电工技术学报2024，Vol.39Issue(7)：2132-2142,11.DOI:10.19595/j.cnki.1000-6753.tces.230667
平板电极下微米级粉尘弥散浓度探测方法与时空演化特性分析
Detection Method and Spatial-Temporal Evolution Characteristics Analysis of Micron Dust Dispersion Concentration under Flat Electrodes
摘要
Abstract
In the process of GIS/GIL production,operation and maintenance,multi-scale dust is inevitably generated due to mechanical vibration,switch contact friction and man-made pollution.And micron level dust is an important part of pollutants,which may be the root cause of unknown discharge in the engineering site.For metal particles with millimeter and sub-millimeter particle sizes,the degree of harm is large and the fault characteristics are obvious.Faults caused can be identified and warned by existing detection methods such as camera photography and ultra-high frequency method.However,for micron level dust,the particle size is small and the fault characteristics are weak.The above detection method is difficult to collect the characteristic information of micron level dust.However,dust with the high physical and chemical activity gradually accumulates under the long-term operation of the equipment,which may induce serious discharge failure of the insulator and endanger the safe operation of the equipment.Therefore,it is necessary to study the detection method of micron level dust and the temporal-spatial evolution law of concentration. Firstly,the light scattering characteristics of 10 000,2 000 and 1 000 mesh dust were analyzed,and the scattered light intensity distribution of dust was obtained.On this basis,a dust concentration detection platform based on plate electrode is designed and built by using the principle of light scattering.Therefore the quantitative detection of dust dispersion concentration is realized.Secondly,this paper carried out an experimental study on the temporal and spatial evolution of dust concentration,and analyzed the variation characteristics of concentration under different pressurization methods,pressurization time,dust particle size and initial dust mass.Finally,during the experiment,it was found that there was a special phenomenon of'agglomeration lifting'when the dust dispersed between the plate electrodes.The feasibility of the light scattering method to detect the concentration was verified by the system based on the plate electrode,which provides a technical idea for the future application in GIS/GIL. The experimental and simulation results show that when the scattering angle is 60 degrees,the scattering light intensity is large,and the interference of other walls on the scattering light can be avoided.And the sensitivity of dust concentration detection system is high based on this design.Through experiments,the relationship between the optical input signal and the electrical output signal of the detection system is established,and the dust concentration can be quantitatively characterized.When exploring the temporal-spatial evolution characteristics of concentration,it is found that dust particle size and initial mass are important factors affecting the change of dispersion concentration.In the process of pressure rise,the concentration evolution includes three stages:slightly rise stage,rise stage and fall stage.There is a peak phenomenon in the dispersion concentration.When the particle size decreases,the voltage required for the peak is smaller,and the concentration peak is larger.With the increase of initial dust mass,the dispersion concentration also shows the law that the voltage corresponding to the peak value decreases and the concentration value increases.For micron level dust,the smaller the particle size or the greater the initial mass,the greater the dispersion concentration amplitude.During the experiment,there is a special phenomenon of'agglomeration lifting'in the process of dust movement.Dust agglomeration lifting may be due to the existence of microscopic forces.When agglomeration lifting occurs,the dust agglomerates are finally adsorbed on the high-voltage electrode,causing electric field distortion,reducing the distance of air gap breakdown and reducing the insulation level of the air gap of the flat electrode.关键词
微米级粉尘/光散射法/浓度检测/弥散特性/时空演化Key words
Micron level dust/light scattering method/concentration detection/dispersion characteristics/spatio-temporal evolution分类
信息技术与安全科学引用本文复制引用
薛乃凡,魏来,李庆民,王媛,杨睿成..平板电极下微米级粉尘弥散浓度探测方法与时空演化特性分析[J].电工技术学报,2024,39(7):2132-2142,11.基金项目
国家重点研发计划(2021YFB2601404)和国家自然科学基金(52127812,51929701)资助项目. （2021YFB2601404）
