CN106295207B - Insulator dirty degree appraisal procedure based on meteorological data statistics - Google Patents

Abstract

The present invention relates to a method for evaluating the degree of pollution of insulators based on meteorological data statistics, which is characterized in that it comprises the following steps: Step S1, meteorological data statistics; Step S2, division of pollution process; Step S3, salt density change calculation; Step S4 , Pollution level assessment. The invention provides a feasible and effective pollution degree evaluation method for transmission line insulators that lack pollution on-line monitoring devices and are located in highly polluted areas, and has important practical significance for formulating and implementing anti-pollution flashover measures based on the pollution degree of insulators.

Description

Evaluation Method of Insulator Pollution Degree Based on Meteorological Data Statistics

technical field

The invention relates to the technical field of power grid disaster prevention and reduction, in particular to a method for evaluating the pollution degree of insulators based on meteorological data statistics.

Background technique

After the insulators of overhead transmission lines are polluted by solid, liquid and gaseous conductive substances under natural conditions, their insulation performance will be significantly reduced under humid weather conditions such as fog, dew, drizzle, melting ice and snow, and may be under operating voltage. A pollution flashover accident occurred. With the development of industry and the aggravation of pollution, pollution flashover accidents occur frequently. According to incomplete statistics, in the winter of 2001, rain, snow, and fog in North China and Northeast China caused pollution flashover accidents in 238 66-500kV transmission lines and 34 substations; The foggy weather caused seven flashover accidents on the 500kV line; five pollution flashover accidents occurred on the ±660kV Yindong DC transmission line put into operation in October 2010, causing huge economic losses.

In terms of pollution flashover prevention, the power sector has formulated a series of anti-pollution flashover measures, such as increasing creepage distance, applying dust-proof paint, using organic synthetic insulators, regular cleaning, and replacing defective or zero-value insulators, etc., and achieved certain results. However, the above-mentioned anti-pollution flashover measures are passive prevention in nature. Due to the lack of effective evaluation of the pollution degree of insulators, the effect of pollution flashover prevention and control is not very satisfactory. my country's current standards mainly use the equivalent salt density as the pollution characteristic quantity, and conduct transmission line design, operation and maintenance, and pollution flashover accident analysis based on the pollution and humidity characteristics of the areas where the transmission line passes and operating experience. At present, the main method of obtaining the salt density value of insulators is manual sampling measurement, which not only requires offline measurement experiments under power outage conditions, but also takes a long time, high cost, and low efficiency, which plays a role in maintenance strategies based on equipment status has a limited effect.

Contents of the invention

The purpose of the present invention is to provide a method for evaluating the pollution degree of insulators based on meteorological data statistics. The present invention starts from the dynamic fouling process of the insulator of the transmission line, and calculates the salt density increase of the insulator after the pollution accumulation process and the salt density after the rain cleaning process by statistically evaluating meteorological parameters related to the dynamic fouling of the insulator within a time period. The reduction amount is combined with the salt density value of the insulator at the initial moment to complete the determination of the pollution level of the insulator at the evaluation moment.

In order to solve the above technical problems, the present invention discloses a method for evaluating the pollution degree of insulators based on meteorological data statistics, which is characterized in that it includes the following steps:

Step S1, meteorological data statistics: count the meteorological data at the tower of the transmission line to be evaluated from the initial time to the evaluation time in units of days;

Step S2, division of pollution process: according to the rainfall information in the meteorological data obtained in step S1, the dynamic pollution process of the insulator is divided into the process of pollution accumulation and rainfall cleaning alternately;

Step S3, Calculation of Salt Density Change: Based on the classic pollution accumulation and rainfall cleaning model, considering the impact of meteorological parameters on the insulator pollution accumulation rate and rainfall cleaning effect, calculate the salt density change of the insulator after the dynamic pollution process;

Step S4, Pollution Level Evaluation: Calculate the salt density variation of the insulator during the entire evaluation period, and determine the current pollution level of the insulator in combination with the salt density value at the initial moment.

Beneficial effects of the present invention:

By counting the change of the equivalent salt density on the surface of the insulator and the corresponding meteorological data, and analyzing the coupling relationship between the dynamic pollution of the insulator and the meteorological data, a method for evaluating the pollution degree of insulators based on meteorological data statistics can be proposed. This method only needs to input meteorological data related to the dynamic pollution of insulators, combined with the calculation parameters of pollution accumulation and rainfall cleaning obtained from historical data statistics, to complete the evaluation of the pollution degree of insulators. The transmission line insulators in the region provide a feasible and effective pollution degree evaluation method, which has important practical significance for the formulation and implementation of anti-pollution flashover measures based on the pollution degree of insulators.

Description of drawings

Fig. 1 is a flow chart of the present invention;

Fig. 2 is a partition diagram of the dynamic fouling process of an insulator according to an embodiment of the present invention.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the present invention is described in further detail:

The insulator pollution degree evaluation method based on meteorological data statistics that the present invention proposes, as shown in Figure 1, it comprises the following steps:

Step S1, meteorological data statistics: count the meteorological data at the tower of the transmission line to be evaluated from the initial time to the evaluation time in units of days;

Step S2, division of pollution process: according to the rainfall information in the meteorological data obtained in step S1, the dynamic pollution process of insulators is divided into the process of pollution accumulation and rainfall cleaning alternately, as shown in Figure 2;

Step S3, Calculation of Salt Density Change: Based on the classic pollution accumulation and rainfall cleaning model, considering the impact of meteorological parameters on the insulator pollution accumulation rate and rainfall cleaning effect, calculate the salt density change of the insulator after the dynamic pollution process;

Step S4, Pollution Level Evaluation: Calculate the salt density variation of the insulator during the entire evaluation period, and determine the current pollution level of the insulator in combination with the salt density value at the initial moment.

The meteorological data counted in step S1 of the above technical solution is the daily air quality index (AQI) and rainfall at the transmission line tower from the initial moment to the evaluation moment.

In the step S2 of the above-mentioned technical solution, it is judged the size of the daily rainfall in the evaluation time period. If the rainfall is zero, it will be divided into a pollution accumulation process; if the rainfall is greater than zero, it will be divided into a rainfall cleaning process, and the continuous pollution accumulation or Rainfall cleaning is classified as one process, and then the entire dynamic fouling process of insulators is divided into alternating processes of pollution accumulation and rainfall cleaning.

The classic pollution accumulation model adopted in step S3 of the above technical solution ignores the dynamic influence of the air pollution degree on pollution accumulation, and the calculation formula is:

In the formula, S _d is the equivalent salt density, in mg/cm ² ; A is the saturated equivalent salt density, and the value of A is related to the structure model and operating environment of the insulator, and the unit is mg/cm ² ; K _l is a constant; t is the fouling time; τ is a constant characterizing the fouling rate; e is a natural constant.

After introducing the influence of the air quality index (AQI), the formula for calculating the salt density increase ΔS _i after the i-th dynamic pollution accumulation process is the pollution accumulation process is:

In the formula, _Si is the equivalent salt density on the surface of the insulator after the i-th dynamic fouling process from the initial moment, unit mg/cm ² ; λ is the average value of the air quality index (AQI) during the fouling process; Δt _i is the duration of the fouling process, in days; A is the saturated equivalent salt density; k ₁ is the correction coefficient of insulator salt density growth; k ₂ is the correction coefficient of insulator salt density growth rate; m is the air quality index (AQI) against Influencing factor of insulator surface salt density growth rate; e is a natural constant.

The classic rainfall cleaning model adopted in step S3 of the above technical solution considers that the cleaning rate of deposited pollutants is proportional to the accumulated amount of pollution, which can be expressed as:

In the formula, S _d is the equivalent salt density, ω is the accumulated rainfall, in mm; k _q is the attenuation coefficient of the salt density effect of rainfall cleaning the surface of the insulator, in mm ^-1 ;

Considering the influence of rainfall time on the cleaning effect of insulator surface pollution, the calculation formula of salt density reduction ΔS _j after the jth dynamic pollution process is the rainfall cleaning process can be expressed as:

In the formula, S _j is the equivalent salt density on the surface of the insulator after the jth dynamic fouling process from the initial moment, in mg/cm ² ; Δt _j is the duration of the cleaning process, in days; k ₃ is the insulator surface The proportion of the washable part; k ₄ is the influence factor of the rainfall time on the cleaning effect of the dirt on the surface of the insulator; e is a natural constant.

In step S4 of the above technical solution, the formula for calculating the salt density change ΔS _k of the insulator after any dynamic fouling process k is:

In the formula, the value of n is 0 or 1, n=0 represents the pollution accumulation process, n=1 represents the rainfall cleaning process; Δt _k is the duration of the process, the unit is day; A is the saturated equivalent salt density; λ is The average value of the air quality index (AQI) during the pollution process; m is the influence factor of the air quality index (AQI) on the growth rate of the insulator surface salt density; k ₁ is the correction coefficient of the insulator salt density growth; k ₂ is the insulator salt density growth rate Rate correction coefficient; k ₃ is the proportion of the insulator surface that can be cleaned; k ₄ is the impact factor of rainfall time on the cleaning effect of insulator surface pollution; e is a natural constant; ω is the cumulative rainfall during the rain cleaning process, in mm.

In step S4 of the above technical solution, the salt density S _p of the insulator at the evaluation moment is calculated as follows:

In the formula, S ₀ is the equivalent salt density on the surface of the insulator to be evaluated at the initial moment, in mg/cm ² ; N is the total number of pollution accumulation and rainfall cleaning processes included in the evaluation period. After completing the calculation of the equivalent salt density on the surface of the insulator, evaluate the pollution level of the insulator according to the "Q/GDW 152-2006 Power System Pollution Classification and External Insulation Selection Standard" formulated by the State Grid Corporation of China.

The content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims (6)

1. a kind of insulator dirty degree appraisal procedure based on meteorological data statistics, it is characterised in that：It includes the following steps：

Step S1, meteorological data counts：As unit of day, statistics initial time to assessment to be assessed section of electric power line pole tower of moment The meteorological data at place；

Step S2, contamination process divides：Rainfall information in the meteorological data obtained according to step S1, by the dynamic of insulator Contamination process is divided into filthy accumulation and the process alternateed is cleaned in rainfall；

Step S3, the close variation of salt calculates：On the basis of classical filthy accumulation and rainfall washing moulding, consider meteorologic parameter to exhausted The influence of edge filth cumulative speed and rainfall cleaning performance calculates the close variation of salt after insulator experience dynamic contamination process Amount；

Step S4, gradation for surface pollution is assessed：Salt close variable quantity of the insulator within the entirely assessment period is sought, in conjunction with initial time Salt density value, determine the current gradation for surface pollution of insulator；

The close variation delta S of salt of insulator after any one dynamic contamination process k is calculated in the step S3_kCalculation formula is：

In formula, n values are 0 or 1, and n=0 indicates that filthy accumulation, n=1 indicate rainfall cleaning process；Δt_kFor the process Duration, unit are day；A is saturation equivalent salt density；λ is the average value of air quality index in filthy accumulation；M is sky Impact factor of the makings volume index to the close rate of rise of insulator surface salt；k₁Increase correction factor for insulator salt density；k₂It is exhausted The close rate of rise correction factor of edge alite；k₃For the ratio of insulator surface part capable of washing；k₄Be rain time to insulate sublist The impact factor of face filth cleaning performance；E is natural constant；ω is the accumulated rainfall in rainfall cleaning process, unit mm；k_q The attenuation coefficient of the close effect of insulator surface salt, unit mm are cleaned for rainfall^-1。

2. the insulator dirty degree appraisal procedure according to claim 1 based on meteorological data statistics, it is characterised in that：Step The meteorological data counted in rapid S1 be air quality index daily at initial time to assessment moment electric power line pole tower and Rainfall.

3. the insulator dirty degree appraisal procedure according to claim 1 based on meteorological data statistics, it is characterised in that：Step Judge that the size of rainfall is then divided into filthy accumulation if rainfall is zero daily in the assessment period in rapid S2；Such as drop Rainfall is more than zero, then is divided into rainfall cleaning process, continuous filthy accumulation or rainfall cleaning is classified as a process, in turn The entire dynamic contamination process of insulator is divided into filthy accumulation and the process alternateed is cleaned in rainfall.

4. the insulator dirty degree appraisal procedure according to claim 1 based on meteorological data statistics, it is characterised in that：Step The filthy Accumulation Model of classics used in rapid S3 has ignored air pollution degree to the dynamic effects of filth accumulation, calculation formula For：

In formula, S_dFor equivalent salt density, unit mg/cm²；A is saturation equivalent salt density, the value of A and the structure model of insulator and operation Environment is related, unit mg/cm²；K_lFor constant；T is the contamination time；τ is the constant for characterizing contamination rate, and e is natural constant；

It is the close growth of salt after filthy accumulation for i-th of dynamic contamination process after introducing the influence of air quality index Measure Δ S_iCalculation formula is：

In formula, S_iFor the equivalent salt density of insulator surface after i-th of dynamic contamination process from initial time, unit mg/cm²；λ For the average value of air quality index during contamination；Δt_iFor the duration of contamination process, unit is day；A is saturation etc. It is close to be worth salt；k₁Increase correction factor for insulator salt density；k₂For insulator salt density rate of rise correction factor；M refers to for air quality Several impact factors to the close rate of rise of insulator surface salt；E is natural constant.

5. the insulator dirty degree appraisal procedure according to claim 1 based on meteorological data statistics, it is characterised in that：Step The classical rainfall washing moulding used in rapid S3 thinks that the cleaning rate of contaminant deposition is directly proportional to filthy amount, is represented by：

In formula, S_dFor equivalent salt density, ω is accumulated rainfall, unit mm；k_qDeclining for the close effect of insulator surface salt is cleaned for rainfall Subtract coefficient, unit mm^-1；

Consider influence of the rain time to pollution severity of insulators cleaning performance, is that rainfall is clear for j-th of dynamic contamination process Wash the close decrement Δ S of salt after journey_jCalculation formula is represented by：

In formula, S_jFor the equivalent salt density of insulator surface after j-th of dynamic contamination process from initial time, unit mg/cm²；Δ t_jFor the duration of cleaning process, unit is day；k₃For the ratio of insulator surface part capable of washing；k₄For rain time pair The impact factor of pollution severity of insulators cleaning performance；E is natural constant；k_qThe close effect of insulator surface salt is cleaned for rainfall Attenuation coefficient, unit mm^-1。

6. the insulator dirty degree appraisal procedure according to claim 1 based on meteorological data statistics, it is characterised in that：Step The close S of salt of assessment moment insulator is calculated in rapid S4_pHave

In formula, S₀For the equivalent salt density of initial time insulator surface to be assessed, unit mg/cm²；N is packet in the assessment period The filthy accumulation contained and rainfall cleaning process sum；ΔS_kFor the close variable quantity of salt of insulator after any one dynamic contamination process k.