A method, device and equipment for evaluating parameters of multiple lightning stroke waveforms of a power transmission line

Abstract

The application discloses a kind of power transmission line multiple lightning waveform parameter evaluation method, device and equipment, it is related to super-high voltage transmission line design technical field, the present application divides lightning mode into back strike and shielding failure, obtains lightning direct back strike line's lightning withstand level and lightning amplitude, while the situation of lightning shielding failure is specifically analyzed, the critical current and lightning withstand level of lightning shielding failure line are analyzed, and the critical current and lightning withstand level of lightning shielding failure line are compared to obtain the lightning current amplitude of lightning shielding failure line under the actual situation of line, unlike the mode of directly using lightning current sensor, but by dividing lightning into direct back strike and shielding failure, and the lightning current amplitude of lightning shielding failure line is emphatically analyzed, so that the situation of analysis is closer to the actual situation of line, the captured lightning current is complete and low distortion, so that the accuracy of multiple lightning waveform parameter evaluation is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ultra-high voltage transmission line design, and particularly relates to a transmission line multiple lightning waveform parameter evaluation method, device and equipment. BACKGROUND

[0002] The ultra-high voltage AC transmission line encounters lightning, especially multiple continuous lightning in a short time, which is an important inducement for system tripping. Compared with single lightning, the multiple lightning waveform parameters are complex and changeable, and there is no standardized basis for lightning overvoltage analysis. Therefore, it is crucial to determine the multiple lightning parameters and support external overvoltage calculation for the actual working condition of the ultra-high voltage line, system insulation coordination and lightning arrester configuration, and it is a hot and difficult point of current research.

[0003] Lightning monitoring data shows that the multiple lightning waveform parameters have great randomness, and each lightning is different. Using uniform multiple lightning parameters for simulation operation often cannot prove whether the system is resistant to multiple lightning, so as to test the robustness of the system, and it is not completely applicable to the system insulation coordination design in the design stage. Moreover, the lightning accident of the power system is occasional, and the overvoltage level of the real fault process is only reflected according to a single lightning current standard.

[0004] At present, the calculation method of the multiple lightning waveform parameters is mainly based on the actual observation data. Foreign countries have arranged multiple observation sites to measure lightning current waveform and other information, such as a special observation station on a building or a special observation station to monitor. Some install monitoring devices on the ultra-high voltage transmission line to collect lightning current waveform striking the tower. In the early stage, the domestic researchers mainly use magnetic steel rods to measure lightning current amplitude on the transmission line. In recent years, researchers have carried out a lot of lightning current waveform measurement work on the transmission line. However, due to the factors such as sampling rate and recording time of the lightning current sensor, the directly captured lightning current often has great distortion phenomenon, and the captured lightning current parameters are disorderly and not representative. Therefore, the evaluation accuracy of the multiple lightning waveform parameters by the means adopted at present is low, and it is difficult to guide the design of the current ultra-high voltage AC transmission line. SUMMARY

[0005] The embodiment of the present application provides a transmission line multiple lightning waveform parameter evaluation method, device and equipment, which can solve the problem of low evaluation accuracy of the multiple lightning waveform parameters by the means adopted at present in the prior art.

[0006] The embodiment of the present application provides a transmission line multiple lightning waveform parameter evaluation method, which comprises the following steps:

[0007] Obtain the lightning tower lightning withstand level and lightning amplitude when lightning counterattacks the line;

[0008] The critical current amplitude of lightning when the lightning bypasses the line is obtained according to the EGM range theory; the striking distance of lightning to the ground, the striking distance of lightning to the conductor and the striking distance of lightning to the ground are obtained according to the critical current amplitude of lightning; the protection angle of the lightning conductor is obtained according to the striking distance of lightning to the ground, the striking distance of lightning to the conductor and the striking distance of lightning to the ground, and the critical striking distance is obtained by using the protection angle of the lightning conductor;

[0009] The critical current of lightning when the lightning bypasses the line is obtained according to the critical current amplitude of lightning, the striking distance of lightning to the ground, the striking distance of lightning to the conductor, the striking distance of lightning to the ground and the critical striking distance; the lightning tower lightning withstand level when the lightning bypasses the line is obtained by checking and calculating the tower where lightning strikes according to the critical current of lightning when the lightning bypasses the line;

[0010] When the lightning withstand level when the lightning bypasses the line is greater than the critical current, the lightning withstand level is divided into the lightning current amplitude; when the lightning withstand level is less than the critical current, the lightning withstand level and the critical current amplitude are both divided into the lightning current amplitude;

[0011] The lightning current parameters under lightning back striking and bypassing the line are obtained by using the lightning striking amplitude when the lightning back strikes the line and the lightning current amplitude when the lightning bypasses the line, and taking the steep wave head, short time interval and long duration as the basis, and combining the lightning parameters of direct lightning.

[0012] Preferably, the equation for obtaining the lightning tower lightning withstand level when the lightning back strikes the line is:

[0013]

[0014] Wherein: k1 is the corona coefficient; k0 is the lightning conductor and conductor coupling coefficient; β is the tower shunt coefficient; R ch is the tower grounding resistance; U 50％ is the 50% flashover voltage of the insulator string; L gt is the tower inductance; H d is the average height of the conductor.

[0015] Preferably, the equation for obtaining the striking distance of lightning to the ground, the striking distance of lightning to the conductor and the striking distance of lightning to the ground is:

[0016] r s = 10I 0.65

[0017] r c = 1.63 × (5.015I 0.578 + U ph ) 1.125

[0018]

[0019] Wherein: r sThe striking distance of lightning to the ground; r c The striking distance of lightning to the conductor; r g The striking distance of lightning to the ground; h c.av The average height of the conductor to the ground; U ph The instantaneous value of the power frequency phase voltage on the conductor.

[0020] Preferably, the acquisition of the lightning conductor protection angle comprises:

[0021] The striking distance of lightning to the ground corresponding to different lightning current amplitudes I s And the striking distance of lightning to the conductor r c Different;

[0022] When the lightning current amplitude I gradually increases, the exposed arc gradually shrinks; when the lightning current amplitude I increases to the critical current I m , the exposed arc shrinks to zero;

[0023] When the lightning current amplitude I is greater than the critical current I m , the lightning will directly hit the lightning conductor or hit the ground, and the lightning will not occur around the strike, at this time θ1=θ2, and:

[0024]

[0025] Where: θ1 is the angle corresponding to the exposed arc at the lower end; θ2 is the angle corresponding to the exposed arc at the upper end; θ is the lightning conductor protection angle; H c The height of the conductor to the ground; SC is the distance from the conductor to the lightning conductor.

[0026] Preferably, the acquisition equation of the critical striking distance is:

[0027]

[0028] Where: θ is the lightning conductor protection angle; θ g The ground inclination angle; h s The average height of the lightning conductor to the ground; h c The average height of the conductor to the ground.

[0029] Preferably, the acquisition equation of the lightning stroke tower lightning withstand level when the lightning strikes the line is:

[0030] I=4U 50％ / Z≈U 50％ / 100

[0031] Where: Z is the wave impedance of the transmission line.

[0032] Preferably, the acquisition of the lightning current parameters under lightning back strike and around strike lines comprises:

[0033] The lightning stroke amplitude when lightning counterattacks the line, and the lightning current amplitude when lightning bypasses the line obtained according to the lightning withstand level and the size of the critical current when lightning bypasses the line, are used to obtain the most severe lightning current parameters under lightning counterattack and bypass of the line, with the wave head steep, short time interval and long duration as the basis, combined with the 95% high probability parameters in the lightning current waveform observation statistics of the CIRGE of the direct lightning.

[0034] The embodiment of the application also provides a power transmission line multiple lightning stroke waveform parameter evaluation device, comprising:

[0035] The lightning counterattack module is used to obtain the lightning stroke tower lightning withstand level when lightning counterattacks the line, and simultaneously obtain the lightning stroke amplitude when lightning counterattacks the line;

[0036] The lightning bypass module is used to obtain the bypass critical current amplitude under the lightning bypass mode according to the EGM striking distance theory, obtain the striking distance of lightning to ground wire, the striking distance of lightning to conductor and the striking distance of lightning to ground according to the bypass critical current amplitude, and obtain the lightning protection angle of the lightning arrester wire and the critical striking distance by using the lightning protection angle of the lightning arrester wire;

[0037] The critical current when lightning bypasses the line is obtained according to the bypass critical current amplitude, the striking distance of lightning to ground wire, the striking distance of lightning to conductor, the striking distance of lightning to ground and the critical striking distance, and the lightning stroke tower lightning withstand level when lightning bypasses the line is obtained by checking and calculating the tower at the lightning stroke position according to the critical current when lightning bypasses the line;

[0038] The bypass lightning current amplitude module is used to divide the lightning withstand level as the lightning current amplitude when the lightning withstand level when lightning bypasses the line is greater than the critical current, and divide the lightning withstand level and the critical current amplitude as the lightning current amplitude when the lightning withstand level is less than the critical current;

[0039] The lightning current parameter obtaining module is used to obtain the lightning current parameters under lightning counterattack and bypass of the line by using the lightning stroke amplitude when lightning counterattacks the line and the lightning current amplitude when lightning bypasses the line, and with the wave head steep, short time interval and long duration as the basis, combined with the direct lightning parameters.

[0040] Preferably, the lightning bypass module comprises a critical unit, a striking distance unit and a calculation unit.

[0041] The critical unit is used to obtain the bypass critical current amplitude under the lightning bypass mode according to the EGM striking distance theory;

[0042] The striking distance unit is used for obtaining the striking distance of lightning to ground wire, the striking distance of lightning to conductor and the striking distance of lightning to ground according to the striking critical current amplitude, and obtaining the lightning wire protection angle according to the striking distance of lightning to ground wire, the striking distance of lightning to conductor and the striking distance of lightning to ground, and obtaining the critical striking distance by using the lightning wire protection angle.

[0043] The accounting unit is used for obtaining the critical current when lightning strikes the line according to the striking critical current amplitude, the striking distance of lightning to ground wire, the striking distance of lightning to conductor, the striking distance of lightning to ground and the critical striking distance, and verifying and accounting the tower at lightning position according to the critical current when lightning strikes the line to obtain the lightning tower lightning withstand level when lightning strikes the line.

[0044] The striking lightning current amplitude module judges the most severe lightning current amplitude when no flashover occurs and the most severe lightning current amplitude when flashover occurs when judging the size of the lightning withstand level and the critical current.

[0045] The lightning current parameter acquisition module selects the parameters under 95% high probability as the multiple lightning waveform parameters under extreme working conditions when obtaining the lightning current parameters.

[0046] The embodiment of the application further provides an electronic device comprising a memory and a processor.

[0047] The memory is used for storing a computer program.

[0048] The processor is used for executing the computer program stored in the memory to realize the steps of the power transmission line multiple lightning stroke waveform parameter evaluation method.

[0049] The embodiment of the application provides a power transmission line multiple lightning stroke waveform parameter evaluation method, device and equipment, which has the following advantages compared with the prior art:

[0050] The present application divides the lightning strike mode into back strike and around strike, obtains the lightning withstand level and lightning amplitude when lightning directly strikes the line, and specifically analyzes the striking distance of lightning to ground wire, the striking distance of lightning to conductor, the striking distance of lightning to ground, and the protection angle and critical striking distance when the lightning arrester is adopted, analyzes the critical current and lightning withstand level when lightning around the line, and compares the critical current and lightning withstand level when lightning around the line to obtain the lightning current amplitude of lightning around the line under the actual condition of the line, which is different from the mode of directly using the lightning current sensor, but by dividing the lightning into direct back strike and around strike, and focusing on analyzing the lightning current amplitude when lightning around the line, the analysis condition is closer to the actual condition of the line, the captured lightning current is complete and has low distortion, and then the lightning amplitude when lightning back strikes the line and the lightning current amplitude when lightning around the line are used to obtain the most severe lightning current parameter, so that the accuracy of the evaluation of multiple lightning waveform parameters is greatly improved, and specific guidance can be provided for the design of the current stage of ultra-high voltage alternating current transmission line.

[0051] Moreover, the tower grounding resistance, 50% flashover voltage of the insulator string, tower inductance, lightning arrester and conductor coupling coefficient, conductor average height, lightning arrester average height, conductor to lightning arrester distance, lightning arrester protection angle, bottom surface inclination angle and other parameters are taken from the actual transmission line, and the design of the actual transmission line is more targeted. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 A whole flowchart of a transmission line multiple lightning strike waveform parameter evaluation method, device and equipment provided by the embodiment of the present application is shown in the figure;

[0053] Figure 2 An electrical geometric model diagram of lightning current around the line of the transmission line multiple lightning strike waveform parameter evaluation method, device and equipment provided by the embodiment of the present application is shown in the figure;

[0054] Figure 3 A most severe back strike multiple lightning bus overvoltage simulation waveform diagram of the transmission line multiple lightning strike waveform parameter evaluation method, device and equipment provided by the embodiment of the present application is shown in the figure;

[0055] Figure 4 A most severe around strike multiple lightning bus overvoltage simulation waveform diagram of the transmission line multiple lightning strike waveform parameter evaluation method, device and equipment provided by the embodiment of the present application is shown in the figure;

[0056] Figure 5 A most severe around strike multiple lightning bus overvoltage simulation waveform diagram of the transmission line multiple lightning strike waveform parameter evaluation method, device and equipment provided by the embodiment of the present application is shown in the figure;

[0057] Figure 6 The most severe anti-charge multiple lightning under the energy absorption process schematic diagram of the arrester of the power transmission line multiple lightning waveform parameter evaluation method, device and equipment provided by the embodiment of the application is shown in the figure;

[0058] Figure 7 The most severe shielding multiple lightning under the energy absorption process schematic diagram of the arrester when no flashover occurs of the power transmission line multiple lightning waveform parameter evaluation method, device and equipment provided by the embodiment of the application is shown in the figure;

[0059] Figure 8 The most severe shielding multiple lightning under the energy absorption process schematic diagram of the arrester when flashover occurs of the power transmission line multiple lightning waveform parameter evaluation method, device and equipment provided by the embodiment of the application is shown in the figure. DETAILED DESCRIPTION

[0060] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application are described in detail below with reference to the accompanying drawings. In the following description, a large number of specific details are set forth in order to provide a sufficient understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the scope of the present application, and therefore the present application is not limited to the specific embodiments disclosed below.

[0061] Referring to Figures 1-8 The embodiment of the present application provides a power transmission line multiple lightning waveform parameter evaluation method, in which the tower grounding resistance, the 50% flashover voltage of the insulator string, the tower inductance, the lightning rod and the conductor coupling coefficient, the average height of the conductor, the average height of the lightning rod to the ground, the distance from the conductor to the lightning rod, the protection angle of the lightning rod, and the bottom surface inclination angle are taken from the power transmission line when calculating the lightning parameters, and there is no unified standard, which is determined according to the specific situation.

[0062] The key points of lightning parameter calculation include:

[0063] ①When the lightning rod is installed in the system, there are two kinds of lightning line conditions that are harmful to the system: one is that the lightning bypasses the lightning rod and strikes the conductor, and the second is that the lightning strikes the tower top; by calculating the line anti-charge lightning level, the shielding failure lightning level and the shielding failure critical current, the invasion lightning current amplitude in the extreme case can be obtained.

[0064] ②In addition to the amplitude, the remaining lightning parameters can be combined with the CIRGE lightning current waveform observation statistical results to optimize the parameters under the 95% high probability for calculation.

[0065] Specifically, the following steps are included:

[0066] Step one: calculate the multiple lightning waveform, first calculate the maximum lightning current amplitude of counterattack, after obtaining the relevant parameters, calculate the lightning tower lightning withstand level I1:

[0067]

[0068] Wherein: k1 is the corona coefficient; k0 is the lightning wire and conductor coupling coefficient; β is the tower shunt coefficient; R ch is the tower grounding resistance; U 50％ is the 50% flashover voltage of the insulator string; L gt is the tower inductance; H d is the average height of the conductor.

[0069] Step two: then, the critical current amplitude of the shielding of the EGM strike distance theory is calculated, as shown in Figure 2 For lightning current amplitude I, the corresponding striking distance r s , r c and r g can be obtained, the formula is as follows:

[0070] r s = 10I 0.65

[0071] r c = 1.63×(5.015I 0.578 + U ph ) 1.125

[0072]

[0073] Wherein: r s is the striking distance of lightning to ground; r c is the striking distance of lightning to conductor; r g is the striking distance of lightning to ground; h c.av is the average height of the conductor to ground; U ph is the instantaneous value of the power frequency phase voltage on the conductor.

[0074] Arc A i B i is the protection arc, arc BD is the exposed arc, DE plane is the ground lightning catching surface, the striking distance r s and r c corresponding to different lightning current amplitudes I are different; with the increase of lightning current amplitude, the exposed arc BD gradually decreases, when the lightning current amplitude increases to the critical current I m , the exposed arc BD is reduced to zero; when the lightning current amplitude is greater than I m , or hit the lightning wire, or hit the ground, no shielding occurs, at this time θ1=θ2, the formula is as follows:

[0075]

[0076] Wherein: θ is the protection angle of the lightning conductor; H c is the height of the conductor to the ground; SC is the distance from the conductor to the lightning conductor; and it can be known that the critical striking distance is r SC :

[0077]

[0078] Wherein: θ is the protection angle of the lightning conductor; θ g is the ground inclination; h s is the average height of the lightning conductor to the ground; h c is the average height of the conductor to the ground.

[0079] The critical current when lightning strikes the line can be obtained through the above formula.

[0080] Step three: select the tower at the lightning strike position for verification and calculation, calculate the lightning strike point of the lightning shielding level, and calculate the flashover lightning current amplitude:

[0081] I = 4U 50％ / Z ≈ U 50％ / 100

[0082] Wherein: Z is the wave impedance of the transmission line.

[0083] Step four: in summary, the critical current and lightning withstand level under the shielding condition are obtained; if the critical current amplitude is greater than the lightning withstand level, the critical current and lightning withstand level two severe lightning conditions are considered; if the critical current amplitude is less than the lightning withstand level, only the lightning withstand level is considered.

[0084] Step five: the lightning strike interval, lightning waveform and other parameters can be combined with the 95% high probability parameters in the CIRGE lightning current waveform observation statistics; the multiple lightning strike number is set to 5 times, and the key waveform parameter statistical results are shown in Table 1. Taking the wave head steep, short time interval and long duration as the index, the most severe lightning current parameters under the shielding and back striking conditions are summarized.

[0085] Table 1: Direct lightning current parameters of CIRGE statistics

[0086]

[0087] Specific application:

[0088] Here, taking a certain 500kV extra-high voltage AC transmission line as an example, the multiple lightning waveform parameters under extreme conditions are calculated.

[0089] Under the back strike condition, the formula for calculating the system coupling coefficient k is k=k0k1, wherein k1 is the corona coefficient, taking 1.28; k0 is the lightning conductor and the conductor coupling coefficient, taking 0.22; the tower shunt coefficient takes 0.88; the tower grounding resistance takes 5.2 Ω; the 50% flashover voltage of the insulator string takes 2445.22 kV; the tower inductance takes 21.65 μH; the average height of the conductor takes 35.5 m; and the back strike lightning withstand level of the lightning fault point 218# tower B phase (right phase) is 186.33 kA, which is calculated according to the formula in step one.

[0090] Under the shielding condition, first, the critical current of lightning is calculated; the tower at both ends of the lightning strike point, the span is 242 m, the lightning conductor is 40.6 m high, the conductor is 34.69 m high, the lightning conductor protection angle is 6.5°, and the mountain slope angle is 35°, which are substituted into the calculation formula of r SC , and the critical striking distance is 111.6 m; then, according to the calculation formulas of r s , r c and r g , the critical current is calculated to be 39.4 kA; secondly, the lightning withstand level under shielding is calculated; when the voltage on the conductor increases with the increase of the lightning current amplitude, if the 50% line insulation impulse flashover voltage is 2445.22 kV, the line insulation will flashover, according to the calculation formula of the flashover lightning current amplitude I, the theoretical analysis of the shielding lightning withstand level is 24.45 kA.

[0091] If the lightning current amplitude is the shielding lightning withstand level, the shielding line will not cause the insulator to flashover at this time, and the energy of the lightning current is not discharged to the ground through the tower, but almost all of it is injected into the line arrester; if the lightning current amplitude is the critical lightning current, it will cause the insulator to flashover, and part of the energy is discharged to the ground through the tower, but since the critical lightning current amplitude is greater than the shielding lightning withstand level, the energy contained in the lightning current itself is relatively large, and the shielding lightning withstand level at this time is less than the shielding critical current, so it is not possible to determine which case has a greater impact on the arrester, therefore:

[0092] The shielding lightning withstand level is selected as the most severe lightning current amplitude when no flashover occurs; the critical current is selected as the most severe lightning current amplitude when flashover occurs.

[0093] After that, according to the CIRGE statistical data mentioned in Table 1, the parameters under the 95% high probability are optimized as the multiple lightning waveform parameters under the extreme working condition on the basis of the maximum lightning current amplitude, the steepest wave head, the shortest lightning interval, and the longest duration, so as to obtain the lightning current parameters under the corresponding back strike and shielding conditions as shown in Tables 2, 3 and 4, the overvoltage simulation results caused by lightning strike as shown in Figures 3-5 , and the response of the arrester as shown in Figures 6-8 .

[0094] Table 2 multiple lightning stroke parameters in the most severe back strike case

[0095]

[0096]

[0097] Table 3 multiple lightning stroke parameters in the most severe shielding failure case without flashover

[0098] Number of strikes Time of occurrence / ms Wave front time / μs Wave tail time / μs Strike amplitude / kA First strike 0 1.8 200 24.45 Second strike 7 0.22 140 24.45 Third strike 14 0.22 140 24.45 Fourth strike 21 0.22 140 24.45 Fifth strike 28 0.22 140 24.45

[0099] Table 4 multiple lightning stroke parameters in the most severe shielding failure case with flashover

[0100] Number of strikes Time of occurrence / ms Wave front time / μs Wave tail time / μs Strike amplitude / kA First strike 0 1.8 200 39.4 Second strike 7 0.22 140 39.4 Third strike 14 0.22 140 39.4 Fourth strike 21 0.22 140 39.4 Fifth strike 28 0.22 140 39.4

[0101] The application directly brings in the multiple lightning stroke parameters under the standard, and the multiple lightning waveform parameter evaluation method based on the calculation of lightning working conditions comprehensively considers the actual situation of the line and a large number of multiple lightning stroke statistical results, and is more targeted; the evaluation method can summarize the most severe lightning stroke situation of the line, and provides certain technical support for the safe operation of the system; when the line is not equipped with a monitoring device, the evaluation method is more direct and effective; in view of a plurality of recorded ultra-high voltage arrester damage accidents in recent years, the evaluation method can meet the protection requirements of multiple lightning strokes, and provide guiding opinions; the evaluation method comprehensively considers the actual situation of the line and the multiple lightning observation statistical results, and gives reasonable boundaries for the multiple lightning overvoltage analysis of the system, and is suitable for the insulation coordination design of the system in the design stage.

[0102] The embodiment of the application also provides a transmission line multiple lightning stroke waveform parameter evaluation device, which comprises:

[0103] The lightning back strike module is used for acquiring the lightning stroke tower lightning withstand level when lightning back strikes the line; and simultaneously acquiring the lightning stroke amplitude when lightning back strikes the line.

[0104] The lightning shielding failure module is used for acquiring the shielding failure critical current amplitude in the lightning shielding failure mode according to the EGM striking distance theory; acquiring the striking distance of lightning to the ground wire, the striking distance of lightning to the conductor and the striking distance of lightning to the ground according to the shielding failure critical current amplitude; and acquiring the lightning wire protection angle according to the striking distance of lightning to the ground wire, the striking distance of lightning to the conductor and the striking distance of lightning to the ground, and acquiring the critical striking distance by using the lightning wire protection angle.

[0105] According to the shielding failure critical current amplitude, the striking distance of lightning to the ground wire, the striking distance of lightning to the conductor, the striking distance of lightning to the ground and the critical striking distance, the critical current when lightning shielding failure occurs is acquired; the tower at the lightning stroke position is checked and calculated according to the critical current when lightning shielding failure occurs, and the lightning stroke tower lightning withstand level when lightning shielding failure occurs is acquired.

[0106] The lightning current amplitude module, when the lightning withstand level of the lightning stroke tower is greater than the critical current when the lightning strikes the line, classifies the lightning withstand level as the lightning current amplitude; when the lightning withstand level is less than the critical current, classifies the lightning withstand level and the critical current amplitude as the lightning current amplitude.

[0107] The lightning current parameter acquisition module acquires the lightning current parameters under the lightning back strike and the lightning stroke line by using the lightning stroke amplitude when the lightning strikes the line and the lightning current amplitude when the lightning strokes the line, and by taking the steep wave head, the short time interval and the long duration as the basis.

[0108] The lightning stroke module comprises a critical unit, a stroke distance unit and a calculation unit.

[0109] The critical unit is used for acquiring the stroke critical current amplitude under the lightning stroke mode according to the EGM stroke distance theory.

[0110] The stroke distance unit is used for acquiring the stroke distance of the lightning to the ground wire, the stroke distance of the lightning to the conductor and the stroke distance of the lightning to the ground according to the stroke critical current amplitude, acquiring the lightning wire protection angle according to the stroke distance of the lightning to the ground wire, the stroke distance of the lightning to the conductor and the stroke distance of the lightning to the ground, and acquiring the critical stroke distance by using the lightning wire protection angle.

[0111] The calculation unit is used for acquiring the critical current when the lightning strokes the line according to the stroke critical current amplitude, the stroke distance of the lightning to the ground wire, the stroke distance of the lightning to the conductor, the stroke distance of the lightning to the ground and the critical stroke distance, and acquiring the lightning stroke tower lightning withstand level when the lightning strokes the line by verifying and calculating the tower at the lightning stroke position according to the critical current when the lightning strokes the line.

[0112] The lightning current amplitude module judges the most severe lightning current amplitude when no flashover occurs and the most severe lightning current amplitude when the flashover occurs.

[0113] The lightning current parameter acquisition module selects the parameters under the 95% high probability as the multiple lightning waveform parameters under the extreme working condition when acquiring the lightning current parameters.

[0114] The embodiment of the application further provides an electronic device comprising a memory and a processor.

[0115] The memory is used for storing the computer program.

[0116] The processor is used for executing the computer program stored in the memory, and realizes the steps of the power line multiple lightning stroke waveform parameter evaluation method.

[0117] In summary, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment containing both software and hardware aspects; and the present application can take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) having computer usable program code embodied in the medium; and the present application can take the form of web implementations, distributed web services architectures, other computer system- related architectures, etc. The embodiments of the present application can be implemented using a variety of computer languages including, for example, object oriented programming language Java and the interpreted scripting language JavaScript.

[0118] The present application is described in reference to the flowchart illustrations and / or block diagrams of the methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart illustrations and / or block diagrams block or blocks. Figure 1 one or more flowcharts or blocks Figure 1 means for carrying out the function specified by the block or blocks.

[0119] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart illustrations and / or block diagrams block or blocks. Figure 1 one or more flowcharts or blocks Figure 1 means for carrying out the function specified by the block or blocks.

[0120] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart illustrations and / or block diagrams block or blocks. Figure 1 one or more flowcharts or blocks Figure 1 means for carrying out the function specified by the block or blocks.

[0121] The above-described embodiments are merely illustrative for the present application and are not in any sense limiting the present application. It should be pointed out that, for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A method for evaluating parameters of multiple lightning stroke waveforms on a power transmission line, characterized by, The method comprises the following steps: obtaining the lightning tower lightning withstand level and the lightning amplitude when lightning strikes a line in a lightning back strike mode; obtaining the critical current amplitude in a lightning shielding mode according to the EGM striking distance theory; obtaining the striking distance of lightning to ground wire, the striking distance of lightning to conductor and the striking distance of lightning to ground according to the critical current amplitude in the lightning shielding mode; and obtaining the lightning wire protection angle according to the striking distance of lightning to ground wire, the striking distance of lightning to conductor and the striking distance of lightning to ground, and obtaining the critical striking distance by using the lightning wire protection angle; obtaining the critical current in the lightning shielding mode according to the critical current amplitude, the striking distance of lightning to ground wire, the striking distance of lightning to conductor, the striking distance of lightning to ground and the critical striking distance; and verifying and checking the tower at the lightning position according to the critical current in the lightning shielding mode, and obtaining the lightning tower lightning withstand level in the lightning shielding mode; when the lightning withstand level in the lightning shielding mode is greater than the critical current, the lightning withstand level is classified as the lightning current amplitude; and when the lightning withstand level is less than the critical current, the lightning withstand level and the critical current amplitude are classified as the lightning current amplitude simultaneously; obtaining the lightning current parameters in the lightning back strike mode and the lightning shielding mode by using the lightning amplitude in the lightning back strike mode and the lightning current amplitude in the lightning shielding mode, and taking the steep wave front, the short time interval and the long duration as the basis, and combining the direct lightning parameters.

2. The method for evaluating parameters of multiple lightning waveform of a transmission line according to claim 1, wherein, The equation for obtaining the lightning tower lightning withstand level in the lightning back strike mode is: where: k 1 is the corona factor; k 0 is the lightning conductor and conductor coupling factor; β is the tower shunt factor; R ch is the tower grounding resistance; U 50% is the 50% flashover voltage of the insulator string; L gt is the tower inductance; H d is the average height of the conductor.

3. The method of claim 1, wherein the method comprises: The equation for obtaining the striking distance of lightning to ground wire, the striking distance of lightning to conductor and the striking distance of lightning to ground is: wherein: r s is the striking distance of lightning to ground; r c is the striking distance of lightning to the conductor; r g is the striking distance of lightning to ground; h c.av is the average height of the conductor above ground; U ph is the instantaneous value of the power frequency phase voltage on the conductor.

4. The method of claim 3, wherein the method further comprises: The lightning wire protection angle is obtained by: Different lightning current amplitudes I Corresponding lightning strike distances to ground r s And lightning strike distances to conductor r c Different; As the amplitude of the lightning current I increases, the exposure arc decreases; and when the amplitude of the lightning current I increases to a critical current I m , the exposure arc decreases to zero. When the lightning current amplitude I is greater than the critical current I m , the lightning will directly hit the lightning conductor or hit the ground, the lightning does not occur around the strike, at this time θ 1= θ 2, there is: Wherein: θ 1 is the angle corresponding to the exposed arc of the lower end; θ 2 is the angle corresponding to the exposed arc of the upper end; θ is the protection angle of the lightning conductor; H c is the height of the conductor to the ground; SC is the distance from the conductor to the lightning conductor.

5. The method of claim 1, wherein the method further comprises: The equation for obtaining the critical striking distance is: where: θ is the lightning protection angle; θ g is the ground inclination angle; h s is the average height of the lightning conductor above the ground; h c is the average height of the conductor above the ground.

6. The method of claim 1, wherein, The equation for obtaining the lightning tower lightning withstand level in the lightning shielding mode is: wherein: Z is the wave impedance of the transmission line.

7. The method of claim 1, wherein the method further comprises: The lightning current parameters in the lightning back strike mode and the lightning shielding mode are obtained by: obtaining the most severe lightning current parameters in the lightning back strike mode and the lightning shielding mode by using the lightning amplitude in the lightning back strike mode, the lightning current amplitude in the lightning shielding mode, taking the steep wave front, the short time interval and the long duration as the basis, and combining the 95% high probability parameters in the lightning current waveform observation statistics of the CIRGE.

8. A device for evaluating waveform parameters of multiple lightning strikes on transmission lines, characterized in that, The method comprises the following steps: a lightning back strike module, configured to obtain the lightning tower lightning withstand level and the lightning amplitude when lightning strikes a line in a lightning back strike mode; a lightning shielding module, configured to obtain the critical current amplitude in a lightning shielding mode according to the EGM striking distance theory; obtain the striking distance of lightning to ground wire, the striking distance of lightning to conductor and the striking distance of lightning to ground according to the critical current amplitude in the lightning shielding mode; and obtain the lightning wire protection angle according to the striking distance of lightning to ground wire, the striking distance of lightning to conductor and the striking distance of lightning to ground, and obtain the critical striking distance by using the lightning wire protection angle; obtain the critical current in the lightning shielding mode according to the critical current amplitude, the striking distance of lightning to ground wire, the striking distance of lightning to conductor, the striking distance of lightning to ground and the critical striking distance; and verify and check the tower at the lightning position according to the critical current in the lightning shielding mode, and obtain the lightning tower lightning withstand level in the lightning shielding mode; The lightning current amplitude module, when lightning strikes the line, the lightning level is greater than the critical current, the lightning level is divided into lightning current amplitude; when the lightning level is less than the critical current, the lightning level and the critical current amplitude are divided into lightning current amplitude at the same time; The lightning current parameter acquisition module uses the lightning amplitude when the lightning strikes the line and the lightning current amplitude when the lightning strikes the line, and takes the steep wave head, short time interval and long duration as the basis, and obtains the lightning current parameters under the lightning strike and the lightning strike line by combining the lightning parameters.

9. The power transmission line multiple lightning waveform parameter evaluation device according to claim 8, characterized in that, The lightning striking module includes a critical unit, a striking distance unit and an accounting unit; The critical unit is used to obtain the critical current amplitude of the lightning striking mode according to the EGM striking distance theory; The striking distance unit is used to obtain the striking distance of lightning to ground wire, the striking distance of lightning to conductor and the striking distance of lightning to ground according to the critical current amplitude of lightning striking; the protection angle of lightning wire is obtained according to the striking distance of lightning to ground wire, the striking distance of lightning to conductor and the striking distance of lightning to ground, and the critical striking distance is obtained by using the protection angle of lightning wire; The accounting unit is used to obtain the critical current when lightning strikes the line according to the critical current amplitude of lightning striking, the striking distance of lightning to ground wire, the striking distance of lightning to conductor, the striking distance of lightning to ground and the critical striking distance; the lightning tower at lightning position is checked according to the critical current when lightning strikes the line, and the lightning tower lightning level when lightning strikes the line is obtained; The results of the lightning current amplitude module in judging the size of lightning level and critical current are the most severe lightning current amplitude when no flashover occurs and the most severe lightning current amplitude when flashover occurs; When the lightning current parameter acquisition module obtains the lightning current parameters, it selects the parameters under 95% high probability as the multiple lightning waveform parameters under extreme working conditions.

10. An electronic device, comprising: It includes: Memory and processor; The memory is used to store computer programs; The processor is used to execute the computer programs stored in the memory, and realizes the steps of the power transmission line multiple lightning waveform parameter evaluation method according to any one of claims 1~7.

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