| With the rapid development of industrial and agricultural production, not only the voltage level of electric power transmitting line on the one hand has increasingly increased but also the scope of electricity network and the power of electricity supply are augmented; On the other hand, because the atmospheric contamination becomes severer, pollutants are accumulated on the surface of insulators for its exposure to the contaminant condition, and under wet conditions leakage current will be generated, which provokes non-uniform heating on the surface of the insulator, causing dry band arcing and possible flashover of insulators. Outside insulation flashover will not only lead to interregnum of power supply, but affect its reliability. It is statistically that the times of contamination flashover accident stay the second place of all the accidents in electric supply system, only inferior to lighting strike accidents in quantity, but economic loss caused by the former is 10 times than that by the latter. Therefore, the importance to promote the level of insulator contamination online detection becomes more and more significant.Based on summarizing the current existing research on the insulator contamination online monitoring technology, the thesis investigates the electrical characteristics and rules of the high voltage contaminated insulators by adopting artificial contamination experiment and an insulator contaminant online monitoring system is designed. In addition, new methods for assessment the surface contamination condition of insulators are proposed. The effectiveness of the methods is testified by laboratory and the field experiment. The main work in the thesis is detailed as follows:1. Preceding researchers' achievements for the contamination flashover are summarized, the physical model of contamination insulator flashover is introduced and the contamination flashover mechanism is analyzed.2. An artificial contamination experimental system is built and the electric...
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