are repeated until the power frequency 1mA reference voltage change rate is not more than 5% and the leakage current is not more than 50% are obtained

S311, redesigning the number and the specification size of the zinc oxide resistance pieces adopted by the whole lightning protection insulator.

Specifically, the number and the specification size of the adopted zinc oxide resistor discs are redesigned according to the maximum impact current energy and thermal stress resistance value of the whole lightning protection insulator.

Therefore, the embodiment of the disclosure solves the problem that the failure rate of the existing lightning protection equipment is still high in field operation due to certain limitation caused by the fact that how the impact current tolerance test result is applied to the design of the lightning protection equipment in the prior art is not discussed, and provides a solution for the design of the number and specification size of the zinc oxide resistor discs of the whole lightning protection insulator considering the influence of the forming process.

According to the embodiment of the invention, the technical parameters of the lightning protection insulator to be tested and the zinc oxide resistor disc thereof are obtained by building the whole lightning protection insulator impulse current test platform, the wave tail impedance, the wave modulation inductance and the resistance value corresponding to the impulse current waveform are set, and 2.6/50 of the total value is obtained

Or 4.0/10

The method comprises the steps of applying impact current waves to a whole lightning protection insulator test sample, calculating the impact current charge quantity, impact energy and thermal stress absorbed by the whole lightning protection insulator, and testing the power frequency 1mA reference voltage U of the whole lightning protection insulator within a period of time after the impact current is applied_1mALeakage current I_1mAAnd calculating the power frequency 1mA reference voltage change rate before and after the lightning protection insulator impulse current test

According to

And I_1mAThe magnitude of the impact current applied to the whole lightning protection insulator is changed, and 2.6/50 of the whole lightning protection insulator meeting the requirements is obtained

、4.0/10

And redesigning the number and specification size of zinc oxide resistance cards adopted by the whole lightning protection insulator according to the maximum value of the impact current, the corresponding impact energy and the thermal stress. Can be used forTo develop 2.6/50 of the whole lightning protection insulator

Lightning current 4/10

The method comprises the steps of carrying out an impact large-current test, obtaining real data of impact energy and thermal stress tolerance when the lightning current is subjected to direct lightning under the operation condition, simulating the impact energy tolerance and the thermal stress characteristic of the large-current direct lightning under the operation condition, providing support for the design of a lightning protection insulator and a zinc oxide resistor disc, and improving the safety and the reliability of field operation.

It is noted that, in this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The foregoing are merely exemplary embodiments of the present disclosure, which enable those skilled in the art to understand or practice the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for testing tolerance characteristics of a lightning protection insulator is characterized by comprising the following steps:

2. The method for testing the endurance characteristics of the lightning protection insulator according to claim 1, wherein the first surge current wave is 2.6/50

A surge current wave, the second surge current wave is 4.0/10

A surge current wave.

3. The method for testing the endurance characteristics of the lightning protection insulator according to claim 1 or 2, wherein obtaining the impact energy absorbed by the entire lightning protection insulator according to the residual voltage and the impact current flowing through the entire lightning protection insulator under the first impact current wave comprises:

as a function of the attenuation coefficient of the wavefront,

respectively, wave tail attenuation coefficients, c is a constant,

4. The method for testing the endurance characteristics of the lightning protection insulator according to claim 1 or 2,

obtaining the thermal stress corresponding to the whole lightning protection insulator under the second impact current wave according to the following formula:

The linear thermal expansion coefficient of the zinc oxide resistance card,

5. The method for testing the endurance characteristics of the lightning protection insulator according to claim 1 or 2, wherein the power frequency reference voltage change rate before and after the impact current test of the whole lightning protection insulator satisfies the following formula:

wherein,

6. The method for testing the endurance characteristics of the lightning protection insulator according to claim 1 or 2, wherein the step of adjusting the inrush current applied to the entire lightning protection insulator according to the comparison result of the power frequency reference voltage change rate and the leakage current comprises:

7. A design method of a lightning protection insulator is characterized by comprising the following steps:

the method for testing the tolerance characteristics of the lightning protection insulator according to any one of claims 1 to 6, wherein the maximum impact energy tolerance value and the maximum thermal stress tolerance value are obtained;

8. The method for designing the lightning protection insulator according to claim 7, wherein the step of designing the number and the specification size of the zinc oxide resistor discs for the whole lightning protection insulator according to the maximum impact energy tolerance value and the maximum thermal stress tolerance value comprises the following steps:

9. The utility model provides a withstand characteristic test circuit of lightning protection insulator which characterized in that includes:

the parameter testing circuit is used for testing the impact current wave flowing through the whole lightning protection insulator under the first impact current wave and the second impact current wave, the residual voltage at two ends of the whole lightning protection insulator, and the power frequency reference voltage and the leakage current of the whole lightning protection insulator corresponding to the first impact current wave and the second impact current wave under the power frequency voltage test;

a calculation and analysis device connected to the parameter testing circuit for executing the method for testing the endurance characteristics of the lightning protection insulator according to any one of claims 1 to 6.

10. The circuit for testing the endurance characteristics of the lightning protection insulator according to claim 9, wherein the surge current wave output circuit comprises a charging transformer, a rectifier silicon stack, a protection resistor, a spherical gap, a capacitor bank, a wave tail impedance, a wave modulating inductor and a wave modulating resistor;