Influence of Voltage Types and Polarity on Contamination of Insulators

In order to study the effect of electric field on the contamination of insulators,a small dust chamber is developed for performing contamination tests of insulator under DC and AC voltages.Conclusions are drawn from the test results:the contamination of insulators is greatly influenced by electric field,and the insulator contamination is more serious under DC voltage than under AC voltage;the maximal ratio of contamination under DC to that under AC is respectively 1.19and 1.66under 10kV and 15kV voltages;compared with negative DC voltage,positive DC voltage induces more severely a contamination;within the voltage range of 0~15kV,the maximal contamination ratio(positive to negative DC)of insulator is 1.10;the distribution of the contamination on the insulator surface appears to be aU-shape,which matches the potential distribution along insulator strings.