Risk Assessment Of Insulator Pollution Flashover Based On Meteorological Correlation Analysis

With the rapid development of the power grid and the continuous improvement of the voltage level,ultra-high voltage overhead transmission lines in China have been widely used,making the problems under the conditions of electrical insulation become more and more serious.The power failure caused by the pollution flashover of the high voltage line insulator seriously affected the safe and stable operation of the power grid,which brings much economic losses.At present,in our country,the measurements are mainly divided into the stain map and the regular cleaning of the insulator.However,there are some limitations,the insulator pollution map is based on previous datas,it can not reflect the current pollution situation,because there is a certain lag;On the other hand,the large-scale cleaning will consume a lot of manpower and material resources,and it can’t guarantee the quality,which lead to the pollution flashover accident still can not be avoided.Therefore,a method is needed to predict the insulator contamination state in real time,and to evaluate the risk of highvoltage line insulator flashover accurately and effectively.Under this background,this paper first analyzes the influence of meteorological factors on the contamination and dampness of insulators,In order to determine the pollution grade,after the salt density distribution tests,the average value of salt density is introduced as the final monitoring object.And the gray clustering algorithm is proposed to quantitatively calculate the correlation between the meteorological factors and the salt density.On the further research,for real-time monitoring the insulator,a prediction of the salt density model is proposed with the BP neural network,the whole volume of the salt density in a certain area can be trained and calculated by inputing the meteorological factors.On the basis of this,the paper establishes a line of pollution flashover probability calculation model based on the positive correlation between the pollution flashover voltage and the pollution flashover probability,which also taking into account the salt density distribution and the relative humidity on the insulator surface.At th same time,the paper proposes a model for the single insulator or the whole line quantitative evaluation index and method of risk assessment for pollution flashover.The actual assessment of the pollution flashover risk in a province power grid indicated the effectiveness of all of the above the proposed method,and it can be used to clean or replace the high pollution insulators in advance.