Bird droppings flashover range correction method for high-altitude power transmission line

Abstract

The embodiment of the application relates to the technical field of high-voltage transmission line safety protection, in particular to a high-altitude region transmission line bird droppings flashover range correction method, which comprises the following steps: collecting electrical structure, high-altitude meteorological parameters, bird droppings characteristics and topographic and geomorphic parameters of a target line and preprocessing to form an input data set; establishing an air insulation attenuation correction relationship according to the altitude parameter, correcting the flashover critical gap value to obtain a basic discharge gap value; determining a low-altitude benchmark initial bird droppings flashover range in combination with the electrical structure and the bird droppings parameters; extracting meteorological, topographic and structural parameters as influence factors to correct the initial range to obtain a first range; and then dividing gradient intervals according to the altitude parameter and determining correction coefficients of each interval, and performing secondary correction on the first range to obtain a second range. Through the three-level progressive correction strategy of altitude insulation attenuation correction, multi-factor coupling correction and altitude gradient interval nonlinear correction, the application realizes accurate quantitative evaluation of the bird droppings flashover danger range.

Description

Technical Field

[0001] This application relates to the field of high-voltage transmission line safety protection technology, and in particular to a method for correcting the flashover range of bird droppings on transmission lines in high-altitude areas. Background Technology

[0002] With the large-scale construction and operation of power grids in high-altitude areas such as the Qinghai-Tibet Plateau in my country, the coverage of high-altitude overhead transmission lines continues to expand. High-altitude areas are characterized by thin air, low air pressure, large diurnal temperature variations, and strong ultraviolet radiation. Simultaneously, these areas have large and frequently active bird populations, making towers and crossarms prime nesting and roosting sites for birds. Bird droppings flashover faults have become one of the core causes of power outages and outages on high-altitude transmission lines, severely restricting the reliability and safe, stable operation of the plateau power grid. Currently, research and engineering solutions for bird droppings flashover problems on transmission lines are mainly based on a critical distance model for bird droppings flashover established through low-altitude experiments, combined with a commonly used altitude correction coefficient for calculation to determine the insulation configuration requirements for high-altitude areas. This scheme uses fixed voltage levels and fixed altitude ranges as the basis for division, assuming that the characteristics and impact range of bird droppings flashover discharge are only strongly correlated with voltage and altitude. It uses static fixed values ​​or simple linear correction modes to determine flashover protection and impact range, without coupling multiple dimensions such as high-altitude air pressure distortion gradient, bird droppings angle, wind deflection disturbance, insulator string type differences, and bird droppings physical properties. This leads to large deviations in flashover range prediction, often leaning towards danger or being overly conservative. In addition, the existing method does not consider the essential impact of low air pressure at high altitudes on air insulation breakdown characteristics and the formation mechanism of bird droppings discharge channels. Moreover, there is currently no engineering-based quantitative correction method specifically for bird droppings flashover range in high-altitude areas. Designers often rely on experience or general specifications for rough processing, lacking scientific basis, which is not conducive to the refined design and differentiated operation and maintenance of high-altitude transmission lines.

[0003] Therefore, there is an urgent need to establish a method for correcting the flashover range of high-altitude bird droppings by comprehensively considering multiple factors such as high-altitude environmental parameters, bird dropping characteristics, wind deflection disturbance, and topography. Summary of the Invention

[0004] To address this, the present invention provides a method for correcting the flashover range of bird droppings on power transmission lines in high-altitude areas, thereby overcoming the problems of large prediction deviations in the flashover range of bird droppings due to the lack of coupling of multi-dimensional factors in the prior art, and the lack of a targeted quantitative correction method for high-altitude areas.

[0005] To achieve the above objectives, this invention provides a method for correcting the flashover range of bird droppings on power transmission lines in high-altitude areas. It includes: Step S1: Collect electrical structure parameters, high-altitude environmental meteorological parameters, bird and bird droppings characteristic parameters, and topographic parameters of the target transmission line. Preprocess the collected parameters to obtain the input dataset. Step S2: Based on the altitude environmental parameters in the input dataset, establish the attenuation correction relationship of air insulation performance under high altitude environment, and correct the flashover critical gap value according to the attenuation correction relationship to obtain the basic critical discharge gap value. Step S3: Based on the basic critical discharge gap value, and combined with the electrical structure parameters and bird and bird droppings characteristic parameters in the input dataset, determine the initial bird droppings flashover range under low-altitude baseline conditions; Step S4: Extract high-altitude environmental meteorological parameters, topographic parameters, and electrical structure parameters from the input dataset as influencing factors, and correct the initial bird droppings flashover range based on the influencing factors to obtain the first bird droppings flashover range; Step S5: Divide the input dataset into several altitude gradient intervals based on the altitude environmental parameters, determine the correction coefficient corresponding to each altitude gradient interval, and correct the first bird droppings flashover range based on the correction coefficient to obtain the second bird droppings flashover range.

[0006] Furthermore, in step S2, the attenuation correction relationship of air insulation performance under high-altitude environment is established, including: Obtain the baseline breakdown field strength under standard atmospheric pressure conditions; The measured atmospheric static pressure, relative air density, and pressure correction index and air density correction index fitted and calibrated from the experimental data are determined based on the altitude environmental parameters in the input dataset. Establish the attenuation correlation between the benchmark breakdown field strength value and the measured atmospheric static pressure at high altitude, the relative air density, the air pressure correction index, and the air density correction index.

[0007] Further, in step S2, obtaining the basic critical discharge gap value includes: The actual breakdown field strength at high altitude is determined based on the attenuation correlation. The corresponding high-altitude flashover critical gap value is determined based on the actual breakdown field strength value at high altitude, and the high-altitude flashover critical gap value is used as the basic critical discharge gap value.

[0008] Further, in step S3, the initial bird droppings flashover range under low-altitude baseline conditions is determined, including: The spatial electric field distortion distribution of the insulator strings, conductors and crossarm ends of the transmission line is determined based on the electrical structure parameters. The trajectory of bird droppings and the extent of the conductive channel are determined based on the characteristic parameters of the birds and bird droppings. The spatial electric field distortion distribution is coupled with the extension range of the conductive channel to delineate the boundary of the flashover risk area, and the initial bird droppings flashover range is formed by enclosing the boundary.

[0009] Further, in step S4, high-altitude environmental meteorological parameters, topographic parameters, and electrical structure parameters from the input dataset are extracted as influencing factors, including: The wind deflection factor affecting the lateral offset is extracted from the high-altitude environmental meteorological parameters. Extract the amplification influence factor that applies to the magnified terrain from the topographic parameters; Extract the structural constraint influence factor acting on the radiation angle constraint from the electrical structure parameters; The wind deflection factor, the amplification factor, and the structural constraint factor are used as influencing factors.

[0010] Further, in step S4, the initial bird droppings flashover range is corrected based on the influencing factor to obtain the first bird droppings flashover range, including: Determine the weights corresponding to the wind deflection influence factor, the amplification influence factor, and the structural constraint influence factor, respectively. The boundary of the initial bird droppings flashover range is weighted and corrected according to the weights of each weight to obtain the first bird droppings flashover range.

[0011] Further, in step S5, several altitude gradient intervals are divided according to the altitude environmental parameters in the input dataset, including: Based on the relationship curve of the decay rate of air insulation performance with altitude in high-altitude environments, the altitude is divided into several continuous altitude gradient intervals, with the inflection point of the decay rate as the interval boundary threshold.

[0012] Further, in step S5, the correction coefficients corresponding to each elevation gradient interval are determined, including: For each altitude gradient interval, a nonlinear correction coefficient corresponding to the air insulation performance attenuation law within that altitude gradient interval is fitted, and the nonlinear correction coefficient is used as the correction coefficient for the corresponding interval.

[0013] Further, in step S5, the first bird droppings flashover range is corrected according to the correction coefficient to obtain the second bird droppings flashover range, including: Determine the elevation gradient range of each spatial location point within the first bird droppings flashover range; Based on the elevation gradient range of each spatial location point, the corresponding correction coefficient is called, and the first bird droppings flashover range is adjusted by the correction coefficient to obtain the second bird droppings flashover range.

[0014] Furthermore, the preprocessing includes: The collected parameters are subjected to outlier removal, and the parameters after outlier removal are then normalized to be dimensionless.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: by constructing a mathematical model of high-altitude air insulation breakdown attenuation, taking the standard atmospheric pressure benchmark breakdown field strength as the benchmark, and introducing three core variables—altitude, air pressure, and relative air density—as well as a correction index calibrated by experiments, the present invention establishes the correlation between breakdown field strength attenuation from standard operating conditions to high-altitude operating conditions, and accordingly calculates the high-altitude flashover critical gap value, thereby achieving accurate correction of the fixed gap value at low altitudes. This solves the problem of flashover critical distance deviation caused by the traditional method ignoring the essential influence of high altitude and low air pressure on the air insulation breakdown characteristics.

[0016] Furthermore, this invention establishes the trajectory equation of bird droppings projectile motion and couples the dual motion components of natural fall and lateral wind deflection. Combining the finite element distortion distribution law of the spatial electric field, it spatially couples the extension range of the bird droppings conductive channel with the electric field distortion region. This locks the horizontal lateral danger width, vertical danger height, and fan-shaped radiation danger angle of bird droppings flashover under the low-altitude benchmark, forming a multi-dimensional initial bird droppings flashover range contour without considering high-altitude attenuation. This provides a benchmark reference for subsequent multi-factor coupling correction and solves the problem of inaccurate flashover range boundary division caused by the coupling judgment of bird droppings falling trajectory and electric field distortion.

[0017] Furthermore, this invention identifies multiple core interference factors, such as altitude insulation attenuation, lateral wind deflection, bird droppings conductivity, tower structure type, canyon topography and wind channels, and seasonal meteorological fluctuations. It objectively determines the contribution weight of each factor using an entropy weight-analytic hierarchy process (AHP) combined weighting method, and constructs a multi-factor coupled correction function. This function weights and corrects the lateral boundary, vertical boundary, and fan-shaped radiation angle of the initial bird droppings flashover range. This achieves multi-factor coordinated correction, where the flashover range expands outward due to greater wind deflection, higher conductivity, more significant insulation attenuation, and stronger canyon effect, while the radiation angle is constrained due to compact towers. This solves the problem of large prediction deviations in flashover range caused by static fixed values ​​or simple linear correction modes in existing technologies that do not couple multi-dimensional factors.

[0018] Furthermore, this invention divides the high-altitude, medium-high-altitude, and ultra-high-altitude regions into three continuous gradient intervals using the inflection point of the air insulation performance decay rate as a threshold. For each interval, a linear fine-tuning coefficient, an exponential decay correction coefficient, and a saturation correction coefficient are fitted respectively. The corresponding coefficients are called according to the interval to which each spatial location point on the flashover range belongs to, and the boundary coordinates are updated point by point. This achieves differentiated nonlinear correction of the flashover range in different altitude intervals, solving the problems of poor adaptability of the traditional unified linear correction mode at different altitude levels and the problem of excessive or insufficient protection design caused by the unlimited amplification of the flashover range in ultra-high-altitude intervals. This improves the precision and engineering applicability of bird droppings flashover range correction for high-altitude transmission lines. Attached Figure Description

[0019] Figure 1 This is a flowchart of a method for correcting the flashover range of bird droppings on power transmission lines in high-altitude areas, as described in this application. Figure 2 This is a flowchart illustrating the process of establishing the attenuation correction relationship of air insulation performance in high-altitude environments in the bird droppings flashover range correction method for high-altitude transmission lines according to embodiments of this application. Detailed Implementation

[0020] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0021] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0022] Please see Figures 1-2 As shown, Figure 1 This is a flowchart of a method for correcting the flashover range of bird droppings on power transmission lines in high-altitude areas, according to an embodiment of this application. Figure 2 This is a flowchart illustrating the process of establishing the attenuation correction relationship of air insulation performance in high-altitude environments in the bird droppings flashover range correction method for high-altitude transmission lines according to embodiments of this application.

[0023] The technical solution provided in this application includes the following steps: Step S1: Collect electrical structure parameters, high-altitude environmental meteorological parameters, bird and bird droppings characteristic parameters, and topographic parameters of the target transmission line. Preprocess the collected parameters to obtain the input dataset. Step S2: Based on the altitude environmental parameters in the input dataset, establish the attenuation correction relationship of air insulation performance under high altitude environment, and correct the flashover critical gap value according to the attenuation correction relationship to obtain the basic critical discharge gap value. Specifically, in this embodiment, the altitude environmental parameters are the absolute altitude of the tower, atmospheric static pressure, and relative air density among the high-altitude environmental meteorological parameters.

[0024] Step S3: Based on the basic critical discharge gap value, and combined with the electrical structure parameters and bird and bird droppings characteristic parameters in the input dataset, determine the initial bird droppings flashover range under low-altitude baseline conditions; Step S4: Extract high-altitude environmental meteorological parameters, topographic parameters, and electrical structure parameters from the input dataset as influencing factors, and correct the initial bird droppings flashover range based on the influencing factors to obtain the first bird droppings flashover range; Step S5: Divide the input dataset into several altitude gradient intervals based on the altitude environmental parameters, determine the correction coefficient corresponding to each altitude gradient interval, and correct the first bird droppings flashover range based on the correction coefficient to obtain the second bird droppings flashover range.

[0025] Specifically, the preprocessing includes: The collected parameters are subjected to outlier removal, and the parameters after outlier removal are then normalized to be dimensionless.

[0026] In this embodiment of the invention, comprehensive input parameters of high-altitude target transmission lines are collected. The parameter categories cover four major categories: electrical structure parameters, high-altitude environmental meteorological parameters, bird and guano characteristic parameters, and topography. The electrical structure parameters include the line's rated voltage level, tower type, crossarm length and width, phase conductor arrangement, insulator string type, insulator string suspension height, inter-string gap distance, conductor height to ground, and tower phase layout parameters. The high-altitude environmental meteorological parameters include the absolute altitude of the tower, atmospheric static pressure, relative air density, annual maximum wind speed, prevailing wind direction, air temperature and humidity, ultraviolet radiation intensity, and seasonal wind disturbance coefficient. The guano characteristic parameters include the guano defecation angle of dominant roosting birds, equivalent guano fall length, guano body fluid conductivity, initial fall velocity, guano diffusion coefficient, and distribution coordinates of fixed bird roosting locations. The topography parameters include the slope of the mountain where the tower is located, the height of surrounding obstructions, canyon wind channel effect coefficient, and local microclimate correction coefficient. The collected raw parameters are preprocessed: the 3σ criterion is used to remove distorted and abnormal data, and the range normalization is performed on physical parameters of different dimensions and orders of magnitude to map all parameters to the same dimensionless interval, thereby eliminating the interference of dimensional differences on model calculation and forming the input dataset.

[0027] Specifically, in step S2, the attenuation correction relationship of air insulation performance under high-altitude environment is established, including: Obtain the baseline breakdown field strength under standard atmospheric pressure conditions; The measured atmospheric static pressure, relative air density, and pressure correction index and air density correction index fitted and calibrated from the experimental data are determined based on the altitude environmental parameters in the input dataset. Establish the attenuation correlation between the benchmark breakdown field strength value and the measured atmospheric static pressure at high altitude, the relative air density, the air pressure correction index, and the air density correction index.

[0028] In this embodiment of the invention, air gaps under standard sea-level conditions have a fixed breakdown field strength. However, at high altitudes, the air is thinner, the air pressure is lower, and the mean free path of air molecules is increased. Under the same gap conditions, the insulation withstand strength decreases significantly, and the critical distance for bird droppings-induced air gap breakdown increases significantly, rendering traditional fixed gap values ​​completely ineffective. Based on the breakdown field strength of a uniform air gap under standard atmospheric pressure, and introducing three core variables—altitude, atmospheric static pressure, and relative air density—a mathematical model for high-altitude air insulation breakdown attenuation is constructed. ; in: The breakdown field strength of the actual air gap at high altitude; The breakdown field strength is based on standard sea level. This refers to the measured atmospheric static pressure at high altitudes. Standard atmospheric pressure at sea level; The relative density of air at high altitudes; , These are the air pressure correction index and the air density correction index, respectively, which are calibrated by fitting high-altitude test data.

[0029] Specifically, in step S2, obtaining the basic critical discharge gap value includes: The actual breakdown field strength at high altitude is determined based on the attenuation correlation. The corresponding high-altitude flashover critical gap value is determined based on the actual breakdown field strength value at high altitude, and the high-altitude flashover critical gap value is used as the basic critical discharge gap value.

[0030] In this embodiment of the invention, based on the actual breakdown field strength value at high altitude, and combined with the electrode shape, inter-electrode distance, and voltage type corresponding to the electrical structure parameters in the input dataset, the maximum gap distance that satisfies the insulation withstand condition is calculated through electric field distribution inversion. This maximum gap distance is used as the critical gap value for flashover at high altitude, and is also used as the basic critical discharge gap value. This value characterizes the critical distance for flashover induced by bird droppings under the effect of insulation attenuation at high altitude, without external wind deflection and terrain disturbance.

[0031] This invention constructs a mathematical model for the breakdown attenuation of air insulation at high altitudes. Using the standard atmospheric pressure benchmark breakdown field strength as a reference, it introduces three core variables—altitude, air pressure, and relative air density—as well as a correction index calibrated by experiments. This establishes the correlation between the breakdown field strength attenuation from standard operating conditions to high-altitude operating conditions, and uses this model to calculate the critical gap value for flashover at high altitudes. This achieves accurate correction of the fixed gap value at low altitudes and solves the problem of flashover critical distance deviation caused by traditional methods neglecting the essential influence of low air pressure at high altitudes on the breakdown characteristics of air insulation.

[0032] Specifically, in step S3, determining the initial guano flashover range under low-altitude baseline conditions includes: The spatial electric field distortion distribution of the insulator strings, conductors and crossarm ends of the transmission line is determined based on the electrical structure parameters. The trajectory of bird droppings and the extent of the conductive channel are determined based on the characteristic parameters of the birds and bird droppings. The spatial electric field distortion distribution is coupled with the extension range of the conductive channel to delineate the boundary of the flashover risk area, and the initial bird droppings flashover range is formed by enclosing the boundary.

[0033] In this embodiment of the invention, the influence of high-altitude insulation attenuation is ignored. Based on low-altitude standard meteorological conditions, an equation for the projectile motion trajectory of bird droppings from the bird's perch location on the crossarm of the tower is established. Simultaneously, considering both natural descent and lateral wind-induced displacement components, the dispersion and falling paths of bird droppings in two-dimensional plane and three-dimensional space are solved. Combining the finite element distortion distribution law of the spatial electric field at the insulator string, conductor, and crossarm ends of the transmission line, the boundary of the region where the electric field distortion intensity exceeds the flashover critical field strength is delineated. Coupled with the extension range of the bird droppings conductive channel and the electric field distortion region, the horizontal lateral danger width, vertical danger height, and fan-shaped radiation danger angle of bird droppings flashover under the low-altitude benchmark are locked, forming an initial bird droppings flashover range contour that does not consider high-altitude attenuation, wind deflection, and differences in bird droppings properties.

[0034] This invention establishes the trajectory equation of bird droppings projectile motion and couples the dual motion components of natural fall and lateral wind deflection. Combining the finite element distortion distribution law of the spatial electric field, it spatially couples the extension range of the bird droppings conductive channel with the electric field distortion region. It locks the horizontal lateral danger width, vertical danger height, and fan-shaped radiation danger angle of bird droppings flashover under low-altitude benchmark, forming a multi-dimensional initial bird droppings flashover range contour without considering high-altitude attenuation. This provides a benchmark reference for subsequent multi-factor coupling correction and solves the problem of inaccurate flashover range boundary division caused by the coupling judgment of bird droppings falling trajectory and electric field distortion.

[0035] Specifically, based on the distribution coordinates of fixed bird habitat locations in the bird and bird droppings characteristic parameters, and combined with the seasonal wind disturbance coefficient, air temperature and humidity, and ultraviolet radiation intensity in the high-altitude environmental meteorological parameters, a spatiotemporal distribution probability model of bird activity is constructed. The dwell probability of birds at each habitat location on the pole is determined under different seasons and meteorological conditions. The dwell probability is used to weight and correct the contribution of the flashover range corresponding to each habitat location. The higher the dwell probability, the greater the weight of the flashover range at that location. When the dwell probability approaches zero, the weight of the flashover range at the corresponding location approaches zero. The corrected flashover ranges of each location are spatially superimposed to obtain the dynamic initial bird droppings flashover range weighted by the bird activity probability.

[0036] In this embodiment of the invention, based on the distribution coordinates of fixed bird habitat locations in the bird and bird droppings characteristic parameters, the main bird habitat locations at the tower crossarm, insulator string ends, and conductor suspension points are determined. Combined with seasonal wind disturbance coefficients, air temperature and humidity, and ultraviolet radiation intensity in high-altitude environmental meteorological parameters, a spatiotemporal distribution probability model of bird activity is constructed. This spatiotemporal distribution probability model uses season as the time dimension and habitat location spatial coordinates and altitude as the spatial dimensions. Based on the wind disturbance coefficients, temperature and humidity, and ultraviolet radiation intensity data corresponding to each season, it calculates... The probability of birds staying at each roosting location under different time windows is used as the weighting coefficient for the risk of bird droppings flashover at that location. The flashover sub-regions corresponding to each roosting location in the initial bird droppings flashover range are weighted and corrected. The higher the roosting probability, the greater the weight of the flashover sub-region at that location when spatially superimposed. When the roosting probability approaches zero, the weight of the corresponding flashover sub-region at that location approaches zero. The weighted and corrected flashover sub-regions corresponding to all roosting locations are spatially superimposed and merged to form the initial bird droppings flashover range weighted by the bird activity probability.

[0037] Specifically, in step S4, high-altitude environmental meteorological parameters, topographic parameters, and electrical structure parameters from the input dataset are extracted as influencing factors, including: The wind deflection factor affecting the lateral offset is extracted from the high-altitude environmental meteorological parameters. Extract the amplification influence factor that applies to the magnified terrain from the topographic parameters; Extract the structural constraint influence factor acting on the radiation angle constraint from the electrical structure parameters; The wind deflection factor, the amplification factor, and the structural constraint factor are used as influencing factors.

[0038] Specifically, before correcting the initial bird droppings flashover range based on the influencing factor, the method further includes: Based on the tower type and crossarm length and width in the electrical structure parameters, construct a tower structure spatial constraint model, determine the spatial distance from the end of the crossarm to the conductor suspension point, the end of the crossarm to the end of the insulator string, and the suspension height of the insulator string, and establish the geometric constraint boundary of the flashover range within the tower structure space; After weighting and correcting the initial bird droppings flashover range based on the influencing factors, the weighted flashover range is further spatially truncated using the geometric constraint boundary. Flashover sub-regions that exceed the geometric constraint boundary are removed, and the retained flashover sub-regions are used as the first bird droppings flashover range.

[0039] In this embodiment of the invention, based on the tower type and crossarm length and width in the electrical structure parameters, the spatial geometric features of the tower structure are extracted, including the spatial distance from the end of the crossarm to the conductor suspension point, the spatial distance from the end of the crossarm to the end of the insulator string, and the suspension height of the insulator string. Using the space occupied by the tower structure and the adjacent electrical clearance range as boundary constraints, a geometric constraint boundary for the flashover range within the tower structure space is established. After weighted correction of the initial bird droppings flashover range's lateral boundary, vertical boundary, and fan-shaped radiation angle according to the weights of each influencing factor, the geometric constraints are further... The bundle boundary performs spatial truncation correction on the weighted flashover range: traverse each spatial location point on the boundary of the weighted flashover range, determine whether each location point is within the structural space enclosed by the geometric constraint boundary, remove location points outside the structural space from the flashover range boundary, retain boundary points within the structural space, and re-enclose the flashover range with the retained boundary points, and discard flashover sub-regions that exceed the structural space constraints as a whole, and finally use the retained flashover sub-regions as the first bird droppings flashover range after dual correction by multi-factor weighting and structural space alienation.

[0040] Specifically, in step S4, the initial bird droppings flashover range is corrected based on the influencing factor to obtain the first bird droppings flashover range, including: Determine the weights corresponding to the wind deflection influence factor, the amplification influence factor, and the structural constraint influence factor, respectively. The boundary of the initial bird droppings flashover range is weighted and corrected according to the weights of each weight to obtain the first bird droppings flashover range.

[0041] In this embodiment of the invention, the core interference factors affecting the flashover range of bird droppings at high altitudes are identified, including: altitude insulation attenuation factor, lateral wind deviation factor, bird droppings conductivity correction factor, tower structure type correction factor, canyon topography wind channel amplification factor, and seasonal meteorological fluctuation factor. An entropy weight-analytic hierarchy process (AHP) is used to calculate the contribution weight of each influencing factor to the flashover range, avoiding subjective bias. A multi-factor coupled correction function is constructed to weight and correct the lateral boundary, vertical boundary, and fan-shaped radiation angle of the initial bird droppings flashover range at low altitudes. The correction logic is as follows: the greater the wind deviation, the higher the bird droppings conductivity, the more significant the altitude insulation attenuation, and the stronger the canyon wind channel effect, the greater the outward expansion and deviation of the flashover danger range. The compact tower layout constrains the flashover radiation angle, achieving initial range correction under the combined effect of multiple factors, resulting in the primary corrected flashover range after multi-condition coupling.

[0042] This invention identifies multiple core interference factors, including altitude-induced insulation attenuation, lateral wind deflection, bird droppings conductivity, tower structure type, canyon topography and wind channels, and seasonal meteorological fluctuations. It employs an entropy-weighted analytic hierarchy process (AHP) to objectively determine the contribution weights of each factor and constructs a multi-factor coupled correction function. This function weights and corrects the lateral and vertical boundaries and fan-shaped radiation angle of the initial bird droppings flashover range. This achieves multi-factor coordinated correction where greater wind deflection, higher conductivity, more significant insulation attenuation, and stronger canyon effects lead to an expansion of the flashover range, while compact towers constrain the radiation angle. This solves the problem of large prediction deviations in flashover range caused by static fixed-value or simple linear correction modes that do not couple multi-dimensional factors in existing technologies.

[0043] Specifically, in step S5, several altitude gradient intervals are divided according to the altitude environmental parameters in the input dataset, including: Based on the relationship curve of the decay rate of air insulation performance with altitude in high-altitude environments, the altitude is divided into several continuous altitude gradient intervals, with the inflection point of the decay rate as the interval boundary threshold.

[0044] Specifically, in step S5, the correction coefficients corresponding to each elevation gradient interval are determined, including: For each altitude gradient interval, a nonlinear correction coefficient corresponding to the air insulation performance attenuation law within that altitude gradient interval is fitted, and the nonlinear correction coefficient is used as the correction coefficient for the corresponding interval.

[0045] Specifically, in step S5, the first bird droppings flashover range is corrected according to the correction coefficient to obtain the second bird droppings flashover range, including: Determine the elevation gradient range of each spatial location point within the first bird droppings flashover range; Based on the elevation gradient range of each spatial location point, the corresponding correction coefficient is called, and the first bird droppings flashover range is adjusted by the correction coefficient to obtain the second bird droppings flashover range.

[0046] In this embodiment of the invention, based on the attenuation rate of air insulation performance in high-altitude areas with increasing altitude, the altitude is divided into three continuous altitude gradient intervals: low altitude, medium-high altitude, and ultra-high altitude, using the two inflection points where the attenuation rate transitions from linear growth to nonlinear accelerated growth and then from nonlinear accelerated growth to near saturation as interval boundary thresholds. For the low altitude interval, a small linear fine-tuning coefficient is fitted to make a small linear incremental correction to the flashover range. For the medium-high altitude interval, an exponential attenuation correction coefficient is fitted to make a nonlinear correction to the flashover range where the correction amount increases rapidly with increasing altitude. For ultra-high altitude ranges, a saturation correction coefficient is fitted to perform saturation suppression correction on the flashover range, which tends to the upper limit, to avoid unlimited expansion of the flashover range. During correction, the altitude gradient range to which each spatial location point on the boundary of the first bird droppings flashover range belongs is determined based on its altitude. The correction coefficient corresponding to that range is called, and the original boundary value of the location point is multiplied or exponentially operated with the correction coefficient. The boundary coordinates of the location point are updated with the calculation result. All boundary location points of the first bird droppings flashover range are traversed point by point to achieve interval-by-interval differentiated correction of the flashover range in different altitude ranges, resulting in the second bird droppings flashover range after two fine corrections.

[0047] This invention divides the high-altitude region into three continuous gradient intervals—low altitude, medium-high altitude, and ultra-high altitude—using the inflection point of the air insulation performance decay rate as a threshold. For each interval, it fits linear fine-tuning coefficients, exponential decay correction coefficients, and saturation correction coefficients. Based on the interval to which each spatial location point on the flashover range boundary belongs, it calls the corresponding coefficients to perform point-by-point calculations to update the boundary coordinates. This achieves differentiated nonlinear correction of the flashover range in different altitude intervals, solving the problems of poor adaptability of the traditional unified linear correction mode at different altitude levels and the problem of excessive or insufficient protection design caused by the unlimited amplification of the flashover range in ultra-high altitude intervals. This improves the precision and engineering applicability of bird droppings flashover range correction for high-altitude transmission lines.

[0048] Specifically, after two levels of correction, the final quantitative output of the corrected flashover range and its standardized engineering application includes: horizontal protection width, vertical protection height, fan-shaped hazard coverage angle, and three-dimensional spatial hazard area outline for bird droppings flashover on high-altitude towers. The corrected flashover range standardization is applied to: defining the installation boundaries of bird spikes, bird baffles, and bird barriers on transmission lines; classifying and screening potential bird damage points and assessing risks on power lines; identifying key sections for operation and maintenance inspections; optimizing the design of bird-proof structures for newly built high-altitude transmission line towers; and encapsulating this method as an algorithm module, embedding it into a power grid operation and maintenance big data platform to achieve automatic calculation, evaluation, and early warning for batch towers.

[0049] The above embodiments are merely illustrative examples and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. A method for correcting the flashover range of bird droppings on power transmission lines in high-altitude areas, characterized in that, include: Step S1: Collect electrical structure parameters, high-altitude environmental meteorological parameters, bird and bird droppings characteristic parameters, and topographic parameters of the target transmission line. Preprocess the collected parameters to obtain the input dataset. Step S2: Based on the altitude environmental parameters in the input dataset, establish the attenuation correction relationship of air insulation performance under high altitude environment, and correct the flashover critical gap value according to the attenuation correction relationship to obtain the basic critical discharge gap value. Step S3: Based on the basic critical discharge gap value, and combined with the electrical structure parameters and bird and bird droppings characteristic parameters in the input dataset, determine the initial bird droppings flashover range under low-altitude baseline conditions; Step S4: Extract high-altitude environmental meteorological parameters, topographic parameters, and electrical structure parameters from the input dataset as influencing factors, and correct the initial bird droppings flashover range based on the influencing factors to obtain the first bird droppings flashover range; Step S5: Divide the input dataset into several altitude gradient intervals based on the altitude environmental parameters, determine the correction coefficient corresponding to each altitude gradient interval, and correct the first bird droppings flashover range based on the correction coefficient to obtain the second bird droppings flashover range.

2. The method according to claim 1, characterized in that, In step S2, the attenuation correction relationship of air insulation performance under high-altitude environment is established, including: Obtain the baseline breakdown field strength under standard atmospheric pressure conditions; The measured atmospheric static pressure, relative air density, and pressure correction index and air density correction index fitted and calibrated from the experimental data are determined based on the altitude environmental parameters in the input dataset. Establish the attenuation correlation between the benchmark breakdown field strength value and the measured atmospheric static pressure at high altitude, the relative air density, the air pressure correction index, and the air density correction index.

3. The method according to claim 1, characterized in that, In step S2, the basic critical discharge gap value is obtained, including: The actual breakdown field strength at high altitude is determined based on the attenuation correlation. The corresponding high-altitude flashover critical gap value is determined based on the actual breakdown field strength value at high altitude, and the high-altitude flashover critical gap value is used as the basic critical discharge gap value.

4. The method according to claim 1, characterized in that, In step S3, the initial guano flashover range under low-altitude baseline conditions is determined, including: The spatial electric field distortion distribution of the insulator strings, conductors and crossarm ends of the transmission line is determined based on the electrical structure parameters. The trajectory of bird droppings and the extent of the conductive channel are determined based on the characteristic parameters of the birds and bird droppings. The spatial electric field distortion distribution is coupled with the extension range of the conductive channel to delineate the boundary of the flashover risk area, and the initial bird droppings flashover range is formed by enclosing the boundary.

5. The method according to claim 1, characterized in that, In step S4, high-altitude environmental meteorological parameters, topographic parameters, and electrical structure parameters are extracted from the input dataset as influencing factors, including: The wind deflection factor affecting the lateral offset is extracted from the high-altitude environmental meteorological parameters. Extract the amplification influence factor that applies to the magnified terrain from the topographic parameters; Extract the structural constraint influence factor acting on the radiation angle constraint from the electrical structure parameters; The wind deflection factor, the amplification factor, and the structural constraint factor are used as influencing factors.

6. The method according to claim 5, characterized in that, In step S4, the initial bird droppings flashover range is corrected based on the influencing factor to obtain the first bird droppings flashover range, including: Determine the weights corresponding to the wind deflection influence factor, the amplification influence factor, and the structural constraint influence factor, respectively. The boundary of the initial bird droppings flashover range is weighted and corrected according to the weights of each weight to obtain the first bird droppings flashover range.

7. The method according to claim 1, characterized in that, In step S5, several altitude gradient intervals are divided according to the altitude environmental parameters in the input dataset, including: Based on the relationship curve of the decay rate of air insulation performance with altitude in high-altitude environments, the altitude is divided into several continuous altitude gradient intervals, with the inflection point of the decay rate as the interval boundary threshold.

8. The method according to claim 7, characterized in that, In step S5, the correction coefficients corresponding to each elevation gradient interval are determined, including: For each altitude gradient interval, a nonlinear correction coefficient corresponding to the air insulation performance attenuation law within that altitude gradient interval is fitted, and the nonlinear correction coefficient is used as the correction coefficient for the corresponding interval.

9. The method according to claim 8, characterized in that, In step S5, the first bird droppings flashover range is corrected according to the correction coefficient to obtain the second bird droppings flashover range, including: Determine the elevation gradient range of each spatial location point within the first bird droppings flashover range; Based on the elevation gradient range of each spatial location point, the corresponding correction coefficient is called, and the first bird droppings flashover range is adjusted by the correction coefficient to obtain the second bird droppings flashover range.

10. The method according to claim 1, characterized in that, The preprocessing includes: The collected parameters are subjected to outlier removal, and the parameters after outlier removal are then normalized to be dimensionless.

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