封闭环境空气局部放电组分研究

Study on the components of air under partial discharge condition in closed space

大量电力设备长期工作在封闭或半封闭环境中,经常发生局部放电,导致放电区域空气组分发生变化。为研究在局部放电条件下封闭环境中空气组分的变化规律,设计3种不同的缺陷模型模拟电力设备常见放电故障类型,搭建局部放电实验平台,基于电化学检测技术对系统进行标定。分析持续放电条件下空气组分的变化规律,根据局部放电过程中放电量大小表征放电阶段。建立空气组分浓度、电压、放电量和放电时间的关系,为电力设备故障预警提供理论依据。实验结果表明:封闭环境空气发生分解时,C、N、O元素参与电离过程,S元素基本不参与反应,CO、NO_(2)、O_(3)在放电前后变化明显,且气体浓度、产出速率、增长趋势与不同缺陷模型稳定局部放电时电压、放电量有关。

Much electrical equipment works in a closed or semi-closed space for a long time.Partial discharges often occur,and lead to the changes of air composition in the partial discharge area.To study the change law of air components in the closed space when the partial discharges occur,this paper designs three different defect models to simulate common failure types of electrical equipment,and builds a partial discharge experiment platform calibrated based on electrochemical detection technology.Then it analyzes the change law of air composition under continuous discharge conditions,and uses the discharge volume in the partial discharge process to represent the discharge stage.Finally,the relationship between the concentration of air component,voltage,discharge volume and discharge time is established.This provides a theoretical basis for early warning of electrical equipment failure.The experimental results show that the elements of C,N and O participate in the ionization process when the air in the closed space decomposes.The S element does not participate in the reaction.The CO,NO_(2) and O_(3) change significantly after a partial discharge.The gas concentration,output rate,and growth trend are related to the voltage and discharge volume when the partial discharge is stabilized in different defect models.