淋雨对短空气间隙操作冲击放电影响的实验研究

为研究降雨条件下空气间隙的操作冲击放电特性,通过实验对比研究获得了干燥和淋雨条件下间隙距离为10～60 cm球-板、棒-板间隙正极性操作冲击放电曲线。研究表明淋雨造成球-板间隙正极性操作冲击击穿电压降低幅度大于棒-板间隙;雨量大小对棒-板间隙击穿电压的影响不明显;雨量为0.5～3.9mm/min时,直径10cm球电极间隙距离30cm,操作冲击击穿电压较干燥条件降低15.8%～32.6%;雨水电导率为100～2000μS/cm时,击穿电压随电导率的增加而降低,但随着间隙距离的增加,球-板、棒-板间隙操作冲击击穿电压降低幅度减弱,且雨水电导率对球-板间隙操作冲击击穿电压的影响更为明显;雨水的存在会使放电时延较干燥时有变短趋势,使间隙在波前击穿的几率增大,且雨水通道会影响放电的发展路径。

Experimental Study on Effects of Rain on Short Air Gaps Discharge With Switching Impulse Voltage

To study discharge characteristics of air gap under rainfall, ball-plate and rod-plate gaps are selected as research models, and switching impulse breakdown voltage curves are obtained under the condition of dry and artificial rain condition in laboratory with clearance distance of 10 ~ 60 cm in this paper. Research shows that influence of ball-plate gap on breakdown voltage is greater than that of rod-plate gap under rain condition. Influence of rainfall intensity on breakdown voltage of rod-plate gap is not obvious. When the rainfall intensity is 0.5~3.9 mm/min, the clearance distance is 30 cm, and the diameter of spherical electrode is 10 cm, the switching impulse breakdown voltage is reduced by 15.8%~32.6% compared to dry condition. When the rain conductivity is in range 100 ~ 2000 μS/cm, breakdown voltage will decrease with increase of the conductivity. But with increase of gap distance, the decrease of switching impulse breakdown voltage will weaken for ball-plate and rod-plate gaps, and effect of rain conductivity on ball-plate gap is more obvious. Rainwater will shorten discharge time, and the breakdown more likely happens at the front of waveform, and the water channel will affect development path of the discharge.