Research On Simulation Of Fog-haze And The Influence Of Fog-haze On Discharge Characteristics Of Rod-plane Short Air Gaps

In C hina, the hazy weather has shown a tendency of long duration and large scale in recent years. The effect of hazy weather on external insulation of power grid has attracted much attention. A lot of researches about fog’s effect on external insulation discharge have been carried out. However, most of these researches are based on salt- fog test and don’t consider the effect of particles in hazy enviroment on discharge, i.e. these researches don’t distinguish the difference between fog and hazy weather. This paper mainly do the following work:Collect TSP and PM2.5 under typical haze weather in C hongqing area,processing to get cationic and anionic solution of TSP and PM2.5. The composition of water soluble inorganic ions is analyzed by ion chromatography, the results showed that NO3-、SO42-、NH4+ accounts for a large proportion, possession 32% of the mass fraction of PM2.5.According to the measurement of fog haze, use of diatomite, Ca SO4 and NH4SO4 which has significant representativeness,simulation of the solid component of haze,ball mill grinding are used to get the required size of haze, and through the aerosol generator to produce haze, with the use of ultrasound fog generator produces the fog can simulate the fog haze weather. The main parameters of haze are controllable using this artificial simulation method.Conduct rod – plane gap discharge test in the simulated fog- haze conditions,, analyzes the fog particle size, concentration, and humidity to the influence of rod-plane short gap discharge voltage.The ac experimental results showed that the humidity and the mist concentration huge influence on Ac discharge voltages: Humidity can be enhanced air insulation performance due to the water molecules; when the fog water content is 1~18 g/m3, Ac breakdown voltages increases as the increase of the mist concentration increases, the highest can be increased 13%. When the fog water content is more than 18 g/m3, Ac breakdown voltages decreases as the increase of the mist concentration, because condensation in the electrode tip distortion electric fields. The haze particles can increase gap discharge voltages, and the smaller the particle size, the higher the breakdown voltage. Mix fog and haze, mist droplets and solid particles collision dissolved and particulate matter will swell, the gap breakdown influence is weakened and breakdown voltage tends to pure fog cases breakdown.The Dc experimental results showed that Fog particles to Dc positive discharge voltage influence law similar to communicate, not significant effects on Dc negative discharge voltage. Through the theoretical analysis,we can know that the presence of particles in two phase body discharge have two competing effects on discharge,When the particle size is small, the adsorption electronic block discharge is stronger than the distortion electric field to promote the role, indicates that the small size of PM2.5 particles can improve air breakdown voltage.