Insulator pollution monitoring device : development, calibration and field evaluation

[摘要] ENGLISH ABSTRACT:The calibration and field evaluation of an Insulator Pollution Monitoring Relay (IPMR)were the main aims of this research programme. A repeatable artificial wetting testmethod was developed after several modifications were made to the steam system,test chamber and the test routine.The IPMR was successfully calibrated with insulators that were artificially pollutedaccording to the solid layer method. Linear and polynomial relationships weredetermined after curve-fitting techniques were performed on the results. Thecalibration showed that the IPMR is capable as a device relating the maximumconductivity during artificial wetting to the ESDD, a severity classification parameter.The IPMR was successfully used in a salt fog chamber to determine if the device iscapable to evaluate the severity of an instantaneous pollution event.The IPMR was successfully installed at a natural pollution test site along the Capewest coast. The conductivity measurements with natural wetting showed goodcorrelation to flashovers experienced. A rule of thumb, developed to indicate apossible risk of flashover, was based on observations made on the relationshipbetween humidity and surface conductivity. The measured IPMR data wassuccessfully applied to quantify the site severity according to the conductivitymeasurement with natural wetting. This calculated severity value could be used in theassessment of flashover probability of high voltage insulators.

[发布机构] Stellenbosch University