695 / 2022-03-31 15:46:22

Space Charge Criterion for Positive Upward Leader Inception of Transmission Lines

space charge,transmission line,upward leader inception criterion,stable leader

The physical simulation model of positive streamer-leader is established. By analyzing the growth process of the leader, it is proposed to judge the transition time of the stable leader by the "inflection point". which is, as the leader elongation calculated by the next iteration is greater than the previous leader elongation, the stable inception of the upward leader is determined by the change of physical quantities during the growth of the leader, which is more objective and clear than the existing commonly used stable transformation conditions. Based on the improved condition of stable pilot transformation, a space charge criterion of initial streamer region for stable initiation of positive upward leader is proposed. By calculating the development process of upward leads under different conditions, it is found that there is a critical value of space charge quantity in the initial flow area when the stable upstream lead starts. The stable upstream leader starts as the space charge quantity in the flow area near the line reaches the critical value. The proposed criterion can better explain the physical process of development of upward leader. The comparison and discussion with the existing upward leader starting criterion and the relevant discharge test verified the accuracy and rationality of the criterion.