A life assessment method for lightning arrester resistor

Abstract

The present invention relates to the technical field of electrical performance testing, and in particular to a life assessment method for a lightning arrester resistor. The method obtains a unit impact loss coefficient and a unit self-loss coefficient through two simulations. The use scenario simulation process is divided into two cases. The pre-lightning loss coefficient is determined according to the unit self-loss coefficient in a case where there is no lightning strike and the use environment parameters; the unit self-loss coefficient is adjusted according to the degree of lightning strike after being struck by lightning, and then the post-lightning loss coefficient after being struck by lightning is obtained. The service life assessment of the lightning arrester resistor is realized by constructing a resistor performance loss function. According to the specific characteristics of the actual use scenario, the present invention takes into account the factor of the resistor's own loss and obtains an accurate loss coefficient for the life assessment of the resistor.

Description

Technical Field

[0001] The invention relates to the technical field of electrical performance testing, and in particular to a life evaluation method for a lightning arrester resistor. Background Art

[0002] Lightning arresters are key devices for limiting overvoltage in power systems. Their overvoltage protection level largely determines the insulation level of various equipment in power systems. During normal operation, lightning arresters are in an insulating state. When overvoltage occurs or lightning high voltage strikes, the arrester immediately acts, quickly changes to low resistance, conducts shunts, discharges impact energy, and ensures that the current generated by overvoltage or lightning strikes passes through the grounding method, limiting the operating voltage of the equipment to a certain level to avoid harming the protected equipment. After the impact current passes, it returns to a high-resistance state again. The arrester resistor will withstand overvoltage shocks such as lightning during work, so there will be certain losses. In order to ensure stability and safety during the power use process, it is necessary to accurately predict the loss of the arrester resistor, and then determine the service life, so that the staff can replace the resistor in time.

[0003] In the prior art, the changes in electrical parameters of the arrester resistor before and after the lightning strike can be measured by simulating lightning strikes, and the performance changes can be determined based on the changes, thereby constructing a performance loss function to predict the life of the resistor. However, in actual use, as environmental parameters change, the resistor itself will experience irreversible loss changes, and as the number and severity of lightning strikes increase in actual use, the resistor itself will also experience irreversible loss. Therefore, the prior art does not take its own loss into account, which will result in the performance loss function being unable to accurately characterize the performance changes of the resistor and unable to accurately predict the life of the resistor. Summary of the invention

[0004] In order to solve the technical problem that the prior art does not take into account the influence of the irreversible loss of the resistor itself on the life prediction, resulting in inaccurate life assessment, the purpose of the present invention is to provide a life assessment method for a lightning arrester resistor, and the technical solution adopted is as follows:

[0005] The present invention provides a life assessment method for a lightning arrester resistor, the method comprising:

[0006] The arrester resistor sample is simulated with lightning strike, and the unit impact loss coefficient is obtained according to the change characteristics of the electrical parameters before and after the simulated lightning strike;

[0007] Simulate environmental changes for arrester resistor samples, and obtain unit self-loss coefficients according to the change characteristics of electrical parameters before and after the simulated environmental changes and the corresponding simulated environmental parameters; the unit self-loss coefficients include unit temperature loss coefficients and unit humidity loss coefficients;

[0008] For the arrester resistor to be analyzed in the simulated usage scenario, obtain the loss coefficient before lightning strike and the loss coefficient after lightning strike; when not struck by lightning, obtain the loss coefficient before lightning strike according to the unit self-loss coefficient and the actual environmental parameters; after each lightning strike, obtain the instantaneous lightning strike loss coefficient according to the loss coefficient before lightning strike, the degree of lightning strike and the unit impact loss coefficient; according to the degree of lightning strike and the unit impact loss coefficient, obtain the adjustment coefficient and adjust the unit self-loss coefficient before the current lightning strike, and obtain the loss coefficient after lightning strike according to the adjusted unit self-loss coefficient and the actual environmental parameters combined with the instantaneous lightning strike loss coefficient;

[0009] A resistor performance loss function is constructed according to the corresponding pre-lightning loss coefficient and post-lightning loss coefficient in the simulated usage scenario, and the life of the arrester resistor is evaluated according to the resistor performance loss function.

[0010] Furthermore, the variation characteristics of the electrical parameters include:

[0011] The difference in leakage current density of arrester resistor samples before and after the simulated lightning strike is taken as the first variation feature;

[0012] The difference in power loss of the arrester resistor sample before and after the simulated lightning strike is taken as the second variation feature;

[0013] The voltage difference of the arrester resistor sample before and after the simulated lightning strike at 1 mA DC is taken as the third variation feature;

[0014] The first change characteristic, the second change characteristic and the third change characteristic are merged to obtain the change characteristic of the electrical parameter.

[0015] Furthermore, the method for obtaining the unit impact loss coefficient includes:

[0016] Multiplying the impulse current amplitude and the impulse time under the simulated lightning strike process to obtain a first state parameter;

[0017] The ratio of the change characteristics of the electrical parameters before and after the simulated lightning strike to the first state parameter is used as the unit impact loss coefficient.

[0018] Furthermore, the method for obtaining the unit self-loss coefficient includes: the simulated environmental change includes a process of changing humidity at a fixed temperature and a process of changing temperature at a fixed humidity;

[0019] In the process of changing the temperature at a fixed humidity, a second state parameter is obtained according to the temperature information and the simulation time during the simulated environment change process; the ratio of the change characteristics of the electrical parameters before and after the simulated environment change to the second state parameter is used as the unit temperature loss coefficient;

[0020] In the process of changing humidity at a fixed temperature, the third state parameter is obtained according to the humidity information and simulation time during the simulated environmental change process, and the ratio of the change characteristics of the electrical parameters before and after the simulated environmental change to the third state parameter is used as the unit humidity loss coefficient.

[0021] Furthermore, the method for obtaining the second state parameter and the third state parameter includes:

[0022] The product of the simulated temperature average value and the simulation time in the process of changing the temperature with fixed humidity is taken as the second state parameter;

[0023] The product of the simulated humidity average value and the simulation time in the process of changing humidity at a fixed temperature is used as the third state parameter.

[0024] Furthermore, the method for obtaining the loss coefficient before lightning strike when not struck by lightning includes:

[0025] The product of the unit temperature loss coefficient and the temperature information in the actual environmental parameters is used as the temperature loss coefficient; the product of the unit humidity loss coefficient and the humidity information in the actual environmental parameters is used as the humidity loss coefficient; the sum of the temperature loss coefficient and the humidity loss coefficient is used as the loss coefficient before lightning strike when not struck by lightning.

[0026] Further, the obtaining of the instantaneous lightning loss coefficient immediately after being struck by lightning comprises:

[0027] Multiply the lightning strike time, lightning strike current intensity, and unit strike loss coefficient to obtain the strike loss amount;

[0028] The lightning loss amount is added to the loss coefficient before being struck by lightning to obtain the instantaneous lightning loss coefficient immediately after being struck by lightning.

[0029] Furthermore, the method for obtaining the adjustment coefficient includes:

[0030] The lightning current intensity of the current lightning strike, the unit impact loss coefficient and the cumulative number of lightning strikes before the current lightning strike are multiplied to obtain an initial adjustment coefficient, and half of the initial adjustment coefficient is used as the adjustment coefficient.

[0031] Furthermore, the adjustment of the unit self-loss coefficient before the current lightning strike includes:

[0032] The unit self-loss coefficient before the current lightning strike is added to the adjustment coefficient to obtain the adjusted unit self-loss coefficient.

[0033] Furthermore, the horizontal axis of the resistor performance loss function is the usage time, and the vertical axis is the corresponding loss coefficient under the simulated usage scenario.

[0034] The present invention has the following beneficial effects:

[0035] The present invention first obtains the unit impact loss coefficient and the unit self-loss coefficient through two simulations. Both coefficients are the losses generated under each unit, which is convenient for subsequent data analysis. In the subsequent data analysis process, the actual application process is divided into two cases, and the loss coefficients generated in the two cases are evaluated respectively, so that the resistor loss in different cases is accurately and effectively obtained. Considering that the main loss cause when not struck by lightning is the length of use, and the main loss cause after being struck by lightning is the irreversible loss caused by the lightning strike, therefore, combining various parameters can obtain accurate loss coefficients in different cases, and then construct a resistor performance loss function, and the life of the arrester resistor can be accurately evaluated through the trend of the resistor performance loss function. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 A flow chart of a life assessment method for a lightning arrester resistor provided by an embodiment of the present invention;

[0038] Figure 2 A flow chart of a method for acquiring characteristics of changes in electrical parameters provided by one embodiment of the present invention;

[0039] Figure 3 A schematic diagram of a unit self-loss coefficient changing with the number of lightning strikes provided by an embodiment of the present invention;

[0040] Figure 4 A schematic diagram of the adjustment coefficient ratio provided by an embodiment of the present invention;

[0041] Figure 5 A schematic diagram of a resistor performance loss function provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the life assessment method of a lightning arrester resistor according to the present invention, its specific implementation method, structure, characteristics and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0043] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0044] A specific scheme of a life assessment method for a lightning arrester resistor provided by the present invention is described in detail below in conjunction with the accompanying drawings.

[0045] See also Figure 1 , which shows a flow chart of a life assessment method for a lightning arrester resistor provided by an embodiment of the present invention, the method comprising:

[0046] Step S101: simulating a lightning strike on a lightning arrester resistor sample, and obtaining a unit impact loss coefficient according to the change characteristics of electrical parameters before and after the simulated lightning strike.

[0047] In some implementations of the embodiments of the present invention, a lightning arrester resistor sample is energized in a laboratory environment, and the lightning strike process is simulated by setting the magnitude of the energized current and the energized time. It should be noted that the lightning arrester resistor sample is a sample randomly selected from a batch, so the measured characteristic quantity is applicable to all lightning arrester resistors in the corresponding batch. In the process of simulating lightning strikes, the change characteristics of the electrical parameters before and after the simulated lightning strike are measured using measuring equipment such as an electrical parameter measurement meter or a sensor, and then the unit impact loss coefficient is obtained according to the change characteristics of the electrical parameters. The unit impact loss coefficient represents the loss that the resistor will generate under a standard unit, and the standard unit is the unit time and the unit current impact amount. In one embodiment of the present invention, the unit of unit time is 1ms, and the unit of unit current impact amount is 1KA. It should be noted that the units of the two states can be specifically set according to the actual situation. Because the subsequent calculations of the embodiments of the present invention need to be dimensionless, there is no need to specifically limit the units, and only the units need to be consistent.

[0048] It should be noted that the calculation data involved in the embodiments of the present invention are all dimension-eliminated data. By eliminating the dimension, the fusion calculation between different unit data can be realized, and the corresponding features can be accurately quantified. The specific method of eliminating the dimension can be implemented by normalization, standardization and other methods, which will not be elaborated or limited here.

[0049] See also Figure 2 , which shows a flow chart of a method for acquiring a characteristic of a change in an electrical parameter provided by an embodiment of the present invention. Preferably, in some implementations of the embodiments of the present invention, the method for acquiring a characteristic of a change in an electrical parameter is as follows: Figure 2 As shown, specifically including:

[0050] Step S201: taking the difference in leakage current density of the arrester resistor sample before and after the simulated lightning strike as the first change feature.

[0051] If the arrester resistor produces a certain amount of loss after the simulated lightning strike, the leakage current density of the resistor in the breakdown area will be significantly different from that before the lightning strike. Therefore, the leakage current density can be used as an important feature to evaluate the change of electrical parameters.

[0052] It should be noted that the collection of leakage current of the resistor sample and the method for obtaining the leakage current density are both technical means well known to those skilled in the art, and the specific contents are not repeated here. Here, a specific implementation of the embodiment of the present invention is taken as an example. The method for obtaining the leakage current density is to divide the leakage current value by the electrode area of ​​the resistor. The difference in leakage current density is the absolute value of the difference between the leakage current density before and after the lightning strike, which is specifically expressed by the formula:

[0053] Where Δσ is the leakage current density, I q To simulate the leakage current before lightning strike, I h To simulate the leakage current after lightning strike, S is the electrode area of ​​the resistor.

[0054] Step S202: taking the power loss difference of the arrester resistor sample before and after the simulated lightning strike as the second change feature.

[0055] If a resistor produces loss after being struck by lightning, its own resistance information will change, and the power loss through the resistor will change significantly. Therefore, the change in power loss can be used as an important feature for evaluating changes in electrical parameters.

[0056] It should be noted that the method for measuring power loss is a technical means well known to those skilled in the art and will not be elaborated here. In a specific implementation of an embodiment of the present invention, the difference in power loss is the absolute value of the difference between the power loss before and after the lightning strike.

[0057] Step S203: taking the voltage difference of the arrester resistor sample under a DC of 1 mA before and after the simulated lightning strike as the third variation feature.

[0058] If the resistor is damaged after being struck by lightning, its resistance information will change, and its voltage at 1 mA DC will increase significantly. Therefore, the voltage difference at 1 mA DC can also be used as an important feature for evaluating the change of electrical parameters. In a specific implementation of the embodiment of the present invention, the absolute value of the difference between the voltage at 1 mA DC before and after the lightning strike is used as the third change feature.

[0059] Step S204: The first change characteristic, the second change characteristic and the third change characteristic are integrated to obtain the change characteristic of the electrical parameter.

[0060] By fusing the three features, a change feature that can accurately characterize the change of the electrical parameter can be obtained. In a specific implementation of the present invention, the fusion method is to normalize the three features and then calculate the average value.

[0061] It should be noted that in some other implementations of the embodiments of the present invention, the variation characteristics of electrical parameters may also be characterized by the difference in electrical parameters such as current and resistance, which will not be elaborated here.

[0062] Preferably, in some implementations of the embodiments of the present invention, since the unit impact damage coefficient represents the amount of resistor loss under a unit current impact amount and unit time, the method for obtaining the unit impact loss coefficient includes:

[0063] The impulse current amplitude and impulse time under the simulated lightning strike process are multiplied to obtain the first state parameter; the ratio of the change characteristics of the electrical parameters before and after the simulated lightning strike to the first state parameter is used as the unit impulse loss coefficient.

[0064] Step S102: Simulate environmental changes for the arrester resistor sample, and obtain the unit self-loss coefficient according to the change characteristics of the electrical parameters before and after the simulated environmental changes, and the corresponding simulated environmental parameters.

[0065] During the actual use of arrester resistors, changes in environmental parameters will also lead to loss attenuation of resistor performance. Considering that the changes in the use environment of resistors mainly include changes in temperature and humidity, it is necessary to simulate environmental changes in arrester resistor samples in a laboratory environment. Similarly, the unit self-loss coefficient is obtained based on the change characteristics of electrical parameters before and after the simulated environmental changes and the corresponding simulated environmental parameters. That is, the unit self-loss coefficient includes the unit temperature loss coefficient and the unit humidity loss coefficient, which represents the loss generated by the arrester resistor itself under the unit simulated environmental parameters.

[0066] Preferably, in some implementations of the embodiments of the present invention, the method for obtaining the unit self-loss coefficient includes:

[0067] During the simulated environmental changes of the arrester resistor samples, the main environmental parameters for the resistors are humidity information and temperature information. The arrester resistor samples need to be simulated according to the changes in temperature and humidity respectively. Therefore, the simulated environmental changes include the process of changing humidity at a fixed temperature and the process of changing temperature at a fixed humidity, so as to obtain the unit temperature loss coefficient and the unit humidity loss coefficient.

[0068] In the process of changing temperature with fixed humidity, similar to the method of obtaining the unit impact loss coefficient, in order to obtain the loss of the resistor under the unit simulated environmental parameters, it is necessary to obtain the second state parameter according to the temperature information and simulation time during the simulated environmental change process. That is, the process of changing temperature with fixed humidity corresponds to one second state parameter.

[0069] After the second state parameter is obtained, the ratio of the change characteristics of the electrical parameters before and after the simulated environment changes to the second state parameter can be used as the unit temperature loss coefficient.

[0070] In a specific implementation of the embodiment of the present invention, the unit temperature loss coefficient is expressed by the formula:

[0071] Wherein K1 is the unit temperature loss coefficient in the process of changing temperature at fixed humidity, R1 is the change characteristic of the electrical parameter in the process of changing temperature at fixed humidity, and H1 is the second state parameter in the process of changing temperature at fixed humidity.

[0072] Similarly, in the process of changing humidity at a fixed temperature, the third state parameter is obtained based on the humidity information and simulation time during the simulated environmental change process, and the ratio of the change characteristics of the electrical parameters before and after the simulated environmental change to the third state parameter is used as the unit temperature loss coefficient.

[0073] In one embodiment of the present invention, the method for obtaining the third state parameter includes: taking the product of the simulated humidity average value and the simulation time length in the process of changing humidity at a fixed temperature as the third state parameter.

[0074] As an example, the specific moisture loss coefficient is expressed as: Wherein K2 is the unit humidity loss coefficient in the process of changing humidity at a fixed temperature, R2 is the change characteristic of the electrical parameter in the process of changing humidity at a fixed temperature, and H2 is the third state parameter in the process of changing humidity at a fixed temperature.

[0075] Preferably, in some implementations of the embodiments of the present invention, the method for obtaining the second state parameter in step S302 includes:

[0076] The product of the simulated temperature average value and the simulation time in the process of changing the temperature with fixed humidity is taken as the second state parameter.

[0077] Step S103: For the arrester resistor to be analyzed in the simulated usage scenario, obtain the loss coefficient before lightning strike and the loss coefficient after lightning strike; when not struck by lightning, obtain the loss coefficient before lightning strike according to the unit self-loss coefficient and the actual environmental parameters; after each lightning strike, obtain the instantaneous lightning loss coefficient according to the loss coefficient before lightning strike, the degree of lightning strike and the unit impact loss coefficient; according to the degree of lightning strike and the unit impact loss coefficient, obtain the adjustment coefficient and adjust the unit self-loss coefficient before this lightning strike, and obtain the loss coefficient after lightning strike according to the adjusted unit self-loss coefficient and the actual environmental parameters and the instantaneous lightning loss coefficient.

[0078] After step S101 and step 102, the unit impact loss coefficient and unit self loss coefficient of the arrester resistor can be obtained through the simulation of the laboratory environment. It is necessary to determine the specific loss coefficient according to the specific use scenario in the simulated actual use process of the arrester resistor based on the obtained experimental results.

[0079] It should be noted that in some implementations of the embodiments of the present invention, in order to facilitate the acquisition of the loss coefficient, after the unit impact loss coefficient and the unit self-loss coefficient are obtained in step 101 and step 102, the two types of unit loss coefficients need to be normalized separately to limit the numerical range to between 0 and 1.

[0080] The embodiment of the present invention divides the simulated usage scenarios into two situations: before being struck by lightning and after being struck by lightning. Each usage scenario needs to analyze the corresponding loss coefficient according to the characteristics of the scenario. That is, the two situations correspond to the loss coefficient before the lightning strike and the loss coefficient after the lightning strike, respectively.

[0081] For the usage scenario without lightning strike, because the arrester resistor is not struck by lightning in this scenario, that is, it is not affected by lightning from the time it is put into use to the real time, the loss generated by the resistor is all its own loss, which is mainly related to the actual environmental parameters. Because the unit self-loss coefficient represents the resistor loss information under the unit environmental parameters, the pre-lightning loss coefficient without lightning strike can be obtained based on the unit self-loss coefficient and the actual environmental parameters.

[0082] Preferably, in one embodiment of the present invention, because the unit self-loss coefficient is divided into a unit temperature loss coefficient and a unit humidity loss coefficient in the process of obtaining the self-loss coefficient, the product of the unit temperature loss coefficient and the temperature information in the actual environmental parameters is used as the temperature loss coefficient in the scene simulation; the product of the unit humidity loss coefficient and the humidity information in the actual environmental parameters is used as the humidity loss coefficient; and the sum of the temperature loss coefficient and the humidity loss coefficient is used as the loss coefficient before lightning strike when not struck by lightning.

[0083] For each use scenario after being struck by lightning, because it is struck by lightning at that moment, there will be an obvious mutation in the loss of the resistor. The unit impact loss coefficient represents the loss generated under the standard unit of lightning strike. Therefore, the impact loss generated under this lightning strike can be obtained according to the degree of lightning strike and the unit impact loss coefficient. Further combined with the loss coefficient before the lightning strike, the instantaneous lightning loss coefficient after each lightning strike can be obtained. Because the lightning strike has caused irreversible loss to the resistor, its own characteristics will change, that is, the unit self-loss coefficient needs to be updated according to the situation of the lightning strike. The stronger the degree of lightning strike, the more the unit self-loss coefficient needs to be adjusted. Therefore, the adjustment coefficient can be obtained based on the degree of lightning strike and the unit impact loss coefficient, and the unit self-loss coefficient before this lightning strike can be adjusted according to the adjustment coefficient. That is, the unit self-loss coefficient needs to be updated after each lightning strike. Please refer to Figure 3 , Figure 3 Taking the unit temperature loss coefficient as an example, a schematic diagram showing the change of the unit temperature loss coefficient with the number of lightning strikes provided by an embodiment of the present invention is shown, wherein Figure 3 The horizontal axis is the number of lightning strikes, and the vertical axis is the unit temperature loss coefficient, that is, as the number of lightning strikes increases, the unit temperature loss coefficient should show an obvious increase. After obtaining the adjusted unit self-loss coefficient, similar to the use scenario without lightning strike, based on the adjusted unit self-loss coefficient and the actual environmental parameters, further combined with the lightning instantaneous loss coefficient, the loss coefficient after lightning strike can be obtained.

[0084] Preferably, in some implementations of the embodiments of the present invention, obtaining the instantaneous lightning loss coefficient immediately after being struck by lightning includes:

[0085] Multiply the impact time of lightning strike, lightning current intensity and unit impact loss coefficient to obtain the strike loss amount; add the strike loss amount to the loss coefficient before the lightning strike to obtain the instantaneous lightning loss coefficient immediately after the lightning strike.

[0086] Preferably, in some implementations of the embodiments of the present invention, the method for obtaining the adjustment coefficient includes:

[0087] Multiply the lightning current intensity of this lightning strike, the unit impact loss coefficient, and the cumulative number of lightning strikes before this lightning strike to obtain the initial adjustment coefficient. That is, the stronger the lightning current intensity of each lightning strike and the greater the cumulative number of lightning strikes before this lightning strike, the greater the irreversible loss of the resistor, and the greater the need to increase the unit self-loss coefficient. In order to accurately adjust the value of the unit self-loss coefficient later, please refer to Figure 4 , which shows a schematic diagram of the adjustment coefficient ratio provided by an embodiment of the present invention, Figure 4The horizontal axis is the initial adjustment coefficient weight, and the vertical axis is the loss coefficient deviation, where the loss coefficient deviation is the difference between the calculated loss coefficient and the actual measured loss coefficient. During the experimental measurement process, it was found that when the half of the initial adjustment coefficient, that is, 0.5, was adjusted, the final loss coefficient was the smallest compared to the actual measured loss coefficient. Therefore, half of the initial adjustment coefficient was used as the adjustment coefficient.

[0088] In some implementations of the embodiments of the present invention, because the unit self-loss coefficient includes the unit temperature loss coefficient and the unit humidity loss coefficient, it is necessary to use the adjustment coefficient to adjust the two unit quantities respectively, and add the unit temperature loss coefficient before the current lightning strike to the adjustment coefficient to obtain the adjusted unit temperature loss coefficient; similarly, add the unit humidity loss coefficient before the current lightning strike to the adjustment coefficient to obtain the adjusted unit humidity loss coefficient. It should be noted that, similar to the method for obtaining the loss coefficient after being struck by lightning and the loss coefficient when not struck by lightning according to the adjusted unit temperature loss coefficient, the adjusted unit humidity loss coefficient, and the actual environmental parameters, the product of the adjusted unit temperature loss coefficient and the temperature information in the actual environmental parameters is used as the temperature loss coefficient after the lightning strike; the product of the adjusted unit humidity loss coefficient and the humidity information in the actual environmental parameters is used as the humidity loss coefficient after the lightning strike; because the lightning strike will generate the lightning strike instantaneous loss coefficient, resulting in a sudden change in the overall loss coefficient, the sum of the temperature loss coefficient after the lightning strike, the humidity loss coefficient after the lightning strike, and the lightning strike instantaneous loss coefficient is used as the loss coefficient after the lightning strike, which will not be repeated here.

[0089] Step S104: construct a resistor performance loss function according to the corresponding pre-lightning loss coefficient and post-lightning loss coefficient in the simulated use scenario, and evaluate the life of the arrester resistor according to the resistor performance loss function.

[0090] According to step S103, the loss coefficient at each usage moment in the simulated usage scenario can be obtained. The loss coefficient at each usage moment can be recorded from the beginning of the scenario simulation to obtain multiple two-dimensional data, and the resistor performance loss function can be obtained through curve fitting.

[0091] In a specific implementation of the embodiment of the present invention, please refer to Figure 5 , which shows a schematic diagram of a resistor performance loss function provided by an embodiment of the present invention, Figure 5 The horizontal axis of the resistor performance loss function is time, and the vertical axis is the loss coefficient. When struck by lightning, the function will have a great mutation, resulting in an obvious step change. After being struck by lightning, the function is still an increasing function and the increase is greater than before being struck by lightning. Therefore, the resistor performance loss function is a curve that starts from the origin, continues to rise, and has a step-like change. Figure 5 The point from the origin to point A is the change of the loss coefficient before the lightning strike, that is, the stage before the lightning strike. In the stage before the lightning strike, it is an increasing function. Figure 5 The midpoint A is struck by lightning, that is, the subsequent stage is the stage after being struck by lightning. In the stage after being struck by lightning, the lightning strike may have a certain degree of continuity. The stage from point A to point B is the stage of the lightning discharge process. At point B, the instantaneous loss coefficient of the lightning strike can be obtained according to the time and size of the lightning strike, that is, the loss coefficient at point B is the instantaneous loss coefficient of the lightning strike; the stage between points B and C is the stage of natural loss after being struck by lightning, and the loss coefficient of this stage is the loss coefficient after the lightning strike; at point C, it is the second lightning strike, and it is obtained by Figure 5 It can be seen that after each lightning strike, the change trend of the loss coefficient in the natural loss stage will change to a certain extent, which means that the resistor has been irreversibly affected.

[0092] The resistor performance loss function has an obvious trend, so the loss coefficient at future moments can be predicted based on the trend of the resistor performance function. Specifically, the scene changes that will occur at future moments can be predicted by predicting factors such as the number of lightning strikes and the degree of lightning strikes, and then the loss coefficient at future moments can be obtained. For example, the number of lightning strikes and the degree of lightning strikes in the future can be evaluated through the past lightning strike statistics in the area, and then simulation settings can be performed to obtain the loss coefficient at future moments; or by setting a loss coefficient threshold, the remaining usable time of the arrester resistor can be determined by judging the future moment corresponding to the loss coefficient threshold, and then the usable life of the arrester resistor in the simulated use scenario can be obtained. The specific life assessment method can be selected according to the actual scenario, and it is not limited here.

[0093] It should be noted that because the environmental changes in different regions are not fixed and unique, the predicted useful life in different usage areas is also different. The useful life of the resistor in the corresponding area can be determined based on the results of simulating the usage scenarios of the same resistor in different regions, and then the replacement cycle of the resistor in the region can be determined or the adaptability of the resistor in the corresponding region can be evaluated.

[0094] It should be noted that the sequence of the above embodiments of the present invention is for description only and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0095] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

Claims

1. A method for evaluating the life of a lightning arrester resistor, characterized in that: The method comprises: The arrester resistor sample is simulated with lightning strike, and the unit impact loss coefficient is obtained according to the change characteristics of the electrical parameters before and after the simulated lightning strike; Simulate environmental changes for arrester resistor samples, and obtain unit self-loss coefficients according to the change characteristics of electrical parameters before and after the simulated environmental changes and the corresponding simulated environmental parameters; the unit self-loss coefficients include unit temperature loss coefficients and unit humidity loss coefficients; For the arrester resistor to be analyzed in the simulated usage scenario, obtain the loss coefficient before lightning strike and the loss coefficient after lightning strike; when not struck by lightning, obtain the loss coefficient before lightning strike according to the unit self-loss coefficient and the actual environmental parameters; after each lightning strike, obtain the instantaneous lightning strike loss coefficient according to the loss coefficient before lightning strike, the degree of lightning strike and the unit impact loss coefficient; according to the degree of lightning strike and the unit impact loss coefficient, obtain the adjustment coefficient and adjust the unit self-loss coefficient before the current lightning strike, and obtain the loss coefficient after lightning strike according to the adjusted unit self-loss coefficient and the actual environmental parameters combined with the instantaneous lightning strike loss coefficient; Constructing a resistor performance loss function according to the corresponding pre-lightning loss coefficient and post-lightning loss coefficient in the simulated usage scenario, and evaluating the life of the arrester resistor according to the resistor performance loss function; The method for obtaining the unit self-loss coefficient includes: the simulated environmental change includes a process of changing humidity at a fixed temperature and a process of changing temperature at a fixed humidity; In the process of changing the temperature at a fixed humidity, a second state parameter is obtained according to the temperature information and the simulation time during the simulated environment change process; the ratio of the change characteristics of the electrical parameters before and after the simulated environment change to the second state parameter is used as the unit temperature loss coefficient; In the process of changing humidity at a fixed temperature, a third state parameter is obtained according to humidity information and simulation time during the simulated environment change process, and a ratio of the change characteristics of the electrical parameters before and after the simulated environment change to the third state parameter is used as a unit humidity loss coefficient; The method for obtaining the second state parameter and the third state parameter includes: The product of the simulated temperature average value and the simulation time in the process of changing the temperature with fixed humidity is taken as the second state parameter; The product of the simulated humidity average value and the simulation time in the process of changing humidity at a fixed temperature is taken as the third state parameter; The step of obtaining the instantaneous lightning loss coefficient immediately after being struck by lightning comprises: Multiply the lightning strike time, lightning strike current intensity, and unit strike loss coefficient to obtain the strike loss amount; The lightning loss amount is added to the loss coefficient before being struck by lightning to obtain the instantaneous lightning loss coefficient immediately after being struck by lightning.

2. The life assessment method of a lightning arrester resistor according to claim 1, characterized in that: The variation characteristics of the electrical parameters include: The difference in leakage current density of arrester resistor samples before and after the simulated lightning strike is taken as the first variation feature; The difference in power loss of the arrester resistor sample before and after the simulated lightning strike is taken as the second variation feature; The voltage difference of the arrester resistor sample before and after the simulated lightning strike at 1 mA DC is taken as the third variation feature; The first change characteristic, the second change characteristic and the third change characteristic are merged to obtain the change characteristic of the electrical parameter.

3. A method for evaluating the life of a lightning arrester resistor according to claim 1 or 2, characterized in that: The method for obtaining the unit impact loss coefficient includes: Multiplying the impulse current amplitude and the impulse time under the simulated lightning strike process to obtain a first state parameter; The ratio of the change characteristics of the electrical parameters before and after the simulated lightning strike to the first state parameter is used as the unit impact loss coefficient.

4. The life assessment method of a lightning arrester resistor according to claim 1, characterized in that: The methods for obtaining the loss coefficient before lightning strike when there is no lightning strike include: The product of the unit temperature loss coefficient and the temperature information in the actual environmental parameters is used as the temperature loss coefficient; the product of the unit humidity loss coefficient and the humidity information in the actual environmental parameters is used as the humidity loss coefficient; the sum of the temperature loss coefficient and the humidity loss coefficient is used as the loss coefficient before lightning strike when not struck by lightning.

5. The life assessment method of a lightning arrester resistor according to claim 1, characterized in that: The method for obtaining the adjustment coefficient includes: The lightning current intensity of the current lightning strike, the unit impact loss coefficient and the cumulative number of lightning strikes before the current lightning strike are multiplied to obtain an initial adjustment coefficient, and half of the initial adjustment coefficient is used as the adjustment coefficient.

6. A method for evaluating the life of a lightning arrester resistor according to claim 5, characterized in that: The adjustment of the unit's own loss coefficient before the current lightning strike includes: The unit self-loss coefficient before the current lightning strike is added to the adjustment coefficient to obtain the adjusted unit self-loss coefficient.

7. The life assessment method of a lightning arrester resistor according to claim 1, characterized in that: The horizontal axis of the resistor performance loss function is the usage time, and the vertical axis is the corresponding loss coefficient under the simulated usage scenario.

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