Study on Pollution Classification and External Insulation Configuration of ±1100kV DC Transmission Line1

Transmission line operating experience of China shows that the insulator pollution flashover seriously threatens safe operation of transmission line
^[1-3]
. Appropriate determination of pollution levels along the proposed lines and the external insulation configuration applied in different pollution areas not only directly determine the result of the transmission line from engineering design perspective and affect the cost of the project, but also relate to the safety and reliability of transmission lines operation. A systematic and comprehensive research were carried out regarding the fouling and moisture characteristics of the Zhundong-Huadong DC line, AC and DC transmission lines operation in the nearby areas and the measurement results of site contamination degree over the years. By a comprehensive analysis and calculation, the paper proposed a method for prediction of the pollution classification of the Zhundong-Huadong lines. The external insulation configuration for different pollution areas are recommended based on the artificial pollution withstand voltage method.