针-板缺陷开关柜局部放电与空气分解组分的关联特性

Correlation Character Between Switch Gear's Partial Discharge Quantity and Air Decomposition Components Under Needle-plate Defect Model

空气开关柜在配电网中扮演着重要的作用,针对开关柜的局部放电监测,提出通过检测空气放电分解组分的方法进行非电法局部放电(PD)监测。在研制的空气局部放电试验平台上,放入针-板缺陷模型产生PD使空气发生分解产生特征气体,通过调节施加在针-板缺陷模型上的电压控制PD强度,利用烟气分析仪分析气体组分及其体积分数的同时,采用脉冲电流法检测放电量,探索气体分解组分、体积分数、产气速率与放电量的关联特性。实验数据结果表明:针-板缺陷模型产生的PD放电可使空气发生分解,生成CO、NO_2等特征气体,其气体的体积分数随着放电时间延长不断增加,放电前期气体体积分数随着放电量呈现线性增长趋势,随着参与反应的物质不断减少,放电后期呈现饱和现象,且NO_2的饱和程度低于CO。CO和NO_2的产气速率由于气体浓度的饱和也呈现与放电量的线性饱和关系。

Air switch gear plays an important role in the distribution network. Therefore, in view of the partial discharge monitoring of switch gear, we put forward a method of monitoring by testing the air decomposition components. In the self-built air partial discharge test platform, air was decomposed to form characteristic gas by PD in needle-plate model, the voltage on the needle-plate was adjusted to control the degree of PD, and the smoke analysis instrument and the dis- charge pulse current method were adopted to explore the correlation characteristics between partial discharge quantity and air decomposition components. Analyses of experimental data show that air can be decomposed in PD discharge needle - plate defects, generating characteristic CO and NO： gas, the gas volume concentration increases as the discharge time in- creasing, and the early stage of the discharge gas volume concentration such as discharge presents the linear growth trend.The reaction matter decreases in discharge and presents a satttration phenomenon, and the degree of saturation of NO2 is below that of CO. Because the gas concentration of CO and NO2 gas rate trends to saturate, the dischage presents a linear relationship of saturation.