Investigative analysis of the impact of the climatic induced pollution upon the insulators in 500 kV HVDC transmission line

The increasing effect of climatic change has mandated the investigation of its negative impact upon electrical power systems. One of the most vulnerable parts of the power system to climatic conditions is the transmission line. Among transmission line technologies, high voltage direct current (HVDC) transmission systems are gaining attention in last decades for their various applications in long distance power transmission and asynchronized connections. In this paper, HVDC transmission system was simulated using ATP/EMTP software package. The insulators of the system were tested for different lightning types under clean and polluted conditions. To evaluate the amount of reduction in insulation performance, two factors were identified as risk of back flashover factor (RBF) and the degradation factor. The computation of RBF was dependent on the parameters of the strike leading to back flashover and the probability of its occurrence. The degradation factor was defined as the percentage of increase of RBF due to polluted conditions. The degradation factor was computed for negative, positive and indirect strikes to be 92%, 29.2% and 33.3% respectively. The results indicate that the climatic pollutive impact could lead to severe degradation that could double the RBF as in negative strikes.