Contamination Depositing Characteristics Of Insulators Under DC Voltage Natural Crosswind Without Precipitation Conditions

As the most study aim at the contamination deposited characteristics ofinsulators for high speed and high concentrations.In order to study the contaminationdeposited characteristics of insulators under natural crosswind and withoutprecipitation conditions, using the wind tunnel laboratory to simulate naturalcrosswind conditions,and considering the situation of the insulators with DC voltage.In this paper, researching the contamination deposited characteristics of compositeinsulator,two-shed porcelain insulator, three-shed porcelain insulator, bell typeporcelain insulator under different voltage polarity and different voltage sizerespectively.And using the flow field principles of fluid mechanics to explain thecontamination deposited characteristics.Finally,CFD technology is taken to simulatethe flow field around the insulators in the contamination deposited process.In this paper, firstly，analyzing the contamination deposited characteristics ofdifferent insulators with DC voltage or without DC voltage and without precipitationby experimental method,recording the contamination deposited situation ofwindward、leeward、upper surface、lower surface of different insulators.Drawing thecontamination deposited curves of the insulators.Analysising the contaminationdeposited rules of the insulators.Then based on computational fluid dynamicsmethods and simulation software FLUENT, establishing3D simulation models ofdifferent insulators and using dispersed phase numerical simulation methods toanalyze the air flow field around the insulator,observing the simulation results.Drawing the conclusion by contrast the experiment and the simulation results.The results show that: the composite insulator has a shorter cycle saturationunder the condition of wind tunnel;the NSDD of composite insulator is largest,two-shed type porcelain insulator and three-shed type porcelain insulator is smaller,bell type porcelain insulator is smallest;the NSDD of lower surface of bell typeporcelain insulator is larger than upper surface,and the others’s upper surface is largerthan lower surface;the NSDD of leeside of both composite insulator and porcelaininsulator is larger than windward at the relevant position;positive voltage has anobvious effect on the increases of the NSDD of upper surface of insulator; negativevoltage has an obvious effect on the increases of the NSDD of lower surface ofinsulator; Positive and negative voltage have an more obvious effect on the increasesof the NSDD of the lower umbrella skirt than the upper umbrella skirt, and with themore voltage increase, the more increases of the NSDD of the upper umbrella skirt on the corresponding position.It is not strict linear relationship between the NSDD of theinsulator and the size of the voltage.